Bilateral remote ischemic conditioning in children: A two-center, double-blind, randomized controlled trial in young children undergoing cardiac surgery

Objective

The study objective was to determine whether adequately delivered bilateral remote ischemic preconditioning is cardioprotective in young children undergoing surgery for 2 common congenital heart defects with or without cyanosis.

Methods

We performed a prospective, double-blind, randomized controlled trial at 2 centers in the United Kingdom. Children aged 3 to 36 months undergoing tetralogy of Fallot repair or ventricular septal defect closure were randomized 1:1 to receive bilateral preconditioning or sham intervention. Participants were followed up until hospital discharge or 30 days. The primary outcome was area under the curve for high-sensitivity troponin-T in the first 24 hours after surgery, analyzed by intention-to-treat. Right atrial biopsies were obtained in selected participants.

Results

Between October 2016 and December 2020, 120 eligible children were randomized to receive bilateral preconditioning (n = 60) or sham intervention (n = 60). The primary outcome, area under the curve for high-sensitivity troponin-T, was higher in the preconditioning group (mean: 70.0 ± 50.9 μg/L/h, n = 56) than in controls (mean: 55.6 ± 30.1 μg/L/h, n = 58) (mean difference, 13.2 μg/L/h; 95% CI, 0.5-25.8; P = .04). Subgroup analyses did not show a differential treatment effect by oxygen saturations (pinteraction = .25), but there was evidence of a differential effect by underlying defect (pinteraction = .04). Secondary outcomes and myocardial metabolism, quantified in atrial biopsies, were not different between randomized groups.

Conclusions

Bilateral remote ischemic preconditioning does not attenuate myocardial injury in children undergoing surgical repair for congenital heart defects, and there was evidence of potential harm in unstented tetralogy of Fallot. The routine use of remote ischemic preconditioning cannot be recommended for myocardial protection during pediatric cardiac surgery.

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.

Feasibility of non-invasive neuro-monitoring during extracorporeal membrane oxygenation in children

INTRODUCTION

Detection of neurological complications during extracorporeal membrane oxygenation (ECMO) may be enhanced with non-invasive neuro-monitoring. We investigated the feasibility of non-invasive neuro-monitoring in a paediatric intensive care (PIC) setting.

METHODS

In a single centre, prospective cohort study we assessed feasibility of recruitment, and neuro-monitoring via somatosensory evoked potentials (SSEP), electroencephalography (EEG) and near infrared spectroscopy (NIRS) during venoarterial (VA) ECMO in paediatric patients (0-15 years). Measures were obtained within 24h of cannulation, during an intermediate period, and finally at decannulation or echo stress testing. SSEP/EEG/NIRS measures were correlated with neuro-radiology findings, and clinical outcome assessed via the Pediatric cerebral performance category (PCPC) scale 30 days post ECMO cannulation.

RESULTS

We recruited 14/20 (70%) eligible patients (median age: 9 months; IQR:4-54, 57% male) over an 18-month period, resulting in a total of 42 possible SSEP/EEG/NIRS measurements. Of these, 32/42 (76%) were completed. Missed recordings were due to lack of access/consent within 24 h of cannulation (5/42, 12%) or PIC death/discharge (5/42, 12%). In each patient, the majority of SSEP (8/14, 57%), EEG (8/14, 57%) and NIRS (11/14, 79%) test results were within normal limits. All patients with abnormal neuroradiology (4/10, 40%), and 6/7 (86%) with poor outcome (PCPC ≥4) developed indirect SSEP, EEG or NIRS measures of neurological complications prior to decannulation. No study-related adverse events or neuro-monitoring data interpreting issues were experienced.

CONCLUSION

Non-invasive neuro-monitoring (SSEP/EEG/NIRS) during ECMO is feasible and may provide early indication of neurological complications in this high-risk population.

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.

Comparative Effectiveness of Diversion of Cerebrospinal Fluid for Children With Severe Traumatic Brain Injury

IMPORTANCE

Diversion of cerebrospinal fluid (CSF) has been used for decades as a treatment for children with severe traumatic brain injury (TBI) and is recommended by evidenced-based guidelines. However, these recommendations are based on limited studies.

OBJECTIVE

To determine whether CSF diversion is associated with improved Glasgow Outcome Score-Extended for Pediatrics (GOS-EP) and decreased intracranial pressure (ICP) in children with severe TBI.

DESIGN, SETTING, AND PARTICIPANTS

This observational comparative effectiveness study was performed at 51 clinical centers that routinely care for children with severe TBI in 8 countries (US, United Kingdom, Spain, the Netherlands, Australia, New Zealand, South Africa, and India) from February 2014 to September 2017, with follow-up at 6 months after injury (final follow-up, October 22, 2021). Children with severe TBI were included if they had Glasgow Coma Scale (GCS) scores of 8 or lower, had intracranial pressure (ICP) monitor placed on-site, and were aged younger than 18 years. Children were excluded if they were pregnant or an ICP monitor was not placed at the study site. Consecutive children were screened and enrolled, data regarding treatments were collected, and at discharge, consent was obtained for outcomes testing. Propensity matching for pretreatment characteristics was performed to develop matched pairs for primary analysis. Data analyses were completed on April 18, 2022.

EXPOSURES

Clinical care followed local standards, including the use of CSF diversion (or not), with patients stratified at the time of ICP monitor placement (CSF group vs no CSF group).

MAIN OUTCOMES AND MEASURES

The primary outcome was GOS-EP at 6 months, while ICP was considered as a secondary outcome. CSF vs no CSF was treated as an intention-to-treat analysis, and a sensitivity analysis was performed for children who received delayed CSF diversion.

RESULTS

A total of 1000 children with TBI were enrolled, including 314 who received CSF diversion (mean [SD] age, 7.18 [5.45] years; 208 [66.2%] boys) and 686 who did not (mean [SD] age, 7.79 [5.33] years; 437 [63.7%] boys). The propensity-matched analysis included 98 pairs. In propensity score-matched analyses, there was no difference between groups in GOS-EP (median [IQR] difference, 0 [-3 to 1]; P = .08), but there was a decrease in overall ICP in the CSF group (mean [SD] difference, 3.97 [0.12] mm Hg; P < .001).

CONCLUSIONS AND RELEVANCE

In this comparative effectiveness study, CSF diversion was not associated with improved outcome at 6 months after TBI, but a decrease in ICP was observed. Given the higher quality of evidence generated by this study, current evidence-based guidelines related to CSF diversion should be reconsidered.

Lactate, Base Excess, and the Pediatric Index of Mortality: Exploratory Study of an International, Multicenter Dataset

OBJECTIVES

To investigate the relationship between ICU admission blood lactate, base excess, and ICU mortality and to explore the effect of incorporating blood lactate into the Pediatric Index of Mortality.

DESIGN

Retrospective cohort study based on data prospectively collected on every PICU admission submitted to the U.K. Pediatric Intensive Care Audit Network and to the Australia and New Zealand Pediatric Intensive Care Registry.

SETTING

Thirty-three PICUs in the United Kingdom/Republic of Ireland and nine PICUs and 20 general ICUs in Australia and New Zealand.

PATIENTS

All ICU admissions between January 1, 2012, and December 31, 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred twenty-three thousand two hundred fifty-two admissions were recorded in both datasets; 81,576 (66.2%) in the United Kingdom/Republic of Ireland and 41,676 (33.8%) in Australia and New Zealand. Of these 75,070 (61%) had a base excess recorded, 63,316 (51%) had a lactate recorded, and 60,876 (49%) had both base excess and lactate recorded. Median lactate value was 1.5 mmol/L (interquartile range, 1-2.4 mmol/L) (United Kingdom/Republic of Ireland: 1.5 [1-2.5]; Australia and New Zealand: 1.4 [1-2.3]). Children with a lactate recorded had a higher illness severity, were more likely to be invasively ventilated, admitted after cardiac surgery, and had a higher mortality rate, compared with admissions with no lactate recorded (p < 0.001). The relationship between lactate and mortality was stronger (odds ratio, 1.32; 95% CI, 1.31-1.34) than between absolute base excess and mortality (odds ratio, 1.13; 95% CI, 1.12-1.14). Addition of lactate to the Pediatric Index of Mortality score led to a small improvement in performance over addition of absolute base excess, whereas adding both lactate and absolute base excess achieved the best performance.

