Conservative versus liberal oxygenation targets in critically ill children: the randomised multiple-centre pilot Oxy-PICU trial

Chest Physiotherapy for Mechanically Ventilated Children: A Systematic Review

The aim of this study was to appraise and summarize the effects of chest physiotherapy in mechanically ventilated children. A systematic review was completed by searching Medline, Embase, Cinahl Plus, PEDro, and Web of Science from inception to February 9, 2021. Studies investigating chest physiotherapy for mechanically ventilated children (0-18 years), in a pediatric intensive care unit were included. Chest physiotherapy was defined as any intervention performed by a qualified physiotherapist. Measurements of effectiveness and safety were included. Exclusion criteria included preterm infants, children requiring noninvasive ventilation, and those in a nonacute setting. Thirteen studies met the inclusion criteria: two randomized controlled trials, three randomized crossover trials, and eight observational studies. The Cochrane risk of bias and the Critical Appraisal Skills Program tools were used for quality assessment. Oxygen saturations decreased after physiotherapy involving manual hyperinflations (MHI) and chest wall vibrations (CWV). Although statistically significant, these results were not of clinical importance. In contrast, oxygen saturations improved after the expiratory flow increase technique; however, this was not clinically significant. An increase in expiratory tidal volume was demonstrated 30 minutes after MHI and CWV. There was no sustained change in tidal volume following a physiotherapy-led recruitment maneuver. Respiratory compliance and dead-space increased immediately after MHI and CWV. Atelectasis scores improved following intrapulmonary percussive ventilation, and MHI and CWV. Evidence to support chest physiotherapy in ventilated children remains inconclusive. There are few high-quality studies, with heterogeneity in interventions and populations. Future studies are required to investigate multiple physiotherapy interventions and the impact on long-term outcomes.

Oxygen Targets in Neonatal Pulmonary Hypertension: Individualized, "Precision-Medicine" Approach

Oxygen is a specific pulmonary vasodilator. Hypoxemia causes pulmonary vasoconstriction, and normoxia leads to pulmonary vasodilation. However, hyperoxia does not enhance pulmonary vasodilation but causes oxidative stress. There are no clinical trials evaluating optimal oxygen saturation or Pao2 in pulmonary hypertension. Data from translational studies and case series suggest that oxygen saturation of 90% to 97% or Pao2 between 50 and 80 mm Hg is associated with the lowest pulmonary vascular resistance.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

Implication of the 2014 World Health Organization Integrated Management of Childhood Illness Pneumonia Guidelines with and without pulse oximetry use in Malawi: A retrospective cohort study

Background

Under-5 pneumonia mortality remains high in low-income countries. In 2014 the World Health Organization (WHO) advised that children with chest indrawing pneumonia, but without danger signs or peripheral oxygen saturation (SpO 2) < 90% be treated in the community, rather than hospitalized. In Malawi there is limited pulse oximetry availability.

Methods

Secondary analysis of 13,413 under-5 pneumonia cases in Malawi. Pneumonia associated case fatality ratios (CFR) were calculated by disease severity under the assumptions of the 2005 and 2014 WHO Integrated Management of Childhood Illness (IMCI) guidelines, with and without pulse oximetry. We investigated if pulse oximetry readings were missing not at random (MNAR).

Results

The CFR of patients classified as having non-severe pneumonia per the 2014 IMCI guidelines doubled under the assumption that pulse oximetry was not available (1.5% without pulse oximetry vs 0.7% with pulse oximetry, P<0.001). When 2014 IMCI guidelines were applied with pulse oximetry and a SpO 2 < 90% as the threshold for referral and/or admission, the number of cases meeting hospitalization criteria decreased by 70.3%. Unrecorded pulse oximetry readings were MNAR with an adjusted odds for mortality of 4.9 (3.8, 6.3), similar to that of a SpO 2 < 90%. Although fewer girls were hospitalized, female sex was an independent mortality risk factor.

Conclusions

In Malawi, implementation of the 2014 WHO IMCI pneumonia guidelines, without pulse oximetry, will miss high risk cases. Alternatively, implementation of pulse oximetry may result in a large reduction in hospitalization rates without significantly increasing non-severe pneumonia associated CFR if the inability to obtain a pulse oximetry reading is considered a WHO danger sign.

Validation and Extension of the Association Between Potentially Excess Oxygen Exposure and Death in Mechanically Ventilated Children

OBJECTIVES

"Cumulative excess oxygen exposure" (CEOE)-previously defined as the mean hourly administered Fio2 above 0.21 when the corresponding hourly Spo2 was 95% or above-was previously shown to be associated with mortality. The objective of this study was to examine the relationship among Fio2, Spo2, and mortality in an independent cohort of mechanically ventilated children.

DESIGN

Retrospective cross-sectional study.

SETTING

Quaternary-care PICU.

PATIENTS

All patients admitted to the PICU between 2012 and 2021 and mechanically ventilated via endotracheal tube for at least 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 3,354 patients, 260 (8%) died. Higher CEOE quartile was associated with increased mortality (p = 0.001). The highest CEOE quartile had an 87% increased risk of mortality (95% CI, 7-236) compared with the first CEOE quartile. The hazard ratio for extended CEOE exposure, which included mechanical ventilation data from throughout the patients' mechanical ventilation time rather than only from the first 24 hours of mechanical ventilation, was 1.03 (95% CI, 1.02-1.03).

