Temporal Trends in Mortality of Critically Ill Patients with Sepsis in the United Kingdom, 1988-2019

Rationale: Sepsis is a frequent cause of ICU admission and mortality. Objectives: To evaluate temporal trends in the presentation and outcomes of patients admitted to the ICU with sepsis and to assess the contribution of changing case mix to outcomes. Methods: We conducted a retrospective cohort study of patients admitted to 261 ICUs in the United Kingdom during 1988-1990 and 1996-2019 with nonsurgical sepsis. Measurements and Main Results: A total of 426,812 patients met study inclusion criteria. The patients had a median (interquartile range) age of 66 (53-75) years, and 55.6% were male. The most common sites of infection were respiratory (60.9%), genitourinary (11.5%), and gastrointestinal (10.3%). Compared with patients in 1988-1990, patients in 2017-2019 were older (median age, 66 vs. 63 yr), were less acutely ill (median Acute Physiology and Chronic Health Evaluation II acute physiology score, 14 vs. 20), and more often had genitourinary sepsis (13.4% vs. 2.0%). Hospital mortality decreased from 54.6% (95% confidence interval [CI], 51.0-58.1%) in 1988-1990 to 32.4% (95% CI, 32.1-32.7%) in 2017-2019, with an adjusted odds ratio of 0.64 (95% CI, 0.54-0.75). The adjusted absolute hospital mortality reduction from 1988-1990 to 2017-2019 was 8.8% (95% CI, 5.6-12.1). Thus, of the observed 22.2-percentage point reduction in hospital mortality, 13.4 percentage points (60% of total reduction) were explained by case mix changes, whereas 8.8 percentage points (40% of total reduction) were not explained by measured factors and may be a result of improvements in ICU management. Conclusions: Over a 30-year period, mortality for ICU admissions with sepsis decreased substantially. Although changes in case mix accounted for the majority of observed mortality reduction, there was an 8.8-percentage point reduction in mortality not explained by case mix.

Use of selective gut decontamination in critically ill children: PICnIC a pilot RCT and mixed-methods study

Background

Healthcare-associated infections are a major cause of morbidity and mortality in critically ill children. In adults, data suggest the use of selective decontamination of the digestive tract may reduce the incidence of healthcare-associated infections. Selective decontamination of the digestive tract has not been evaluated in the paediatric intensive care unit population.

Objectives

To determine the feasibility of conducting a multicentre, cluster-randomised controlled trial in critically ill children comparing selective decontamination of the digestive tract with standard infection control.

Design

Parallel-group pilot cluster-randomised controlled trial with an integrated mixed-methods study.

Setting

Six paediatric intensive care units in England.

Participants

Children (> 37 weeks corrected gestational age, up to 16 years) requiring mechanical ventilation expected to last for at least 48 hours were eligible for the PICnIC pilot cluster-randomised controlled trial. During the ecology periods, all children admitted to the paediatric intensive care units were eligible. Parents/legal guardians of recruited patients and healthcare professionals working in paediatric intensive care units were eligible for inclusion in the mixed-methods study.

Interventions

The interventions in the PICnIC pilot cluster-randomised controlled trial included administration of selective decontamination of the digestive tract as oro-pharyngeal paste and as a suspension given by enteric tube during the period of mechanical ventilation.

Main outcome measures

The decision as to whether a definitive cluster-randomised controlled trial is feasible is based on multiple outcomes, including (but not limited to): (1) willingness and ability to recruit eligible patients; (2) adherence to the selective decontamination of the digestive tract intervention; (3) acceptability of the definitive cluster-randomised controlled trial; (4) estimation of recruitment rate; and (5) understanding of potential clinical and ecological outcome measures.

Results

A total of 368 children (85% of all those who were eligible) were enrolled in the PICnIC pilot cluster-randomised controlled trial across six paediatric intensive care units: 207 in the baseline phase (Period One) and 161 in the intervention period (Period Two). In sites delivering selective decontamination of the digestive tract, the majority (98%) of children received at least one dose of selective decontamination of the digestive tract, and of these, 68% commenced within the first 6 hours. Consent for the collection of additional swabs was low (44%), though data completeness for potential outcomes, including microbiology data from routine clinical swab testing, was excellent. Recruited children were representative of the wider paediatric intensive care unit population. Overall, 3.6 children/site/week were recruited compared with the potential recruitment rate for a definitive cluster-randomised controlled trial of 3 children/site/week, based on data from all UK paediatric intensive care units. The proposed trial, including consent and selective decontamination of the digestive tract, was acceptable to parents and staff with adaptations, including training to improve consent and communication, and adaptations to the administration protocol for the paste and ecology monitoring. Clinical outcomes that were considered important included duration of organ failure and hospital stay, healthcare-acquired infections and survival.

Limitations

The delivery of the pilot cluster-randomised controlled trial was disrupted by the COVID-19 pandemic, which led to slow set-up of sites, and a lack of face-to face training.

Conclusions

PICnIC's findings indicate that a definitive cluster-randomised controlled trial in selective decontamination of the digestive tract in paediatric intensive care units is feasible with the inclusion modifications, which would need to be included in a definitive cluster-randomised controlled trial to ensure that the efficiency of trial processes is maximised.

Future work

A definitive trial that incorporates the protocol adaptations and outcomes arising from this study is feasible and should be conducted.

Trial registration

This trial is registered as ISRCTN40310490.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/152/01) and is published in full in Health Technology Assessment; Vol. 28, No. 8. See the NIHR Funding and Awards website for further award information.

Using healthcare systems data for outcomes in clinical trials: issues to consider at the design stage

BACKGROUND

Healthcare system data (HSD) are increasingly used in clinical trials, augmenting or replacing traditional methods of collecting outcome data. This study, PRIMORANT, set out to identify, in the UK context, issues to be considered before the decision to use HSD for outcome data in a clinical trial is finalised, a methodological question prioritised by the clinical trials community.

METHODS

The PRIMORANT study had three phases. First, an initial workshop was held to scope the issues faced by trialists when considering whether to use HSDs for trial outcomes. Second, a consultation exercise was undertaken with clinical trials unit (CTU) staff, trialists, methodologists, clinicians, funding panels and data providers. Third, a final discussion workshop was held, at which the results of the consultation were fed back, case studies presented, and issues considered in small breakout groups.

RESULTS

Key topics included in the consultation process were the validity of outcome data, timeliness of data capture, internal pilots, data-sharing, practical issues, and decision-making. A majority of consultation respondents (n = 78, 95%) considered the development of guidance for trialists to be feasible. Guidance was developed following the discussion workshop, for the five broad areas of terminology, feasibility, internal pilots, onward data sharing, and data archiving.

CONCLUSIONS

We provide guidance to inform decisions about whether or not to use HSDs for outcomes, and if so, to assist trialists in working with registries and other HSD providers to improve the design and delivery of trials.

Conservative versus liberal oxygenation targets in critically ill children (Oxy-PICU): a UK multicentre, open, parallel-group, randomised clinical trial

BACKGROUND

The optimal target for systemic oxygenation in critically ill children is unknown. Liberal oxygenation is widely practiced, but has been associated with harm in paediatric patients. We aimed to evaluate whether conservative oxygenation would reduce duration of organ support or incidence of death compared to standard care.

METHODS

Oxy-PICU was a pragmatic, multicentre, open-label, randomised controlled trial in 15 UK paediatric intensive care units (PICUs). Children admitted as an emergency, who were older than 38 weeks corrected gestational age and younger than 16 years receiving invasive ventilation and supplemental oxygen were randomly allocated in a 1:1 ratio via a concealed, central, web-based randomisation system to conservative peripheral oxygen saturations ([SpO2] 88-92%) or liberal (SpO2 >94%) targets. The primary outcome was the duration of organ support at 30 days following random allocation, a rank-based endpoint with death either on or before day 30 as the worst outcome (a score equating to 31 days of organ support), with survivors assigned a score between 1 and 30 depending on the number of calendar days of organ support received. The primary effect estimate was the probabilistic index, a value greater than 0·5 indicating more than 50% probability that conservative oxygenation is superior to liberal oxygenation for a randomly selected patient. All participants in whom consent was available were included in the intention-to-treat analysis. The completed study was registered with the ISRCTN registry (ISRCTN92103439).

FINDINGS

Between Sept 1, 2020, and May 15, 2022, 2040 children were randomly allocated to conservative or liberal oxygenation groups. Consent was available for 1872 (92%) of 2040 children. The conservative oxygenation group comprised 939 children (528 [57%] of 927 were female and 399 [43%] of 927 were male) and the liberal oxygenation group included 933 children (511 [56%] of 920 were female and 409 [45%] of 920 were male). Duration of organ support or death in the first 30 days was significantly lower in the conservative oxygenation group (probabilistic index 0·53, 95% CI 0·50-0·55; p=0·04 Wilcoxon rank-sum test, adjusted odds ratio 0·84 [95% CI 0·72-0·99]). Prespecified adverse events were reported in 24 (3%) of 939 patients in the conservative oxygenation group and 36 (4%) of 933 patients in the liberal oxygenation group.

INTERPRETATION

Among invasively ventilated children who were admitted as an emergency to a PICU receiving supplemental oxygen, a conservative oxygenation target resulted in a small, but significant, greater probability of a better outcome in terms of duration of organ support at 30 days or death when compared with a liberal oxygenation target. Widespread adoption of a conservative oxygenation saturation target (SpO2 88-92%) could help improve outcomes and reduce costs for the sickest children admitted to PICUs.

FUNDING

UK National Institute for Health and Care Research Health Technology Assessment Programme.

Simvastatin in Critically Ill Patients with Covid-19

BACKGROUND

The efficacy of simvastatin in critically ill patients with coronavirus disease 2019 (Covid-19) is unclear.

METHODS

In an ongoing international, multifactorial, adaptive platform, randomized, controlled trial, we evaluated simvastatin (80 mg daily) as compared with no statin (control) in critically ill patients with Covid-19 who were not receiving statins at baseline. The primary outcome was respiratory and cardiovascular organ support-free days, assessed on an ordinal scale combining in-hospital death (assigned a value of -1) and days free of organ support through day 21 in survivors; the analyis used a Bayesian hierarchical ordinal model. The adaptive design included prespecified statistical stopping criteria for superiority (>99% posterior probability that the odds ratio was >1) and futility (>95% posterior probability that the odds ratio was <1.2).

RESULTS

Enrollment began on October 28, 2020. On January 8, 2023, enrollment was closed on the basis of a low anticipated likelihood that prespecified stopping criteria would be met as Covid-19 cases decreased. The final analysis included 2684 critically ill patients. The median number of organ support-free days was 11 (interquartile range, -1 to 17) in the simvastatin group and 7 (interquartile range, -1 to 16) in the control group; the posterior median adjusted odds ratio was 1.15 (95% credible interval, 0.98 to 1.34) for simvastatin as compared with control, yielding a 95.9% posterior probability of superiority. At 90 days, the hazard ratio for survival was 1.12 (95% credible interval, 0.95 to 1.32), yielding a 91.9% posterior probability of superiority of simvastatin. The results of secondary analyses were consistent with those of the primary analysis. Serious adverse events, such as elevated levels of liver enzymes and creatine kinase, were reported more frequently with simvastatin than with control.

CONCLUSIONS

Although recruitment was stopped because cases had decreased, among critically ill patients with Covid-19, simvastatin did not meet the prespecified criteria for superiority to control. (REMAP-CAP ClinicalTrials.gov number, NCT02735707.).

