Earlier Initiation of Therapeutic Hypothermia by Non-Tertiary Neonatal Units in Victoria, Australia

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.

Body temperature, heart rate and long-term outcome of cooled infants: an observational study

BACKGROUND

Therapeutic hypothermia is a standard of care for neonatal encephalopathy; however, approximately one in two newborn infants fails to respond to this treatment. Recent studies have suggested potential relationships between body temperature, heart rate and the outcome of cooled infants.

METHODS

The clinical data of 756 infants registered to the Baby Cooling Registry of Japan between January 2012 and December 2016 were analysed to assess the relationship between body temperature, heart rate and adverse outcomes (death or severe impairment at 18 months corrected age).

RESULTS

A lower body temperature at admission was associated with adverse outcomes in the univariate analysis (P < 0.001), the significance of which was lost when adjusted for the severity of encephalopathy and other covariates. A higher body temperature during cooling and higher heart rate before and during cooling were associated with adverse outcomes in both univariate (all P < 0.001) and multivariate (P = 0.012, P < 0.001 and P < 0.001, respectively) analyses.

CONCLUSIONS

Severe hypoxia-ischaemia might be a common causative of faster heart rates before and during cooling and low body temperature before cooling, whereas causal relationships between slightly higher temperatures during cooling and adverse outcomes need to be elucidated in future studies.

IMPACT

In a large cohort of encephalopathic newborn infants, dual roles of body temperature to the outcome were shown; adverse outcomes were associated with a lower body temperature at admission and higher body temperature during cooling. A higher heart rate before and during cooling were associated with adverse outcomes. Severe hypoxia-ischaemia might be a common causative of faster heart rates before and during cooling and low body temperature before cooling. The exact mechanism underlying the relationship between slightly higher body temperature during cooling and adverse outcomes remains unknown, which needs to be elucidated in future studies.

Telemedicine Consultation to Assess Neonatal Encephalopathy in Rural Community Hospitals and Tertiary Care Centers

INTRODUCTION

Teleconsultation is used in tertiary care hospitals to evaluate neonatal encephalopathy. Neonates born in community hospitals, however, often experience delayed evaluation due to transport to the tertiary care center. We studied teleconsultations in community hospitals to decrease this disparity.

METHODS

Prospective observational study in 9 community hospitals and 1 neonatal intensive care unit. Inclusion criteria: gestational age greater than or equal to 35 weeks and one of the following: umbilical cord pH less than or equal to 7.2, 5-minute Apgar less than 7, prolonged respiratory support, perinatal event, or abnormal neurological exam. We performed synchronized, unscheduled telemedicine consults with the main outcome of time to teleconsultation.

RESULTS

From April 2018 to September 2020, we performed 53 teleconsultations: 34 (64%) in community hospitals and 19 (36%) in the tertiary care center. Teleconsultations occurred at a median of 98 minutes (IQR, 76-127) in community hospitals versus 68 minutes (IQR, 43-91) in the tertiary care center (p = .004). Nine (26%) neonates born in a community hospital remained with their parents and were not transferred to the tertiary care center for further assessment.

DISCUSSION

Neonates born in rural community hospitals have slightly later teleconsultations than neonates born in the tertiary care center. Telemedicine use reduced this disparity from nearly 5 hours in our prior study to 98 minutes in this study by permitting evaluation of neonates in community hospitals without transporting them to the tertiary care center.

CONCLUSIONS

Teleconsultations to evaluate neonatal encephalopathy are a feasible, accessible, and reliable way to bring expert-level care into rural community hospitals.

Association of outborn versus inborn birth status on the in-hospital outcomes of neonates treated with therapeutic hypothermia: A propensity score-weighted cohort study

OBJECTIVE

To compare the risk of in-hospital mortality and morbidity between outborn and inborn neonates treated with whole body hypothermia.

METHODS

The association of outborn birth status with in-hospital mortality and morbidity, prior to NICU discharge or transfer, was assessed in a large historical cohort of neonates who had therapeutic hypothermia initiated on the day of birth. The cohort was restricted to neonates born at ≥35 weeks gestational age from 2007 to 2018. Since the sample was non-random, inverse probability weighting (IPW) derived from propensity scores was used to reduce imbalance in baseline maternal and neonatal characteristics between outborn and inborn neonates. Cox proportional hazards regression was used to assess the association between outborn status and in-hospital mortality.

RESULTS

There were 4447 neonates included in the study (2463 outborn). Outborn status was not significantly associated with an increased risk of in-hospital mortality in the unadjusted cohort (HR = 1.17, 95% CI 0.97-1.42, p = 0.10) or IPW cohort (HR = 1.09, 95% CI 0.95-1.26, p = 0.22). However, in the IPW cohort, outborn neonates were significantly more likely to have seizures (28% vs 24%, p = 0.006), anticonvulsant exposure (46% vs 41%, p = 0.002), and gastrostomy tube placement (5.8% vs 3.8%, p = 0.009) during their newborn hospitalization.

CONCLUSION

Outborn status was not significantly associated with increased in-hospital mortality among neonates treated with whole body hypothermia. However, outborn neonates were more likely to have seizures, receive anticonvulsant treatment, and undergo gastrostomy tube placement. Further study is needed to better understand the etiologies of these outcome disparities and potential implications for long-term neurodevelopmental outcomes.

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.