CONCLUSIONS

Potentially excess oxygen exposure in patients whose oxygen saturation was at least 95% was associated with increased mortality.

Oxygen saturation targets for children with respiratory distress: a systematic review

Background

In children with respiratory distress, supplemental oxygen is indicated at peripheral oxygen saturation (SpO2) thresholds of 90-94%. However, these thresholds are poorly studied. We conducted a systematic review to summarise the existing evidence for SpO2 thresholds in children with respiratory distress.

Methods

Electronic databases and registries were searched for original articles published from 1 January 2010 to 7 January 2022 comparing two or more SpO2 thresholds in children with respiratory distress. Primary outcomes were safety, including mortality, neurocognitive outcomes and readmissions, and effectiveness, including admission rate and length of hospital stay. Methodological appraisal was performed using the Cochrane Risk of Bias 2 (RoB-2) or Risk of Bias in Non-Randomized Studies - of Interventions (ROBINS-I) tools. Results were narratively synthesised.

Results

We retrieved 3384 results; seven studies were included. Lower thresholds ranged from 80% to 92% and were compared with higher thresholds ranging from 92% to 94%. Studies were highly heterogeneous in setting, design, population and outcomes. Risk of bias varied from low to high. Lower SpO2 thresholds had equivalent mortality, neurocognitive outcomes and readmissions or re-attendance to healthcare to higher thresholds. Lower SpO2 thresholds showed a significant decrease in admission rates by up to 40% and shortened hospitalisation duration by 10-18 h.

Conclusions

The current SpO2 thresholds of 90-94% in children with respiratory distress may be too high, which could lead to unnecessary hospitalisations and prolonged hospitalisation duration. SpO2 thresholds as low as 88% are potentially safe in children with respiratory distress and may reduce hospitalisation rates and length of stay. However, high-quality evidence is needed to support this.

Adaptive Clinical Trials in Pediatric Critical Care: A Systematic Review

OBJECTIVES

This systematic review investigates the use of adaptive designs in randomized controlled trials (RCTs) in pediatric critical care.

DATA SOURCES

PICU RCTs, published between 1986 and 2020, stored in the www.PICUtrials.net database and MEDLINE, EMBASE, CENTRAL, and LILACS databases were searched (March 9, 2022) to identify RCTs published in 2021. PICU RCTs using adaptive designs were identified through an automated full-text screening algorithm.

STUDY SELECTION

All RCTs involving children (< 18 yr old) cared for in a PICU were included. There were no restrictions to disease cohort, intervention, or outcome. Interim monitoring by a Data and Safety Monitoring Board that was not prespecified to change the trial design or implementation of the study was not considered adaptive.

DATA EXTRACTION

We extracted the type of adaptive design, the justification for the design, and the stopping rule used. Characteristics of the trial were also extracted, and the results summarized through narrative synthesis. Risk of bias was assessed using the Cochrane Risk of Bias Tool 2.

DATA SYNTHESIS

Sixteen of 528 PICU RCTs (3%) used adaptive designs with two types of adaptations used; group sequential design and sample size reestimation. Of the 11 trials that used a group sequential adaptive design, seven stopped early due to futility and one stopped early due to efficacy. Of the seven trials that performed a sample size reestimation, the estimated sample size decreased in three trials and increased in one trial.

CONCLUSIONS

Little evidence of the use of adaptive designs was found, with only 3% of PICU RCTs incorporating an adaptive design and only two types of adaptations used. Identifying the barriers to adoption of more complex adaptive trial designs is needed.

Perspectives of Health Care Personnel on the Benefits of Bronchiolitis Interventions

OBJECTIVES

Many interventions in bronchiolitis are low-value or poorly studied. Inpatient bronchiolitis management is multidisciplinary, with varying degrees of registered nurse (RN) and respiratory therapist (RT) autonomy. Understanding the perceived benefit of interventions for frontline health care personnel may facilitate deimplementation efforts. Our objective was to examine perceptions surrounding the benefit of common inpatient bronchiolitis interventions.

METHODS

We conducted a cross-sectional survey of inpatient pediatric RNs, RTs, and physicians/licensed practitioners (P/LPs) (eg, advanced-practice practitioners) from May to December of 2021 at 9 university-affiliated and 2 community hospitals. A clinical vignette preceded a series of inpatient bronchiolitis management questions.

RESULTS

A total of 331 surveys were analyzed with a completion rate of 71.9%: 76.5% for RNs, 57.4% for RTs, and 71.2% for P/LPs. Approximately 54% of RNs and 45% of RTs compared with 2% of P/LPs believe albuterol would be "extremely or somewhat likely" to improve work of breathing (P < .001). Similarly, 52% of RNs, 32% of RTs, and 23% of P/LPs thought initiating or escalating oxygen in the absence of hypoxemia was likely to improve work of breathing (P < .001). Similar differences in perceived benefit were observed for steroids, nebulized hypertonic saline, and deep suctioning, but not superficial nasal suctioning. Hospital type (community versus university-affiliated) did not impact the magnitude of these differences.

