Preemptive Morphine During Therapeutic Hypothermia After Neonatal Encephalopathy: A Secondary Analysis

Oral Clonidine-based Strategy to Reduce Opiate Use during Cooling for Neonatal Encephalopathy: An Observational Study

OBJECTIVE

To determine whether an enteral, clonidine-based sedation strategy (CLON) during therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE) would decrease opiate use, while maintaining similar short-term safety and efficacy profiles to a morphine-based strategy (MOR).

STUDY DESIGN

This was a single-center, observational study conducted at a level IV neonatal intensive care unit from January 1, 2017, to October 1, 2021. From April 13, 2020, to August 13, 2020, MOR was transitioning to CLON. Thus, patients receiving TH for HIE were grouped to MOR (before April 13, 2020) and CLON (after August 13, 2020). We calculated the total and rescue morphine milligram equivalent (MME)/ kg (primary outcome) and frequency of hemodynamic changes (secondary outcome) for both groups.

RESULTS

MOR and CLON groups (74 and 25 neonates, respectively) had similar baseline characteristics and need for rescue sedative intravenous infusion (21.6% MOR and 20% CLON). Both, MME/ kg and need for rescue opiates (combined bolus and infusions) were higher in MOR than CLON (p < 0.001). As days in TH advanced, a lower percentage of CLON patients needed rescue opiates (92% on day 1 to 68% on day 3). MOR patients received a higher cumulative dose of dopamine and more frequently required a second inotrope and hydrocortisone for hypotension. MOR had a lower respiratory rate during TH (p=0.01 vs. CLON).

CONCLUSIONS

Our CLON protocol is non-inferior to MOR, maintaining perceived effectiveness and hemodynamic safety, with an apparently reduced need for opiates and inotropes.

Whole-Body Hypothermia vs Targeted Normothermia for Neonates With Mild Encephalopathy: A Multicenter Pilot Randomized Clinical Trial

Importance

Although whole-body hypothermia is widely used after mild neonatal hypoxic-ischemic encephalopathy (HIE), safety and efficacy have not been evaluated in randomized clinical trials (RCTs), to our knowledge.

Objective

To examine the effect of 48 and 72 hours of whole-body hypothermia after mild HIE on cerebral magnetic resonance (MR) biomarkers.

Design, Setting, and Participants

This open-label, 3-arm RCT was conducted between October 31, 2019, and April 28, 2023, with masked outcome analysis. Participants were neonates at 6 tertiary neonatal intensive care units in the UK and Italy born at or after 36 weeks' gestation with severe birth acidosis, requiring continued resuscitation, or with an Apgar score less than 6 at 10 minutes after birth and with evidence of mild HIE on modified Sarnat staging. Statistical analysis was per intention to treat.

Interventions

Random allocation to 1 of 3 groups (1:1:1) based on age: neonates younger than 6 hours were randomized to normothermia or 72-hour hypothermia (33.5 °C), and those 6 hours or older and already receiving whole-body hypothermia were randomized to rewarming after 48 or 72 hours of hypothermia.

Main Outcomes and Measures

Thalamic N-acetyl aspartate (NAA) concentration (mmol/kg wet weight), assessed by cerebral MR imaging and thalamic spectroscopy between 4 and 7 days after birth using harmonized sequences.

Results

Of 225 eligible neonates, 101 were recruited (54 males [53.5%]); 48 (47.5%) were younger than 6 hours and 53 (52.5%) were 6 hours or older at randomization. Mean (SD) gestational age and birth weight were 39.5 (1.1) weeks and 3378 (380) grams in the normothermia group (n = 34), 38.7 (0.5) weeks and 3017 (338) grams in the 48-hour hypothermia group (n = 31), and 39.0 (1.1) weeks and 3293 (252) grams in the 72-hour hypothermia group (n = 36). More neonates in the 48-hour (14 of 31 [45.2%]) and 72-hour (13 of 36 [36.1%]) groups required intubation at birth than in the normothermic group (3 of 34 [8.8%]). Ninety-nine neonates (98.0%) had MR imaging data and 87 (86.1%), NAA data. Injury scores on conventional MR biomarkers were similar across groups. The mean (SD) NAA level in the normothermia group was 10.98 (0.92) mmol/kg wet weight vs 8.36 (1.23) mmol/kg wet weight (mean difference [MD], -2.62 [95% CI, -3.34 to -1.89] mmol/kg wet weight) in the 48-hour and 9.02 (1.79) mmol/kg wet weight (MD, -1.96 [95% CI, -2.66 to -1.26] mmol/kg wet weight) in the 72-hour hypothermia group. Seizures occurred beyond 6 hours after birth in 4 neonates: 1 (2.9%) in the normothermia group, 1 (3.2%) in the 48-hour hypothermia group, and 2 (5.6%) in the 72-hour hypothermia group.

