Therapeutic Hypothermia During Neonatal Transport: Active Cooling Helps Reach the Target

Efficacy of Therapeutic Hypothermia During Transport of Newborns With Perinatal Hypoxic-Ischaemic Encephalopathy: Experience From Newborn and Paediatric Transport Service, New South Wales

AIM

To examine the efficacy of current non-servo-based cooling methods used by NETS NSW in treating hypoxic ischaemic encephalopathy (HIE) with therapeutic hypothermia (TH) in neonatal retrieval.

METHODS

A retrospective observational study of infants treated with TH for HIE retrieved by NETS NSW from January 2017 to June 2020 inclusive. Primary outcomes were the proportion of neonates achieving TH within 6 h of life and maintaining temperature in a therapeutic range.

RESULTS

82 patients were included in analysis. Mean gestational age (GA) was 39 weeks (IQR 38-40) and mean birthweight (BW) 3297 g (SD 607 g). 68 infants (82.9%) were passively cooled while 14 (17.1%) were cooled with gel packs. 20 infants (21.4%) had rectal temperature monitoring before retrieval. 45 infants (55.6%) reached TH within 6 h of birth. Only 56 infants (68.3%) reached TH during retrieval. Of these infants, 45 (80.4%) had subsequent temperatures outside the therapeutic range.

CONCLUSIONS

Infants receiving TH through non-servo-controlled methods are commonly exposed to temperature instability and overcooling. Introduction of servo-controlled cooling devices is required to improve care and management of perinatal HIE in retrieval.

Servo-controlled therapeutic hypothermia during neonatal transport: a before-and-after quality improvement project

The purpose of this paper is to compare the achievement of target temperature and the short-term neurological outcome according to the use of servo-controlled hypothermia in transport. This is a monocentric retrospective observational before-and-after uncontrolled study of newborns transported for neonatal encephalopathy. The first group was transported from 01/01/2019 to 12/31/2019 in passive hypothermia and the second group from 01/01/2021 to 12/31/2021 in controlled hypothermia. We included patients who had a total of 72 h of servo-controlled therapeutic hypothermia (CTH). We excluded those who had no or less than 72 h of CTH. There were 33 children transported in passive hypothermia in 2019 and 23 children transported in CTH in 2021. There were 9/28 (32%) patients in 2019 who reached the target temperature on arrival at the NICU compared with 20/20 (100%) in 2021 (p value < 0.01). There was a trend towards earlier age of therapeutic hypothermia if started in transport: 3.1 h ± 1.0 vs 4.0 h ± 2.4 for passive hypothermia (p value 0.07). There was no difference in age of arrival in NICU (4.0 h ± 1.2 with CTH vs 3.8 h ± 2.2 without CTH). We found no difference in short-term outcome (survival, abnormal MRI, seizures on EEG) between the two groups.

CONCLUSION

The use of servo-controlled therapeutic hypothermia makes it possible to reach the temperature target, without increasing the age of arrival in the NICU.

WHAT IS KNOWN

• CTH is rarely used during transport in France even if passive hypothermia rarely reaches temperature target, inducing overcooling and hyperthermia.

WHAT IS NEW

• This study shows better temperature control on arrival in the NICU with CTH compared to passive hypothermia, with no increase in arrival time.

Short-Term Outcomes of Neonates with Hypoxic-Ischemic Encephalopathy Receiving Active Versus Passive Cooling During Transport

Therapeutic hypothermia (TH) is the only currently approved treatment for neonatal hypoxic-ischemic encephalopathy (HIE) and must be started within 6 hours to optimize effectiveness. This narrow therapeutic window often requires initiation of TH before or during transport. The goal of this study was to assess the effects of servo-controlled TH versus passive hypothermia during transport on short-term outcomes in newborns with HIE. This was a single-center retrospective case-control study of neonates with HIE treated with active or passive TH during transport. Primary outcomes included brain injury on magnetic resonance imaging (MRI) and presence of seizures. Seventy-six neonates were included-13 active and 63 passive. The active TH group was more likely to arrive within goal temperature. No difference was noted between groups in seizures or TH complications. Active TH was associated with increased injury on MRI. Active TH resulted in tighter temperature control, but no improvement in short-term outcomes in our cohort. The MRI findings may be due to differences in overall disease severity, which could not be adjusted for, given the modest sample size.