The effect of conservative oxygen therapy on mortality in adult critically ill patients: A systematic review and meta-analysis of randomised controlled trials

Background

Oxygen is the commonest intervention provided to critically ill patients requiring mechanical ventilation. Despite this, it is unclear how much oxygen should be administered to patients in order to promote the best clinical outcomes and it has been suggested that a strategy of conservative oxygen therapy (COT) may be advantageous. We therefore sought to answer the question of whether COT versus usual or liberal oxygen therapy was beneficial to adult patients receiving mechanical ventilation on an intensive care unit (ICU) by performing a systematic review and meta-analysis.

Methods

Studies were included if they were randomised controlled trials comparing COT to liberal or usual oxygen therapy strategies in acutely ill adults (aged ⩾18 years) admitted to an ICU, and reported an outcome of interest. Studies were excluded if they were limited to a specific single disease diagnosis. The review was registered on PROSPERO (CRD42022308436). Risk of bias was assessed using a modified Cochrane Risk of Bias assessment tool. Effect estimates were pooled using a random effects model with the between study variance estimated using restricted maximum likelihood and standard errors calculated using the method of Hartung-Knapp/Sidik-Jonkman. Between study heterogeneity was quantified using the I2 statistic. The certainty in the body of evidence was assessed using GRADE criteria.

Results

Nine eligible studies with 5727 participants fulfilled all eligibility criteria. Trials varied in their definitions of COT and liberal or usual oxygen therapy. The pooled estimate of risk ratio for 90 day mortality for COT versus comparator was 0.99 (95% confidence interval 0.88-1.12, 95% prediction interval 0.82-1.21). There was low heterogeneity among studies (I2 = 22.4%). The finding that mortality was similar for patients managed with COT or usual/liberal oxygen therapy was graded as moderate certainty.

Conclusions

In critically ill adults admitted to an ICU, COT is neither beneficial nor harmful when compared to usual or liberal oxygen therapy. Trials to date have been inconsistent in defining both COT and liberal or usual oxygen therapy, which may have had an impact on the results of this meta-analysis. Future research should focus on unifying definitions and outcome measures.

Timing and burden of persistent critical illnessin UK intensive care units: An observational cohort study

Background

Persistent critical illness is a recognisable clinical syndrome defined conceptually as when the patient's reason for being in the intensive care unit (ICU) is more related to their ongoing critical illness than their original reason for admission. Our objectives were: (1) to assess the day in ICU on which chronic factors (e.g., age, gender and comorbidities) were more predictive of survival than acute factors (e.g. admission diagnosis, physiological derangements) measured on the day of admission; (2) to assess the consistency of this finding across major patient subgroups and over time and (3) to compare case mix characteristics and outcomes for patients determined to develop persistent critical illness (based on ICU length of stay) with other patients.

Methods

Observational cohort study using a high-quality clinical database from the national clinical audit of adult critical care. 217 adult ICUs in England, Wales and Northern Ireland. 835,946 adult patients admitted to participating ICUs between 1 April 2009 and 31 March 2016. The main outcome measure was mortality at discharge from acute hospital.

Results

We fitted two statistical models ('chronic' and 'acute') and updated these based upon patients with an ICU length of stay of at least 1, 2, etc., up to 28 days. The discrimination of the chronic model first exceeded that of the acute model on day 11. Patients with longer stays (>10 days) comprised 9% of admissions but used 45% of ICU bed-days. After a mean ICU length of stay of 22 days and a subsequent 28 days in hospital, 30% died.

Conclusions

Persistent critical illness is commonly encountered in clinical practice and is associated with increased healthcare utilisation and adverse outcomes. Improvements in our understanding of the longer term outcomes and in the development of tools to aid prognostication are urgently required - for humane as well as health economic reasons.

Effect of Angiotensin-Converting Enzyme Inhibitor and Angiotensin Receptor Blocker Initiation on Organ Support-Free Days in Patients Hospitalized With COVID-19: A Randomized Clinical Trial

IMPORTANCE

Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.

Objective

To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non-critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).

INTERVENTIONS

Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.

MAIN OUTCOMES AND MEASURES

The primary outcome was organ support-free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.

RESULTS

On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support-free days among critically ill patients was 10 (-1 to 16) in the ACE inhibitor group (n = 231), 8 (-1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support-free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).

CONCLUSIONS AND RELEVANCE

In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Regional citrate anticoagulation versus systemic heparin anticoagulation for continuous kidney replacement therapy in intensive care

PURPOSE

Many intensive care units (ICUs) have transitioned from systemic heparin anticoagulation (SHA) to regional citrate anticoagulation (RCA) for continuous kidney replacement therapy (CKRT). We evaluated the clinical and health economic impacts of ICU transition to RCA.

MATERIALS AND METHODS

We surveyed all adult general ICUs in England and Wales to identify transition dates and conducted a micro-costing study in eight ICUs. We then conducted an interrupted time-series analysis of linked, routinely collected health records.

RESULTS

In 69,001 patients who received CKRT (8585 RCA, 60,416 SHA) in 181 ICUs between 2009 and 2017, transition to RCA was not associated with a change in 90-day mortality (adjusted odds ratio 0.98, 95% CI 0.89-1.08) but was associated with step-increases in duration of kidney support (0.53 days, 95% CI 0.28-0.79), advanced cardiovascular support (0.23 days, 95% CI 0.09-0.38) and ICU length of stay (0.86 days, 95% CI 0.24-1.49). The estimated one-year incremental net monetary benefit per patient was £ - 2376 (95% CI £ - 3841-£ - 911), with an estimated likelihood of cost-effectiveness of <0.1%.

CONCLUSIONS

Transition to RCA was associated with significant increases in healthcare resource use, without corresponding clinical benefit, and is highly unlikely to be cost-effective over a one-year time horizon.

Randomization to a Liberal Versus Conservative Oxygenation Target: Redox Responses in Critically Ill Children

RATIONALE

Optimal systemic oxygenation targets in pediatric critical illness are unknown. A U-shaped relationship exists between blood oxygen levels and PICU mortality. Redox stress or iatrogenic injury from intensive treatments are potential mechanisms of harm from hyperoxia.

OBJECTIVES

To measure biomarkers of oxidative status in children admitted to PICU and randomized to conservative (oxygen-hemoglobin saturation [Sp o2 ] 88-92%) versus liberal (Sp o2 > 94%) peripheral oxygenation targets.

DESIGN

Mechanistic substudy nested within the Oxygen in PICU (Oxy-PICU) pilot randomized feasibility clinical trial ( ClinicalTrials.gov : NCT03040570).

SETTING

Three U.K. mixed medical and surgical PICUs in university hospitals.

PATIENTS

Seventy-five eligible patients randomized to the Oxy-PICU randomized feasibility clinical trial.

INTERVENTIONS

Randomization to a conservative (Sp o2 88-92%) versus liberal (Sp o2 > 94%) peripheral oxygenation target.

MEASUREMENTS AND MAIN RESULTS

Blood and urine samples were collected at two timepoints: less than 24 hours and up to 72 hours from randomization in trial participants (March 2017 to July 2017). Plasma was analyzed for markers of ischemic/oxidative response, namely thiobarbituric acid-reactive substances (TBARS; lipid peroxidation marker) and ischemia-modified albumin (protein oxidation marker). Total urinary nitrate/nitrite was measured as a marker of reactive oxygen and nitrogen species (RONS). Blood hypoxia-inducible factor (HIF)-1a messenger RNA (mRNA) expression (hypoxia response gene) was measured by reverse transcription- polymerase chain reaction. Total urinary nitrate/nitrite levels were greater in the liberal compared with conservative oxygenation group at 72 hours (median difference 32.6 μmol/mmol of creatinine [95% CI 13.7-93.6]; p < 0.002, Mann-Whitney test). HIF-1a mRNA expression was increased in the conservative group compared with liberal in less than 24-hour samples (6.0-fold [95% CI 1.3-24.0]; p = 0.032). There were no significant differences in TBARS or ischemia-modified albumin.

CONCLUSIONS

On comparing liberal with conservative oxygenation targets, we show, first, significant redox response (increase in urinary markers of RONS), but no changes in markers of lipid or protein oxidation. We also show what appears to be an early hypoxic response (increase in HIF-1a gene expression) in subjects exposed to conservative rather than liberal oxygenation targets.

The association between time of in hospital cardiac arrest and mortality; a retrospective analysis of two UK databases

AIMS

The incidence of in hospital cardiac arrest (IHCA) varies throughout the day. This study aimed to report the variation in incidence of IHCA, presenting rhythm and outcome based on the hour in which IHCA occurred.

METHODS

We conducted a retrospective analysis of the National Cardiac Arrest Audit (NCAA) including patients who suffered an IHCA from 1st April 2011 to 31st December 2019. We then linked the NCAA and intensive care Case Mix Programme databases to explore the effect of time of IHCA on hospital survival in the subgroup of patients admitted to intensive care following IHCA.

RESULTS

We identified 115,690 eligible patients in the NCAA database. Pulseless electrical activity was the commonest presenting rhythm (54.8%). 66,885 patients died in the immediate post resuscitation period. Overall, hospital survival in the NCAA cohort was 21.3%. We identified 13,858 patients with linked ICU admissions in the Case Mix Programme database; 37.0% survived to hospital discharge. The incidence of IHCA peaked at 06.00. Rates of return of spontaneous circulation, survival to hospital discharge and good neurological outcome were lowest between 05.00 and 07.00. Among those admitted to ICU, no clear diurnal variation in hospital survival was seen in the unadjusted or adjusted analysis. This pattern was consistent across all presenting rhythms.

CONCLUSIONS

We observed higher rates of IHCA, and poorer outcomes at night. However, in those admitted to ICU, this variation was absent. This suggests patient factors and processes of care issues contribute to the variation in IHCA seen throughout the day.

The effect of blood pressure on mortality following out-of-hospital cardiac arrest: a retrospective cohort study of the United Kingdom Intensive Care National Audit and Research Centre database

BACKGROUND

Hypotension following out-of-hospital cardiac arrest (OHCA) may cause secondary brain injury and increase mortality rates. Current guidelines recommend avoiding hypotension. However, the optimal blood pressure following OHCA is unknown. We hypothesised that exposure to hypotension and hypertension in the first 24 h in ICU would be associated with mortality following OHCA.

METHODS

We conducted a retrospective analysis of OHCA patients included in the Intensive Care National Audit and Research Centre Case Mix Programme from 1 January 2010 to 31 December 2019. Restricted cubic splines were created following adjustment for important prognostic variables. We report the adjusted odds ratio for associations between lowest and highest mean arterial pressure (MAP) and systolic blood pressure (SBP) in the first 24 h of ICU care and hospital mortality.

RESULTS

A total of 32,349 patients were included in the analysis. Hospital mortality was 56.2%. The median lowest and highest MAP and SBP were similar in survivors and non-survivors. Both hypotension and hypertension were associated with increased mortality. Patients who had a lowest recorded MAP in the range 60-63 mmHg had the lowest associated mortality. Patients who had a highest recorded MAP in the range 95-104 mmHg had the lowest associated mortality. The association between SBP and mortality followed a similar pattern to MAP.

CONCLUSIONS

We found an association between hypotension and hypertension in the first 24 h in ICU and mortality following OHCA. The inability to distinguish between the median blood pressure of survivors and non-survivors indicates the need for research into individualised blood pressure targets for survivors following OHCA.

Protocol for a Randomized Multiple Center Trial of Conservative Versus Liberal Oxygenation Targets in Critically Ill Children (Oxy-PICU): Oxygen in Pediatric Intensive Care

OBJECTIVES

Oxygen administration is a fundamental part of pediatric critical care, with supplemental oxygen offered to nearly every acutely unwell child. However, optimal targets for systemic oxygenation are unknown. Oxy-PICU aims to evaluate the clinical effectiveness and cost-effectiveness of a conservative peripheral oxygen saturation (Sp o2 ) target of 88-92% compared with a liberal target of more than 94%.