Conclusions and Relevance

In this pilot RCT, whole-body hypothermia did not improve cerebral MR biomarkers after mild HIE, although neonates in the hypothermia groups were sicker at baseline. Safety and efficacy of whole-body hypothermia should be evaluated in RCTs.

Trial Registration

ClinicalTrials.gov Identifier: NCT03409770.

Global cross-sectional survey on neonatal pharmacologic sedation and analgesia practices and pain assessment tools: impact of the sociodemographic index (SDI)

BACKGROUND

There is variability in the use of sedatives and analgesics in neonatal intensive care units (NICUs). We aimed to investigate the use of analgesics and sedatives and the management of neonatal pain and distress.

METHODS

This was a global, prospective, cross-sectional study. A survey was distributed May-November 2022. The primary outcome of this research was to compare results between countries depending on their socio-sanitary level using the sociodemographic index (SDI). We organized results based on geographical location.

RESULTS

The survey collected 1304 responses, but we analyzed 924 responses after database cleaning. Responses from 98 different countries were analyzed. More than 60% of NICUs reported having an analgosedation guideline, and one-third of respondents used neonatal pain scales in more than 80% of neonates. We found differences in the management of sedation and analgesia between NICUs on different continents, but especially between countries with different SDIs. Countries with a higher SDI had greater availability of and adherence to analgosedation guidelines, as well as higher rates of analgosedation for painful or distressing procedures. Countries with different SDIs reported differences in analgosedation for neonatal intubation, invasive ventilation, and therapeutic hypothermia, among others.

CONCLUSIONS

Socio-economic status of countries impacts on neonatal analgosedation management.

IMPACT

There is significant variability in the pain management practices in neonates. There is a lack of knowledge related to how neonatal pain management practices differ between regions. Sociodemographic index is a key factor associated with differences in neonatal pain management practices across global regions.

Analgesia and sedation strategies in neonates undergoing whole-body therapeutic hypothermia: A scoping review

BACKGROUND

Therapeutic hypothermia (TH) is a widely practiced neuroprotective strategy for neonates with hypoxic-ischemic encephalopathy. Induced hypothermia is associated with shivering, cold pain, agitation, and distress.

OBJECTIVE

This scoping review determines the breadth of research undertaken for pain and stress management in neonates undergoing hypothermia therapy, the pharmacokinetics of analgesic and sedative medications during hypothermia and the effect of such medication on short- and long-term neurological outcomes.

METHODS

We searched the following online databases namely, (i) MEDLINE, (ii) Web of Science, (iii) Cochrane Library, (iv) Scopus, (v) CINAHL, and (vi) EMBASE to identify published original articles between January 2005 and December 2022. We included only English full-text articles on neonates treated with TH and reported the sedation/analgesia strategy used. We excluded articles that reported TH on transport or extracorporeal membrane oxygenation, did not report the intervention strategies for sedation/analgesia, and reported hypoxic-ischemic encephalopathy in which hypothermia was not applied.

RESULTS

The eligible publications (n = 97) included cohort studies (n = 72), non-randomized experimental studies (n = 2), pharmacokinetic studies (n = 4), dose escalation feasibility trial (n = 1), cross-sectional surveys (n = 5), and randomized control trials (n = 13). Neonatal Pain, Agitation, and Sedation Scale (NPASS) is the most frequently used pain assessment tool in this cohort. The most frequently used pharmacological agents are opioids (Morphine, Fentanyl), benzodiazepine (Midazolam) and Alpha2 agonists (Dexmedetomidine). The proportion of neonates receiving routine sedation-analgesia during TH is center-specific and varies from 40-100% worldwide. TH alters most drugs' metabolic rate and clearance, except for Midazolam. Dexmedetomidine has additional benefits of thermal tolerance, neuroprotection, faster recovery, and less likelihood of seizures. There is a wide inter-individual variability in serum drug levels due to the impact of temperature, end-organ dysfunction, postnatal age, and body weight on drug metabolism.