The Association Between Neonatal Intensive Care Unit Arrival Temperatures and Short-Term Outcomes of Neonates with Moderate and Severe Hypoxic-Ischemic Encephalopathy

Therapeutic hypothermia (TH) is the only treatment method that is known to reduce mortality and neurological sequela rates in newborns with moderate and severe hypoxic-ischemic encephalopathy (HIE). We aimed to evaluate the relationship between rectal temperatures measured upon arrival to our unit and short-term outcomes in newborns with HIE/TH. This was a retrospective study conducted between January 2022 and January 2023. The neonates were divided into three groups according to their rectal temperatures measured upon arrival at our unit as follows: Group 1) <33°C, Group 2) 33-34°C (group arriving at target temperature), and Group 3) >34°C. Short-term outcomes and mortality were compared between the groups. Group 1 consisted of 17 (19.8%) neonates, Group 2 consisted of 34 (39.5%) neonates, and Group 3 consisted of 35 (40.7%) neonates who had HIE and an indication for TH. Rectal temperature on arrival to the unit was not related to the rate of clinical convulsions, rates of abnormal attenuated electroencephalography and magnetic resonance imaging findings, rate of pulmonary hypertension, duration of mechanical ventilation and length of hospital stay. Although the mortality rate was 29% in Group 1, it was 3% and 6% in Groups 2 and 3, respectively (p = 0.016). No relationship was found between the rectal temperature upon arrival to the NICU and the short-term outcomes in HIE/TH neonates. However, the mortality rate in those who were overcooled was significantly higher compared with the other groups.

Establishing a regional registry for neonatal encephalopathy: impact on identification of gaps in practice

BACKGROUND

Neonatal encephalopathy (NE) continues to be a significant risk for death and disability. To address this risk, regional guidelines were developed with the support of a malpractice insurance patient safety organization. A NE registry was also established to include 14 centers representing around 50% of deliveries in the state of Massachusetts. The aim of this study was to identify areas of variation in practice that could benefit from quality improvement projects.

METHODS

This manuscript reports on the establishment of the registry and the primary findings to date.

RESULTS

From 2018 to 2020, 502 newborns with NE were evaluated for Therapeutic Hypothermia (TH), of which 246 (49%) received TH, representing a mean of 2.91 per 1000 live births. The study reports on prenatal characteristics, delivery room resuscitation, TH eligibility screening, and post-natal management of newborns with NE who did and did not receive TH.

CONCLUSIONS

The registry has allowed for the identification of areas of variation in clinical practices, which have guided ongoing quality improvement projects. The authors advocate for the establishment of local and regional registries to standardize and improve NE patient care. They have made the registry data collection tools freely available for other centers to replicate this work.

IMPACT

Malpractice insurance companies can take an active role in supporting clinicians in establishing clinical practice guidelines and regional registries. Establishing a collaborative regional neonatal encephalopathy (NE) registry is feasible. Data Collection tools for a NE registry have been made publicly available to be adopted and replicated by other groups. Establishing a regional NE registry allowed for the identification of gaps in knowledge, variations in practice, and the opportunity to advance care through quality improvement projects.

Comparing Three Methods of Therapeutic Hypothermia Among Transported Neonates with Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) and associated multiorgan injury are significant causes of morbidity and mortality in term and near-term neonates. Therapeutic hypothermia (TH) is the current standard of care for neuroprotection in neonates with HIE. In our experience, the majority of babies born with HIE were found in nontertiary care facilities in our region, where effective methods of cooling during transport to tertiary care centers are desirable. Most centers initiate passive TH at referral hospitals, while active cooling is typically initiated during transport. The objective of this study was to evaluate the effectiveness of three methods of cooling during transport of neonates with HIE in southern Alberta. In this prospective cohort study, 186 neonates with HIE were transported between January 2013 and December 2021. Among the 186 neonates, 47 were passively cooled, 36 actively cooled with gel packs, and 103 cooled with a servo-controlled cooling device. The clinical characteristics were comparable for the three groups, with no difference in adverse events. Fifteen neonates (8%) died and 54 neonates (29%) suffered radiologically determined brain injury. Servo-controlled cooling was found to be superior to other methods in maintaining a target temperature without significant fluctuation during transport and with temperature in the target range on arrival at tertiary care facilities. The rate of overcooling was also lower in the servo-controlled group compared with other groups. There were no statistically significant differences between the groups in relation to mortality and brain MRI changes associated with HIE. Adjusting for GA, 10-minute Apgar score, base excess, HIE stage, and need for intubation during transport, passive cooling increased the odds of temperature fluctuation outside the range by 12-fold and gel pack cooling by 13-fold compared with servo-controlled cooling. The use of servo-controlled TH devices should be the preferred practice wherever feasible. (REB17-1334_REN3).