CONCLUSIONS

Variation exists in the perceived benefit of several low-value or poorly studied bronchiolitis interventions among health care personnel, with RNs/RTs generally perceiving higher benefit. Deimplementation, educational, and quality improvement efforts should be designed with an interprofessional framework.

Admission Pao2 and Mortality Among PICU Patients and Select Diagnostic Subgroups

OBJECTIVES

Evaluate the relationship between admission Pao2 and mortality in a large multicenter dataset and among diagnostic subgroups.

DESIGN

Retrospective cohort study.

SETTING

North American PICUs participating in Virtual Pediatric Systems, LLC (VPS), 2015-2019.

PATIENTS

Noncardiac patients 18 years or younger admitted to a VPS PICU with admission Pao2.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirteen thousand seventy-one patient encounters were included with an overall mortality of 13.52%. Age categories were equally distributed among survivors and nonsurvivors with the exception of small differences among neonates and adolescents. Importantly, there was a tightly fitting quadratic relationship between admission Pao2 and mortality, with the highest mortality rates seen among hypoxemic and hyperoxemic patients (likelihood-ratio test p < 0.001). This relationship persisted after adjustment for illness severity using modified Pediatric Index of Mortality 3 scores. A similar U-shaped relationship was demonstrated among patients with diagnoses of trauma, head trauma, sepsis, renal failure, hemorrhagic shock, and drowning. However, among the 1,500 patients admitted following cardiac arrest, there was no clear relationship between admission Pao2 and mortality.

CONCLUSIONS

In a large multicenter pediatric cohort, admission Pao2 demonstrates a tightly fitting quadratic relationship with mortality. The persistence of this relationship among some but not all diagnostic subgroups suggests the pathophysiology of certain disease states may modify the hyperoxemia association.

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

RATIONALE

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

OBJECTIVES

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

DESIGN

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

SETTING

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

PATIENTS

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

INTERVENTIONS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

The Local and Systemic Exposure to Oxygen in Children With Severe Bronchiolitis on Invasive Mechanical Ventilation: A Retrospective Cohort Study

OBJECTIVES

Oxygen supplementation is a cornerstone treatment in critically ill children with bronchiolitis in the PICU. However, potential deleterious effects of high-dose oxygen are well-known. In this study, we aim to describe the pulmonary (local) and arterial (systemic) oxygen exposure over the duration of invasive mechanical ventilation (IMV) in children with severe bronchiolitis. Our secondary aim was to estimate potentially avoidable exposure to high-dose oxygen in these patients.

DESIGN

Retrospective cohort study.

SETTING

Single-center, tertiary-care PICU.

PATIENTS

Children younger than 2 years old admitted to the PICU for severe bronchiolitis receiving IMV.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Hourly measurements of Fio2 and peripheral oxygen saturation (Spo2), and arterial blood gas data were collected up to day 10 of IMV. A total of 24,451 hours of IMV were observed in 176 patients (median age of 1.0 mo [interquartile range (IQR), 1.0-2.3 mo]). The pulmonary exposure to oxygen was highest during the first day of IMV (median time-weighted average [TWA]-Fio2 0.46 [IQR, 0.39-0.53]), which significantly decreased over subsequent days. The systemic exposure to oxygen was relatively low, as severe hyperoxemia (TWA-Pao2 > 248 Torr [> 33 kPa]) was not observed. However, overuse of oxygen was common with 52.3% of patients (n = 92) having at least 1 day of possible excessive oxygen exposure and 14.8% (n = 26) with severe exposure. Furthermore, higher oxygen dosages correlated with increasing overuse of oxygen (rrepeated measures, 0.59; 95% CI, 0.54-0.63). Additionally, caregivers were likely to keep Fio2 greater than or equal to 0.50 when Spo2 greater than or equal to 97%.

CONCLUSIONS

Moderate to high-dose pulmonary oxygen exposure and potential overuse of oxygen were common in this cohort of severe bronchiolitis patients requiring IMV; however, this was not accompanied by a high systemic oxygen burden. Further studies are needed to determine optimal oxygenation targets to prevent overzealous use of oxygen in this vulnerable population.

The United Kingdom Paediatric Critical Care Society Study Group: The 20-Year Journey Toward Pragmatic, Randomized Clinical Trials

Over the past two decades, pediatric intensive care research networks have been formed across North America, Europe, Asia, and Australia/New Zealand. The U.K. Paediatric Critical Care Society Study Group (PCCS-SG) has over a 20-year tradition of fostering collaborative research, leading to the design and successful conduct of randomized clinical trials (RCTs). To date, the PCCS-SG network has delivered 13 different multicenter RCTs, covering a spectrum of study designs, methodologies, and scale. Lessons from the early years have led PCCS-SG to now focus on the entire process needed for developing an RCT, starting from robust preparatory steps such as surveys, data analysis, and feasibility work through to a definitive RCT. Pilot RCTs have been an important part of this process as well. Facilitators of successful research have included the presence of a national registry to facilitate efficient data collection; close partnerships with established Clinical Trials Units to bring together clinicians, methodologists, statisticians, and trial managers; greater involvement of transport teams to recruit patients early in trials of time-sensitive interventions; and the funded infrastructure of clinical research staff within the National Health Service to integrate research within the clinical service. The informal nature of PCCS-SG has encouraged buy-in from clinicians. Greater international collaboration and development of embedded trial platforms to speed up the generation and dissemination of trial findings are two key future strategic goals for the PCCS-SG research network.