CONCLUSIONS

At PICU admission, blood lactate is more strongly associated with ICU mortality than absolute base excess. Adding lactate into the Pediatric Index of Mortality model may result in a small improvement in performance. Any improvement in Pediatric Index of Mortality performance must be balanced against the added burden of data capture when considering potential incorporation into the Pediatric Index of Mortality model.

Early mobilisation and rehabilitation in the PICU: a UK survey

OBJECTIVE

To understand the context and professional perspectives of delivering early rehabilitation and mobilisation (ERM) within UK paediatric intensive care units (PICUs).

DESIGN

A web-based survey administered from May 2019 to August 2019.

SETTING

UK PICUs.

PARTICIPANTS

A total of 124 staff from 26 PICUs participated, including 22 (18%) doctors, 34 (27%) nurses, 28 (23%) physiotherapists, 19 (15%) occupational therapists and 21 (17%) were other professionals.

RESULTS

Key components of participants' definitions of ERM included tailored, multidisciplinary rehabilitation packages focused on promoting recovery. Multidisciplinary involvement in initiating ERM was commonly reported. Over half of respondents favoured delivering ERM after achieving physiological stability (n=69, 56%). All age groups were considered for ERM by relevant health professionals. However, responses differed concerning the timing of initiation. Interventions considered for ERM were more likely to be delivered to patients when PICU length of stay exceeded 28 days and among patients with acquired brain injury or severe developmental delay. The most commonly identified barriers were physiological instability (81%), limited staffing (79%), sedation requirement (73%), insufficient resources and equipment (69%), lack of recognition of patient readiness (67%), patient suitability (63%), inadequate training (61%) and inadequate funding (60%). Respondents ranked reduction in PICU length of stay (74%) and improvement in psychological outcomes (73%) as the most important benefits of ERM.

CONCLUSION

ERM is gaining familiarity and endorsement in UK PICUs, but significant barriers to implementation due to limited resources and variation in content and delivery of ERM persist. A standardised protocol that sets out defined ERM interventions, along with implementation support to tackle modifiable barriers, is required to ensure the delivery of high-quality ERM.

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.

Co-ordinated multidisciplinary intervention to reduce time to successful extubation for children on mechanical ventilation: the SANDWICH cluster stepped-wedge RCT

BACKGROUND

Daily assessment of patient readiness for liberation from invasive mechanical ventilation can reduce the duration of ventilation. However, there is uncertainty about the effectiveness of this in a paediatric population.

OBJECTIVES

To determine the effect of a ventilation liberation intervention in critically ill children who are anticipated to have a prolonged duration of mechanical ventilation (primary objective) and in all children (secondary objective).

DESIGN

A pragmatic, stepped-wedge, cluster randomised trial with economic and process evaluations.

SETTING

Paediatric intensive care units in the UK.

PARTICIPANTS

Invasively mechanically ventilated children (aged < 16 years).

INTERVENTIONS

The intervention incorporated co-ordinated multidisciplinary care, patient-relevant sedation plans linked to sedation assessment, assessment of ventilation parameters with a higher than usual trigger for undertaking an extubation readiness test and a spontaneous breathing trial on low levels of respiratory support to test extubation readiness. The comparator was usual care. Hospital sites were randomised sequentially to transition from control to intervention and were non-blinded.

MAIN OUTCOME MEASURES

The primary outcome measure was the duration of invasive mechanical ventilation until the first successful extubation. The secondary outcome measures were successful extubation, unplanned extubation and reintubation, post-extubation use of non-invasive ventilation, tracheostomy, post-extubation stridor, adverse events, length of intensive care and hospital stay, mortality and cost per respiratory complication avoided at 28 days.

RESULTS

The trial included 10,495 patient admissions from 18 paediatric intensive care units from 5 February 2018 to 14 October 2019. In children with anticipated prolonged ventilation (n = 8843 admissions: control, n = 4155; intervention, n = 4688), the intervention resulted in a significantly shorter time to successful extubation [cluster and time-adjusted median difference -6.1 hours (interquartile range -8.2 to -5.3 hours); adjusted hazard ratio 1.11, 95% confidence interval 1.02 to 1.20; p = 0.02] and a higher incidence of successful extubation (adjusted relative risk 1.01, 95% confidence interval 1.00 to 1.02; p = 0.03) and unplanned extubation (adjusted relative risk 1.62, 95% confidence interval 1.05 to 2.51; p = 0.03), but not reintubation (adjusted relative risk 1.10, 95% confidence interval 0.89 to 1.36; p = 0.38). In the intervention period, the use of post-extubation non-invasive ventilation was significantly higher (adjusted relative risk 1.22, 95% confidence interval 1.01 to 1.49; p = 0.04), with no evidence of a difference in intensive care length of stay or other harms, but hospital length of stay was longer (adjusted hazard ratio 0.89, 95% confidence interval 0.81 to 0.97; p = 0.01). Findings for all children were broadly similar. The control period was associated with lower, but not statistically significantly lower, total costs (cost difference, mean £929.05, 95% confidence interval -£516.54 to £2374.64) and significantly fewer respiratory complications avoided (mean difference -0.10, 95% confidence interval -0.16 to -0.03).

LIMITATIONS

The unblinded intervention assignment may have resulted in performance or detection bias. It was not possible to determine which components were primarily responsible for the observed effect. Treatment effect in a more homogeneous group remains to be determined.

CONCLUSIONS

The intervention resulted in a statistically significant small reduction in time to first successful extubation; thus, the clinical importance of the effect size is uncertain.

FUTURE WORK

Future work should explore intervention sustainability and effects of the intervention in other paediatric populations.

TRIAL REGISTRATION

This trial is registered as ISRCTN16998143.

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

Effect of a Sedation and Ventilator Liberation Protocol vs Usual Care on Duration of Invasive Mechanical Ventilation in Pediatric Intensive Care Units: A Randomized Clinical Trial

IMPORTANCE

There is limited evidence on the optimal strategy for liberating infants and children from invasive mechanical ventilation in the pediatric intensive care unit.

OBJECTIVE

To determine if a sedation and ventilator liberation protocol intervention reduces the duration of invasive mechanical ventilation in infants and children anticipated to require prolonged mechanical ventilation.

DESIGN, SETTING, AND PARTICIPANTS

A pragmatic multicenter, stepped-wedge, cluster randomized clinical trial was conducted that included 17 hospital sites (18 pediatric intensive care units) in the UK sequentially randomized from usual care to the protocol intervention. From February 2018 to October 2019, 8843 critically ill infants and children anticipated to require prolonged mechanical ventilation were recruited. The last date of follow-up was November 11, 2019.

INTERVENTIONS

Pediatric intensive care units provided usual care (n = 4155 infants and children) or a sedation and ventilator liberation protocol intervention (n = 4688 infants and children) that consisted of assessment of sedation level, daily screening for readiness to undertake a spontaneous breathing trial, a spontaneous breathing trial to test ventilator liberation potential, and daily rounds to review sedation and readiness screening and set patient-relevant targets.

MAIN OUTCOMES AND MEASURES

The primary outcome was the duration of invasive mechanical ventilation from initiation of ventilation until the first successful extubation. The primary estimate of the treatment effect was a hazard ratio (with a 95% CI) adjusted for calendar time and cluster (hospital site) for infants and children anticipated to require prolonged mechanical ventilation.