CONCLUSIONS

No multidimensional pain scale has been tested for reliability and construct validity in hypothermic encephalopathic neonates. There is an increasing trend towards using routine sedation/analgesia during TH worldwide. Wide variability in the type of medication used, administration (bolus versus infusion), and dose ranges used emphasizes the urgent need for standardized practice recommendations and guidelines. There is insufficient data on the long-term neurological outcomes of exposure to these medications, adjusted for underlying brain injury and severity of encephalopathy. Future studies will need to develop framework tools to enable precise control of sedation/analgesia drug exposure customized to individual patient needs.

Variations in care of neonates during therapeutic hypothermia: call for care practice bundle implementation

BACKGROUND

Therapeutic hypothermia (TH) is the gold-standard treatment for moderate and severe neonatal encephalopathy (NE). Care during TH has implications for long-term outcomes. Outcome variability exists among neonatal intensive care units (NICUs) in Canada, but care variations are not understood well. This study examines variations in care practices for neonates with NE treated with TH in NICUs across Canada.

METHODS

A non-anonymous, web-based questionnaire was emailed to tertiary NICUs in Canada providing TH for NE to assess care practices during the first days of life and neurodevelopmental follow-up.

RESULTS

Ninety-two percent (24/26) responded. Centres followed national guidelines regarding the use of the modified Sarnat score to assess the initial severity of NE, the need to initiate TH within the first 6 h of birth, and the importance of follow-up. However, other practices varied, including ventilation mode, definition/treatment of hypotension, routine echocardiography, use of sedation, use of electroencephalogram (EEG), MRI timing, placental analysis, and follow-up duration.

CONCLUSIONS

NICUs across Canada follow available national guidelines, but variations exist in practices for managing NE during TH. Development and implementation of a consensus-based care bundle for neonates during TH may reduce practice variability and improve outcomes.

IMPACT

This survey describes the current HIE care practices and variation among tertiary centres in Canada. Variations exist in the care of neonates with NE treated with TH in NICUs across Canada. This paper Identifies areas of variation that are not discussed in detail in the national guidelines and will help to set up quality improvement initiatives. Elucidating the variation in care practices calls for the creation and implementation of a national, consensus-based care bundle, with the objective to improve the outcomes of these critically ill neonates.

Adequacy of sedation analgesia to support the comfort of neonates undergoing therapeutic hypothermia and its impact on short-term neonatal outcomes

Objectives

We aimed to evaluate (1) whether sedation analgesia (SA) used during therapeutic hypothermia (TH) was efficient to support the wellbeing of neonates with hypoxic-ischemic encephalopathy, (2) the SA level and its adjustment to clinical pain scores, and (3) the impact of inadequate SA on short-term neonatal outcomes evaluated at discharge.

Methods

This was an observational retrospective study performed between 2011 and 2018 in two level III centers in Alsace, France. We analyzed the wellbeing of infants by using the COMFORT-Behavior (COMFORT-B) clinical score and SA level during TH, according to which we classified infants into four groups: those with excess SA, adequate SA, lack of SA, and variability of SA. We analyzed the variations in doses of SA and their justification. We also determined the impact of inadequate SA on neonatal outcomes at discharge by multivariate analyses with multinomial regression, with adequate SA as the reference.

Results

A total of 110 patients were included, 89 from Strasbourg university hospital and 21 from Mulhouse hospital. The COMFORT-B score was assessed 95.5% of the time. Lack of SA was mainly found on the first day of TH (15/110, 14%). In all, 62 of 110 (57%) infants were in excess of SA over the entire duration of TH. Most dose variations were related to clinical pain scores. Inadequate SA was associated with negative short-term consequences. Infants with excess of SA had a longer duration of mechanical ventilation [mean ratio 1.46, 95% confidence interval (CI), 1.13-1.89, p = 0.005] and higher incidence of abnormal neurological examination at discharge (odds ratio 2.61, 95% CI, 1.10-6.18, p = 0.029) than infants with adequate SA.

