Sedation modality in acute respiratory distress syndrome: does method of sedation affect length of stay, outcomes, or adverse events? A systematic review

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is a life-threatening, diffuse inflammatory pulmonary condition characterised by the Berlin criteria. Incidence of ARDS is estimated at 2.5-19% globally with high mortality and morbidity. Interest has been increasing in the use of inhaled sedatives because of a more rapid awakening and fewer adverse effects compared with intravenous propofol. The primary aim of this systematic review protocol is to investigate the length of critical care stay between ARDS patients who have been mechanically ventilated with inhaled anaesthetic sedatives (ie, sevoflurane and isoflurane) compared with those patients who are prescribed conventional sedatives (ie, propofol).

METHODS AND ANALYSIS

Cochrane Central Register of Controlled Trials, Ovid (Embase, MEDLINE), PubMed, EBSCO (CINAHL Plus), Google Scholar will be searched and stratified by the reviewers. The literature search will be limited to English articles. Published full text peer-reviewed articles will be included.The International Prospective Register of Systematic Reviews (PROSPERO) Registration number is: CRD42023390988.

ETHICS AND DISSEMINATION

Ethics approval is not required for this systematic review. The results will be presented at local/regional meetings and dissemination will occur through peer-reviewed publication.

Development and prioritisation of policy recommendations for medication safety improvement for intensive care units: a European Association of Hospital Pharmacists Special Interest Group Delphi Study

OBJECTIVES

Medication errors (MEs) are a leading cause of morbidity and mortality in the healthcare system. Patients admitted to intensive care units (ICUs) are potentially more susceptible to MEs due to severity of illness, the complexity of treatments they receive and the challenging nature of the ICU setting. The European Association of Hospital Pharmacists established a Special Interest Group (SIG) to undertake a programme of work to develop and prioritise recommendations to support medication safety improvement in ICUs across Europe.

METHODS

Initial policy recommendations for medication safety within the ICU environment were developed following reviews of the literature and engagement with relevant stakeholders. A Delphi panel of 21 members of the SIG, that comprised healthcare professionals (HCPs) with expertise in ICU and/or medication safety, was convened in 2022. We conducted two rounds using a modified Delphi technique whereby participants anonymously ranked on a 9-point Likert Scale the policy recommendations according to their priority for implementation.

RESULTS

In total, 32 policy recommendations were developed. In Delphi Round 1, 19 HCPs participated; consensus was achieved on most recommendations and partial consensus on six. In Delphi Round 2, 18 HCPs participated. After two Delphi rounds, consensus was achieved on all 32 recommendations. All recommendations were considered 'high priority' except one that was considered 'medium priority'.

CONCLUSIONS

Through this study it was possible to develop and prioritise evidence-based policy recommendations to enhance medication safety, which may contribute to reducing MEs in ICUs across Europe. All recommendations were considered 'high priority' for implementation except one, indicating the perceived value of these recommendations in improving medication safety through preventing MEs in ICUs.

Management of heparin-induced thrombocytopenia during extracorporeal membrane oxygenation support: a case of neutropenia caused by argatroban anticoagulation

We present the case of a man in his 70s admitted to the intensive care unit (ICU) after mitral valve replacement and coronary artery bypass graft surgery requiring extracorporeal membrane oxygenation support due to haemodynamic instability. He received anticoagulation therapy with heparin sodium and, after 5 days, the patient presented with thrombocytopenia and deep venous thrombosis. Heparin-induced thrombocytopenia was suspected based on a positive 4T score and confirmed by antiplatelet factor 4/heparin antibodies, so argatroban was initiated as an alternative anticoagulation therapy. In the following days the patient developed severe neutropenia requiring discontinuation of argatroban and the administration of granulocyte colony-stimulating factor. According to the Naranjo Adverse Drug Reaction Probability Scale, this event would be classified as a 'probable' argatroban-related adverse event. Argatroban should be conisdered as a possible cause of neutropenia and appropriate interventions need to be implemented due to the gravity of this adverse event in the ICU.