DESIGN

Pragmatic, open, multiple-center, parallel group randomized control trial with integrated economic evaluation.

SETTING

Fifteen PICUs across England, Wales, and Scotland.

PATIENTS

Infants and children age more than 38 week-corrected gestational age to 16 years who are accepted to a participating PICU as an unplanned admission and receiving invasive mechanical ventilation with supplemental oxygen for abnormal gas exchange.

INTERVENTION

Adjustment of ventilation and inspired oxygen settings to achieve an Sp o2 target of 88-92% during invasive mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

Randomization is 1:1 to a liberal Sp o2 target of more than 94% or a conservative Sp o2 target of 88-92% (inclusive), using minimization with a random component. Minimization will be performed on: age, site, primary reason for admission, and severity of abnormality of gas exchange. Due to the emergency nature of the treatment, approaching patients for written informed consent will be deferred to after randomization. The primary clinical outcome is a composite of death and days of organ support at 30 days. Baseline demographics and clinical status will be recorded as well as daily measures of oxygenation and organ support, and discharge outcomes. This trial received Health Research Authority approval on December 23, 2019 (reference: 272768), including a favorable ethical opinion from the East of England-Cambridge South Research Ethics Committee (reference number: 19/EE/0362). Trial findings will be disseminated in national and international conferences and peer-reviewed journals.

New-onset atrial fibrillation in intensive care: epidemiology and outcomes

Aims

New-onset atrial fibrillation (NOAF) is common in patients treated on an intensive care unit (ICU), but the long-term impacts on patient outcomes are unclear. We compared national hospital and long-term outcomes of patients who developed NOAF in ICU with those who did not, before and after adjusting for comorbidities and ICU admission factors.

Methods and results

Using the RISK-II database (Case Mix Programme national clinical audit of adult intensive care linked with Hospital Episode Statistics and mortality data), we conducted a retrospective cohort study of 4615 patients with NOAF and 27 690 matched controls admitted to 248 adult ICUs in England, from April 2009 to March 2016. We examined in-hospital mortality; hospital readmission with atrial fibrillation (AF), heart failure, and stroke up to 6 years post discharge; and mortality up to 8 years post discharge. Compared with controls, patients who developed NOAF in the ICU were at a higher risk of in-hospital mortality [unadjusted odds ratio (OR) 3.22, 95% confidence interval (CI) 3.02–3.44], only partially explained by patient demographics, comorbidities, and ICU admission factors (adjusted OR 1.50, 95% CI 1.38–1.63). They were also at a higher risk of subsequent hospitalization with AF [adjusted cause-specific hazard ratio (aCHR) 5.86, 95% CI 5.33–6.44], stroke (aCHR 1.47, 95% CI 1.12–1.93), and heart failure (aCHR 1.28, 95% CI 1.14–1.44) independent of pre-existing comorbidities.

Conclusion

Patients who develop NOAF during an ICU admission are at a higher risk of in-hospital death and readmissions to hospital with AF, heart failure, and stroke than those who do not.

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Therapy on Liberation From Respiratory Support in Acutely Ill Children Admitted to Pediatric Critical Care Units: A Randomized Clinical Trial

IMPORTANCE

The optimal first-line mode of noninvasive respiratory support for acutely ill children is not known.

OBJECTIVE

To evaluate the noninferiority of high-flow nasal cannula therapy (HFNC) as the first-line mode of noninvasive respiratory support for acute illness, compared with continuous positive airway pressure (CPAP), for time to liberation from all forms of respiratory support.

DESIGN, SETTING, AND PARTICIPANTS

Pragmatic, multicenter, randomized noninferiority clinical trial conducted in 24 pediatric critical care units in the United Kingdom among 600 acutely ill children aged 0 to 15 years who were clinically assessed to require noninvasive respiratory support, recruited between August 2019 and November 2021, with last follow-up completed in March 2022.

INTERVENTIONS

Patients were randomized 1:1 to commence either HFNC at a flow rate based on patient weight (n = 301) or CPAP of 7 to 8 cm H2O (n = 299).

MAIN OUTCOMES AND MEASURES

The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which a participant was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio of 0.75. Seven secondary outcomes were assessed, including mortality at critical care unit discharge, intubation within 48 hours, and use of sedation.

RESULTS

Of the 600 randomized children, consent was not obtained for 5 (HFNC: 1; CPAP: 4) and respiratory support was not started in 22 (HFNC: 5; CPAP: 17); 573 children (HFNC: 295; CPAP: 278) were included in the primary analysis (median age, 9 months; 226 girls [39%]). The median time to liberation in the HFNC group was 52.9 hours (95% CI, 46.0-60.9 hours) vs 47.9 hours (95% CI, 40.5-55.7 hours) in the CPAP group (absolute difference, 5.0 hours [95% CI -10.1 to 17.4 hours]; adjusted hazard ratio 1.03 [1-sided 97.5% CI, 0.86-∞]). This met the criterion for noninferiority. Of the 7 prespecified secondary outcomes, 3 were significantly lower in the HFNC group: use of sedation (27.7% vs 37%; adjusted odds ratio, 0.59 [95% CI, 0.39-0.88]); mean duration of critical care stay (5 days vs 7.4 days; adjusted mean difference, -3 days [95% CI, -5.1 to -1 days]); and mean duration of acute hospital stay (13.8 days vs 19.5 days; adjusted mean difference, -7.6 days [95% CI, -13.2 to -1.9 days]). The most common adverse event was nasal trauma (HFNC: 6/295 [2.0%]; CPAP: 18/278 [6.5%]).

CONCLUSIONS AND RELEVANCE

Among acutely ill children clinically assessed to require noninvasive respiratory support in a pediatric critical care unit, HFNC compared with CPAP met the criterion for noninferiority for time to liberation from respiratory support.

TRIAL REGISTRATION

ISRCTN.org Identifier: ISRCTN60048867.

Erratum: Heparin versus citrate anticoagulation for continuous renal replacement therapy in intensive care: the RRAM observational study

Data corrected and figures revised.

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Following Extubation on Liberation From Respiratory Support in Critically Ill Children: A Randomized Clinical Trial

IMPORTANCE

The optimal first-line mode of noninvasive respiratory support following extubation of critically ill children is not known.

OBJECTIVE

To evaluate the noninferiority of high-flow nasal cannula (HFNC) therapy as the first-line mode of noninvasive respiratory support following extubation, compared with continuous positive airway pressure (CPAP), on time to liberation from respiratory support.

DESIGN, SETTING, AND PARTICIPANTS

This was a pragmatic, multicenter, randomized, noninferiority trial conducted at 22 pediatric intensive care units in the United Kingdom. Six hundred children aged 0 to 15 years clinically assessed to require noninvasive respiratory support within 72 hours of extubation were recruited between August 8, 2019, and May 18, 2020, with last follow-up completed on November 22, 2020.

INTERVENTIONS

Patients were randomized 1:1 to start either HFNC at a flow rate based on patient weight (n = 299) or CPAP of 7 to 8 cm H2O (n = 301).

MAIN OUTCOMES AND MEASURES

The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which the child was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio (HR) of 0.75. There were 6 secondary outcomes, including mortality at day 180 and reintubation within 48 hours.

RESULTS

Of the 600 children who were randomized, 553 children (HFNC, 281; CPAP, 272) were included in the primary analysis (median age, 3 months; 241 girls [44%]). HFNC failed to meet noninferiority, with a median time to liberation of 50.5 hours (95% CI, 43.0-67.9) vs 42.9 hours (95% CI, 30.5-48.2) for CPAP (adjusted HR, 0.83; 1-sided 97.5% CI, 0.70-∞). Similar results were seen across prespecified subgroups. Of the 6 prespecified secondary outcomes, 5 showed no significant difference, including the rate of reintubation within 48 hours (13.3% for HFNC vs 11.5 % for CPAP). Mortality at day 180 was significantly higher for HFNC (5.6% vs 2.4% for CPAP; adjusted odds ratio, 3.07 [95% CI, 1.1-8.8]). The most common adverse events were abdominal distension (HFNC: 8/281 [2.8%] vs CPAP: 7/272 [2.6%]) and nasal/facial trauma (HFNC: 14/281 [5.0%] vs CPAP: 15/272 [5.5%]).

CONCLUSIONS AND RELEVANCE

Among critically ill children requiring noninvasive respiratory support following extubation, HFNC compared with CPAP following extubation failed to meet the criterion for noninferiority for time to liberation from respiratory support.

TRIAL REGISTRATION

isrctn.org Identifier: ISRCTN60048867.

Use of selective gut decontamination in critically ill children: protocol for the Paediatric Intensive Care and Infection Control (PICnIC) pilot study

INTRODUCTION

Healthcare-associated infections (HCAIs) are a major cause of morbidity and mortality in critically ill children. In critically ill adults, there are data that suggest the use of Selective Decontamination of the Digestive tract (SDD), alongside standard infection control measures reduce mortality and the incidence of HCAIs. SDD-enhanced infection control has not been compared directly with standard infection prevention strategies in the Paediatric Intensive Care Unit (PICU) population. The aim of this pilot study is to determine the feasibility of conducting a multicentre cluster randomised controlled trial (cRCT) in critically ill children comparing SDD with standard infection control.

METHODS AND ANALYSIS

Paediatric Intensive Care and Infection Control is a parallel group pilot cRCT, with integrated mixed-methods study, comparing incorporation of SDD into infection control procedures to standard care. After a 1-week pretrial ecology surveillance period, recruitment to the cRCT will run for a period of 18 weeks, comprising: (1) baseline control period (2) pre, mid and post-trial ecology surveillance periods and (3) intervention period. Six PICUs (in England, UK) will begin with usual care in period 1, then will be randomised 1:1 by the trial statistician using computer-based randomisation, to either continue to deliver usual care or commence delivery of the intervention (SDD) in period 2. Outcomes measures include parent and healthcare professionals' views on trial feasibility, adherence to the SDD intervention, estimation of recruitment rate and understanding of potential patient-centred primary and secondary outcome measures for the definitive trial. The planned recruitment for the cRCT is 324 participants.

ETHICS AND DISSEMINATION

The trial received favourable ethical opinion from West Midlands-Black Country Research Ethics Committee (reference: 20/WM/0061) and approval from the Health Research Authority (IRAS number: 239324). Informed consent is not required for SDD intervention or anonymised data collection but is sought for investigations as part of the study, any identifiable data collected and monitoring of medical records. Results will be disseminated via publications in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

ISRCTN40310490.

Heparin versus citrate anticoagulation for continuous renal replacement therapy in intensive care: the RRAM observational study

BACKGROUND

In the UK, 10% of admissions to intensive care units receive continuous renal replacement therapy with regional citrate anticoagulation replacing systemic heparin anticoagulation over the last decade. Regional citrate anticoagulation is now used in > 50% of intensive care units, despite little evidence of safety or effectiveness.

AIM

The aim of the Renal Replacement Anticoagulant Management study was to evaluate the clinical and health economic impacts of intensive care units moving from systemic heparin anticoagulation to regional citrate anticoagulation for continuous renal replacement therapy.

DESIGN

This was an observational comparative effectiveness study.

SETTING

The setting was NHS adult general intensive care units in England and Wales.

PARTICIPANTS

Participants were adults receiving continuous renal replacement therapy in an intensive care unit participating in the Intensive Care National Audit & Research Centre Case Mix Programme national clinical audit between 1 April 2009 and 31 March 2017.