Closed–loop oxygen control improves oxygenation in pediatric patients under high–flow nasal oxygen—A randomized crossover study

Background

We assessed the effect of a closed–loop oxygen control system in pediatric patients receiving high–flow nasal oxygen therapy (HFNO).

Methods

A multicentre, single–blinded, randomized, and cross–over study. Patients aged between 1 month and 18 years of age receiving HFNO for acute hypoxemic respiratory failure (AHRF) were randomly assigned to start with a 2–h period of closed–loop oxygen control or a 2–h period of manual oxygen titrations, after which the patient switched to the alternative therapy. The endpoints were the percentage of time spent in predefined SpO2 ranges (primary), FiO2, SpO2/FiO2, and the number of manual adjustments.

Findings

We included 23 patients, aged a median of 18 (3–26) months. Patients spent more time in a predefined optimal SpO2 range when the closed–loop oxygen controller was activated compared to manual oxygen titrations [91⋅3% (IQR 78⋅4–95⋅1%) vs. 63⋅0% (IQR 44⋅4–70⋅7%)], mean difference [28⋅2% (95%–CI 20⋅6–37⋅8%); P &lt; 0.001]. Median FiO2 was lower [33⋅3% (IQR 26⋅6–44⋅6%) vs. 42⋅6% (IQR 33⋅6–49⋅9%); P = 0.07], but median SpO2/FiO2 was higher [289 (IQR 207–348) vs. 194 (IQR 98–317); P = 0.023] with closed–loop oxygen control. The median number of manual adjustments was lower with closed–loop oxygen control [0⋅0 (IQR 0⋅0–0⋅0) vs. 0⋅5 (IQR 0⋅0–1⋅0); P &lt; 0.001].

Conclusion

Closed-loop oxygen control improves oxygenation therapy in pediatric patients receiving HFNO for AHRF and potentially leads to more efficient oxygen use. It reduces the number of manual adjustments, which may translate into decreased workloads of healthcare providers.

Clinical trial registration

[www.ClinicalTrials.gov], identifier [NCT 05032365].

State-of-the-art management of the acutely unwell child

Children make up around one-fifth of all emergency department visits in the USA and UK, with an increasing trend of emergency admissions requiring intensive care. Anaesthetists play a vital role in the management of paediatric emergencies contributing to stabilisation, emergency anaesthesia, transfers and non-technical skills that optimise team performance. From neonates to adolescents, paediatric patients have diverse physiology and present with a range of congenital and acquired pathologies that often differ from the adult population. With increasing centralisation of paediatric services, staff outside these centres have less exposure to caring for children, yet are often the first responders in managing these high stakes situations. Staying abreast of the latest evidence for managing complex low frequency emergencies is a challenge. This review focuses on recent evidence and pertinent clinical updates within the field. The challenges of maintaining skills and training are explored as well as novel advancements in care.

Factors to be Considered in Advancing Pediatric Critical Care Across the World

This article reviews the many factors that have to be taken into account as we consider the advancement of pediatric critical care (PCC) in multiple settings across the world. The extent of PCC and the range of patients who are cared for in this environment are considered. Along with a review of the ongoing treatment and technology advances in the PCC setting, the structures and systems required to support these services are also considered. Finally the question of how PCC can be made sustainable in a volatile world with the impacts of global crises such as climate change is addressed.

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

OBJECTIVES

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

DESIGN

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

SETTING

Fifteen PICUs across England, Wales, and Scotland.

PATIENTS

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

INTERVENTION

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

MEASUREMENTS AND MAIN RESULTS

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

Excessive Oxygen Supplementation in the First Day of Mechanical Ventilation Is Associated With Multiple Organ Dysfunction and Death in Critically Ill Children

OBJECTIVES

To determine if greater cumulative exposure to oxygen despite adequate oxygenation over the first 24 hours of mechanical ventilation is associated with multiple organ dysfunction syndrome at 7 days and inhospital mortality in critically ill children.

DESIGN

Retrospective, observational cohort study.

SETTING

Two urban, academic PICUs.

PATIENTS

Patients less than 18 years old who required mechanical ventilation within 3 days of admission between 2010 and 2018 (Lurie Children's Hospital) or 2010 and 2016 (Comer Children's Hospital).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 5,406 mechanically ventilated patients, of which 960 (17.8%) had multiple organ dysfunction syndrome on day 7 of admission and 319 died (5.9%) during their hospitalization. Cumulative exposure to greater amounts of supplemental oxygen, while peripheral oxygen saturation was 95% or more during the first 24 hours of mechanical ventilation was independently associated with an increased risk of both multiple organ dysfunction syndrome on day 7 and inhospital mortality after adjusting for confounders. Patients in the highest quartile of cumulative oxygen exposure had an increased odds of multiple organ dysfunction syndrome on day 7 (adjusted odds ratio, 3.9; 95% CI, 2.7-5.9) and inhospital mortality (adjusted odds ratio, 1.7; 95% CI, 1.1-2.9), when compared with those in the lowest quartile of cumulative oxygen exposure after adjusting for age, presence of multiple organ dysfunction syndrome on day 1 of mechanical ventilation, immunocompromised state, and study site.