RESULTS

There were a total of 8843 infants and children (median age, 8 months [interquartile range, 1 to 46 months]; 42% were female) who completed the trial. There was a significantly shorter median time to successful extubation for the protocol intervention compared with usual care (64.8 hours vs 66.2 hours, respectively; adjusted median difference, -6.1 hours [interquartile range, -8.2 to -5.3 hours]; adjusted hazard ratio, 1.11 [95% CI, 1.02 to 1.20], P = .02). The serious adverse event of hypoxia occurred in 9 (0.2%) infants and children for the protocol intervention vs 11 (0.3%) for usual care; nonvascular device dislodgement occurred in 2 (0.04%) vs 7 (0.1%), respectively.

CONCLUSIONS AND RELEVANCE

Among infants and children anticipated to require prolonged mechanical ventilation, a sedation and ventilator liberation protocol intervention compared with usual care resulted in a statistically significant reduction in time to first successful extubation. However, the clinical importance of the effect size is uncertain.

TRIAL REGISTRATION

isrctn.org Identifier: ISRCTN16998143.

Traumatic Brain Injury Practice Guidelines: Variability in U.K. PICUs

OBJECTIVES

Traumatic brain injury in children is a leading cause of morbidity and mortality. Lack of high-quality evidence may lead to variation in management within and between PICUs. We examined U.K. pediatric traumatic brain injury management guidelines for extent of variability.

DESIGN

Analysis of U.K. PICU traumatic brain injury guidelines for areas of consistency and variation among each other and against the second edition of Brain Trauma Foundation pediatric traumatic brain injury guidelines.

SETTING

Not applicable.

SUBJECTS

Not applicable.

INTERVENTIONS

Textual analysis of U.K. PICU guidelines.

MEASUREMENTS AND MAIN RESULTS

Twelve key clinical topics in three traumatic brain injury management domains were identified. We performed textual analysis of recommendations from anonymized local guidelines and compared them against each other and the Brain Trauma Foundation pediatric traumatic brain injury guidelines. Fifteen guidelines used by 16 of the 20 U.K. PICUs that manage traumatic brain injury were analyzed. Relatively better consistency was observed for intracranial pressure treatment thresholds (10/15), avoiding prophylactic hyperventilation (15/15), cerebrospinal fluid drainage (13/15), barbiturate (14/15), and decompressive craniectomy (12/15) for intracranial hypertension. There was less consistency in indications for intracranial pressure monitoring (3/15), cerebral perfusion pressure targets (2/15), target osmolarities (7/15), and hyperventilation for intracranial hypertension (2/15). Variability in choice and hierarchy of the interventions for intracranial hypertension were observed, albeit with some points of consistency.

CONCLUSIONS

Significant variability in pediatric traumatic brain injury management guidelines exists. Despite the heterogeneity, we have highlighted a few points of consistency within the key topic areas of pediatric traumatic brain injury management. We anticipate that this provides impetus for further work around standardization.

Reliability in the assessment of paediatric somatosensory evoked potentials post cardiac arrest

OBJECTIVE

To measure inter- and intra-rater agreement in the interpretation of cortical somatosensory evoked potential (SSEP) components following paediatric cardiac arrest (CA) in multi-professional neurophysiology teams.

METHODS

Thirteen professionals blinded to patient outcome interpreted 96 SSEPs in paediatric patients 24-/48-/72-hours following CA. Of these, 34 were duplicates used to assess intra-rater agreement. Consistent interpretations (absent/present/indeterminate) between scientists (who record/identify SSEP components) and neurophysiologists (who provide prognostic SSEP interpretation) were expressed as percentages. Rates of agreement were calculated using Fleiss' kappa coefficient (K).

RESULTS

Unanimous agreement between professionals was present in 40% (95%CI: 28-54%) of the interpreted SSEPs, with a K value of 0.62 (95%CI: 0.55-0.70) based on average agreement. Agreement was similar between neurophysiologists (K = 0.67; 95%CI: 0.57-0.77) and scientists (K = 0.62; 95%CI: 0.54-0.70) but lower in patients < 2 years old (K = 0.23; 95%CI: 0.14-0.33) and in those with poor outcome (K = 0.21; 95%CI: 0.07-0.35). No SSEP was unanimously interpreted as absent and 92% (95%CI: 89-95%) of duplicate SSEPs were interpreted consistently.

CONCLUSION

Despite substantial agreement when interpreting prognostic SSEPs, this was significantly lower in children with poor outcome and of younger age.

SIGNIFICANCE

Clinicians using SSEPs in the intensive care unit should be aware of the inter-rater variability when interpreting SSEPs as absent.

The Prognostic Value of Somatosensory Evoked Potentials in Children After Cardiac Arrest: The SEPIA Study

PURPOSE

Absent cortical somatosensory evoked potentials (SSEPs) reliably predict poor neurologic outcome in adults after cardiac arrest (CA). However, there is less evidence to support this in children. In addition, targeted temperature management, test timing, and a lack of blinding may affect test accuracy.

METHODS

A single-center, prospective cohort study of pediatric (aged 24 hours to 15 years) patients in which prognostic value of SSEPs were assessed 24, 48, and 72 hours after CA. Targeted temperature management (33-34°C for 24 hours) followed by gradual rewarming to 37°C was used. Somatosensory evoked potentials were graded as present, absent, or indeterminate, and results were blinded to clinicians. Neurologic outcome was graded as "good" (score 1-3) or "poor" (4-6) using the Pediatric Cerebral Performance Category scale 30 days after CA and blinded to SSEP interpreter.

RESULTS

Twelve patients (median age, 12 months; interquartile range, 2-150; 92% male) had SSEPs interpreted as absent (6/12) or present (6/12) <72 hours after CA. Outcome was good in 7 of 12 patients (58%) and poor in 5 of 12 patients (42%). Absent SSEPs predicted poor outcome with 88% specificity (95% confidence interval, 53% to 98%). One patient with an absent SSEP had good outcome (Pediatric Cerebral Performance Category 3), and all patients with present SSEPs had good outcome (specificity 100%; 95% confidence interval, 51% to 100%). Absence or presence of SSEP was consistent across 24-hour (temperature = 34°C), 48-hour (t = 36°C), and 72-hour (t = 36°C) recordings after CA.

CONCLUSIONS

Results support SSEP utility when predicting favorable outcome; however, predictions resulting in withdrawal of life support should be made with caution and never in isolation because in this very small sample there was a false prediction of unfavorable outcome. Further prospective, blinded studies are needed and encouraged.

Bilateral Remote Ischaemic Conditioning in Children (BRICC) trial: protocol for a two-centre, double-blind, randomised controlled trial in young children undergoing cardiac surgery

INTRODUCTION

Myocardial protection against ischaemic-reperfusion injury is a key determinant of heart function and outcome following cardiac surgery in children. However, with current strategies, myocardial injury occurs routinely following aortic cross-clamping, as demonstrated by the ubiquitous rise in circulating troponin. Remote ischaemic preconditioning, the application of brief, non-lethal cycles of ischaemia and reperfusion to a distant organ or tissue, is a simple, low-risk and readily available technique which may improve myocardial protection. The Bilateral Remote Ischaemic Conditioning in Children (BRICC) trial will assess whether remote ischaemic preconditioning, applied to both lower limbs immediately prior to surgery, reduces myocardial injury in cyanotic and acyanotic young children.

METHODS AND ANALYSIS

The BRICC trial is a two-centre, double-blind, randomised controlled trial recruiting up to 120 young children (age 3 months to 3 years) undergoing primary repair of tetralogy of Fallot or surgical closure of an isolated ventricular septal defect. Participants will be randomised in a 1:1 ratio to either bilateral remote ischaemic preconditioning (3×5 min cycles) or sham immediately prior to surgery, with follow-up until discharge from hospital or 30 days, whichever is sooner. The primary outcome is reduction in area under the time-concentration curve for high-sensitivity (hs) troponin-T release in the first 24 hours after aortic cross-clamp release. Secondary outcome measures include peak hs-troponin-T, vasoactive inotrope score, arterial lactate and central venous oxygen saturations in the first 12 hours, and lengths of stay in the paediatric intensive care unit and the hospital.