INTERVENTIONS

Exposure - continuous renal replacement therapy in an intensive care unit after completion of transition to regional citrate anticoagulation. Comparator - continuous renal replacement therapy in an intensive care unit before starting transition to regional citrate anticoagulation or had not transitioned.

OUTCOME MEASURES

Primary effectiveness - all-cause mortality at 90 days. Primary economic - incremental net monetary benefit at 1 year. Secondary outcomes - mortality at hospital discharge, 30 days and 1 year; days of renal, cardiovascular and advanced respiratory support in intensive care unit; length of stay in intensive care unit and hospital; bleeding and thromboembolic events; prevalence of end-stage renal disease at 1 year; and estimated lifetime incremental net monetary benefit.

DATA SOURCES

Individual patient data from the Intensive Care National Audit & Research Centre Case Mix Programme were linked with the UK Renal Registry, Hospital Episode Statistics (for England), Patient Episodes Data for Wales and Civil Registrations (Deaths) data sets, and combined with identified periods of systemic heparin anticoagulation and regional citrate anticoagulation (survey of intensive care units). Staff time and consumables were obtained from micro-costing. Continuous renal replacement therapy system failures were estimated from the Post-Intensive Care Risk-adjusted Alerting and Monitoring data set. EuroQol-3 Dimensions, three-level version, health-related quality of life was obtained from the Intensive Care Outcomes Network study.

RESULTS

Out of the 188 (94.9%) units that responded to the survey, 182 (96.8%) use continuous renal replacement therapy. After linkage, data were available from 69,001 patients across 181 intensive care units (60,416 during periods of systemic heparin anticoagulation use and 8585 during regional citrate anticoagulation use). The change to regional citrate anticoagulation was not associated with a step change in 90-day mortality (odds ratio 0.98, 95% confidence interval 0.89 to 1.08). Secondary outcomes showed step increases in days of renal support (difference in means 0.53 days, 95% confidence interval 0.28 to 0.79 days), advanced cardiovascular support (difference in means 0.23 days, 95% confidence interval 0.09 to 0.38 days) and advanced respiratory support (difference in means, 0.53 days, 95% CI 0.03 to 1.03 days) with a trend toward fewer bleeding episodes (odds ratio 0.90, 95% confidence interval 0.76 to 1.06) with transition to regional citrate anticoagulation. The micro-costing study indicated that regional citrate anticoagulation was more expensive and was associated with an estimated incremental net monetary loss (step change) of -£2376 (95% confidence interval -£1912 to £911). The estimated likelihood of cost-effectiveness at 1 year was less than 0.1%.

LIMITATIONS

Lack of patient-level treatment data means that the results represent average effects of changing to regional citrate anticoagulation in intensive care units. Administrative data are subject to variation in data quality over time, which may contribute to observed trends.

CONCLUSIONS

The introduction of regional citrate anticoagulation has not improved outcomes for patients and is likely to have substantially increased costs. This study demonstrates the feasibility of evaluating effects of changes in practice using routinely collected data.

FUTURE WORK

(1) Prioritise other changes in clinical practice for evaluation and (2) methodological research to understand potential implications of trends in data quality.

TRIAL REGISTRATION

This trial is registered as ClinicalTrials.gov NCT03545750.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 13. See the NIHR Journals Library website for further project information.

Comparison of methods for predicting COVID-19-related death in the general population using the OpenSAFELY platform

BACKGROUND

Obtaining accurate estimates of the risk of COVID-19-related death in the general population is challenging in the context of changing levels of circulating infection.

METHODS

We propose a modelling approach to predict 28-day COVID-19-related death which explicitly accounts for COVID-19 infection prevalence using a series of sub-studies from new landmark times incorporating time-updating proxy measures of COVID-19 infection prevalence. This was compared with an approach ignoring infection prevalence. The target population was adults registered at a general practice in England in March 2020. The outcome was 28-day COVID-19-related death. Predictors included demographic characteristics and comorbidities. Three proxies of local infection prevalence were used: model-based estimates, rate of COVID-19-related attendances in emergency care, and rate of suspected COVID-19 cases in primary care. We used data within the TPP SystmOne electronic health record system linked to Office for National Statistics mortality data, using the OpenSAFELY platform, working on behalf of NHS England. Prediction models were developed in case-cohort samples with a 100-day follow-up. Validation was undertaken in 28-day cohorts from the target population. We considered predictive performance (discrimination and calibration) in geographical and temporal subsets of data not used in developing the risk prediction models. Simple models were contrasted to models including a full range of predictors.

RESULTS

Prediction models were developed on 11,972,947 individuals, of whom 7999 experienced COVID-19-related death. All models discriminated well between individuals who did and did not experience the outcome, including simple models adjusting only for basic demographics and number of comorbidities: C-statistics 0.92-0.94. However, absolute risk estimates were substantially miscalibrated when infection prevalence was not explicitly modelled.

CONCLUSIONS

Our proposed models allow absolute risk estimation in the context of changing infection prevalence but predictive performance is sensitive to the proxy for infection prevalence. Simple models can provide excellent discrimination and may simplify implementation of risk prediction tools.

Neurological complications after first dose of COVID-19 vaccines and SARS-CoV-2 infection

Emerging reports of rare neurological complications associated with COVID-19 infection and vaccinations are leading to regulatory, clinical and public health concerns. We undertook a self-controlled case series study to investigate hospital admissions from neurological complications in the 28 days after a first dose of ChAdOx1nCoV-19 (n = 20,417,752) or BNT162b2 (n = 12,134,782), and after a SARS-CoV-2-positive test (n = 2,005,280). There was an increased risk of Guillain-Barré syndrome (incidence rate ratio (IRR), 2.90; 95% confidence interval (CI): 2.15-3.92 at 15-21 days after vaccination) and Bell's palsy (IRR, 1.29; 95% CI: 1.08-1.56 at 15-21 days) with ChAdOx1nCoV-19. There was an increased risk of hemorrhagic stroke (IRR, 1.38; 95% CI: 1.12-1.71 at 15-21 days) with BNT162b2. An independent Scottish cohort provided further support for the association between ChAdOx1nCoV and Guillain-Barré syndrome (IRR, 2.32; 95% CI: 1.08-5.02 at 1-28 days). There was a substantially higher risk of all neurological outcomes in the 28 days after a positive SARS-CoV-2 test including Guillain-Barré syndrome (IRR, 5.25; 95% CI: 3.00-9.18). Overall, we estimated 38 excess cases of Guillain-Barré syndrome per 10 million people receiving ChAdOx1nCoV-19 and 145 excess cases per 10 million people after a positive SARS-CoV-2 test. In summary, although we find an increased risk of neurological complications in those who received COVID-19 vaccines, the risk of these complications is greater following a positive SARS-CoV-2 test.

Children's Oxygen Administration Strategies And Nutrition Trial (COAST-Nutrition): a protocol for a phase II randomised controlled trial

Background: To prevent poor long-term outcomes (deaths and readmissions) the integrated global action plan for pneumonia and diarrhoea recommends under the 'Treat' element of Protect, Prevent and Treat interventions the importance of continued feeding but gives no specific recommendations for nutritional support. Early nutritional support has been practiced in a wide variety of critically ill patients to provide vital cell substrates, antioxidants, vitamins, and minerals essential for normal cell function and decreasing hypermetabolism. We hypothesise that the excess post-discharge mortality associated with pneumonia may relate to the catabolic response and muscle wasting induced by severe infection and inadequacy of the diet to aid recovery. We suggest that providing additional energy-rich, protein, fat and micronutrient ready-to-use therapeutic feeds (RUTF) to help meet additional nutritional requirements may improve outcome. Methods: COAST-Nutrition is an open, multicentre, Phase II randomised controlled trial in children aged 6 months to 12 years hospitalised with suspected severe pneumonia (and hypoxaemia, SpO 2 <92%) to establish whether supplementary feeds with RUTF given in addition to usual diet for 56-days (experimental) improves outcomes at 90-days compared to usual diet alone (control). Primary endpoint is change in mid-upper arm circumference (MUAC) at 90 days and/or as a composite with 90-day mortality. Secondary outcomes include anthropometric status, mortality, readmission at days 28 and 180. The trial will be conducted in four sites in two countries (Uganda and Kenya) enrolling 840 children followed up to 180 days. Ancillary studies include cost-economic analysis, molecular characterisation of bacterial and viral pathogens, evaluation of putative biomarkers of pneumonia, assessment of muscle and fat mass and host genetic studies.   Discussion: This study is the first step in providing an option for nutritional support following severe pneumonia and will help in the design of a large Phase III trial. Registration: ISRCTN10829073 (6 th June 2018) PACTR202106635355751 (2 nd June 2021).

Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal vs Standard Care Ventilation on 90-Day Mortality in Patients With Acute Hypoxemic Respiratory Failure: The REST Randomized Clinical Trial

IMPORTANCE

In patients who require mechanical ventilation for acute hypoxemic respiratory failure, further reduction in tidal volumes, compared with conventional low tidal volume ventilation, may improve outcomes.

OBJECTIVE

To determine whether lower tidal volume mechanical ventilation using extracorporeal carbon dioxide removal improves outcomes in patients with acute hypoxemic respiratory failure.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020.

INTERVENTIONS

Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with conventional low tidal volume ventilation (n = 210).

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality 90 days after randomization. Prespecified secondary outcomes included ventilator-free days at day 28 and adverse event rates.

RESULTS

Among 412 patients who were randomized (mean age, 59 years; 143 [35%] women), 405 (98%) completed the trial. The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee. The 90-day mortality rate was 41.5% in the lower tidal volume ventilation with extracorporeal carbon dioxide removal group vs 39.5% in the standard care group (risk ratio, 1.05 [95% CI, 0.83-1.33]; difference, 2.0% [95% CI, -7.6% to 11.5%]; P = .68). There were significantly fewer mean ventilator-free days in the extracorporeal carbon dioxide removal group compared with the standard care group (7.1 [95% CI, 5.9-8.3] vs 9.2 [95% CI, 7.9-10.4] days; mean difference, -2.1 [95% CI, -3.8 to -0.3]; P = .02). Serious adverse events were reported for 62 patients (31%) in the extracorporeal carbon dioxide removal group and 18 (9%) in the standard care group, including intracranial hemorrhage in 9 patients (4.5%) vs 0 (0%) and bleeding at other sites in 6 (3.0%) vs 1 (0.5%) in the extracorporeal carbon dioxide removal group vs the control group. Overall, 21 patients experienced 22 serious adverse events related to the study device.

CONCLUSIONS AND RELEVANCE

Among patients with acute hypoxemic respiratory failure, the use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality. However, due to early termination, the study may have been underpowered to detect a clinically important difference.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02654327.

Children's Oxygen Administration Strategies And Nutrition Trial (COAST-Nutrition): a protocol for a phase II randomised controlled trial

Background: To prevent poor long-term outcomes (deaths and readmissions) the integrated global action plan for pneumonia and diarrhoea recommends under the 'Treat' element of Protect, Prevent and Treat interventions the importance of continued feeding but gives no specific recommendations for nutritional support. Early nutritional support has been practiced in a wide variety of critically ill patients to provide vital cell substrates, antioxidants, vitamins, and minerals essential for normal cell function and decreasing hypermetabolism. We hypothesise that the excess post-discharge mortality associated with pneumonia may relate to the catabolic response and muscle wasting induced by severe infection and inadequacy of the diet to aid recovery. We suggest that providing additional energy-rich, protein, fat and micronutrient ready-to-use therapeutic feeds (RUTF) to help meet additional nutritional requirements may improve outcome. Methods: COAST-Nutrition is an open, multicentre, Phase II randomised controlled trial in children aged 6 months to 12 years hospitalised with suspected severe pneumonia (and hypoxaemia, SpO 2 <92%) to establish whether supplementary feeds with RUTF given in addition to usual diet for 56-days (experimental) improves outcomes at 90-days compared to usual diet alone (control). Primary endpoint is change in mid-upper arm circumference (MUAC) at 90 days and/or as a composite with 90-day mortality. Secondary outcomes include anthropometric status, mortality, readmission at days 28 and 180. The trial will be conducted in four sites in two countries (Uganda and Kenya) enrolling 840 children followed up to 180 days. Ancillary studies include cost-economic analysis, molecular characterisation of bacterial and viral pathogens, evaluation of putative biomarkers of pneumonia, assessment of muscle and fat mass and host genetic studies.   Discussion: This study is the first step in providing an option for nutritional support following severe pneumonia and will help in the design of a large Phase III trial. Registration: ISRCTN10829073 (6 th June 2018) PACTR202106635355751 (2 nd June 2021).

Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study

OBJECTIVE

To assess the association between covid-19 vaccines and risk of thrombocytopenia and thromboembolic events in England among adults.

DESIGN

Self-controlled case series study using national data on covid-19 vaccination and hospital admissions.

SETTING

Patient level data were obtained for approximately 30 million people vaccinated in England between 1 December 2020 and 24 April 2021. Electronic health records were linked with death data from the Office for National Statistics, SARS-CoV-2 positive test data, and hospital admission data from the United Kingdom's health service (NHS).

PARTICIPANTS

29 121 633 people were vaccinated with first doses (19 608 008 with Oxford-AstraZeneca (ChAdOx1 nCoV-19) and 9 513 625 with Pfizer-BioNTech (BNT162b2 mRNA)) and 1 758 095 people had a positive SARS-CoV-2 test. People aged ≥16 years who had first doses of the ChAdOx1 nCoV-19 or BNT162b2 mRNA vaccines and any outcome of interest were included in the study.

MAIN OUTCOME MEASURES

The primary outcomes were hospital admission or death associated with thrombocytopenia, venous thromboembolism, and arterial thromboembolism within 28 days of three exposures: first dose of the ChAdOx1 nCoV-19 vaccine; first dose of the BNT162b2 mRNA vaccine; and a SARS-CoV-2 positive test. Secondary outcomes were subsets of the primary outcomes: cerebral venous sinus thrombosis (CVST), ischaemic stroke, myocardial infarction, and other rare arterial thrombotic events.

RESULTS

The study found increased risk of thrombocytopenia after ChAdOx1 nCoV-19 vaccination (incidence rate ratio 1.33, 95% confidence interval 1.19 to 1.47 at 8-14 days) and after a positive SARS-CoV-2 test (5.27, 4.34 to 6.40 at 8-14 days); increased risk of venous thromboembolism after ChAdOx1 nCoV-19 vaccination (1.10, 1.02 to 1.18 at 8-14 days) and after SARS-CoV-2 infection (13.86, 12.76 to 15.05 at 8-14 days); and increased risk of arterial thromboembolism after BNT162b2 mRNA vaccination (1.06, 1.01 to 1.10 at 15-21 days) and after SARS-CoV-2 infection (2.02, 1.82 to 2.24 at 15-21 days). Secondary analyses found increased risk of CVST after ChAdOx1 nCoV-19 vaccination (4.01, 2.08 to 7.71 at 8-14 days), after BNT162b2 mRNA vaccination (3.58, 1.39 to 9.27 at 15-21 days), and after a positive SARS-CoV-2 test; increased risk of ischaemic stroke after BNT162b2 mRNA vaccination (1.12, 1.04 to 1.20 at 15-21 days) and after a positive SARS-CoV-2 test; and increased risk of other rare arterial thrombotic events after ChAdOx1 nCoV-19 vaccination (1.21, 1.02 to 1.43 at 8-14 days) and after a positive SARS-CoV-2 test.

CONCLUSION

Increased risks of haematological and vascular events that led to hospital admission or death were observed for short time intervals after first doses of the ChAdOx1 nCoV-19 and BNT162b2 mRNA vaccines. The risks of most of these events were substantially higher and more prolonged after SARS-CoV-2 infection than after vaccination in the same population.

Treatment strategies for new onset atrial fibrillation in patients treated on an intensive care unit: a systematic scoping review

BACKGROUND

New-onset atrial fibrillation (NOAF) in patients treated on an intensive care unit (ICU) is common and associated with significant morbidity and mortality. We undertook a systematic scoping review to summarise comparative evidence to inform NOAF management for patients admitted to ICU.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Web of Science, OpenGrey, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, ISRCTN, ClinicalTrials.gov, EU Clinical Trials register, additional WHO ICTRP trial databases, and NIHR Clinical Trials Gateway in March 2019. We included studies evaluating treatment or prevention strategies for NOAF or acute anticoagulation in general medical, surgical or mixed adult ICUs. We extracted study details, population characteristics, intervention and comparator(s), methods addressing confounding, results, and recommendations for future research onto study-specific forms.

RESULTS

Of 3,651 citations, 42 articles were eligible: 25 primary studies, 12 review articles and 5 surveys/opinion papers. Definitions of NOAF varied between NOAF lasting 30 s to NOAF lasting > 24 h. Only one comparative study investigated effects of anticoagulation. Evidence from small RCTs suggests calcium channel blockers (CCBs) result in slower rhythm control than beta blockers (1 study), and more cardiovascular instability than amiodarone (1 study). Evidence from 4 non-randomised studies suggests beta blocker and amiodarone therapy may be equivalent in respect to rhythm control. Beta blockers may be associated with improved survival compared to amiodarone, CCBs, and digoxin, though supporting evidence is subject to confounding. Currently, the limited evidence does not support therapeutic anticoagulation during ICU admission.

CONCLUSIONS

From the limited evidence available beta blockers or amiodarone may be superior to CCBs as first line therapy in undifferentiated patients in ICU. The little evidence available does not support therapeutic anticoagulation for NOAF whilst patients are critically ill. Consensus definitions for NOAF, rate and rhythm control are needed.

Realising the full potential of data-enabled trials in the UK: a call for action

RATIONALE

Clinical trials are the gold standard for testing interventions. COVID-19 has further raised their public profile and emphasised the need to deliver better, faster, more efficient trials for patient benefit. Considerable overlap exists between data required for trials and data already collected routinely in electronic healthcare records (EHRs). Opportunities exist to use these in innovative ways to decrease duplication of effort and speed trial recruitment, conduct and follow-up.

APPROACH

The National Institute of Health Research (NIHR), Health Data Research UK and Clinical Practice Research Datalink co-organised a national workshop to accelerate the agenda for 'data-enabled clinical trials'. Showcasing successful examples and imagining future possibilities, the plenary talks, panel discussions, group discussions and case studies covered: design/feasibility; recruitment; conduct/follow-up; collecting benefits/harms; and analysis/interpretation.

REFLECTION

Some notable studies have successfully accessed and used EHR to identify potential recruits, support randomised trials, deliver interventions and supplement/replace trial-specific follow-up. Some outcome measures are already reliably collected; others, like safety, need detailed work to meet regulatory reporting requirements. There is a clear need for system interoperability and a 'route map' to identify and access the necessary datasets. Researchers running regulatory-facing trials must carefully consider how data quality and integrity would be assessed. An experience-sharing forum could stimulate wider adoption of EHR-based methods in trial design and execution.

DISCUSSION

EHR offer opportunities to better plan clinical trials, assess patients and capture data more efficiently, reducing research waste and increasing focus on each trial's specific challenges. The short-term emphasis should be on facilitating patient recruitment and for postmarketing authorisation trials where research-relevant outcome measures are readily collectable. Sharing of case studies is encouraged. The workshop directly informed NIHR's funding call for ambitious data-enabled trials at scale. There is the opportunity for the UK to build upon existing data science capabilities to identify, recruit and monitor patients in trials at scale.

Randomised controlled trial of oxygen therapy and high-flow nasal therapy in African children with pneumonia

Purpose

The life-saving role of oxygen therapy in African children with severe pneumonia is not yet established.

Methods

The open-label fractional-factorial COAST trial randomised eligible Ugandan and Kenyan children aged > 28 days with severe pneumonia and severe hypoxaemia stratum (SpO₂ < 80%) to high-flow nasal therapy (HFNT) or low-flow oxygen (LFO: standard care) and hypoxaemia stratum (SpO₂ 80–91%) to HFNT or LFO (liberal strategies) or permissive hypoxaemia (ratio 1:1:2). Children with cyanotic heart disease, chronic lung disease or > 3 h receipt of oxygen were excluded. The primary endpoint was 48 h mortality; secondary endpoints included mortality or neurocognitive sequelae at 28 days.

Results

The trial was stopped early after enrolling 1852/4200 children, including 388 in the severe hypoxaemia stratum (median 7 months; median SpO₂ 75%) randomised to HFNT (n = 194) or LFO (n = 194) and 1454 in the hypoxaemia stratum (median 9 months; median SpO₂ 88%) randomised to HFNT (n = 363) vs LFO (n = 364) vs permissive hypoxaemia (n = 727). Per-protocol 15% of patients in the permissive hypoxaemia group received oxygen (when SpO₂ < 80%). In the severe hypoxaemia stratum, 48-h mortality was 9.3% for HFNT vs. 13.4% for LFO groups. In the hypoxaemia stratum, 48-h mortality was 1.1% for HFNT vs. 2.5% LFO and 1.4% for permissive hypoxaemia. In the hypoxaemia stratum, adjusted odds ratio for 48-h mortality in liberal vs permissive comparison was 1.16 (0.49–2.74; p = 0.73); HFNT vs LFO comparison was 0.60 (0.33–1.06; p = 0.08). Strata-specific 28 day mortality rates were, respectively: 18.6, 23.4 and 3.3, 4.1, 3.9%. Neurocognitive sequelae were rare.

Conclusions

Respiratory support with HFNT showing potential benefit should prompt further trials.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06385-3.

Changes in temperature management and outcome after out-of-hospital cardiac arrest in United Kingdom intensive care units following publication of the targeted temperature management trial

AIM

To investigate how the publication of the targeted temperature management (TTM) trial in December 2013 affected the trends in temperature management and outcome following admission to UK intensive care units (ICUs) after out-of-hospital cardiac arrest (OHCA).

METHODS

We used a national ICU database of 1,181,405 consecutive admissions to 235 adult ICUs. OHCA admissions mechanically ventilated in the first 24 h in the ICU were divided into a pre-TTM trial cohort of patients admitted before publication of the TTM trial (January 2010-December 2013) and post-TTM cohort of patients admitted after TTM trial publication (January 2014-December 2017). The primary outcome variables were lowest temperature in the first 24 h in ICU and survival to hospital discharge.

RESULTS

The lowest temperature recorded in the first-24 h of admission was significantly higher in the post-TTM cohort (n = 18,106) than in the pre-TTM cohort (n = 12,162) (mean 34.7 (±1.6) versus 33.6 °C (±1.8); absolute difference 1.12 °C (95% CI 1.08-1.16). The post-TTM cohort had a greater prevalence of fever (>38.0 °C) (24.8% vs 14.7%; (odds ratio (OR) 1.91 (95% CI 1.80-2.03); p < 0.001)) and higher unadjusted in-hospital mortality (63.7% vs 61.6%). In a multilevel model, accounting for time trend and including site as a random effect, neither the step change in acute hospital mortality following publication of the TTM trial result (OR 1.04, 95% CI 0.95-1.15; p = 0.37), nor the change in slope (from OR 1.00 per year, 95% CI 0.97-1.04, to 1.04 per year, 95% CI 1.02-1.07; p = 0.059), was statistically significant. Adjusted analyses were limited by the models' dependence on temperature and temperature-related variables.