CONCLUSIONS

Greater cumulative exposure to excess supplemental oxygen in the first 24 hours of mechanical ventilation is independently associated with an increased risk of multiple organ dysfunction syndrome on day 7 of admission and inhospital mortality in critically ill children.

Association of Arterial Hyperoxia With Outcomes in Critically Ill Children: A Systematic Review and Meta-analysis

IMPORTANCE

Oxygen supplementation is a cornerstone treatment in pediatric critical care. Accumulating evidence suggests that overzealous use of oxygen, leading to hyperoxia, is associated with worse outcomes compared with patients with normoxia.

OBJECTIVES

To evaluate the association of arterial hyperoxia with clinical outcome in critically ill children among studies using varied definitions of hyperoxia.

DATA SOURCES

A systematic search of EMBASE, MEDLINE, Cochrane Library, and ClinicalTrials.gov from inception to February 1, 2021, was conducted.

STUDY SELECTION

Clinical trials or observational studies of children admitted to the pediatric intensive care unit that examined hyperoxia, by any definition, and described at least 1 outcome of interest. No language restrictions were applied.

DATA EXTRACTION AND SYNTHESIS

The Meta-analysis of Observational Studies in Epidemiology guideline and Newcastle-Ottawa Scale for study quality assessment were used. The review process was performed independently by 2 reviewers. Data were pooled with a random-effects model.

MAIN OUTCOMES AND MEASURES

The primary outcome was 28-day mortality; this time was converted to mortality at the longest follow-up owing to insufficient studies reporting the initial primary outcome. Secondary outcomes included length of stay, ventilator-related outcomes, extracorporeal organ support, and functional performance.

RESULTS

In this systematic review, 16 studies (27 555 patients) were included. All, except 1 randomized clinical pilot trial, were observational cohort studies. Study populations included were post-cardiac arrest (n = 6), traumatic brain injury (n = 1), extracorporeal membrane oxygenation (n = 2), and general critical care (n = 7). Definitions and assessment of hyperoxia differed among included studies. Partial pressure of arterial oxygen was most frequently used to define hyperoxia and mainly by categorical cutoff. In total, 11 studies (23 204 patients) were pooled for meta-analysis. Hyperoxia, by any definition, showed an odds ratio of 1.59 (95% CI, 1.00-2.51; after Hartung-Knapp adjustment, 95% CI, 1.05-2.38) for mortality with substantial between-study heterogeneity (I2 = 92%). This association was also found in less heterogeneous subsets. A signal of harm was observed at higher thresholds of arterial oxygen levels when grouped by definition of hyperoxia. Secondary outcomes were inadequate for meta-analysis.

CONCLUSIONS AND RELEVANCE

These results suggest that, despite methodologic limitations of the studies, hyperoxia is associated with mortality in critically ill children. This finding identifies the further need for prospective observational studies and importance to address the clinical implications of hyperoxia in critically ill children.

A feasibility randomised controlled trial of targeted oxygen therapy in mechanically ventilated critically ill patients

BACKGROUND

Despite oxygen being the commonest drug administered to critically ill patients we do not know which oxygen saturation (SpO2) target results in optimal survival outcomes in those receiving mechanical ventilation. We therefore conducted a feasibility randomised controlled trial in the United Kingdom (UK) to assess whether it would be possible to host a larger national multi-centre trial to evaluate oxygenation targets in mechanically ventilated patients.

METHODS

We set out to recruit 60 participants across two sites into a trial in which they were randomised to receive conservative oxygenation (SpO2 88-92%) or usual care (control - SpO2 ≥96%). The primary outcome was feasibility; factors related to safety and clinical outcomes were also assessed.

RESULTS

A total of 34 patients were recruited into the study until it was stopped due to time constraints. A number of key barriers to success were identified during the course of the study. The conservative oxygenation intervention was feasible and appeared to be safe in this small patient cohort and it achieved wide separation of the median time-weighted average (IQR) SpO2 at 91% (90-92%) in conservative oxygenation group versus 97% (96-97%) in control group.

CONCLUSION

Whilst conservative oxygenation was a feasible and safe intervention which achieved clear group separation in oxygenation levels, the model used in this trial will require alterations to improve future participant recruitment rates in the UK.

Liberal or conservative oxygen therapy for ventilated patients in the ICU: a meta-analysis of randomized controlled trials

Background

The acknowledgment that conservative oxygen therapy (COT) was related to better prognosis in the intensive care unit (ICU) was challenged recently. We conducted an updated meta-analysis aimed to determine whether liberal oxygen therapy (LOT) or COT is associated with better improve clinical outcomes.

Methods

We systematically searched the electronic databases (PubMed, Web of Science and Embase) up to May 2021 for randomized controlled trials (RCTs). The primary outcome was the mortality of the final follow-up time and secondary outcomes were ICU mortality, the ICU length of stay and the number of ventilator-free days.

Results

A total of 7 RCTs were included, with 2166 patients admitted to the ICU. There was no significant difference in the primary outcome between the LOT and COT. Additionally, LOT could not significantly increase ICU mortality and the ICU length of stay compared with COT.