ETHICS AND DISSEMINATION

The trial was approved by the West Midlands-Solihull National Health Service Research Ethics Committee (16/WM/0309) on 5 August 2016. Findings will be disseminated to the academic community through peer-reviewed publications and presentation at national and international meetings. Parents will be informed of the results through a newsletter in conjunction with a local charity.

TRIAL REGISTRATION NUMBER

ISRCTN12923441.

NEUROlogical Prognosis After Cardiac Arrest in Kids (NEUROPACK) study: protocol for a prospective multicentre clinical prediction model derivation and validation study in children after cardiac arrest

INTRODUCTION

Currently, we are unable to accurately predict mortality or neurological morbidity following resuscitation after paediatric out of hospital (OHCA) or in-hospital (IHCA) cardiac arrest. A clinical prediction model may improve communication with parents and families and risk stratification of patients for appropriate postcardiac arrest care. This study aims to the derive and validate a clinical prediction model to predict, within 1 hour of admission to the paediatric intensive care unit (PICU), neurodevelopmental outcome at 3 months after paediatric cardiac arrest.

METHODS AND ANALYSIS

A prospective study of children (age: >24 hours and <16 years), admitted to 1 of the 24 participating PICUs in the UK and Ireland, following an OHCA or IHCA. Patients are included if requiring more than 1 min of cardiopulmonary resuscitation and mechanical ventilation at PICU admission Children who had cardiac arrests in PICU or neonatal intensive care unit will be excluded. Candidate variables will be identified from data submitted to the Paediatric Intensive Care Audit Network registry. Primary outcome is neurodevelopmental status, assessed at 3 months by telephone interview using the Vineland Adaptive Behavioural Score II questionnaire. A clinical prediction model will be derived using logistic regression with model performance and accuracy assessment. External validation will be performed using the Therapeutic Hypothermia After Paediatric Cardiac Arrest trial dataset. We aim to identify 370 patients, with successful consent and follow-up of 150 patients. Patient inclusion started 1 January 2018 and inclusion will continue over 18 months.

ETHICS AND DISSEMINATION

Ethical review of this protocol was completed by 27 September 2017 at the Wales Research Ethics Committee 5, 17/WA/0306. The results of this study will be published in peer-reviewed journals and presented in conferences.

TRIAL REGISTRATION NUMBER

NCT03574025.

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.

Trends in long-stay admissions to a UK paediatric intensive care unit

OBJECTIVE

Prolonged admission to a paediatric intensive care unit (PICU) consumes significant healthcare resource. An increase in the number of long-stay admissions and bed utilisation has been reported elsewhere in the world but not in the UK. If an increasing trend of long-stay admissions is evident, this may have significant implications for provision of paediatric intensive care in the future.

DESIGN/SETTING/PATIENTS

We retrospectively analysed prospectively collected data from Birmingham Children's Hospital, UK, over a 20-year period from 1998 to 2017. PICU admissions, bed-days, length of stay and mortality trends were analysed and reported over four different epochs (1998-2002, 2003-2007, 2008-2012 and 2013-2017) for long-stay admissions (PICU length of stay ≥28 days) and others. Differences in patient demographics, diagnostic categorisation and hospital utilisation were also analysed.

RESULTS

In total, 24 203 admissions accounted for 131 553 bed-days over the 20-year period. 705 (2.9%) long-stay admissions accounted for 42 312 (32%) bed-days. Proportion of long-stay admissions and corresponding bed-days increased from 1.6% and 20.5% in 1998-2002 to 4.5% and 42.6%, respectively, in 2013-2017 (p<0.001). Long-stay patients had a significantly higher number of hospital admissions (median: 4 vs 2, p<0.001) per patient and overall hospital length of stay (median: 98 vs 15, p<0.001) bed-days compared with other patients. Long-stay admissions were associated with significantly higher crude mortality (23% vs 6%, p<0.001) compared with other admissions.

CONCLUSIONS

A significant increase in the proportion of prolonged PICU admissions with disproportionately high resource utilisation and mortality is evident over two decades.

Sedation AND Weaning In Children (SANDWICH): protocol for a cluster randomised stepped wedge trial

INTRODUCTION

Weaning from ventilation is a complex process involving several stages that include recognition of patient readiness to begin the weaning process, steps to reduce ventilation while optimising sedation in order not to induce distress and removing the endotracheal tube. Delay at any stage can prolong the duration of mechanical ventilation. We developed a multicomponent intervention targeted at helping clinicians to safely expedite this process and minimise the harms associated with unnecessary mechanical ventilation.

METHODS AND ANALYSIS

This is a 20-month cluster randomised stepped wedge clinical and cost-effectiveness trial with an internal pilot and a process evaluation. It is being conducted in 18 paediatric intensive care units in the UK to evaluate a protocol-based intervention for reducing the duration of invasive mechanical ventilation. Following an initial 8-week baseline data collection period in all sites, one site will be randomly chosen to transition to the intervention every 4 weeks and will start an 8-week training period after which it will continue the intervention for the remaining duration of the study. We aim to recruit approximately 10 000 patients. The primary analysis will compare data from before the training (control) with that from after the training (intervention) in each site. Full details of the analyses will be in the statistical analysis plan.

ETHICS AND DISSEMINATION

This protocol was reviewed and approved by NRES Committee East Midlands-Nottingham 1 Research Ethics Committee (reference: 17/EM/0301). All sites started patient recruitment on 5 February 2018 before randomisation in April 2018. Results will be disseminated in 2020. The results will be presented at national and international conferences and published in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

ISRCTN16998143.

Attitudes towards fever amongst UK paediatric intensive care staff

The role played by fever in the outcome of critical illness in children is unclear. This survey of medical and nursing staff in 35 paediatric intensive care units and transport teams in the United Kingdom and Ireland established attitudes towards the management of children with fever. Four hundred sixty-two medical and nursing staff responded to a web-based survey request. Respondents answered eight questions regarding thresholds for temperature control in usual clinical practice, indications for paracetamol use, and readiness to participate in a clinical trial of permissive temperature control. The median reported threshold for treating fever in clinical practice was 38 °C (IQR 38-38.5 °C). Paracetamol was reported to be used as an analgesic and antipyretic but also for non-specific comfort indications. There was a widespread support for a clinical trial of a permissive versus a conservative approach to fever in paediatric intensive care units. Within a trial, 58% of the respondents considered a temperature of 39 °C acceptable without treatment.

CONCLUSIONS

Staff on paediatric intensive care units in the United Kingdom and Ireland tends to treat temperatures within the febrile range. There was a willingness to conduct a randomized controlled trial of treatment of fever. What is known: • The effect of fever on the outcome in paediatric critical illness is unknown. • Paediatricians have traditionally been reluctant to allow fever in sick children. What is new: • Paediatric intensive care staff report a tendency towards treating fever, with a median reported treatment threshold of 38 °C. • There is widespread support amongst PICU staff in the UK for a randomized controlled trial of temperature in critically ill children. • Within a trial setting, PICU staff attitudes to fever are more permissive than in clinical practice.

Observational study of children admitted to United Kingdom and Republic of Ireland Paediatric Intensive Care Units after out-of-hospital cardiac arrest

AIMS

To estimate the prevalence of children admitted after out-of-hospital cardiac arrest (OHCA) to UK and Republic of Ireland (RoI) Paediatric Intensive Care Units (PICUs) and factors associated with mortality to inform future clinical trial feasibility.

METHOD

Observational study using a prospectively collected dataset of the Paediatric Intensive Care Audit Network (PICANet) of 33 UK and RoI PICUs (January 2003 to June 2010). Cases (0 to <16 years), with documented OHCA surviving to PICU admission and requiring mechanical ventilation were included. Main outcomes were prevalence for admission and death within PICU. Factors associated with mortality were examined with multiple logistic regression analysis.