Discussion

Adequate SA was not easy to achieve during TH. Close and regular monitoring of SA level may help achieve adequate SA. Excess of SA can be harmful for newborns with hypoxic-ischemic encephalopathy who are undergoing TH.

Interventions for the Management of Pain and Sedation in Newborns Undergoing Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy: A Systematic Review

BACKGROUND

Newborn infants undergoing therapeutic hypothermia (TH) are exposed to multiple painful and stressful procedures. The aim of this systematic review was to assess benefits and harms of pharmacological and non-pharmacological interventions for the management of pain and sedation in newborn infants undergoing TH for hypoxic-ischemic encephalopathy.

METHODS

We included randomized and observational studies reporting any intervention (either drugs or non-pharmacological interventions) to manage pain and sedation in newborn infants (> 33 weeks' gestational age) undergoing TH. We included any dose, duration and route of administration. We also included any type and duration of non-pharmacological interventions. Our prespecified primary outcomes were analgesia and sedation assessed using validated pain scales in the neonatal population; circulatory instability; mortality to discharge; and neurodevelopmental disability. A systematic literature search was conducted in the PubMed, Embase, CINAHL, Cochrane CENTRAL, Scopus, and Web of Science databases, with no language restrictions. Included studies underwent risk-of-bias assessment (Cochrane risk-of-bias tool and ROBINS-I) and data extraction performed by two authors independently. The plan had been to use effect measures such as mean difference for continuous outcomes and risk ratio for dichotomous outcomes, however the included studies are presented in a narrative synthesis due to their paucity and heterogeneity.

RESULTS

Ten studies involving 3551 infants were included-one trial and nine observational studies. Most studies examined the use of phenobarbital or other antiepileptic drugs with primary outcomes related to seizure activity. The single trial that was included compared pentoxifylline with placebo. Among the primary outcomes, six studies reported circulatory instability and five reported mortality to discharge without relevant differences; two studies reported on neurodevelopmental disability and one study reported on pain scale. Three studies were ongoing.

CONCLUSIONS

We found limited evidence to establish the benefits and harms of the interventions for the management of pain and sedation in newborn infants undergoing TH. Long-term outcomes were not reported. Given the very low certainty of evidence-due to imprecision of the estimates, inconsistency and limitations in study design (all nine observational studies with overall serious risk of bias)-for all outcomes, clinical trials are required to determine the most effective interventions in this population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42020205755.

Opioid exposure during therapeutic hypothermia and short-term outcomes in neonatal encephalopathy

OBJECTIVE

To assess the association between opioid exposure during therapeutic hypothermia (TH) for perinatal hypoxic-ischemic encephalopathy (HIE) and in-hospital outcomes.

STUDY DESIGN

In this retrospective cohort study, linked data were accessed on infants ≥36 weeks gestation, who underwent TH for HIE, born from 2010-2016 in 23 Neonatal Intensive Care Units participating in Children's Hospitals Neonatal Consortium and Pediatric Health Information Systems. We excluded infants who received opioids for >5 days.

RESULTS

The cohort (n = 1484) was categorized as No opioid [240(16.2%)], Low opioid (1-2 days) [574 (38.7%)] and High opioid group (HOG, 3-5 days) [670 (45.2%)]. After adjusting for HIE severity, opioids were not associated with abnormal MRI, but were associated with decreased likelihood of complete oral feeds at discharge. HOG had increased likelihood of prolonged hospital stay and ventilation.

CONCLUSION

Opioid exposure during TH was not associated with abnormal MRI; its association with adverse short-term outcomes suggests need for cautious empiric use.