Conclusions

The present study showed that COT was not significantly superior to LOT in clinical outcomes. Therefore, additional high-quality studies with novel designs are required to further elucidate this controversy.

Perceptions of Hyperoxemia and Conservative Oxygen Therapy in the Management of Acute Respiratory Failure

Rationale: Mechanically ventilated patients in the intensive care unit (ICU) are often managed to maximize oxygenation, yet hyperoxemia may be deleterious to some. Little is known about how ICU providers weigh tradeoffs between hypoxemia and hyperoxemia when managing acute respiratory failure. Objectives: To define ICU providers' mental models for managing oxygenation for patients with acute respiratory failure and identify barriers and facilitators to conservative oxygen therapy. Methods: In two large U.S. tertiary care hospitals, we performed semistructured interviews with a purposive sample of ICU nurses, respiratory therapists, and physicians. We assessed perceptions of oxygenation management, hyperoxemia, and conservative oxygen therapies through interviews, which we audio recorded and transcribed verbatim. We analyzed transcripts for representative themes using an iterative thematic-analysis approach. Results: We interviewed 10 nurses, 10 respiratory therapists, 4 fellows, and 5 attending physicians before reaching thematic saturation. Major themes included perceptions of hyperoxemia, attitudes toward conservative oxygen therapy, and aspects of titrated-oxygen-therapy implementation. Many providers did not recognize the term "hyperoxemia," whereas others described a poor understanding; several stated they never encounter hyperoxemia clinically. Concerns about hyperoxemia varied: some providers believed that typical ventilation strategies emphasizing progressive lowering of the fraction of inspired oxygen mitigated worries about excess oxygen administration, whereas others maintained that hyperoxemia is harmful only to patients with chronic lung disease. Almost all interviewees expressed familiarity with lower oxygen saturations in chronic obstructive pulmonary disease. Cited barriers to conservative oxygen therapy included concerns about hypoxemia, particularly among nurses and respiratory therapists; perceptions that hyperoxemia is not harmful; and a lack of clear evidence supporting conservative oxygen therapy. Interviewees suggested that interprofessional education and convincing clinical trial evidence could facilitate uptake of conservative oxygenation. Conclusions: This study describes attitudes toward hyperoxemia and conservative oxygen therapy. These preferences and uncertain benefits and risks of conservative oxygen therapy should be considered during future implementation efforts. Successful oxygen therapy implementation most likely will require 1) improving awareness of hyperoxemia's effects, 2) normalizing lower saturations in patients without chronic lung disease, 3) addressing ingrained beliefs regarding oxygen management and oxygen's safety, and 4) using interprofessional education to obtain buy-in across providers and inform the ICU team.

Hyperoxemia Is Associated With Mortality in Critically Ill Children

Multiple studies among adults have suggested a non-linear relationship between arterial partial pressure of oxygen (PaO₂) and clinical outcomes. Meta-analyses in this population suggest that high levels of supplemental oxygen resulting in hyperoxia are associated with mortality. This mini-review focuses on the non-neonatal pediatric literature examining the relationship between PaO₂ and mortality. While only one pilot pediatric randomized-controlled trials exists, over the past decade, there have been at least eleven observational studies examining the relationship between PaO₂ values and mortality in critically ill children. These analyses of mixed-case pediatric ICU populations have generally reported a parabolic (“u-shaped”) relationship between PaO₂ and mortality, similar to that seen in the adult literature. However, the estimates of the point at which hyperoxemia becomes deleterious have varied widely (300–550 mmHg). Where attempted, this effect has been robust to analyses restricted to the first PaO₂ value obtained, those obtained within 24 h of admission, anytime during admission, and the number of hyperoxemic blood gases over time. These findings have also been noted when using various methods of risk-adjustment (accounting for severity of illness scores or complex chronic conditions). Similar relationships were found in the majority of studies restricted to patients undergoing care after cardiac arrest. Taken together, the majority of the literature suggests that there is a robust parabolic relationship between PaO₂ and risk-adjusted pediatric ICU mortality, but that the exact threshold at which hyperoxemia becomes deleterious is unclear, and likely beyond the typical target value for most clinical indications. Findings suggest that clinicians should remain judicious and thoughtful in the use of supplemental oxygen therapy in critically ill children.

[Paediatric Life Support]

The European Resuscitation Council (ERC) Paediatric Life Support (PLS) guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations of the International Liaison Committee on Resuscitation (ILCOR). This section provides guidelines on the management of critically ill or injured infants, children and adolescents before, during and after respiratory/cardiac arrest.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

Research Priorities for U.K. Pediatric Critical Care in 2019: Healthcare Professionals' and Parents' Perspectives

OBJECTIVES

The Paediatric Intensive Care Society Study Group conducted a research prioritization exercise with the aim to identify and agree research priorities in Pediatric Critical Care in the United Kingdom both from a healthcare professional and parent/caregiver perspective.

DESIGN

A modified three-round e-Delphi survey, followed by a survey of parents of the top 20 healthcare professional priorities.

SETTING

U.K. PICUs.