Neonatal Transport Safety Metrics and Adverse Event Reporting: A Systematic Review

OBJECTIVE

Neonatal transports are an essential component of regionalized medical systems. Neonates who are unstable after birth require transport to a higher level of care by neonatal transport teams. Data on adverse events on neonatal transports are limited. The aim of this study was to identify, evaluate, and summarize the findings of all relevant studies on adverse events on neonatal transports.

METHODS

We identified 38 studies reporting adverse events on neonatal transports from January 1, 2000, to December 31, 2019. The adverse events were distributed into 5 categories: vital sign abnormalities, laboratory value abnormalities, equipment challenges, system challenges, cardiopulmonary resuscitation, and transport-related mortality.

RESULTS

Most of the evidence surrounds vital sign abnormalities during transport (n = 28 studies), with hypothermia as the most frequently reported abnormal vital sign. Fourteen studies addressed laboratory abnormalities, 12 reported on events related to equipment issues, and 4 reported on system issues that lead to adverse events on transport. Of the 38 included studies, 12 included mortality related to transport as an outcome, and 4 reported on cardiopulmonary resuscitation during transport. There were significant variations in samples, definitions of adverse events, and research quality.

CONCLUSION

Adverse events during neonatal transport have been illuminated in various ways, with vital sign abnormalities most commonly explored in the literature. However, considerable variation in studies limits a clear understanding of the relative frequencies of each type of adverse event. The transport safety field would benefit from more efforts to standardize adverse event definitions, collect safety data prospectively, and pool data across larger care systems.

Cooling strategies during neonatal transport for hypoxic-ischaemic encephalopathy

AIM

We reviewed the literature on cooling methods during transport of newborn infants with hypoxic-ischaemic encephalopathy (HIE) born in a non-tertiary centre and transferred to a neonatal intensive care unit for therapeutic hypothermia.

METHODS

The electronic databases CENTRAL, MEDLINE, Embase, CINAHL, and Scopus were searched from inception up to 8 March 2022 for studies comparing cooling versus no cooling, active versus passive cooling, and servo-controlled versus non-servo-controlled cooling. Odds ratio and confidence of interval were calculated for dichotomous outcomes and mean difference and confidence interval for continuous outcomes.

RESULTS

The final analysis included 14 studies, 1 randomised and 13 non-randomised, involving 1098 newborn infants. Compared with the other cooling methods, servo-controlled active cooling was more likely to maintain body temperature within the target range of 33°C-34°C on arrival at a neonatal intensive care unit: odds ratio 13.58, 95% confidence interval 4.32-42.66, risk difference 0.33, 95% confidence interval 0.19-0.46; 224 participants; three studies; I² 0%. The certainty of evidence was low. Only five studies reported mortality rates.

CONCLUSION

Servo-controlled active cooling may be the preferred method during transport of newborn infants with HIE. A future area of focus should be long-term neurodevelopmental outcomes after servo-controlled active cooling.

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.

LXA4 protects against hypoxic-ischemic damage in neonatal rats by reducing the inflammatory response via the IκB/NF-κB pathway

Hypoxia and the resultant decreases in cerebral blood flow in the perinatal period can lead to neonatal hypoxic-ischemic (HI) brain injury, which can, in turn, cause severe disability or even death. However, the efficacy of current treatment strategies remains limited. Several studies have demonstrated that lipoxin A4 (LXA4), as one of the earliest types of endogenous lipid mediators, can inhibit the accumulation of neutrophils, arrest inflammation, and promote the resolution of inflammation. However, research on LXA4 in the nervous system has rarely been carried out. In the present study, we sought to investigate the protective effect of LXA4 on HI brain damage in neonatal rats, as well as the underlying mechanisms. Through experiments conducted using an HI animal model, we found that the LXA4 intervention promoted the recovery of neuronal function and tissue structure following brain injury while maintaining the integrity of the blood-brain barrier in addition to reducing cerebral edema, infarct volume, and inflammatory responses. Our results suggest that LXA4 interfered with neuronal oxygen-glucose deprivation insults, reduced the expression of inflammatory factors, inhibited apoptosis, and promoted neuronal survival in vitro. Finally, the LXA4 intervention attenuated HI-induced activation of inhibitor kappa B (IκB) and degradation of nuclear factor-κB (NF-κB). In conclusion, our data suggest that LXA4 exerts a neuroprotective effect against neonatal HI brain damage through the IκB/NF-κB pathway. Our findings will help inform future studies regarding the effects of LXA4 on neuroinflammation, blood-brain barrier integrity, and neuronal apoptosis.