RESULTS

827 of 111,170 admissions (0.73%; 95% CI [0.48 to 0.98%]) were identified as children admitted following OHCA. PICU mortality for OHCA was 50.5% (418/827). Recruitment into an adequately sized clinical trial would not be feasible with the current prevalence rate. Characteristics at PICU admission associated with increased risk of death included; bilateral unreactive pupils, genetically inherited condition, inter-hospital transfer to PICU, requirement for vasoactive drugs and greater base deficit. Factors associated with reduced risk of death were submersion or a respiratory aetiology and pre-existing respiratory or cardiac conditions.

CONCLUSIONS

Less than 120 children a year are admitted to PICUs in the UK and RoI after OHCA, limiting options for conducting UK intervention trials. The risk factors associated with mortality identified in this study will allow risk stratification in future studies.

Defining criteria and resource use for high dependency care in children: an observational economic study

OBJECTIVES

Internationally there is no consensus on defining and funding of paediatric high dependency care (HDC). This study tested whether a new UK Healthcare Resource Group (HRG) classification for HDC, with two categories of basic and advanced HDC, can identify children who consume greater staff resource. It also explored the impact of a change in basic HDC HRG criteria introduced in April 2011.

DESIGN

Observational study of medical and nursing staff resource use.

SETTING

16 paediatric wards across 6 regional hospitals; 1 tertiary children's hospital (November 2010 to March 2011).

PARTICIPANTS

1098 infants and children admitted to paediatric wards.

MAIN OUTCOME MEASURES

Number of children meeting criteria for basic and advanced HDC HRGs; care in a cubicle; medical and nursing staff costs, extrapolated from time spent at patient bedside.

RESULTS

223 (20.3%) children met original HDC criteria (15.9% basic, 4.4% advanced). This fell to 88 (8.0%) with the change in basic HDC definition (3.6% basic, 4.4% advanced). Children who met original HDC criteria consumed greater bedside staff resource than those not meeting criteria (cost ratio 1.0:1.75:2.96 (non-HDC:basic HDC:advanced HDC)), with revised criteria identifying a (smaller) basic group with greater staff resource use (cost ratio 1.0:2.35:2.76). Being cared for in a cubicle was not associated with greater staff costs.

CONCLUSIONS

HDC HRG criteria identify children who consume significantly greater staff resources. Revision of the definition has resulted in a large reduction of cases meeting the criteria but identifies a group consuming greater staff resources.

Early change in blood glucose concentration is an indicator of mortality in critically ill children

OBJECTIVE

Hyperglycaemia is associated with increased mortality in critically ill patients. A number of studies have highlighted an association between increased variability of blood glucose (BG) concentration and mortality, supporting a survival disadvantage if BG homeostasis is lost. By exploring the longitudinal BG profile of individual children over time, this study investigates the importance of intact homeostasis early after admission to the paediatric intensive care unit (PICU).

DESIGN, SETTING, AND PATIENTS

Retrospective single-centre observational study in a large multi-specialty PICU in the UK. Children admitted between August 2003 and February 2006 were included unless they met exclusion criteria. Data were merged from the PICU clinical database and blood gas analyser database by means of a unique PICU identifier. BG was measured frequently on a blood gas analyser (Bayer Rapidlink). Primary outcome was 100-day mortality. BG parameters were investigated for possible associations with mortality.

MEASUREMENTS AND MAIN RESULTS

A total of 1,763 patients were included (median age 1.1 years; IQR 0.1-5.8). Although admission BG was not associated with mortality, a survival advantage was found in children who showed a reduction in BG on day 1 relative to the admission BG value (p < 0.001). This remained statistically significant (p = 0.007) after adjusting for severity of illness.

CONCLUSIONS

This study supports an association between early BG profile and mortality in children admitted to PICU, with increased survival in those who demonstrate a fall in BG on day 1 relative to PICU admission. These findings are consistent with a survival advantage of intact BG homeostasis.

Survey of the use of therapeutic hypothermia after cardiac arrest in UK paediatric emergency departments

OBJECTIVES

To ascertain current use of therapeutic hypothermia (TH) after paediatric cardiac arrest in UK emergency departments (EDs), and views on participating in a UK randomised controlled trial (RCT) incorporating early induction of TH in ED.

DESIGN

Anonymous web-based survey of 77 UK Emergency Medicine (EM) consultants from 28 UK EDs that see children during the period April-June 2010.

RESULTS

62% (48/77) of surveyed consultants responded from 21/28 (75%) EDs. All managed children post cardiac arrest. 90% (43/48) were aware of the literature concerning TH after cardiac arrest in adults. However, 63% (30/48) had never used TH in paediatric practice. All departments had at least one method of inducing TH (surface cooling; air/water blankets; intravenous cold fluid or catheters). Reasons stated for not inducing TH included no equipment available (26%; 11/42), TH not advocated by the local PICU (24%; 10/42) and not enough evidence for its use (24%; 10/42). TH was considered based on advice from the local Paediatric Intensive Care Units (68%; 17/25) or likelihood of recovery after arrest (32%; 8/25). There was strong support for a UK RCT of TH versus normothermia (85%; 40/47). The proposed RCT was felt to be ethical (87%; 40/48) with use of deferred consent acceptable (74%; 34/46).

CONCLUSION

UK EM consultants are aware of TH but infrequently initiate the therapy in children for a number of reasons. Their involvement would enable early induction of TH in EDs after paediatric cardiac arrest during a UK RCT. The authors have demonstrated the availability of suitable equipment and EM consultant support for participation in such a RCT.

Severe head injury in children: intensive care unit activity and mortality in England and Wales

OBJECTIVE

To explore the relationship between volume of paediatric intensive care unit (PICU) head injury (HI) admissions, specialist paediatric neurosurgical PICU practice, and mortality in England and Wales.

METHODS

Analysis of HI cases (age  <16 years) from the Paediatric Intensive Care Audit Network national cohort of sequential PICU admissions in 27 units in England and Wales, in the 5 years 2004-2008. Risk-adjusted mortality using the Paediatric Index of Mortality (PIM) model was compared between PICUs aggregated into quartile groups, first to fourth based on descending number of HI admissions/year: highest volume, medium-higher volume, medium-lower volume, and lowest volume. The effect of category of PICU interventions - observation only, mechanical ventilation (MV) only, and intracranial pressure (ICP) monitoring - on outcome was also examined. Observations were reported in relation to specialist paediatric neurosurgical PICU practice.

RESULTS

There were 2575 admissions following acute HI (4.4% of non-cardiac surgery PICU admissions in England and Wales). PICU mortality was 9.3%. Units in the fourth-quartile (lowest volume) group did not have significant specialist paediatric neurosurgical activity on the PICU; the other groups did. Overall, there was no effect of HI admissions by individual PICU on risk-adjusted mortality. However, there were significant effects for both intensive care intervention category (p<0.001) and HI admissions by grouping (p<0.005). Funnel plots and control charts using the PIM model showed a hierarchy in increasing performance from lowest volume (group IV), to medium-higher volume (group II), to highest volume (group I), to medium-lower volume (group III) sectors of the health care system.

CONCLUSIONS

The health care system in England and Wales for critically ill HI children requiring PICU admission performs as expected in relation to the PIM model. However, the lowest-volume sector, comprising 14 PICUs with little or no paediatric neurosurgical activity on the unit, exhibits worse than expected outcome, particularly in those undergoing ICP monitoring. The best outcomes are seen in units in the mid-volume sector. These data do not support the hypothesis that there is a simple relationship between PICU volume and performance.

Survey of the use of therapeutic hypothermia post cardiac arrest

OBJECTIVES

Therapeutic hypothermia improves neurological outcome in adults after ventricular fibrillation cardiac arrest and neonates with hypoxic ischaemic encephalopathy. There is currently no clinical research to support its use in the paediatric population. This survey aims to ascertain current practice in the UK, and attitudes and opinions to guide the feasibility of a UK multicentre, randomised, controlled trial of therapeutic hypothermia after cardiac arrest in children (The Cold-PACK Post Arrest Cooling in Kids study).