Cerebral Oxygenation and Metabolism After Hypoxia-Ischemia

Perinatal hypoxia-ischemia (HI) is still a significant contributor to mortality and adverse neurodevelopmental outcomes in term and preterm infants. HI brain injury evolves over hours to days, and involves complex interactions between the endogenous protective and pathological processes. Understanding the timing of evolution of injury is vital to guide treatment. Post-HI recovery is associated with a typical neurophysiological profile, with stereotypic changes in cerebral perfusion and oxygenation. After the initial recovery, there is a delayed, prolonged reduction in cerebral perfusion related to metabolic suppression, followed by secondary deterioration with hyperperfusion and increased cerebral oxygenation, associated with altered neurovascular coupling and impaired cerebral autoregulation. These changes in cerebral perfusion are associated with the stages of evolution of injury and injury severity. Further, iatrogenic factors can also affect cerebral oxygenation during the early period of deranged metabolism, and improving clinical management may improve neuroprotection. We will review recent evidence that changes in cerebral oxygenation and metabolism after HI may be useful biomarkers of prognosis.

Opioid analgesia and temperature regulation are associated with EEG background activity and MRI outcomes in neonates with mild-to-moderate hypoxic-ischemic encephalopathy undergoing therapeutic hypothermia

BACKGROUND

Therapeutic hypothermia (TH) without sedation may lead to discomfort, which may be associated with adverse consequences in neonates with hypoxic-ischemic encephalopathy (HIE). The aim of this study was to assess the association between level of exposure to opioids and temperature, with electroencephalography (EEG) background activity post-TH and magnetic resonance imaging (MRI) brain injury in neonates with HIE.

METHODS

Thirty-one neonates with mild-to-moderate HIE who underwent TH were identified. MRIs were reviewed for presence of brain injury. Quantitative EEG background features including EEG discontinuity index and spectral power densities were calculated during rewarming and post-rewarming periods. Dose of opioids administered during TH and temperatures were collected from the medical charts. Multivariable linear and logistic regression analyses were conducted to assess the associations between cumulative dose of opioids and temperature with EEG background and MRI while adjusting for markers of HIE severity.

RESULTS

Higher opioid doses (β = -0.21, p = 0.02) and reduced skin temperature (β = 0.14, p < 0.01) were associated with lower EEG discontinuity index recorded post-TH. Higher opioid doses (β = 0.75, p = 0.01) and reduced skin temperature (β = -0.39, p = 0.02) were also associated with higher EEG Delta power post-TH. MRI brain injury was observed in 14 patients (45%). In adjusted regression analyses, higher opioid doses (OR = 0.00; 95%CI: 0-0.19; p = 0.01), reduced skin temperature (OR = 41.19; 95%CI: 2.27-747.86; p = 0.01) and reduced cooling device output temperature (OR = 1.91; 95%CI: 1.05-3.48; p = 0.04) showed an association with lower odds of brain injury.

CONCLUSIONS

Higher level of exposure to opioids and reduced skin temperature during TH in mild-to-moderate HIE were associated with improved EEG background activity post-TH. Moreover, higher exposure to opioids, reduced skin temperature and reduced device output temperature were associated with lower odds of brain injury on MRI.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

New Horizons in Mild Hypoxic-ischemic Encephalopathy: A Standardized Algorithm to Move past Conundrum of Care

Hypoxic-ischemic encephalopathy (HIE) presents clinically with a neonatal encephalopathy (NE) whereby the mild spectrum is difficult to classify immediately after birth. For decades trials have focused exclusively on infants with moderate-severe HIE s, as these infants were easier to identify after birth and had the highest risk of adverse outcomes. Twenty years after those trials, the PRIME study finally solved the first part of the conundrum by providing a definition of mild HIE in the first 6 hours. There is strong biological plausibility and preclinical evidence supporting the efficacy of therapeutic hypothermia (TH) but there is a lack of comparative clinical data to establish the risk-benefit in mild HIE. The fundamental question of how best to manage mild HIE remains unanswered. This review will summarize (1) the evidence that neonates with mild HIE are at significant risk for adverse outcomes, (2) the gaps/controversies in management, and (3) an algorithm of care is proposed to ensure standardized management of mild HIE and the direction of future trials.

Clonidine for sedation in infants during therapeutic hypothermia with neonatal encephalopathy: pilot study

OBJECTIVE

To determine a safe dose of clonidine (CLON) to be used in infants with hypoxic ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH).