Implementing early rehabilitation and mobilisation for children in UK paediatric intensive care units: the PERMIT feasibility study

Background

Early rehabilitation and mobilisation encompass patient-tailored interventions, delivered within intensive care, but there are few studies in children and young people within paediatric intensive care units.

Objectives

To explore how healthcare professionals currently practise early rehabilitation and mobilisation using qualitative and quantitative approaches; co-design the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual of early rehabilitation and mobilisation interventions, with primary and secondary patient-centred outcomes; explore feasibility and acceptability of implementing the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual within three paediatric intensive care units.

Design

Mixed-methods feasibility with five interlinked studies (scoping review, survey, observational study, codesign workshops, feasibility study) in three phases.

Setting

United Kingdom paediatric intensive care units.

Participants

Children and young people aged 0-16 years remaining within paediatric intensive care on day 3, their parents/guardians and healthcare professionals.

Interventions

In Phase 3, unit-wide implementation of manualised early rehabilitation and mobilisation.

Main outcome measures

Phase 1 observational study: prevalence of any early rehabilitation and mobilisation on day 3. Phase 3 feasibility study: acceptability of early rehabilitation and mobilisation intervention; adverse events; acceptability of study design; acceptability of outcome measures.

Data sources

Searched Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, PEDro, Open grey and Cochrane CENTRAL databases.

Review methods

Narrative synthesis.

Results

In the scoping review we identified 36 full-text reports evaluating rehabilitation initiated within 7 days of paediatric intensive care unit admission, outlining non-mobility and mobility early rehabilitation and mobilisation interventions from 24 to 72 hours and delivered twice daily. With the survey, 124/191 (65%) responded from 26/29 (90%) United Kingdom paediatric intensive care units; the majority considered early rehabilitation and mobilisation a priority. The observational study followed 169 patients from 15 units; prevalence of any early rehabilitation and mobilisation on day 3 was 95.3%. We then developed a manualised early rehabilitation and mobilisation intervention informed by current evidence, experience and theory. All three sites implemented the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual successfully, recruited to target (30 patients recruited) and followed up the patients until day 30 or discharge; 21/30 parents consented to complete additional outcome measures.

Limitations

The findings represent the views of National Health Service staff but may not be generalisable. We were unable to conduct workshops and interviews with children, young people and parents to support the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual development due to pandemic restrictions.

Conclusions

A randomised controlled trial is recommended to assess the effectiveness of the manualised early rehabilitation and mobilisation intervention.

Future work

A definitive cluster randomised trial of early rehabilitation and mobilisation in paediatric intensive care requires selection of outcome measure and health economic evaluation.

Study registration

The study is registered as PROSPERO CRD42019151050. The Phase 1 observational study is registered Clinicaltrials.gov NCT04110938 (Phase 1) (registered 1 October 2019) and the Phase 3 feasibility study is registered NCT04909762 (Phase 3) (registered 2 June 2021).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/21/06) and is published in full in Health Technology Assessment; Vol. 27, No. 27. See the NIHR Funding and Awards website for further award information.

Comparison of outcomes for fixed and weight-based four-factor prothrombin complex concentrate dosing regimens

OBJECTIVES

Although fixed dose regimens using four-factor prothrombin complex concentrate (4F-PCC) are more widely accepted, using a 'one size fits all' approach remains an area of uncertainty. The primary objective of this study was to compare percentages of haemostasis between fixed dose and weight-based dose 4F-PCC regimens for multiple bleed types and anticoagulants. Secondary objectives compared differences in the time to administration and in-hospital mortality.

METHODS

This retrospective, cohort study took place at a community hospital and included patients ≥18 years of age receiving 4F-PCC for major bleeding while on either warfarin or a factor-Xa inhibitor between January 2015 and December 2022. Patients received either fixed dose (treatment) or weight-based dose (comparison). Patients who had been treated for a non-urgent procedure, with unknown haemorrhage source, not on anticoagulation, coagulopathic from hepatic failure, had received dabigatran or were allergic to heparin were excluded. Fisher's exact test and logistic regression were used to analyse primary and secondary outcomes.