Meta-analysis comparing temperature on arrival at the referral hospital of newborns with hypoxic ischemic encephalopathy cooled with a servo-controlled device versus no device during transport

BACKGROUND

Therapeutic hypothermia reduces mortality and neurological injury for neonates with hypoxic ischemic encephalopathy (HIE). The aim of this meta-analysis is to evaluate use of servo-controlled devices during transport to the referral hospital.

METHODS

PubMed and Medline (Ovid) searches were used to identify studies comparing HIE patients' temperatures on arrival at the referral hospital for those cooled with servo-controlled devices versus no device during transport. Random effects models were used to conduct a meta-analysis comparing the two groups' proportion of patients arriving in the target temperature range as well as the mean and variability in body temperature on arrival. Studies' level of evidence and risk of bias were also assessed.

RESULTS

Eight published studies with total of 573 patients met the inclusion criteria, with a "B" grade of recommendation overall. A significantly higher proportion of infants cooled with a servo-controlled device arrived in the target temperature range (pooled relative risk = 2.47, 95% confidence interval: 1.46-4.17, p < 0.001). The arrival temperature in the device cooled group was on average 0.82°C lower (95% CI: 0.29-1.35°C, p = 0.002) with an 82% lower temperature variance.

CONCLUSIONS

Although the predominance of observational studies and presence of some risks of bias somewhat limits the strength of recommendation, the existing research consistently indicates that using a servo-controlled device during transport of neonates with HIE increases the probability of arriving at the referral hospital in the target temperature range, with a lower body temperature and less variability. Future research is needed to investigate differences in mortality and neurological impairment.

Whole-body vibration in neonatal transport: a review of current knowledge and future research challenges

Interfacility transport to tertiary care for high-risk neonates has become an integral part of equitable access to optimal perinatal healthcare. Excellence in clinical care requires expertise in transport medicine and the coordination of safe transport processes. However, concerns remain regarding environmental stressors involved in the transportation of sick high-risk neonates, including noise and vibration. In order to mitigate the potential deleterious effects of these physical stressors during transport, further knowledge of the burden of exposure, injury mechanisms and engineering interventions/modifications as adjuncts during transport would be beneficial. We reviewed the current literature with a focus on the contribution of new and emerging technologies in the transport environment with particular reference to whole-body vibration. This review intends to highlight what is known about vibration as a physical stressor in neonates and areas for further research; with the goal to making recommendations for minimizing these stressors during transport.

Neonatal Transport: Current Trends and Practices

Since the inception of organized neonatal transport in the 1940s, advances in clinical care and technology have made the neonatal intensive care unit even more mobile in terms of care delivery. There currently exists an emphasis on quality metrics and simulation-based training for transport team members to achieve high levels of individual and team competence. Emerging therapies such as active cooling for neuroprotective hypothermia and high-frequency ventilation provide evidence-based care in the transport environment to enhance clinical outcomes. Accreditation of neonatal transport programs is now embraced as an indicator of competency and compliance with transport standards.

Cerebral oxygen metabolism during and after therapeutic hypothermia in neonatal hypoxic-ischemic encephalopathy: a feasibility study using magnetic resonance imaging

BACKGROUND

Therapeutic hypothermia is the standard-of-care treatment for infants diagnosed with moderate-to-severe hypoxic-ischemic encephalopathy (HIE). MRI for assessing brain injury is usually performed after hypothermia because of logistical challenges in bringing acutely sick infants receiving hypothermia from the neonatal intensive care unit (NICU) to the MRI suite. Perhaps examining and comparing early cerebral oxygen metabolism disturbances to those after rewarming will lead to a better understanding of the mechanisms of brain injury in HIE and the effects of therapeutic hypothermia.

OBJECTIVE

The objectives were to assess the feasibility of performing a novel T2-relaxation under spin tagging (TRUST) MRI technique to measure venous oxygen saturation very early in the time course of treatment, 18-24 h after the initiation of therapeutic hypothermia, to provide a framework to measure neonatal cerebral oxygen metabolism noninvasively, and to compare parameters between early and post-hypothermia MRIs.