PATIENTS

U.K. PICU healthcare professionals who are members of the professional society and parents and family members of children, with experience of a U.K. PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Forty-nine healthcare professional submitted topics in round 1, 98 participated in round 2, and 102 in round 3. These topics were categorized into eight broad domain areas, and within these, there were 73 specific topics in round 2. At round 3, 18 topics had a mean score less than 5.5 and were removed, leaving 55 topics for ranking in round 3. Ninety-five parents and family members completed the surveys from at least 17 U.K. PICUs. Both parents and healthcare professional prioritized research topics associated with the PICU workforce. Healthcare professional research priorities reflected issues that impacted on day-to-day management and practice. Parents' prioritized research addressing acute situations such as infection identification of and sepsis management or research addressing long-term outcomes for children and parents after critical illness. Parents prioritized research into longer term outcomes more than healthcare professional. Parental responses showed clear support for the concept of research in PICU, but few novel research questions were proposed.

CONCLUSIONS

This is the first research prioritization exercise within U.K. PICU setting to include parents' and families' perspectives and compare these with healthcare professional. Results will guide both funders and future researchers.

European Resuscitation Council Guidelines 2021: Paediatric Life Support

These European Resuscitation Council Paediatric Life Support (PLS) guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the management of critically ill infants and children, before, during and after cardiac arrest.

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.

Lung-Protective Mechanical Ventilation Strategies in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Reduced morbidity and mortality associated with lung-protective mechanical ventilation is not proven in pediatric acute respiratory distress syndrome. This study aims to determine if a lung-protective mechanical ventilation protocol in pediatric acute respiratory distress syndrome is associated with improved clinical outcomes.

DESIGN

This pilot study over April 2016 to September 2019 adopts a before-and-after comparison design of a lung-protective mechanical ventilation protocol. All admissions to the PICU were screened daily for fulfillment of the Pediatric Acute Lung Injury Consensus Conference criteria and included.

SETTING

Multidisciplinary PICU.

PATIENTS

Patients with pediatric acute respiratory distress syndrome.

INTERVENTIONS

Lung-protective mechanical ventilation protocol with elements on peak pressures, tidal volumes, end-expiratory pressure to FIO2 combinations, permissive hypercapnia, and permissive hypoxemia.

MEASUREMENTS AND MAIN RESULTS

Ventilator and blood gas data were collected for the first 7 days of pediatric acute respiratory distress syndrome and compared between the protocol (n = 63) and nonprotocol groups (n = 69). After implementation of the protocol, median tidal volume (6.4 mL/kg [5.4-7.8 mL/kg] vs 6.0 mL/kg [4.8-7.3 mL/kg]; p = 0.005), PaO2 (78.1 mm Hg [67.0-94.6 mm Hg] vs 74.5 mm Hg [59.2-91.1 mm Hg]; p = 0.001), and oxygen saturation (97% [95-99%] vs 96% [94-98%]; p = 0.007) were lower, and end-expiratory pressure (8 cm H2O [7-9 cm H2O] vs 8 cm H2O [8-10 cm H2O]; p = 0.002] and PaCO2 (44.9 mm Hg [38.8-53.1 mm Hg] vs 46.4 mm Hg [39.4-56.7 mm Hg]; p = 0.033) were higher, in keeping with lung protective measures. There was no difference in mortality (10/63 [15.9%] vs 18/69 [26.1%]; p = 0.152), ventilator-free days (16.0 [2.0-23.0] vs 19.0 [0.0-23.0]; p = 0.697), and PICU-free days (13.0 [0.0-21.0] vs 16.0 [0.0-22.0]; p = 0.233) between the protocol and nonprotocol groups. After adjusting for severity of illness, organ dysfunction and oxygenation index, the lung-protective mechanical ventilation protocol was associated with decreased mortality (adjusted hazard ratio, 0.37; 95% CI, 0.16-0.88).

CONCLUSIONS

In pediatric acute respiratory distress syndrome, a lung-protective mechanical ventilation protocol improved adherence to lung-protective mechanical ventilation strategies and potentially mortality.

Clinical trials and future directions in pediatric acute respiratory distress syndrome

The pediatric acute respiratory distress syndrome (PARDS), a description specific for children with acute respiratory distress syndrome (ARDS), was proposed in the recent Pediatric Acute Lung Injury Consensus Conference (PALICC, 2015). This recent standardization of PARDS diagnosis is expected to aid in uniform earlier recognition of the entity, enable use of consistent management strategies and potentially increase the ease of enrollment in future PARDS clinical trials-all of which are expected to optimize outcomes in PARDS. Clinical trials in PARDS are few but ongoing studies are expected to lay the foundation for future clinical studies. The Randomized Evaluation of Sedation Titration for Respiratory Failure trial (RESTORE) trial has revealed that a goal directed sedation protocol does not reduce the duration of invasive ventilation in critically ill children. PROSpect trial is a large multi-institute clinical trial that is expected to reveal optimal ventilation strategies and patient positioning (supine vs. prone) in patients with severe PARDS. The PARDS neuromuscular blockade (NMB) study is expected to yield important information about the impact of active NMB on PARDS outcomes. Information from these studies could be used to design future clinical trials in PARDS and to lessen the anecdotal or extrapolated experiences from adult clinical studies that often guide clinical practices in PARDS management. Finally, it is expected that these definitions and management strategies will be revised periodically as our understanding of PARDS evolves. Emerging data on PARDS subtypes suggest that patient heterogeneity is an important factor in designing these clinical trials.