METHODS

Anonymous survey of UK paediatric intensive care consultants (n=149).

RESULTS

A total of 113 (76%) of 149 surveys were returned; 65% responded that they do not know if therapeutic hypothermia improves survival after cardiac arrest. Despite this, 48% 'always' or 'often' use therapeutic hypothermia after return of spontaneous circulation following cardiac arrest in children. Among those who never use therapeutic hypothermia (33%) the commonest explanation given was 'not enough research evidence' (91%). With respect to the dose of therapeutic hypothermia the median duration of cooling used is 24-48 h (range 4-72 h) and median target temperature 34°C to 35°C (range 32°C to 37°C); 68% target a temperature range higher than that applied in the published adult and neonatal studies (33±1°C). There was strong support for a trial of therapeutic hypothermia being ethical (89%) and using deferred consent (85%).

CONCLUSIONS

Wide variation in UK practice in the use of therapeutic hypothermia and a state of clinical equipoise is demonstrated by this survey, which shows important support for UK multicentre collaboration in a future trial of therapeutic hypothermia after cardiac arrest.

Hypothermia therapy after traumatic brain injury in children

BACKGROUND

Hypothermia therapy improves survival and the neurologic outcome in animal models of traumatic brain injury. However, the effect of hypothermia therapy on the neurologic outcome and mortality among children who have severe traumatic brain injury is unknown.

METHODS

In a multicenter, international trial, we randomly assigned children with severe traumatic brain injury to either hypothermia therapy (32.5 degrees C for 24 hours) initiated within 8 hours after injury or to normothermia (37.0 degrees C). The primary outcome was the proportion of children who had an unfavorable outcome (i.e., severe disability, persistent vegetative state, or death), as assessed on the basis of the Pediatric Cerebral Performance Category score at 6 months.

RESULTS

A total of 225 children were randomly assigned to the hypothermia group or the normothermia group; the mean temperatures achieved in the two groups were 33.1+/-1.2 degrees C and 36.9+/-0.5 degrees C, respectively. At 6 months, 31% of the patients in the hypothermia group, as compared with 22% of the patients in the normothermia group, had an unfavorable outcome (relative risk, 1.41; 95% confidence interval [CI], 0.89 to 2.22; P=0.14). There were 23 deaths (21%) in the hypothermia group and 14 deaths (12%) in the normothermia group (relative risk, 1.40; 95% CI, 0.90 to 2.27; P=0.06). There was more hypotension (P=0.047) and more vasoactive agents were administered (P<0.001) in the hypothermia group during the rewarming period than in the normothermia group. Lengths of stay in the intensive care unit and in the hospital and other adverse events were similar in the two groups.

CONCLUSIONS

In children with severe traumatic brain injury, hypothermia therapy that is initiated within 8 hours after injury and continued for 24 hours does not improve the neurologic outcome and may increase mortality. (Current Controlled Trials number, ISRCTN77393684 [controlled-trials.com].).

Norwood procedure for hypoplastic left heart syndrome: BT shunt or RV-PA conduit?

BACKGROUND

The Norwood procedure is the first stage palliative procedure for hypoplastic left heart syndrome (HLHS). Traditionally the pulmonary circulation has been supplied via a modified Blalock Taussig (BT) shunt but a recent modification, adopted in some UK centres, substitutes a conduit between right ventricle and pulmonary arteries (RV-PA conduit). It is argued that this will result in a more favourable balance between pulmonary and systemic circulations.

AIM

To compare the early postoperative haemodynamic profile between patients undergoing a BT shunt or an RV-PA conduit.

METHODS

Retrospective review in a tertiary referral PICU of 51 children with HLHS undergoing the Norwood procedure with either a BT shunt (Group 1; n = 23) or an RV-PA conduit (Group 2; n = 28). Data items were extracted at 10 set time points in the initial 96 h, postoperatively.

RESULTS

Diastolic BP was significantly lower in Group 1 (p<0.001) with a trend towards a higher systolic BP and no difference in mean BP. No between-group differences were found in markers of pulmonary blood flow (PaO2, PaCO2, PaO2/FiO2 ratio), or in markers of systemic blood flow (blood lactate, oxygen extraction ratio), or in estimated ratio of pulmonary:systemic blood flow (Qp:Qs). Despite lower diastolic blood pressure in Group 1 renal and hepatic function did not differ over five post-operative days between groups.

CONCLUSIONS

With the exception of a higher diastolic blood pressure in the RV-PA conduit group, we found no difference in the early haemodynamic profile between patients undergoing an RV-PA conduit or a BT shunt.

Severe head injury in children: emergency access to neurosurgery in the United Kingdom

OBJECTIVE

To determine the scale of acute neurosurgery for severe traumatic brain injury (TBI) in childhood, and whether surgical evacuation for haematoma is achieved within four hours of presentation to an emergency department.

METHODS

A 12 month audit of emergency access to all specialist neurosurgical and intensive care services in the UK. Severe TBI in a child was defined as that necessitating admission to intensive care.

RESULTS

Of 448 children with severe head injuries, 91 (20.3%) underwent emergency neurosurgery, and 37% of these surgical patients had at least one non-reactive and dilated pupil. An acute subdural or epidural haematoma was present in 143/448 (31.9%) children, of whom 66 (46.2%) underwent surgery. Children needing surgical evacuation of haematoma were at a median distance of 29 km (interquartile range (IQR) 11.8-45.7) from their neurosurgical centre. One in four children took longer than one hour to reach hospital after injury. Once in an accident and emergency department, 41% took longer than fours hours to arrive at the regional centre. The median interval between time of accident and arrival at the surgical centre was 4.5 hours (IQR 2.23-7.73), and 79% of inter-hospital transfers were undertaken by the referring hospital rather than the regional centre. In cases where the regional centre undertook the transfer, none were completed within four hours of presentation-the median interval was 6.3 hours (IQR 5.1-8.12).

CONCLUSIONS

The system of care for severely head injured children in the UK does not achieve surgical evacuation of a significant haematoma within four hours. The recommendation to use specialist regional paediatric transfer teams delays rather than expedites the emergency service.

Intracranial pressure complicating severe traumatic brain injury in children: monitoring and management

OBJECTIVE

To identify factors associated with the use of intracranial pressure (ICP) monitoring and to establish which ICP-targetted therapies are being used in children with severe traumatic brain injury (TBI) in the United Kingdom. To evaluate current practice against recently published guidelines.

DESIGN AND SETTING

Prospective data collection of clinical and demographic information from paediatric and adult intensive care units in the UK and Ireland admitting children (< 16 years) with TBI between February 2001 and August 2003.

RESULTS

Detailed clinical information was obtained for 501 children, with information on the use of ICP monitoring available in 445. ICP monitoring was used in only 59% (75/127) of children presenting with an emergency room Glasgow Coma Scale of 8 or below. Large between centre variation was seen in the use of ICP monitoring, independent of severity of injury. There were 86 children who received ICP-targetted therapies without ICP monitoring. Wide between centre variation was found in the use of ICP-targetted therapies and in general aspects of management, such as fluid restriction, the use of muscle relaxants and prophylactic anticonvulsants. Intra-ventricular catheters are rarely placed (6% of cases); therefore cerebrospinal fluid drainage is seldom used as a first-line therapy for raised ICP. Jugular venous bulb oximetry (4%), brain microdialysis (< 1%) and brain tissue oxygen monitoring (< 1%) are rarely used in current practice. Contrary to published guidelines, moderate to severe hyperventilation is being used without monitoring for cerebral ischaemia.

CONCLUSIONS

There is an urgent need for greater standardisation of practice across UK centres admitting children with severe TBI.

Epidemiology of traumatic brain injury in children receiving intensive care in the UK

AIMS

To describe the epidemiology of children with traumatic brain injury (TBI) admitted to paediatric intensive care units (PICUs) in the UK.