STUDY DESIGN

A pilot prospective study was performed to determine the effect of CLON on autonomic parameters, the pharmacokinetics (PK) of CLON, and the amount of morphine (MOR) given "as needed" for shivering and agitation in a cohort of infants (n = 12) with HIE undergoing TH compared to a historical control group (n = 28).

RESULTS

The CLON group received less "as needed" MOR than the MOR-only group for agitation/shivering (p < 0.001), and the CLON vs. MOR-only group spent 92% vs. 79% of cooling time at the target core body temperature (CBT; p = 0.03, CLON vs. MOR).

CONCLUSIONS

Intravenous CLON (1 mcg/kg Q8h) is well tolerated in infants treated with TH for HIE. CLON stabilizes CBT in the ideal range during cooling, which may be optimal for neuroprotection.

Pharmacologic Analgesia and Sedation in Neonates

Chronic pain and agitation in neonatal life impact the developing brain. Oral sweet-tasting solutions should be used judiciously to mitigate behavioral responses to mild painful procedures, keeping in mind that the long-term impact is unknown. Rapidly acting opioids should be used as part of premedication cocktails for nonemergent endotracheal intubations. Continuous low-dose morphine or dexmedetomidine may be considered for preterm or term neonates exhibiting signs of stress during mechanical ventilation and therapeutic hypothermia, respectively. Further research is required regarding the pharmacokinetics, pharmacodynamics, safety, and efficacy of pharmacologic agents used to mitigate mild, moderate, and chronic pain and stress in neonates.

Proposing a care practice bundle for neonatal encephalopathy during therapeutic hypothermia

Neonates with neonatal encephalopathy (NE) often present with multi-organ dysfunction that requires multidisciplinary specialized management. Care of the neonate with NE is thus complex with interaction between the brain and various organ systems. Illness severity during the first days of birth, and not only during the initial hypoxia-ischemia event, is a significant predictor of adverse outcomes in neonates with NE treated with therapeutic hypothermia (TH). We thus propose a care practice bundle dedicated to support the injured neonatal brain that is based on the current best evidence for each organ system. The impact of using such bundle on outcomes in NE remains to be demonstrated.

Hypothermia for moderate or severe neonatal encephalopathy in low-income and middle-income countries (HELIX): a randomised controlled trial in India, Sri Lanka, and Bangladesh

BACKGROUND

Although therapeutic hypothermia reduces death or disability after neonatal encephalopathy in high-income countries, its safety and efficacy in low-income and middle-income countries is unclear. We aimed to examine whether therapeutic hypothermia alongside optimal supportive intensive care reduces death or moderate or severe disability after neonatal encephalopathy in south Asia.

METHODS

We did a multicountry open-label, randomised controlled trial in seven tertiary neonatal intensive care units in India, Sri Lanka, and Bangladesh. We enrolled infants born at or after 36 weeks of gestation with moderate or severe neonatal encephalopathy and a need for continued resuscitation at 5 min of age or an Apgar score of less than 6 at 5 min of age (for babies born in a hospital), or both, or an absence of crying by 5 min of age (for babies born at home). Using a web-based randomisation system, we allocated infants into a group receiving whole body hypothermia (33·5°C) for 72 h using a servo-controlled cooling device, or to usual care (control group), within 6 h of birth. All recruiting sites had facilities for invasive ventilation, cardiovascular support, and access to 3 Tesla MRI scanners and spectroscopy. Masking of the intervention was not possible, but those involved in the magnetic resonance biomarker analysis and neurodevelopmental outcome assessments were masked to the allocation. The primary outcome was a combined endpoint of death or moderate or severe disability at 18-22 months, assessed by the Bayley Scales of Infant and Toddler Development (third edition) and a detailed neurological examination. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT02387385.

