Therapeutic hypothermia in mild neonatal encephalopathy: a national survey of practice in the UK

Abstract

Although major cooling trials (and subsequent guidelines) excluded babies with mild encephalopathy, anecdotal evidence suggests that cooling is often offered to these infants. We report a national survey on current cooling practices for babies with mild encephalopathy in the UK. From 74 neonatal units contacted, 68 were cooling centres. We received 54 responses (79%) and included 48 (five excluded due to incomplete data and one found later not to offer cooling). Of these, 36 centres (75%) offered cooling to infants with mild encephalopathy. Although most of the participating units reported targeting 33–34°C core temperature, seven (19%) considered initiating cooling beyond 6 hours of age and 13 (36%) discontinued cooling prior to 72 hours. Babies were ventilated for cooling in two (6%) units and 13 (36%) sedated all cooled babies. Enteral feeding was withheld in 15 (42%) units and reduced below 25% of requirements in eight (22%) units. MRI and neurodevelopmental outcome evaluation were offered to all cooled babies in 29 (80%) and 27 (75%) units, respectively. Further research is necessary to ensure optimal neuroprotection in mild encephalopathy.

Predictive value of early EEG for seizures in neonates with hypoxic–ischemic encephalopathy undergoing therapeutic hypothermia

“…This changing attitude has been explained by many arguments, including reports of adverse neurodevelopmental outcome in neonates with mild HIE, 33,34 difficulty in grading neonatal encephalopathy soon after birth, and concern about missing the 6-h window for initiating cooling. 28 Since the clinical evolution of the encephalopathy can be rapid, it is possible that in our cohort some neonates who were cooled had only a mild encephalopathy.…”

“…This proportion of neonates with normal or mildly abnormal EEG is higher than previously reported in neonates treated with TH. 5,27 Possible explanations include a drift toward cooling neonates with milder encephalopathy as described in other cohorts, 28,29 earlier recognition of encephalopathy, and faster implementation of cooling leading to the possibility that, by the time EEG is started, the brain activity has already improved in some neonates. Furthermore, our definition of excessively discontinuous background encompasses a wide range of interburst intervals (up to 15 s).…”

“…Lately, many centers have started offering TH to neonates with mild encephalopathy, 28,29 despite lack of data in support of this practice. This changing attitude has been explained by many arguments, including reports of adverse neurodevelopmental outcome in neonates with mild HIE, 33,34 difficulty in grading neonatal encephalopathy soon after birth, and concern about missing the 6-h window for initiating cooling.…”

Prognostic Accuracy of Heart Rate Variability Analysis in Neonatal Encephalopathy: A Systematic Review

“…This approach has been common practice in many studies to date (because babies with mild NE were thought to be “intact survivors”), but emerging evidence suggests that babies who suffer mild NE may not have intact neurodevelopment but instead present with more subtle delays later into childhood [25, 26]. This systematic review, along with our recent survey highlighting clinician uncertainty about treatment choices in babies with mild encephalopathy [27], raises the importance of developing an accurate and early bedside tool to identify babies at risk of adverse neurodevelopment. In fact, it underlines the point that severity stratification tools in NE must shift from the traditional dichotomous approach to one that more accurately represents the full spectrum of NE.…”

Evidence that therapeutic hypothermia should be continued for 72 hours

“…Similarly, a recent national survey in the UK on current cooling practices for babies with mild HIE showed that 75% of centres offered cooling to infants with mild encephalopathy,3 and 36% discontinued cooling before 72 hours. It is possible that the optimal duration of hypothermia might be less for infants with mild HIE, but this simply cannot and should not be assumed until formal randomised trials have been undertaken.…”