METHODS

Prospective collection of clinical and demographic information from paediatric and adult intensive care units in the UK and Eire between February 2001 and August 2003.

RESULTS

The UK prevalence rate for children (0-14 years) admitted to intensive care with TBI between February 2001 and August 2003 was 5.6 per 100,000 population per year (95% Poisson exact confidence intervals 5.17 to 6.05). Children admitted to PICUs with TBI were more deprived than the population as a whole (mean Townsend score for TBI admissions 1.19 v 0). The commonest mechanism of injury was a pedestrian accident (36%), most often occurring in children over 10. There was a significant summer peak in admissions in children under 10 years. Time of injury peaked in the late afternoon and early evening, a pattern that remained constant across the days of the week. Injuries involving motor vehicles have the highest mortality rates (23% of vehicle occupants, 12% of pedestrians) compared with cyclists (8%) and falls (3%). In two thirds of admissions (65%) TBI was an isolated injury.

CONCLUSIONS

TBI in children requiring intensive care is more common in those from poorer backgrounds who have been involved in accidents as pedestrians. The summer peak in injury occurrence for 0-10 year olds and late afternoon timing give clear targets for community based injury prevention.

A new formula for blood transfusion volume in the critically ill

BACKGROUND

Published formulae, frequently used to predict the volume of transfused red cells required to achieve a desired rise in haemoglobin (Hb) or haematocrit (Hct), do not appear to have been validated in clinical practice.

AIMS

To examine the relation between transfusion volume and the resulting rise in Hb and Hct in critically ill children.

METHODS

Phase 1: Sample of 50% of children admitted during 1997; 237 of these 495 patients received at least one packed red cell transfusion; 82 children were transfused without confounding factors that could influence the Hb/Hct response to transfusion and were analysed further. Actual rise in Hb concentration or haematocrit was compared to that expected from use of existing formulae. A new formula was developed. Phase 2: In 50 children receiving a packed red cell transfusion during 2001, actual rise in Hb concentration was compared to expected rise in Hb with use of the new formula.

RESULTS

Phase 1: Existing formulae performed poorly; median ratio of actual/predicted rise in Hb or Hct ranged from 0.61 to 0.85. Using the regression coefficients new formulae were developed for both Hb and Hct. These formulae were applicable across all age and diagnostic groups. Phase 2: Median ratio of actual/predicted rise in Hb improved to 0.95 with use of the new formula.

CONCLUSIONS

Existing formulae underestimate the volume of packed red cells required to achieve a target Hb or Hct. Adoption of the new formulae could reduce the number of transfusion episodes in PICU, cutting costs and reducing risk.

Effect of peritoneal dialysis on intra-abdominal pressure and cardio-respiratory function in infants following cardiac surgery

OBJECTIVE

To investigate the relationship between dialysate volume, intra-abdominal pressure, and cardio-respiratory function in infants following cardiac surgery.

DESIGN

Prospective pilot study.

SETTING

Paediatric intensive care unit.

PATIENTS

Six infants undergoing peritoneal dialysis within 24 h of cardiopulmonary bypass.

INTERVENTIONS

Manipulation of the volume of dialysate at levels of 0, 10, 20, and 30 ml/kg in variable order.

MEASUREMENTS AND MAIN RESULTS

Intra-abdominal pressure was measured at each volume of dialysate via a pressure transducer connected to the dialysis catheter. Haemodynamic data was collected, including cardiac output, which was measured by thermodilution via a 3.5-French gauge catheter placed in the pulmonary arterial pathway. Respiratory data included PaO2, PaCO2, and dynamic compliance. Intra-abdominal pressure increased with increasing volume of dialysate (p < 0.001), though there was considerable variation between patients in the magnitude of increase. Intra-abdominal pressure remained low even with 30 ml/kg in the abdomen. In three infants, intra-abdominal pressure was re-measured in the absence of muscle relaxants, and was found to be higher in each case. No negative effects on cardiac output, markers of delivery of oxygen, or respiratory function were seen even at volumes of 30 ml/kg. Cardiac index was significantly higher with 10 ml/kg than when the abdomen was empty or contained a larger volume (p < 0.05).

CONCLUSIONS

In this small group of infants, intra-abdominal pressure increased with increasing volumes of dialysate but remained low, even with 30 ml/kg in the abdomen, and was not associated with any deleterious effects on cardio-respiratory performance.

Early postoperative body temperature and developmental outcome after open heart surgery in infants

BACKGROUND

Experimental data have suggested that early postoperative temperature management after cerebral ischemia may alter neurologic outcome. We explored whether minor deviations in early postoperative body temperature after infant heart surgery affects developmental outcome.

METHODS

In a study of infants undergoing repair of congenital heart disease, 95% of whom had a period of deep hypothermic circulatory arrest, postoperative temperature data were collected following cardiac surgery. Subjects were infants who had been enrolled in one of two prospective randomized single-center trials. Development was tested at age one year (the Bayley Scales of Infant Development) and at four years (Wechsler Preschool and Primary Scale of Intelligence, including Full Scale IQ, a Verbal IQ, and a Performance IQ).

RESULTS

Perioperative temperature data were reviewed in 329 patients, of whom 244 (74%) were evaluated at age one year and 156 (48%) were evaluated at four years. The temperature profile was recorded during the rewarming phase and for 36 hours postoperatively on the Intensive Care Unit. There were no significant associations between postoperative temperature and any of the neurodevelopmental tests at age one or four years. A further analysis assessing the percentage of time over specific temperature cutoff points of 37.5 degrees C, 38 degrees C, 38.5 degrees C, and 39 degrees C, revealed no significant effect.

CONCLUSIONS

Neurodevelopmental outcome at one and four years after repair of complex congenital heart disease was not significantly affected by the early postoperative body temperature profile of the infant when a management strategy aiming for normothermia is employed.

Distribution of pulmonary blood flow in the perfluorocarbon-filled lung

OBJECTIVE

Partial liquid ventilation (PLV) improves gas exchange in animal studies of lung injury. Perfluorocarbons (PFCs) are heavy liquids and are therefore preferentially delivered to the most dependent areas of lung. We hypothesised that improved oxygenation during PLV might be the consequence of a redistribution of pulmonary blood flow away from poorly ventilated, dependent alveoli, leading to improved ventilation/perfusion (V/Q) matching. This study investigated whether partially filling the lung with PFC would result in a redistribution of pulmonary blood flow.

DESIGN

Prospective experimental study.

SETTING

Hospital research institute laboratory.

PARTICIPANTS

Six anaesthetised pigs without lung injury.

INTERVENTIONS

Animals were anaesthetised and ventilated (gas tidal volume 12 ml/kg, PEEP 5, FIO2 1.0, rate 16). Whilst the pigs were maintained in the supine position, regional pulmonary blood flow was measured during conventional gas ventilation and repeated during PLV. Flow to regions of lung was determined by injection of radioactive microspheres (Co(57), Sn(113), Sc(46)). Measurements were performed with ventilation held at end-expiratory pressure and, in two PLV animals only, repeated with ventilation held at peak inspiratory pressure.

RESULTS

During conventional gas ventilation, blood flow followed a linear distribution with the highest flow to the most dependent lung. In the lung partially filled with PFC a diversion of blood flow away from the most dependent lung was seen (p = 0.007), resulting in a more uniform distribution of flow down the lung (p = 0.006). Linear regression analysis (r2 = 0.75) also confirmed a difference in distribution pattern. On applying an inspiratory hold to the liquid-containing lung, blood flow was redistributed back towards the dependent lung.

CONCLUSIONS

Partially filling the lung with PFC results in a redistribution of pulmonary blood flow away from the dependent region of the lung. During PLV a different blood flow distribution may be seen between inspiration and expiration. The clinical significance of these findings has yet to be determined.