CONCLUSIONS

The lowest temperature recorded in the first-24 h of admission in OHCA patients was higher in the post-TTM cohort compared with the pre-TTM cohort. There has been an increase in the proportion of patients with fever (>38 °C) in the first 24 h. Although crude mortality was slightly higher in the post-TTM cohort, an analysis accounting for time trend and variation between critical care units, found no significant change associated with the TTM publication.

Trends in Intensive Care for Patients with COVID-19 in England, Wales, and Northern Ireland

Rationale: By describing trends in intensive care for patients with coronavirus disease (COVID-19) we aim to support clinical learning, service planning, and hypothesis generation.Objectives: To describe variation in ICU admission rates over time and by geography during the first wave of the epidemic in England, Wales, and Northern Ireland; to describe trends in patient characteristics on admission to ICU, first-24-hours physiology in ICU, processes of care in ICU and patient outcomes; and to explore deviations in trends during the peak period.Methods: A cohort of 10,741 patients with COVID-19 in the Case Mix Program national clinical audit from February 1 to July 31, 2020, was used. Analyses were stratified by time period (prepeak, peak, and postpeak periods) and geographical region. Logistic regression was used to estimate adjusted differences in 28-day in-hospital mortality between periods.Measurements and Main Results: Admissions to ICUs peaked almost simultaneously across regions but varied 4.6-fold in magnitude. Compared with patients admitted in the prepeak period, patients admitted in the postpeak period were slightly younger but with higher degrees of dependency and comorbidity on admission to ICUs and more deranged first-24-hours physiology. Despite this, receipt of invasive ventilation and renal replacement therapy decreased, and adjusted 28-day in-hospital mortality was reduced by 11.8% (95% confidence interval, 8.7%-15.0%). Many variables exhibited u-shaped or n-shaped curves during the peak.Conclusions: The population of patients with COVID-19 admitted to ICUs, and the processes of care in ICUs, changed over the first wave of the epidemic. After adjustment for important risk factors, there was a substantial improvement in patient outcomes.

Trends in Intensive Care for Patients with COVID-19 in England, Wales, and Northern Ireland

Rationale: By describing trends in intensive care for patients with coronavirus disease (COVID-19) we aim to support clinical learning, service planning, and hypothesis generation.Objectives: To describe variation in ICU admission rates over time and by geography during the first wave of the epidemic in England, Wales, and Northern Ireland; to describe trends in patient characteristics on admission to ICU, first-24-hours physiology in ICU, processes of care in ICU and patient outcomes; and to explore deviations in trends during the peak period.Methods: A cohort of 10,741 patients with COVID-19 in the Case Mix Program national clinical audit from February 1 to July 31, 2020, was used. Analyses were stratified by time period (prepeak, peak, and postpeak periods) and geographical region. Logistic regression was used to estimate adjusted differences in 28-day in-hospital mortality between periods.Measurements and Main Results: Admissions to ICUs peaked almost simultaneously across regions but varied 4.6-fold in magnitude. Compared with patients admitted in the prepeak period, patients admitted in the postpeak period were slightly younger but with higher degrees of dependency and comorbidity on admission to ICUs and more deranged first-24-hours physiology. Despite this, receipt of invasive ventilation and renal replacement therapy decreased, and adjusted 28-day in-hospital mortality was reduced by 11.8% (95% confidence interval, 8.7%-15.0%). Many variables exhibited u-shaped or n-shaped curves during the peak.Conclusions: The population of patients with COVID-19 admitted to ICUs, and the processes of care in ICUs, changed over the first wave of the epidemic. After adjustment for important risk factors, there was a substantial improvement in patient outcomes.

Reduced exposure to vasopressors through permissive hypotension to reduce mortality in critically ill people aged 65 and over: the 65 RCT

BACKGROUND

Vasopressors are administered to critical care patients to avoid hypotension, which is associated with myocardial injury, kidney injury and death. However, they work by causing vasoconstriction, which may reduce blood flow and cause other adverse effects. A mean arterial pressure target typically guides administration. An individual patient data meta-analysis (Lamontagne F, Day AG, Meade MO, Cook DJ, Guyatt GH, Hylands M, et al. Pooled analysis of higher versus lower blood pressure targets for vasopressor therapy septic and vasodilatory shock. Intensive Care Med 2018;44:12-21) suggested that greater exposure, through higher mean arterial pressure targets, may increase risk of death in older patients.

OBJECTIVE

To estimate the clinical effectiveness and cost-effectiveness of reduced vasopressor exposure through permissive hypotension (i.e. a lower mean arterial pressure target of 60-65 mmHg) in older critically ill patients.

DESIGN

A pragmatic, randomised clinical trial with integrated economic evaluation.

SETTING

Sixty-five NHS adult general critical care units.

PARTICIPANTS

Critically ill patients aged ≥ 65 years receiving vasopressors for vasodilatory hypotension.

INTERVENTIONS

Intervention - permissive hypotension (i.e. a mean arterial pressure target of 60-65 mmHg). Control (usual care) - a mean arterial pressure target at the treating clinician's discretion.

MAIN OUTCOME MEASURES

The primary clinical outcome was 90-day all-cause mortality. The primary cost-effectiveness outcome was 90-day incremental net monetary benefit. Secondary outcomes included receipt and duration of advanced respiratory and renal support, mortality at critical care and acute hospital discharge, and questionnaire assessment of cognitive decline and health-related quality of life at 90 days and 1 year.

RESULTS

Of 2600 patients randomised, 2463 (permissive hypotension, n = 1221; usual care, n = 1242) were analysed for the primary clinical outcome. Permissive hypotension resulted in lower exposure to vasopressors than usual care [mean duration 46.0 vs. 55.9 hours, difference -9.9 hours (95% confidence interval -14.3 to -5.5 hours); total noradrenaline-equivalent dose 31.5 mg vs. 44.3 mg, difference -12.8 mg (95% CI -18.0 mg to -17.6 mg)]. By 90 days, 500 (41.0%) patients in the permissive hypotension group and 544 (43.8%) patients in the usual-care group had died (absolute risk difference -2.85%, 95% confidence interval -6.75% to 1.05%; p = 0.154). Adjustment for prespecified baseline variables resulted in an odds ratio for 90-day mortality of 0.82 (95% confidence interval 0.68 to 0.98) favouring permissive hypotension. There were no significant differences in prespecified secondary outcomes or subgroups; however, patients with chronic hypertension showed a mortality difference favourable to permissive hypotension. At 90 days, permissive hypotension showed similar costs to usual care. However, with higher incremental life-years and quality-adjusted life-years in the permissive hypotension group, the incremental net monetary benefit was positive, but with high statistical uncertainty (£378, 95% confidence interval -£1347 to £2103).

LIMITATIONS

The intervention was unblinded, with risk of bias minimised through central allocation concealment and a primary outcome not subject to observer bias. The control group event rate was higher than anticipated.

CONCLUSIONS

In critically ill patients aged ≥ 65 years receiving vasopressors for vasodilatory hypotension, permissive hypotension did not significantly reduce 90-day mortality compared with usual care. The absolute treatment effect on 90-day mortality, based on 95% confidence intervals, was between a 6.8-percentage reduction and a 1.1-percentage increase in mortality.

FUTURE WORK

Future work should (1) update the individual patient data meta-analysis, (2) explore approaches for evaluating heterogeneity of treatment effect and (3) explore 65 trial conduct, including use of deferred consent, to inform future trials.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN10580502.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 14. See the NIHR Journals Library website for further project information.

Prognostic Factors for 30-Day Mortality in Critically Ill Patients With Coronavirus Disease 2019: An Observational Cohort Study

OBJECTIVES

To identify characteristics that predict 30-day mortality among patients critically ill with coronavirus disease 2019 in England, Wales, and Northern Ireland.

DESIGN

Observational cohort study.

SETTING

A total of 258 adult critical care units.

PATIENTS

A total of 10,362 patients with confirmed coronavirus disease 2019 with a start of critical care between March 1, 2020, and June 22, 2020, of whom 9,990 were eligible (excluding patients with a duration of critical care less than 24 hr or missing core variables).

MEASUREMENTS AND MAIN RESULTS

The main outcome measure was time to death within 30 days of the start of critical care. Of 9,990 eligible patients (median age 60 yr, 70% male), 3,933 died within 30 days of the start of critical care. As of July 22, 2020, 189 patients were still receiving critical care and a further 446 were still in acute hospital. Data were missing for between 0.1% and 7.2% of patients across prognostic factors. We imputed missing data ten-fold, using fully conditional specification and continuous variables were modeled using restricted cubic splines. Associations between the candidate prognostic factors and time to death within 30 days of the start of critical care were determined after adjustment for multiple variables with Cox proportional hazards modeling. Significant associations were identified for age, ethnicity, deprivation, body mass index, prior dependency, immunocompromise, lowest systolic blood pressure, highest heart rate, highest respiratory rate, Pao2/Fio2 ratio (and interaction with mechanical ventilation), highest blood lactate concentration, highest serum urea, and lowest platelet count over the first 24 hours of critical care. Nonsignificant associations were found for sex, sedation, highest temperature, and lowest hemoglobin concentration.

CONCLUSIONS

We identified patient characteristics that predict an increased likelihood of death within 30 days of the start of critical care for patients with coronavirus disease 2019. These findings may support development of a prediction model for benchmarking critical care providers.

Evaluating the clinical and cost-effectiveness of permissive hypotension in critically ill patients aged 65 years or over with vasodilatory hypotension: Protocol for the 65 randomised clinical trial

Vasodilatory shock is common in critically ill patients and vasopressors are a mainstay of therapy. A meta-analysis suggested that use of a higher, as opposed to a lower, mean arterial pressure target to guide titration of vasopressor therapy, could be associated with a higher risk of death in older critically ill patients. The 65 trial is a pragmatic, multi-centre, parallel-group, open-label, randomised clinical trial of permissive hypotension (a mean arterial pressure target of 60 -65 mmHg during vasopressor therapy) versus usual care in critically ill patients aged 65 years or over with vasodilatory hypotension. The trial is conducted in 2600 patients from 65 United Kingdom adult, general critical care units. The primary outcome is all-cause mortality at 90 days. An economic evaluation is embedded. The 65 trial received favourable ethical opinion from the South Central - Oxford C Research Ethics Committee and approval from the Health Research Authority. The results will be presented at national and international conferences and published in peer-reviewed medical journals. Trial registration: ISRCTN10580502.

Anxiety, depression and post-traumatic stress disorder management after critical illness: a UK multi-centre prospective cohort study

BACKGROUND

Survivors of critical illness have significant psychopathological comorbidity. The treatments offered by primary health care professionals to affected patients are unstudied.

AIM

To report the psychological interventions after GPs received notification of patients who showed severe symptoms of anxiety, depression or Post-Traumatic Stress Disorder.

METHODS

Design: Multi-centre prospective cohort sub-study of the ICON study.

SETTING

NHS primary care in the United Kingdom.

PARTICIPANTS

Adult patients, November 2006-October 2010 who had received at least 24 h of intensive care, where the general practitioner recorded notification that the patient had reported severe symptoms or caseness using the Hospital Anxiety and Depression Scale (HADS) or the Post-Traumatic Stress Disorder Check List-Civilian (PCL-C).

INTERVENTIONS

We notified general practitioners (GPs) by post if a patient reported severe symptoms or caseness and sent a postal questionnaire to determine interventions after notification.

MAIN OUTCOME MEASURE

Primary or secondary healthcare interventions instigated by general practitioners following notification of a patient's caseness.