RESULTS

94 patients met the inclusion criteria; 38 patients were assigned to the treatment group and 56 to the comparator group. There was no statistical evidence of a difference in the achievement of haemostasis between groups (45% vs 46%, p=0.872). The fixed dose patients received the dose on average 13 min faster than weight-based (32 min vs 46 min, p=0.031). There was no difference in mortality (29% vs 29%, p=0.968).

CONCLUSION

Fixed 4F-PCC regimens may achieve similar outcomes and a faster time to administration compared with weight-based regimens.

Medication-related problems in critical care survivors: a systematic review

OBJECTIVES

There are numerous, often single centre discussions of assorted medication-related problems after hospital discharge in patients who survive critical illness. However, there has been little synthesis of the incidence of medication-related problems, the classes of medications most often studied, the factors that are associated with greater patient risk of such problems or interventions that can prevent them.

METHODS

We undertook a systematic review to understand medication management and medication problems in critical care survivors in the hospital discharge period. We searched OVID Medline, Embase, PsychINFO, CINAHL and the Cochrane database (2001-2022). Two reviewers independently screened publications to identify studies that examined medication management at hospital discharge or thereafter in critical care survivors. We included randomised and non-randomised studies. We extracted data independently and in duplicate. Data extracted included medication type, medication-related problems and frequency of medication issues, alongside demographics such as study setting. Cohort study quality was assessed using the Newcastle Ottowa Score checklist. Data were analysed across medication categories.

RESULTS

The database search initially retrieved 1180 studies; following the removal of duplicates and studies which did not fit the inclusion criteria, 47 papers were included. The quality of studies included varied. The outcomes measured and the timepoints at which data were captured also varied, which impacted the quality of data synthesis. Across the studies included, we found that as many as 80% of critically ill patients experienced medication-related problems in the posthospital discharge period. These issues included inappropriate continuation of newly prescribed drugs such as antipsychotics, gastrointestinal prophylaxis and analgesic medications, as well as inappropriate discontinuation of chronic disease medications, such as secondary prevention cardiac drugs.

CONCLUSIONS

Following critical illness, a high proportion of patients experience problems with their medications. These changes were present across multiple health systems. Further research is required to understand optimal medicine management across the full recovery trajectory of critical illness.

PROSPERO REGISTRATION NUMBER

CRD42021255975.

Extracorporeal carbon dioxide removal compared to ventilation alone in patients with acute hypoxaemic respiratory failure: cost-utility analysis of the REST RCT

Background

Acute hypoxaemic respiratory failure requiring mechanical ventilation is a major cause of morbidity and mortality and has significant resource implications in terms of intensive care unit and hospital stay.

Objective

To assess the cost-effectiveness of extracorporeal carbon dioxide removal compared to ventilation alone in patients with acute hypoxaemic respiratory failure.

Design

A cost-utility analysis embedded within a pragmatic, multicentre, allocation-concealed, open-label, randomised controlled trial.

Participants

Four hundred and twelve (of a planned sample size of 1120) adult patients receiving mechanical ventilation for acute hypoxaemic respiratory failure, were recruited between May 2016 and December 2019 from 51 intensive care units in the UK.

Interventions

Participants were randomised (1 : 1) to receive extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with ventilation alone (n = 210).

Outcomes

Health-related quality of life via the EuroQol-5 Dimensions, five-level version, health resource use and associated costs were measured over the study period. The cost per quality-adjusted life-year was estimated at 12 months post randomisation.

Results

Mean EuroQol-5 Dimensions, five-level version utility scores were low and similar for each group. Quality-adjusted life-years were calculated for those patients with complete EuroQol-5 Dimensions, five-level version data (extracorporeal carbon dioxide removal n = 140, ventilation alone n = 143) and there was no discernible difference in quality-adjusted life-years at 12 months (mean difference -0.01; 95% confidence interval -0.06 to 0.05; 140). Total 12-month health resource use cost (including intervention costs) was calculated for those patients with complete cost data (extracorporeal carbon dioxide removal n = 125, ventilation alone n = 126) and costs were statistically significantly higher in the extracorporeal carbon dioxide removal group (mean difference £7668.76, 95% confidence interval 159.75, 15,177.77). Multiple imputation was used for missing total cost and quality-adjusted life-year data in the cost-utility analysis. Ventilation alone dominated extracorporeal carbon dioxide removal and there was 0% probability of extracorporeal carbon dioxide removal being cost-effective compared to ventilation alone for all willingness to pay thresholds per quality-adjusted life-year considered (£0-50,000).