MATERIALS AND METHODS

Early (18-24 h after initiating hypothermia) MRIs were performed during hypothermia treatment in nine infants with HIE (six with moderate and three with severe HIE). Six infants subsequently had an MRI after hypothermia. Mean values of cerebral blood flow, oxygen extraction fraction, and cerebral metabolic rate of oxygen from MRIs during hypothermia were compared between infants with moderate and severe HIE; and in those with moderate HIE, we compared cerebral oxygen metabolism parameters between MRIs performed during and after hypothermia.

RESULTS

During the initial hypothermia MRI at 23.5±5.2 h after birth, infants with severe HIE had lower oxygen extraction fraction (P=0.04) and cerebral metabolic rate of oxygen (P=0.03) and a trend toward lower cerebral blood flow (P=0.33) compared to infants with moderate HIE. In infants with moderate HIE, cerebral blood flow decreased and oxygen extraction fraction increased between MRIs during and after hypothermia (although not significantly); cerebral metabolic rate of oxygen (P=0.93) was not different.

CONCLUSION

Early MRIs were technically feasible while maintaining hypothermic goal temperatures in infants with HIE. Cerebral oxygen metabolism early during hypothermia is more disturbed in severe HIE. In infants with moderate HIE, cerebral blood flow decreased and oxygen extraction fraction increased between early and post-hypothermia scans. A comparison of cerebral oxygen metabolism parameters between early and post-hypothermia MRIs might improve our understanding of the evolution of HIE and the benefits of hypothermia. This approach could guide the use of adjunctive neuroprotective strategies in affected infants.

Impact of Education on Hypothermia Delivery during Neonatal Transport

BACKGROUND

Moderate therapeutic hypothermia (TH) initiated within 6 h of life reduces adverse neurodevelopmental outcomes in infants after perinatal hypoxic ischaemic insult. For infants born in non-tertiary centres, TH may be initiated manually en route to a neonatal intensive care unit (NICU). However, both over- and undercooling is reported with this strategy, precluding some infants from the benefits of TH.

OBJECTIVES

To evaluate the impact of a region-wide educational programme on the safety and efficacy of manual cooling administered by the Wellington Neonatal Transport Service (NeTS).

METHODS

Clinical records of infants with hypoxic ischaemic encephalopathy (HIE) retrieved by the Wellington NeTS for TH between January 2012 and June 2017 were reviewed retrospectively. Temperature outcomes of infants retrieved before and after the education programme were compared.

RESULTS

A total of 101 infants were cooled manually by Wellington NeTS for TH during the study period. Education and training significantly reduced the rate of overcooling to ≤32.0°C (4/43 [9%] vs. 0/58, p = 0.02). However, there was no difference in the proportion of infants who achieved target rectal temperature within 6 h of life (29/43 [65%] vs. 35/58 [60%], p = 0.57).

CONCLUSIONS

Introduction of a region-wide educational programme may have improved the safety of manual cooling during neonatal transport but it had a negligible impact on its efficacy. The use of servo-controlled cooling during transport should therefore be considered to improve access to the optimal neuroprotective benefits of TH for outborn infants with HIE.

Turkish Neonatal Society guideline on the safe transport of newborn

The rational presentation form of perinatal care in developed countries is evaluated within the regionalization program. Neonatal transport is the main step for the regionalization of perinatal care. It is a very important factor for reducing neonatal mortality and morbidity, especially in developing countries. Neonatal transport is a system integrity that includes more than one essential matter. Neonatal transport requires special hardware and serious organization because it can be a caused of mortality and morbidity in its own right. This guideline deals with the transport of newborn infants (definitions, personnel, technical equipment, stabilization conditions, special medical conditions, communication), and the current situation in our country and standard approaches. It should not be forgotten that changes in public space will also change the approach and that every baby should be evaluated within himself or special conditions.

Therapeutic Hypothermia: How Can We Optimize This Therapy to Further Improve Outcomes?

Neonatal hypoxic-ischemic encephalopathy remains associated with considerable death and disability. In multiple randomized controlled trials, therapeutic hypothermia for neonatal moderate or severe hypoxic-ischemic encephalopathy among term infants has been shown to be safe and effective in reducing death and disability in survivors. In this article, the current status of infant and childhood outcomes following this therapy is reviewed. The clinical approaches that may help to optimize this innovative neuroprotective therapy are presented.