RESULTS

Of the 11,726 patients, sent questionnaire packs containing HADS and PCL-C, 4361 (37%) responded. A notification of severe symptoms was sent to their GP in 25% (1112) of cases. Of notified GPs, 65% (725) responded to our postal questionnaire. Of these 37% (266) had no record of receipt of the original notification. Of the 459 patients where GPs had record of notification (the study group for this analysis), 21% (98) had pre-existing psychopathology. Of those without a pre-existing diagnosis 45% (162) received further psychological assessment or treatment. GP screening or follow-up alone occurred in 18% (64) whilst 27% (98) were referred to mental health services or received drug therapy following notification.

CONCLUSIONS

Postal questionnaire identifies a burden of psychopathology in survivors of critical illness that have otherwise gone undiagnosed following discharge from an intensive care unit (ICU). After being alerted to the presence of psychological symptoms, GPs instigate treatment in 27% and augmented surveillance in 18% of cases.

TRIAL REGISTRATION

ISRCTN69112866 (assigned 02/05/2006).

COVID-19 in critical care: epidemiology of the first epidemic wave across England, Wales and Northern Ireland

PURPOSE

To describe critical care patients with COVID-19 across England, Wales and Northern Ireland and compare them with a historic cohort of patients with other viral pneumonias (non-COVID-19) and with international cohorts of COVID-19.

METHODS

Extracted data on patient characteristics, acute illness severity, organ support and outcomes from the Case Mix Programme, the national clinical audit for adult critical care, for a prospective cohort of patients with COVID-19 (February to August 2020) are compared with a recent retrospective cohort of patients with other viral pneumonias (non-COVID-19) (2017-2019) and with other international cohorts of critical care patients with COVID-19, the latter identified from published reports.

RESULTS

10,834 patients with COVID-19 (70.1% male, median age 60 years, 32.6% non-white ethnicity, 39.4% obese, 8.2% at least one serious comorbidity) were admitted across 289 critical care units. Of these, 36.9% had a PaO₂/FiO₂ ratio of ≤ 13.3 kPa (≤ 100 mmHg) consistent with severe ARDS and 72% received invasive ventilation. Acute hospital mortality was 42%, higher than for 5782 critical care patients with other viral pneumonias (non-COVID-19) (24.7%), and most COVID-19 deaths (88.7%) occurred before 30 days. Meaningful international comparisons were limited due to lack of standardised reporting.

CONCLUSION

Critical care patients with COVID-19 were disproportionately non-white, from more deprived areas and more likely to be male and obese. Conventional severity scoring appeared not to adequately reflect their acute severity, with the distribution across PaO₂/FiO₂ ratio categories indicating acutely severe respiratory disease. Critical care patients with COVID-19 experience high mortality and place a great burden on critical care services.

Critical care outcomes, for the first 200 patients with confirmed COVID-19, in England, Wales and Northern Ireland: A report from the ICNARC Case Mix Programme

Background

Early in a pandemic, outcomes are biased towards patients with shorter durations of critical illness. We describe 60-day outcomes for patients critically ill with confirmed COVID-19 and explore the potential bias in the weekly reported data by ICNARC.

Methods

First 200 consecutive patients with confirmed COVID-19, admitted for critical care in England, Wales and Northern Ireland, followed-up for a minimum of 60 days from admission. Outcomes included survival and duration of critical care, receipt/duration of organ support in critical care and hospital survival.

Results

Mean age was 62.6 years, 70.5% were male, 52.0% were white, 39.2% obese and 9.0% had serious comorbidities. Median APACHE II score was 16 (IQR 12, 19). After 60 days, 83 (41.5%) patients had been discharged from hospital, 15 (7.5%) had been discharged from critical care but remained in hospital, 1 (0.5%) was still receiving critical care, 90 (45.0%) had died while receiving critical care and 11 (5.5%) had died in hospital after discharge from critical care. Median duration of critical care was 14.0 days (IQR 6.1, 23.0) for survivors and 10.0 days (IQR 5.0, 16.0) for non-survivors of critical care. Overall, 158 (79.0%) patients received advanced respiratory support for a median of 13 (IQR 8, 20) calendar days. Compared with weekly reports during the pandemic, critical care mortality started higher than but then decreased below that of the first 200 consecutive patients. Duration of critical care, for both survivors and non-survivors increased over time; however, both were still lower than those for the first 200 consecutive patients. Receipt and duration of organ support increased to values similar to those for the first 200 consecutive patients.

Conclusion

COVID-19 in critical care has high mortality and places a large burden on resources. Analysis of preliminary data with limited follow-up should be interpreted with caution, particularly for future planning in a pandemic.

Risk of severe COVID-19 disease with ACE inhibitors and angiotensin receptor blockers: cohort study including 8.3 million people

BACKGROUND

There is uncertainty about the associations of angiotensive enzyme (ACE) inhibitor and angiotensin receptor blocker (ARB) drugs with COVID-19 disease. We studied whether patients prescribed these drugs had altered risks of contracting severe COVID-19 disease and receiving associated intensive care unit (ICU) admission.

METHODS

This was a prospective cohort study using routinely collected data from 1205 general practices in England with 8.28 million participants aged 20-99 years. We used Cox proportional hazards models to derive adjusted HRs for exposure to ACE inhibitor and ARB drugs adjusted for sociodemographic factors, concurrent medications and geographical region. The primary outcomes were: (a) COVID-19 RT-PCR diagnosed disease and (b) COVID-19 disease resulting in ICU care.

FINDINGS

Of 19 486 patients who had COVID-19 disease, 1286 received ICU care. ACE inhibitors were associated with a significantly reduced risk of COVID-19 disease (adjusted HR 0.71, 95% CI 0.67 to 0.74) but no increased risk of ICU care (adjusted HR 0.89, 95% CI 0.75 to 1.06) after adjusting for a wide range of confounders. Adjusted HRs for ARBs were 0.63 (95% CI 0.59 to 0.67) for COVID-19 disease and 1.02 (95% CI 0.83 to 1.25) for ICU care.There were significant interactions between ethnicity and ACE inhibitors and ARBs for COVID-19 disease. The risk of COVID-19 disease associated with ACE inhibitors was higher in Caribbean (adjusted HR 1.05, 95% CI 0.87 to 1.28) and Black African (adjusted HR 1.31, 95% CI 1.08 to 1.59) groups than the white group (adjusted HR 0.66, 95% CI 0.63 to 0.70). A higher risk of COVID-19 with ARBs was seen for Black African (adjusted HR 1.24, 95% CI 0.99 to 1.58) than the white (adjusted HR 0.56, 95% CI 0.52 to 0.62) group.

INTERPRETATION

ACE inhibitors and ARBs are associated with reduced risks of COVID-19 disease after adjusting for a wide range of variables. Neither ACE inhibitors nor ARBs are associated with significantly increased risks of receiving ICU care. Variations between different ethnic groups raise the possibility of ethnic-specific effects of ACE inhibitors/ARBs on COVID-19 disease susceptibility and severity which deserves further study.

Development, Validation, and Clinical Utility Assessment of a Prognostic Score for 1-Year Unplanned Rehospitalization or Death of Adult Sepsis Survivors

IMPORTANCE

The longer-term risk of rehospitalizations and death of adult sepsis survivors is associated with index sepsis illness characteristics.

OBJECTIVE

To derive and validate a parsimonious prognostic score for unplanned rehospitalizations or death in the first year after hospital discharge of adult sepsis survivors.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the Intensive Care National Audit & Research Centre Case Mix Programme database on adult sepsis survivors identified from consecutive critical care admissions to 192 adult general critical care units in England, United Kingdom, between April 1, 2009, and March 31, 2014 (94 748 patients in the derivation cohort), and between April 1, 2014, and March 31, 2015 (24 669 patients in the validation cohort). Statistical analysis was performed from July 5 to October 31, 2019. Generic characteristics (age, sex, race/ethnicity, 2015 Index of Multiple Deprivation [IMD2015] in England quintiles, preadmission dependence, previous hospitalizations in the year preceding index sepsis admission, comorbidity, admission type, Acute Physiology and Chronic Health Evaluation II physiology score, hospital length of stay, worst blood lactate and blood hemoglobin concentrations, and type of hospital) and sepsis-specific characteristics (site of infection, numbers of organ dysfunctions, and organ support) at the index sepsis admission were used as predictors.

MAIN OUTCOMES AND MEASURES

Prognostic score derived and validated using multivariable logistic regression for the outcome of unplanned rehospitalization or death in the first year after hospital discharge of adult sepsis survivors, as well as clinical usefulness assessed using decision curve analysis. Prognostic score validation was performed for internal validation with bootstrapping and temporal cohort external validation.

RESULTS

This cohort study included 94 748 patients (51 164 men [54.0%]; mean [SD] age, 61.3 [17.0] years) in the derivation cohort and 24 669 patients (13 255 men [53.7%]; mean [SD] age, 62.1 [16.8%]) in the validation cohort. Unplanned rehospitalization or death in the first year after hospital discharge occurred for 48 594 patients (51.3%) in the derivation cohort and 13 129 patients (53.2%) in the validation cohort. Eight independent predictors were identified and weighted to generate a prognostic score for every patient: previous hospitalizations, age in 10-year increments, IMD2015 in England quintiles, preadmission dependence, comorbidities, admission type, blood hemoglobin level, and site of infection. The total prognostic score ranged from 0 to 22 points, with lower scores indicating a lower risk of the outcome. The derivation and validation cohorts had similar rates of prognostic scores of 0 to 4 points (5088 of 16 684 patients [30.5%] and 471 of 1725 patients [27.3%]) and prognostic scores of 11 points or more (15 732 of 21 641 patients [72.7%] and 5753 of 7952 patients [72.3%]). The area under the receiver operating characteristic curve for the prognostic score was 0.675 (95% CI, 0.672-0.679). The decision curve analysis highlighted an optimal score cutoff of 7 points or more.

CONCLUSIONS AND RELEVANCE

The prognostic score reported in this study uses 8 internationally feasible predictors measured during the index sepsis admission and provides clinically useful information on sepsis survivors' risk of unplanned rehospitalization or death in the first year after hospital discharge.

FIRST-line support for assistance in breathing in children (FIRST-ABC): a master protocol of two randomised trials to evaluate the non-inferiority of high-flow nasal cannula (HFNC) versus continuous positive airway pressure (CPAP) for non-invasive respiratory support in paediatric critical care

INTRODUCTION

Even though respiratory support is a common intervention in paediatric critical care, there is no randomised controlled trial (RCT) evidence regarding the effectiveness of two commonly used modes of non-invasive respiratory support (NRS), continuous positive airway pressure (CPAP) and high-flow nasal cannula therapy (HFNC). FIRST-line support for assistance in breathing in children is a master protocol of two pragmatic non-inferiority RCTs to evaluate the clinical and cost-effectiveness of HFNC (compared with CPAP) as the first-line mode of support in critically ill children.

METHODS AND ANALYSIS

We will recruit participants over a 30-month period at 25 UK paediatric critical care units (paediatric intensive care units/high-dependency units). Patients are eligible if admitted/accepted for admission, aged >36 weeks corrected gestational age and <16 years, and assessed by the treating clinician to require NRS for an acute illness (step-up RCT) or within 72 hours of extubation following a period of invasive ventilation (step-down RCT). Due to the emergency nature of the treatment, written informed consent will be deferred to after randomisation. Randomisation will occur 1:1 to CPAP or HFNC, stratified by site and age (<12 vs ≥12 months). The primary outcome is time to liberation from respiratory support for a continuous period of 48 hours. A total sample size of 600 patients in each RCT will provide 90% power with a type I error rate of 2.5% (one sided) to exclude the prespecified non-inferiority margin of HR of 0.75. Primary analyses will be undertaken separately in each RCT in both the intention-to-treat and per-protocol populations.