Conclusions

Extracorporeal carbon dioxide removal was associated with significantly higher costs, but no benefit in health-related quality of life. Given the data, extracorporeal carbon dioxide removal is not considered to be a cost-effective approach to treating patients with acute hypoxaemic respiratory failure.

Limitations

These included the absence of a baseline healthy utility score, minor data loss related to not obtaining complete intensive care unit readmission data for Scottish participants, and not estimating long-term cost-effectiveness due to the study closing early.

Future work

Measuring baseline health-related quality of life in critical care studies is difficult; future economic evaluations in this setting should consider measuring health-related quality of life as soon as possible after the patients regain capacity.

Trial registration

This trial is registered as NCT02654327 and ISRCTN 31262122.

Funding

This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number 13/143/02.

Description of the 2020 NEMSIS Public-Release Research Dataset

Background: The National Emergency Medical Services Information System (NEMSIS) is a federally funded program designed to standardize Emergency Medical Services (EMS) patient care reporting and facilitate state and national data repositories for the assessment and improvement of EMS systems of care. This manuscript characterizes the 2020 submissions to the National EMS Database, detailing the strengths and limitations associated with use of these data for public health surveillance, improving prehospital patient care, critical resource allocation, clinician safety, system quality assurance and research purposes.Methodology: Using the 2020 NEMSIS Public-Release Research Dataset (NEMSIS dataset), we evaluated the dataset completeness (i.e., presence of missing/null values), dataset content and assessed data generalizability. The analysis focused on 911 EMS activations resulting in the treatment and transport of a patient, except for out-of-hospital cardiac arrests for which all patients were included regardless of transport status.Results: In 2020, 43,488,767 EMS activations were reported to the National EMS Database by 12,319 agencies serving 50 states and territories. Of the 19,533,036 911 EMS activations reportedly treating and transporting a patient, the majority were attended by "non-volunteer" clinicians (77%) working in a fire-based EMS agency (35%) certified to offer Advanced Life Support (ALS) Paramedic service (80%) and located in an urban area (82%). 911 call centers most often dispatched EMS for "sick person" (20%), while EMS clinicians most likely reported asthenia (7%) as the patient's primary symptom as well as the clinician's primary impression (6%), and documented "fall on same level, slip, or trip" as the most common cause of injury (37%). The NEMSIS dataset demonstrates some "missingness" and element inconsistencies, but methods may be employed to mitigate these data limitations.Conclusions: The National EMS Database is a free and publicly available resource for evaluating EMS system utilization, response, and prehospital patient care. Understanding the characteristics of the underlying dataset and known data limitations will help ensure proper analysis and reporting of research and quality metrics based on nationally standardized NEMSIS data.

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.

Pharmacological and non-pharmacological treatments and outcomes for new-onset atrial fibrillation in ICU patients: the CAFE scoping review and database analyses

BACKGROUND

New-onset atrial fibrillation occurs in around 10% of adults treated in an intensive care unit. New-onset atrial fibrillation may lead to cardiovascular instability and thromboembolism, and has been independently associated with increased length of hospital stay and mortality. The long-term consequences are unclear. Current practice guidance is based on patients outside the intensive care unit; however, new-onset atrial fibrillation that develops while in an intensive care unit differs in its causes and the risks and clinical effectiveness of treatments. The lack of evidence on new-onset atrial fibrillation treatment or long-term outcomes in intensive care units means that practice varies. Identifying optimal treatment strategies and defining long-term outcomes are critical to improving care.