Association of Severe Hyperoxemia Events and Mortality Among Patients Admitted to a Pediatric Intensive Care Unit

IMPORTANCE

A high Pao2, termed hyperoxemia, is postulated to have deleterious health outcomes. To date, the association between hyperoxemia during the ongoing management of critical illness and mortality has been incompletely evaluated in children.

OBJECTIVE

To examine whether severe hyperoxemia events are associated with mortality among patients admitted to a pediatric intensive care unit (PICU).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted over a 10-year period (January 1, 2009, to December 31, 2018); all 23 719 PICU encounters at a quaternary children's hospital with a documented arterial blood gas measurement were evaluated.

EXPOSURES

Severe hyperoxemia, defined as Pao2 level greater than or equal to 300 mm Hg (40 kPa).

MAIN OUTCOMES AND MEASURES

The highest Pao2 values during hospitalization were dichotomized according to the definition of severe hyperoxemia and assessed for association with in-hospital mortality using logistic regression models incorporating a calibrated measure of multiple organ dysfunction, extracorporeal life support, and the total number of arterial blood gas measurements obtained during an encounter.

RESULTS

Of 23 719 PICU encounters during the inclusion period, 6250 patients (13 422 [56.6%] boys; mean [SD] age, 7.5 [6.6] years) had at least 1 measured Pao2 value. Severe hyperoxemia was independently associated with in-hospital mortality (adjusted odds ratio [aOR], 1.78; 95% CI, 1.36-2.33; P < .001). Increasing odds of in-hospital mortality were observed with 1 (aOR, 1.47; 95% CI, 1.05-2.08; P = .03), 2 (aOR, 2.01; 95% CI, 1.27-3.18; P = .002), and 3 or more (aOR, 2.53; 95% CI, 1.62-3.94; P < .001) severely hyperoxemic Pao2 values obtained greater than or equal to 3 hours apart from one another compared with encounters without hyperoxemia. A sensitivity analysis examining the hypothetical outcomes of residual confounding indicated that an unmeasured binary confounder with an aOR of 2 would have to be present in 37% of the encounters with severe hyperoxemia and 0% of the remaining cohort to fail to reject the null hypothesis (aOR of severe hyperoxemia, 1.31; 95% CI, 0.99-1.72).

CONCLUSIONS AND RELEVANCE

Greater numbers of severe hyperoxemia events appeared to be associated with increased mortality in this large, diverse cohort of critically ill children, supporting a possible exposure-response association between severe hyperoxemia and outcome in this population. Although further prospective evaluation appears to be warranted, this study's findings suggest that guidelines for ongoing management of critically ill children should take into consideration the possible detrimental effects of severe hyperoxemia.

Permissive versus restrictive temperature thresholds in critically ill children with fever and infection: a multicentre randomized clinical pilot trial

Background

Fever improves pathogen control at a significant metabolic cost. No randomized clinical trials (RCT) have compared fever treatment thresholds in critically ill children. We performed a pilot RCT to determine whether a definitive trial of a permissive approach to fever in comparison to current restrictive practice is feasible in critically ill children with suspected infection.

Methods

An open, parallel-group pilot RCT with embedded mixed methods perspectives study in four UK paediatric intensive care units (PICUs) and associated retrieval services.

Participants were emergency PICU admissions aged > 28 days to < 16 years receiving respiratory support and supplemental oxygen.

Subjects were randomly assigned to permissive (antipyretic interventions only at ≥ 39.5 °C) or restrictive groups (antipyretic interventions at ≥ 37.5 °C) whilst on respiratory support. Parents were invited to complete a questionnaire or take part in an interview. Focus groups were conducted with staff at each unit. Outcomes were measures of feasibility: recruitment rate, protocol adherence and acceptability, between group separation of temperature and safety.

Results

One hundred thirty-eight children met eligibility criteria of whom 100 (72%) were randomized (11.1 patients per month per site) without prior consent (RWPC). Consent to continue in the trial was obtained in 87 cases (87%). The mean maximum temperature (95% confidence interval) over the first 48 h was 38.4 °C (38.2–38.6) in the restrictive group and 38.8 °C (38.6–39.1) in the permissive group, a mean difference of 0.5 °C (0.2–0.8). Protocol deviations were observed in 6.8% (99/1438) of 6-h time periods and largely related to patient comfort in the recovery phase. Length of stay, duration of organ support and mortality were similar between groups. No pre-specified serious adverse events occurred. Staff (n = 48) and parents (n = 60) were supportive of the trial, including RWPC. Suggestions were made to only include invasively ventilated children for the duration of intubation.

Conclusion

Uncertainty around the optimal fever threshold for antipyretic intervention is relevant to many emergency PICU admissions. A more permissive approach was associated with a modest increase in mean maximum temperature. A definitive trial should focus on the most seriously ill cases in whom antipyretics are rarely used for their analgesic effects alone.

Trial registration

ISRCTN16022198. Registered on 14 August 2017.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2354-4) contains supplementary material, which is available to authorized users.