ETHICS AND DISSEMINATION

This master protocol received favourable ethical opinion from National Health Service East of England-Cambridge South Research Ethics Committee (reference: 19/EE/0185) and approval from the Health Research Authority (reference: 260536). Results will be disseminated via publications in peer-reviewed medical journals and presentations at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN60048867.

Evaluating the clinical and cost-effectiveness of permissive hypotension in critically ill patients aged 65 years or over with vasodilatory hypotension: Statistical and health economic analysis plan for the 65 trial in article

The 65 trial is a pragmatic, multicentre, parallel-group, open-label, randomised clinical trial of permissive hypotension (targeting a mean arterial pressure target of 60-65 mmHg during vasopressor therapy) versus usual care in critically ill patients aged 65 years or over with vasodilatory hypotension. The trial will recruit 2600 patients from 65 United Kingdom adult general critical care units. The primary outcome is all-cause mortality at 90 days. An economic evaluation is embedded. This paper describes the proposed statistical and health economic analysis for the 65 trial.

The interaction between arterial oxygenation and carbon dioxide and hospital mortality following out of hospital cardiac arrest: a cohort study

BACKGROUND

Outcomes following out of hospital cardiac arrest (OHCA) are poor. The optimal arterial oxygen and carbon dioxide (PaCO₂) levels for managing patients following OHCA are unknown. We hypothesized that abnormalities in arterial oxygenation (PaO₂/FiO₂ ratio or PaO₂) and PaCO₂ would be associated with hospital mortality following OHCA. We hypothesized that PaCO₂ would significantly modify the oxygenation-mortality relationship.

METHODS

This was an observational cohort study using data from OHCA survivors admitted to adult critical care units in England, Wales and Northern Ireland from 2011 to 2018. Logistic regression analyses were performed to assess the relationship between hospital mortality and oxygenation and PaCO₂.

RESULTS

The analysis included 23,625 patients. In comparison with patients with a PaO₂/FiO₂ > 300 mmHg, those with a PaO₂/FiO₂ ≤ 100 mmHg had higher mortality (adjusted OR, 1.79; 95% CI, 1.48 to 2.15; P < 0.001). In comparison to hyperoxemia (PaO₂ > 100 mmHg), patients with hypoxemia (PaO₂ < 60 mmHg) had higher mortality (adjusted OR, 1.34; 95% CI, 1.10 to 1.65; P = 0.004). In comparison with normocapnia, hypercapnia was associated with lower mortality. Hypocapnia (PaCO2 ≤ 35 mmHg) was associated with higher mortality (adjusted OR, 1.91; 95% CI, 1.63 to 2.24; P < 0.001). PaCO₂ modified the PaO₂/FiO₂-mortality and PaO₂-mortality relationships, though these relationships were complex. Patients who were both hyperoxic and hypercapnic had the lowest mortality.

CONCLUSIONS

Low PaO₂/FiO₂ ratio, hypoxemia and hypocapnia are associated with higher mortality following OHCA. PaCO₂ modifies the relationship between oxygenation and mortality following OHCA; future studies examining this interaction are required.

Does delaying discharge from intensive care until after tracheostomy removal affect 30-day mortality? Propensity score matched cohort study

OBJECTIVE

To investigate the short-term mortality effect of discharge from an intensive care unit (ICU) with a tracheostomy in place in comparison to delaying discharge until after tracheostomy removal.

DESIGN

A propensity score matched cohort study using data from the TracMan study.

SETTING

Seventy-two UK ICUs taking part in the TracMan study, a randomised controlled trial comparing early tracheostomy (within 4 days of critical care admission) with deferred tracheostomy (after 10 days if still indicated).

PARTICIPANTS

622 patients who underwent a tracheostomy while in the TracMan study between November 2004 and November 2008. 144 patients left ICU with a tracheostomy. 999 days of observation from 294 patients were included in the control pool.

INTERVENTIONS

We matched patients discharged with a tracheostomy in place 1:1 with patients who remained in an ICU until either their tracheostomy was removed or they died with the tracheostomy in place. Propensity models were developed according to discharge destination, accounting for likely confounding factors.

PRIMARY OUTCOME MEASURE

The primary outcome was 30-day mortality from the matching day. For the 'discharged with a tracheostomy' group, this was death within 30 days after the discharge day. For the 'remained in ICU' group, this was death within 30 days after the matched day.

RESULTS

22 (15.3%) patients who left ICU with a tracheostomy died within 30 days compared with 26 (18.1%) who remained in ICU (relative risk 0.98, 95% CI 0.43 to 2.23).

CONCLUSION

Keeping patients on an ICU to provide tracheostomy care was not found to affect mortality. Tracheostomy presence may indicate a higher risk of mortality due to underlying diseases and conditions rather than posing a risk in itself.The TracMan trial was registered on the ISRCTN database (ISRCTN28588190).

Different temperature thresholds for antipyretic intervention in critically ill children with fever due to infection: the FEVER feasibility RCT

BACKGROUND

Fever accelerates host immune system control of pathogens but at a high metabolic cost. The optimal approach to fever management and the optimal temperature thresholds used for treatment in critically ill children are unknown.

OBJECTIVES

To determine the feasibility of conducting a definitive randomised controlled trial (RCT) to evaluate the clinical effectiveness and cost-effectiveness of different temperature thresholds for antipyretic management.

DESIGN

A mixed-methods feasibility study comprising three linked studies - (1) a qualitative study exploring parent and clinician views, (2) an observational study of the epidemiology of fever in children with infection in paediatric intensive care units (PICUs) and (3) a pilot RCT with an integrated-perspectives study.

SETTING

Participants were recruited from (1) four hospitals in England via social media (for the FEVER qualitative study), (2) 22 PICUs in the UK (for the FEVER observational study) and (3) four PICUs in England (for the FEVER pilot RCT).

PARTICIPANTS

(1) Parents of children with relevant experience were recruited to the FEVER qualitative study, (2) patients who were unplanned admissions to PICUs were recruited to the FEVER observational study and (3) children admitted with infection requiring mechanical ventilation were recruited to the FEVER pilot RCT. Parents of children and clinicians involved in the pilot RCT.

INTERVENTIONS

The FEVER qualitative study and the FEVER observational study had no interventions. In the FEVER pilot RCT, children were randomly allocated (1 : 1) using research without prior consent (RWPC) to permissive (39.5 °C) or restrictive (37.5 °C) temperature thresholds for antipyretics during their PICU stay while mechanically ventilated.

MAIN OUTCOME MEASURES

(1) The acceptability of FEVER, RWPC and potential outcomes (in the FEVER qualitative study), (2) the size of the potentially eligible population and the temperature thresholds used (in the FEVER observational study) and (3) recruitment and retention rates, protocol adherence and separation between groups and distribution of potential outcomes (in the FEVER pilot RCT).

RESULTS

In the FEVER qualitative study, 25 parents were interviewed and 56 clinicians took part in focus groups. Both the parents and the clinicians found the study acceptable. Clinicians raised concerns regarding temperature thresholds and not using paracetamol for pain/discomfort. In the FEVER observational study, 1853 children with unplanned admissions and infection were admitted to 22 PICUs between March and August 2017. The recruitment rate was 10.9 per site per month. The majority of critically ill children with a maximum temperature of > 37.5 °C received antipyretics. In the FEVER pilot RCT, 100 eligible patients were randomised between September and December 2017 at a recruitment rate of 11.1 per site per month. Consent was provided for 49 out of 51 participants in the restrictive temperature group, but only for 38 out of 49 participants in the permissive temperature group. A separation of 0.5 °C (95% confidence interval 0.2 °C to 0.8 °C) between groups was achieved. A high completeness of outcome measures was achieved. Sixty parents of 57 children took part in interviews and/or completed questionnaires and 98 clinicians took part in focus groups or completed a survey. Parents and clinicians found the pilot RCT and RWPC acceptable. Concerns about children being in pain/discomfort were cited as reasons for withdrawal and non-consent by parents and non-adherence to the protocol by clinicians.

LIMITATIONS

Different recruitment periods for observational and pilot studies may not fully reflect the population that is eligible for a definitive RCT.

CONCLUSIONS

The results identified barriers to delivering the definitive FEVER RCT, including acceptability of the permissive temperature threshold. The findings also provided insight into how these barriers may be overcome, such as by limiting the patient inclusion criteria to invasive ventilation only and by improved site training. A definitive FEVER RCT using a modified protocol should be conducted, but further work is required to agree important outcome measures for clinical trials among critically ill children.

TRIAL REGISTRATION

The FEVER observational study is registered as NCT03028818 and the FEVER pilot RCT is registered as Current Controlled Trials ISRCTN16022198.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 5. See the NIHR Journals Library website for further project information.

The impact of the Tracey judgment on the rates and outcomes of in-hospital cardiac arrests in UK hospitals participating in the National Cardiac Arrest Audit

AIMS

The aim was to determine if the 17 June 2014 Tracey judgment regarding 'do not attempt cardiopulmonary resuscitation' decisions led to increases in the rate of in-hospital cardiac arrests resulting in a resuscitation attempt (IHCA) and/or proportion of resuscitation attempts deemed futile.

METHOD

Using UK National Cardiac Arrest Audit data, the IHCA rate and proportion of resuscitation attempts deemed futile were compared for two periods (pre-judgment (01 July 2012 - 16 June 2014, inclusive) and post-judgment (01 July 2014 - 30 June 2016, inclusive)) using interrupted time series analyses.

RESULTS

A total of 43,109 IHCAs (115 hospitals) were analysed. There were fewer IHCAs post- than pre-judgment (21,324 vs 21,785, respectively). The IHCA rate was declining over time before the judgment but there was an abrupt and statistically significant increase in the period immediately following the judgment (p<0.001). This was not sustained post-judgment. The proportion of resuscitation attempts deemed futile was smaller post-judgment than pre-judgment (8.2% vs 14.9%, respectively). The rate of attempts deemed futile decreased post-judgment (p<0.001).

CONCLUSION

The IHCA rate increased immediately after the Tracey judgment while the proportion of resuscitation attempts deemed futile decreased. The precise mechanisms for these changes are unclear.

Renal replacement anticoagulant management: Protocol and analysis plan for an observational comparative effectiveness study of linked data sources

Acute kidney injury is common in critical illness. In patients with severe acute kidney injury, renal replacement therapy is needed to prevent harm from metabolic and electrolyte disturbances and fluid overload. In the UK, continuous renal replacement therapy (CRRT) is the preferred modality, which requires anticoagulation. Over the last decade, conventional systemic heparin anticoagulation has started being replaced by regional citrate anticoagulation for CRRT, which is now used in approximately 50% of ICUs. This shift towards regional citrate anticoagulation for CRRT is occurring with little evidence of safety or longer term effectiveness. Renal replacement anticoagulant management (RRAM) is an observational comparative effectiveness study, utilising existing data sources to address the clinical and cost-effectiveness of the change to regional citrate anticoagulation for CRRT in UK ICUs. The study will use data from approximately 85,000 patients who were treated in adult, general ICUs participating in the case mix programme national clinical audit between 1 April 2009 and 31 March 2017. A survey of health service providers’ anticoagulation practices will be combined with treatment and hospital outcome data from the case mix programme and linked with long-term outcomes from the Civil Registrations (deaths), Hospital Episodes Statistics for England, Patient Episodes Data for Wales, and the UK Renal Registry datasets. The primary clinical effectiveness outcome is all-cause mortality at 90-days. The study will incorporate an economic evaluation with micro-costing of both regional citrate anticoagulation and systemic heparin anticoagulation.

Study registration: NCT03545750