Core temperature after birth in babies with neonatal encephalopathy in a sub‐Saharan African hospital setting

Abstract

Key points Therapeutic hypothermia (HT) to 33.0–34.0°C for 72 h provides optimal therapy for infants with neonatal encephalopathy (NE) in high‐resource settings. HT is not universally implemented in low‐ and middle‐income countries as a result of both limited resources and evidence. Facilitated passive cooling, comprising infants being allowed to passively lower their body temperature in the days after birth, is an emerging practice in some West African neonatal units. In this observational study, we demonstrate that infants undergoing facilitated passive cooling in a neonatal unit in Accra, Ghana, achieve temperatures within the HT target range ∼20% of the 72 h. Depth of HT fluctuates and can be excessive, as well as not maintained, especially after 24 h. Sustained and deeper passive cooling was evident for severe NE and for those that died. It is important to prevent excessive cooling, to understand that severe NE babies cool more and to be aware of facilitated passive cooling with respect to the design of clinical trials in low‐ and mid‐resource settings. Abstract Neonatal encephalopathy (NE) is a significant worldwide problem with the greatest burden in sub‐Saharan Africa. Therapeutic hypothermia (HT), comprising the standard of care for infants with moderate‐to‐severe NE in settings with sophisticated intensive care, is not available to infants in many sub‐Saharan African countries, including Ghana. We prospectively assessed the temperature response in relation to outcome in the 80 h after birth in a cohort of babies with NE undergoing ‘facilitated passive cooling’ at Korle Bu Teaching Hospital, Accra, Ghana. We hypothesized that NE infants demonstrate passive cooling. Thirteen infants (69% male) ≥36 weeks with moderate‐to‐severe NE were enrolled. Ambient mean ± SD temperature was 28.3 ± 0.7°C. Infant core temperature was 34.2 ± 1.2°C over the first 24 h and 35.0 ± 1.0°C over 80 h. Nadir mean temperature occurred at 15 h. Temperatures were within target range for HT with respect to 18 ± 14% of measurements within the first 72 h. Axillary temperature was 0.5 ± 0.2°C below core. Three infants died before discharge. Core temperature over 80 h for surviving infants was 35.3 ± 0.9°C and 33.96 ± 0.7°C for those that died (P = 0.043). Temperature profile negatively correlated with Thompson NE score on day 4 (r2 = 0.66): infants with a Thompson score of 0–6 had higher temperatures than those with a score of 7–15 (P = 0.021) and a score of 16+/deceased (P = 0.007). More severe NE was associated with lower core temperatures. Passive cooling is a physiological response after hypoxia–ischaemia; however, the potential neuroprotective effect of facilitated passive cooling is unknown. An awareness of facilitated passive cooling in babies with NE is important for the design of clinical trials of neuroprotection in low and mid resource settings.

Active cooling temperature required to achieve therapeutic hypothermia correlates with short‐term outcome in neonatal hypoxic‐ischaemic encephalopathy

“…In a low resource setting, Enweronu‐Laryea et al . () observed an inverse correlation between core temperature in neonates with HIE and severity of encephalopathy on day 4. Our findings suggest that, even in the high‐resource setting where core temperature is kept constant, monitoring the device output temperature can be a useful tool for assessing central injury and the physiological status of the infant.…”

“…In neonates with moderate to severe HIE, spontaneous hypothermia occurs, and the more severely affected newborns have lower body temperatures compared to infants with moderate or mild injury (Enweronu‐Laryea et al . ). These observed phenomena suggest potential disruption of the thermoregulatory feedback loop.…”

“…In the absence of thermoregulatory interventions, the core temperature during the first day of life in asphyxiated neonates is significantly lower than in uninjured term newborns (Burnard & Cross, 1958). In neonates with moderate to severe HIE, spontaneous hypothermia occurs, and the more severely affected newborns have lower body temperatures compared to infants with moderate or mild injury (Enweronu-Laryea et al 2019). These observed phenomena suggest potential disruption of the thermoregulatory feedback loop.…”

“…This may partly explain the phenomenon of spontaneous hypothermia after birth asphyxia, which was first described in 1958 (Burnard & Cross, 1958). More recently, the degree of spontaneous hypothermia has been linked to the severity of injury, suggesting disruption of the thermoregulatory circuitry (Enweronu-Laryea et al 2019). The correlation between degree of spontaneous hypothermia and severity of injury and outcome have not yet been described, although it has previously proposed as a potential biomarker for degree of injury in this population (Jayasinghe, 2015).…”

Should hypoxic babies get a little cold at birth?

“…In an article in this issue of The Journal of Physiology , Enweronu‐Laryea et al . () report one of the key limitations: similarly to the historical experience (Silverman & Sinclair, ), a cohort of 14 infants with encephalopathy cared for in a sub‐Saharan African hospital developed poorly controlled spontaneous hypothermia after birth. In this cohort, it is very striking that the mean rectal temperature in the first 24 h, 34.2°C, is just above the target range (33–34°C) for therapeutic hypothermia.…”