OBJECTIVES

In patients treated in an intensive care unit, the objectives were to (1) evaluate existing evidence for the clinical effectiveness and safety of pharmacological and non-pharmacological new-onset atrial fibrillation treatments, (2) compare the use and clinical effectiveness of pharmacological and non-pharmacological new-onset atrial fibrillation treatments, and (3) determine outcomes associated with new-onset atrial fibrillation.

METHODS

We undertook a scoping review that included studies of interventions for treatment or prevention of new-onset atrial fibrillation involving adults in general intensive care units. To investigate the long-term outcomes associated with new-onset atrial fibrillation, we carried out a retrospective cohort study using English national intensive care audit data linked to national hospital episode and outcome data. To analyse the clinical effectiveness of different new-onset atrial fibrillation treatments, we undertook a retrospective cohort study of two large intensive care unit databases in the USA and the UK.

RESULTS

Existing evidence was generally of low quality, with limited data suggesting that beta-blockers might be more effective than amiodarone for converting new-onset atrial fibrillation to sinus rhythm and for reducing mortality. Using linked audit data, we showed that patients developing new-onset atrial fibrillation have more comorbidities than those who do not. After controlling for these differences, patients with new-onset atrial fibrillation had substantially higher mortality in hospital and during the first 90 days after discharge (adjusted odds ratio 2.32, 95% confidence interval 2.16 to 2.48; adjusted hazard ratio 1.46, 95% confidence interval 1.26 to 1.70, respectively), and higher rates of subsequent hospitalisation with atrial fibrillation, stroke and heart failure (adjusted cause-specific hazard ratio 5.86, 95% confidence interval 5.33 to 6.44; adjusted cause-specific hazard ratio 1.47, 95% confidence interval 1.12 to 1.93; and adjusted cause-specific hazard ratio 1.28, 95% confidence interval 1.14 to 1.44, respectively), than patients who did not have new-onset atrial fibrillation. From intensive care unit data, we found that new-onset atrial fibrillation occurred in 952 out of 8367 (11.4%) UK and 1065 out of 18,559 (5.7%) US intensive care unit patients in our study. The median time to onset of new-onset atrial fibrillation in patients who received treatment was 40 hours, with a median duration of 14.4 hours. The clinical characteristics of patients developing new-onset atrial fibrillation were similar in both databases. New-onset atrial fibrillation was associated with significant average reductions in systolic blood pressure of 5 mmHg, despite significant increases in vasoactive medication (vasoactive-inotropic score increase of 2.3; p < 0.001). After adjustment, intravenous beta-blockers were not more effective than amiodarone in achieving rate control (adjusted hazard ratio 1.14, 95% confidence interval 0.91 to 1.44) or rhythm control (adjusted hazard ratio 0.86, 95% confidence interval 0.67 to 1.11). Digoxin therapy was associated with a lower probability of achieving rate control (adjusted hazard ratio 0.52, 95% confidence interval 0.32 to 0.86) and calcium channel blocker therapy was associated with a lower probability of achieving rhythm control (adjusted hazard ratio 0.56, 95% confidence interval 0.39 to 0.79) than amiodarone. Findings were consistent across both the combined and the individual database analyses.

CONCLUSIONS

Existing evidence for new-onset atrial fibrillation management in intensive care unit patients is limited. New-onset atrial fibrillation in these patients is common and is associated with significant short- and long-term complications. Beta-blockers and amiodarone appear to be similarly effective in achieving cardiovascular control, but digoxin and calcium channel blockers appear to be inferior.

FUTURE WORK

Our findings suggest that a randomised controlled trial of amiodarone and beta-blockers for management of new-onset atrial fibrillation in critically ill patients should be undertaken. Studies should also be undertaken to provide evidence for or against anticoagulation for patients who develop new-onset atrial fibrillation in intensive care units. Finally, given that readmission with heart failure and thromboembolism increases following an episode of new-onset atrial fibrillation while in an intensive care unit, a prospective cohort study to demonstrate the incidence of atrial fibrillation and/or left ventricular dysfunction at hospital discharge and at 3 months following the development of new-onset atrial fibrillation should be undertaken.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN13252515.

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. 71. See the NIHR Journals Library website for further project information.

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.