Renovascular and growth effects of childhood sarcoid

A boy developed early onset sarcoidosis, an extremely rare mimic of juvenile chronic arthritis. Renal granulomas caused severe hypertension and renal impairment, which was controlled by azathioprine and steroids. Severe uveitis caused visual impairment. Impaired growth and delayed puberty, not previously described in childhood sarcoidosis, required growth hormone and testosterone treatment.

Cardiovascular abnormalities in end stage renal failure: the effect of anaemia or uraemia?

Children with end stage renal failure and anaemia have an increased cardiac index and often gross ventricular hypertrophy. Correction of anaemia with recombinant human erythropoietin (r-HuEpo) for less than six months results in a reduction in the cardiac index without a significant reduction in left ventricular hypertrophy. Seven children receiving dialysis (group 1) were studied to determine whether a reduction in left ventricular hypertrophy would occur after a 12 month period of r-HuEpo. A decrease in the cardiac index was seen by six months, and a significant reduction in left ventricular mass index and cardiothoracic ratio was seen by 12 months. Successful renal transplantation also results in a reduction in the cardiac index and left ventricular hypertrophy, but the relative contributions of correction of anaemia and correction of biochemical disturbance is unknown because they usually improve simultaneously. To investigate this, six children (group 2) who already had a mean haemoglobin concentration of 107 g/l while receiving dialysis were followed up for 12 months after successful transplantation. They showed no significant change in haemoglobin concentration, but a dramatic improvement in biochemistry. There was no significant change in cardiovascular function. Anaemia is the more dominant influence on cardiovascular function in end stage renal failure.

Assessing iron status in children with chronic renal failure on erythropoietin: which measurements should we use?

Iron deficiency severely limits the efficacy of recombinant human erythropoietin (EPO). In order to determine how best to identify and monitor children at risk of developing iron deficiency, we serially measured several parameters of iron status in nine children before and during a 24-week period of EPO therapy. Serum ferritin was the best predictor of development of iron deficiency, five of the nine children developed iron deficiency, characterised by a poor haemoglobin response or evidence of microcytosis and hypochromia; all had a serum ferritin of 60 micrograms/l or less at the start of EPO. Haemoglobin response was also related to change in mean red cell volume (MCV); a falling MCV, irrespective of absolute value, accompanying a poor response to EPO. Iron treatment in five children resulted in significant improvements in haemoglobin and iron status parameters. Although MCV remained low, there was a marked increase in red cell volume distribution width after iron, which may be of value in monitoring the response to iron therapy. We suggest that children with a serum ferritin of 60 micrograms/l or less and those who develop a falling MCV during EPO treatment should receive high-dose oral iron supplementation before and during treatment with EPO.

Non-cardiac benefits of human recombinant erythropoietin in end stage renal failure and anaemia

Recombinant human erythropoietin (r-HuEpo) is now available to correct the anaemia of end stage renal failure. The clinical consequences of increasing the haemoglobin concentration in children on dialysis are incompletely documented; a placebo controlled study is essential when assessing subjective changes, for example in appetite or other aspects of quality of life. A single blind, placebo controlled crossover study in 11 children with end stage renal failure was performed to assess the clinical benefits resulting from correction of anaemia. Ten of the 11 children completed 36 weeks of the study and seven completed both 24 week limbs. Subcutaneous administration of r-HuEpo twice a week resulted in an increase in haemoglobin concentration, from 73 to 112 g/l. This was associated with an objective improvement in exercise tolerance, and a subjective improvement in physical performance and health, and better school attendance. No consistent effect was seen on appetite, growth, psychosocial functioning, biochemical control, or peritoneal dialysis efficiency. A small but clinically unimportant increase in systolic and diastolic blood pressure was seen in five children. One child on antihypertensive treatment required an increase in dosage during r-HuEpo while another child required a reduction in treatment. These findings, together with the important cardiac benefits previously described during r-HuEpo treatment, support the use of r-HuEpo in all children with end stage renal failure and anaemia.

Cardiac abnormalities in end stage renal failure and anaemia

Thirteen anaemic children on dialysis were assessed to determine the incidence of cardiac changes in end stage renal failure. Nine children had an increased cardiothoracic ratio on radiography. The electrocardiogram was abnormal in every case but no child had left ventricular hypertrophy as assessed by voltage criteria. However, left ventricular hypertrophy, often gross, was found on echocardiography in 12 children and affected the interventricular septum disproportionately. Cardiac index was increased in 10 patients as a result of an increased left ventricular stroke volume rather than heart rate. Left ventricular hypertrophy was significantly greater in those on treatment for hypertension and in those with the highest cardiac index. Abnormal diastolic ventricular function was found in 6/11 children. Children with end stage renal failure have significant cardiac abnormalities that are likely to contribute to the high cardiovascular mortality in this group. Anaemia and hypertension, or its treatment, probably contribute to these changes. Voltage criteria on electrocardiogram are of no value in detecting left ventricular hypertrophy. Echocardiography must be performed, with the results corrected for age and surface area, in order to detect and follow these abnormalities.

Short term correction of anaemia with recombinant human erythropoietin and reduction of cardiac output in end stage renal failure

Children with end stage renal failure and anaemia have an increased cardiac index and often gross ventricular hypertrophy. The contribution of anaemia to these abnormalities is uncertain. Eleven children with end stage renal failure and anaemia (haemoglobin concentration < 90 g/l) were enrolled into a single blind, placebo controlled, crossover study to assess the cardiovascular effects of reversing anaemia using subcutaneous human recombinant erythropoietin (r-HuEpo). Each limb lasted 24 weeks; seven children completed both limbs of the study. Haemoglobin increased with r-HuEpo, remaining above 100 g/l for a mean of 11 weeks. Cardiac index fell as a result of a reduction in both left ventricular stroke volume and heart rate. Left ventricular end diastolic diameter also decreased. In five children left ventricular wall thickness and left ventricular mass decreased with r-HuEpo, but this failed to reach significance for the whole group. Blood pressure did not change in six normotensive children completing an r-HuEpo limb; the decrease in cardiac index was therefore balanced by an increase in peripheral vascular resistance. Three children were taking anti-hypertensive treatment at the start of the study; one required an increase, and one a decrease, in treatment during the r-HuEpo limb. Short term treatment with r-HuEpo reduces cardiac index. A longer study is needed to determine whether this will, in time, result in a significant reduction in left ventricular hypertrophy.

The direct measurement of glomerular filtration rate from the continuous monitoring of DTPA clearance

A method of measuring glomerular filtration rate is proposed, intended for use during gamma camera renography and involving the continuous monitoring of DTPA activity in blood, a single blood sample, and a urine collection. Data obtained from experiments using a CsI scintillation detector are presented and used to demonstrate the validity of the method. In a comparison with a direct measurement of renal clearance of DTPA the proposed method showed an average overestimate of 13% compared to an overestimate of 30% for an uncorrected single-compartment model calculation of filtration rate. Some limited data using a gamma camera to monitor the DTPA activity in blood are also presented.

Oesophageal and severe gut involvement in the haemolytic uraemic syndrome

Between 1982 and 1989, 78 children with diarrhoea-associated haemolytic uraemic syndrome (HUS) were referred to this hospital. Most presented with abdominal pain, bloody diarrhoea and vomiting. Seven had severe gastrointestinal involvement, four of whom required resection for bowel perforation or necrosis. One also developed an oesophageal stricture, a previously unreported complication of HUS. These seven children had a high incidence of other complications including hypertension, and cerebral and pancreatic involvement. One died from severe cerebral involvement, one has a residual neurological deficit and one has residual renal impairment. Severe gastrointestinal involvement did not significantly affect the long-term outcome. Simple haematological indices helped predict severe gut involvement. Four of the 78 children had undergone appendicectomy before the diagnosis of HUS was made. The operative findings were in no case typical of primary acute appendicitis, although histological examination did confirm inflammation of the appendix in two patients. Diagnosis is difficult in early disease, but increased awareness may help prevent unnecessary appendicectomy.