FINDINGS

We screened 2296 infants between Aug 15, 2015, and Feb 15, 2019, of whom 576 infants were eligible for inclusion. After exclusions, we recruited 408 eligible infants and we assigned 202 to the hypothermia group and 206 to the control group. Primary outcome data were available for 195 (97%) of the 202 infants in the hypothermia group and 199 (97%) of the 206 control group infants. 98 (50%) infants in the hypothermia group and 94 (47%) infants in the control group died or had a moderate or severe disability (risk ratio 1·06; 95% CI 0·87-1·30; p=0·55). 84 infants (42%) in the hypothermia group and 63 (31%; p=0·022) infants in the control group died, of whom 72 (36%) and 49 (24%; p=0·0087) died during neonatal hospitalisation. Five serious adverse events were reported: three in the hypothermia group (one hospital readmission relating to pneumonia, one septic arthritis, and one suspected venous thrombosis), and two in the control group (one related to desaturations during MRI and other because of endotracheal tube displacement during transport for MRI). No adverse events were considered causally related to the study intervention.

INTERPRETATION

Therapeutic hypothermia did not reduce the combined outcome of death or disability at 18 months after neonatal encephalopathy in low-income and middle-income countries, but significantly increased death alone. Therapeutic hypothermia should not be offered as treatment for neonatal encephalopathy in low-income and middle-income countries, even when tertiary neonatal intensive care facilities are available.

FUNDING

National Institute for Health Research, Garfield Weston Foundation, and Bill & Melinda Gates Foundation.

TRANSLATIONS

For the Hindi, Malayalam, Telugu, Kannada, Singhalese, Tamil, Marathi and Bangla translations of the abstract see Supplementary Materials section.

Management of comfort and sedation in neonates with neonatal encephalopathy treated with therapeutic hypothermia

Ensuring comfort for neonates undergoing therapeutic hypothermia (TH) after neonatal encephalopathy (NE) exemplifies a vital facet of neonatal neurocritical care. Physiologic markers of stress are frequently present in these neonates. Non-pharmacologic comfort measures form the foundation of care, benefitting both the neonate and parents. Pharmacological sedatives may also be indicated, yet have the potential to both mitigate and intensify the neurotoxicity of a hypoxic-ischemic insult. Morphine represents current standard of care with a history of utilization and extensive pharmacokinetic data to guide safe and effective dosing. Dexmedetomidine, as an alternative to morphine, has several appealing characteristics, including neuroprotective effects in animal models; robust pharmacokinetic studies in neonates with NE treated with TH are required to ensure a safe and effective standard dosing approach. Future studies in neonates treated with TH must address comfort, adverse events, and long-term outcomes in the context of specific sedation practices.

Morphine and fentanyl exposure during therapeutic hypothermia does not impair neurodevelopment

BACKGROUND

Hypothermia-treated and intubated infants with moderate or severe hypoxic-ischemic encephalopathy (HIE) usually receive morphine for sedation and analgesia (SA) during therapeutic hypothermia (TH) and endotracheal ventilation. Altered drug pharmacokinetics in this population increases the risk of drug accumulation. Opioids are neurotoxic in preterm infants. In term infants undergoing TH, the long-term effects of morphine exposure are unknown. We examined the effect of opioid administration during TH on neurodevelopmental outcome and time to extubation after sedation ended.

METHODS

In this prospectively collected population-based cohort of 282 infants with HIE treated with TH (2007-2017), the cumulative opioid dose of morphine and equipotent fentanyl (10-60 µg/kg/h) administered during the first week of life was calculated. Clinical outcomes and concomitant medications were also collected. Of 258 survivors, 229 underwent Bayley-3 neurodevelopmental assessments of cognition, language and motor function at 18-24 months. Multivariate stepwise linear regression analysis was used to examine the relation between cumulative opioid dose and Bayley-3 scores. Three severity-groups (mild-moderate-severe) were stratified by early (<6 h) amplitude-integrated electroencephalography (aEEG) patterns.

FINDINGS

The cumulative dose of opioid administered as SA during TH was median (IQR) 2121 µg/kg (1343, 2741). Time to extubation was independent of SA dose (p > 0.2). There was no significant association between cumulative SA dose and any of the Bayley-3 domains when analysing the entire cohort or any of the aEEG severity groups.

INTERPRETATION

Higher cumulative opioid doses in TH-treated infants with HIE was not associated with worse Bayley-3 scores at 18-24 months of age.

FUNDING

The Bristol cooling program was funded by the Children's Medical Research Charity SPARKS managing donations for our research from the UK and US, the UK Moulton Foundation, the Lærdal Foundation for Acute Medicine in Norway and the Norwegian Research Council (JKG).