Servo‐controlled cooling during neonatal transport for babies with hypoxic‐ischaemic encephalopathy is practical and beneficial: Experience from a large UK neonatal transport service

Abstract

Aim Servo‐controlled therapeutic hypothermia is a routine therapy for babies with hypoxic‐ischaemic encephalopathy in the neonatal unit and is delivered in designated cooling centres. It is increasingly being used during neonatal transport in the UK to deliver this therapy in a timelier manner for babies not born in a cooling centre. Prior to the implementation of this treatment, passive cooling alone was used in transport. Comparison of passive and servo‐controlled cooling during neonatal transfers with reference to: (i) the proportion of babies in the therapeutic range (33–34°C) at three time points during the transport mission (arrival of the team at the referring unit, departure of the team from the referring unit and at the completion of transport); (ii) the proportion of babies overcooled at any point once the transport team was present (<33°C); and (iii) duration of phases of the transfer to evaluate the impact of active cooling on how long it takes to undertake transfer. Methods This was a retrospective observational study comparing babies with passive and servo‐controlled hypothermia (January 2015 to May 2016) following introduction of the servo‐controlled cooling mattress. Results A total of 48 patients were treated with hypothermia in transit (29 passive, 19 servo‐controlled). The median gestational age (GA) was 40 weeks (interquartile range: 39–41) and mean birthweight (BW) 3420 g (standard deviation 600 g); there was no differences in GA, BW and clinical characteristics between the groups. There was a statistically significant difference in the temperature at the end of the transport, where 94% (n = 18) of babies who received servo‐controlled cooling were in the target temperature in comparison with only 65% (n = 19) of the passive cooling group babies (P = 0.045). In addition, none of the babies in the servo‐controlled group were warm (>34°C) at the end of the transfer. Babies who underwent servo‐controlled cooling are more likely to maintain a target temperature (33–34°C) (17 (89%) vs. 17 (58%), P = 0.021); in particular, there is less overcooling (<33°C) in this group (2 (10%) vs. 15 (51%), P = 0.004). Total mission time was not significantly different. Conclusion The use of servo‐controlled cooling devices during neonatal transport improves the ability to maintain the baby's temperature within the target range (33–34°C) with less overcooling.

Therapeutic Hypothermia on Transport: The Quest for Efficiency: Results of a Quality Improvement Project

“…We acknowledge the following limitations: this study is a QI initiative in a single-center institution without formal evaluation of the different modes of cooling during transport, specifically given standardized recommendations and studies that already exist in this domain. [7][8][9][10]12,17,19 Although we collected developmental outcome data on all our TH patients, we did not link cases to developmental outcomes for this study. The earlier neonates eligible for TH have passive cooling safely initiated, the lower the risk of missing an opportunity to reach better outcomes.…”

“…However, the availability of portable servo-controlled cooling devices (SCDs) for transport makes it possible for teams to commence active cooling at the referring unit upon their arrival, decreasing the time to target temperature range with enhanced temperature control management compared to passive cooling. [7][8][9][10][11][12][13] Despite the demonstrated benefits of SCD's when used in transport, 10,12 more recent studies continue to show achieving target temperature within the 6-hour window remains a challenge for TTs with proportions between 55% and 63%. 8 Given both the timing and safe delivery of TH are imperative to optimize patient outcome(s), 13,14 early identification and referral of patients for tertiary-level clinical support are essential, with TH initiation pending the arrival of TTs.…”

Cooling strategies during neonatal transport for hypoxic‐ischaemic encephalopathy

“…studies involving 1098 newborn infants were included. [35][36][37][38][39][40][41][42][43][44][45][46][47][48] The PRISMA flow chart is presented in Figure 1. In the study by Akula et al, therapeutic hypothermia was initiated by the transport team in the one group, while in the other the newborn infant was not cooled during transport.…”

“…One was an RCT 42 (OR 1.54, 95% CI 0.50-4.69), one an NRSI 46 (OR 1.47, 95% CI 0.34-6.38), and the third an NRSI judged at critical risk of bias. 44 Five studies 41,43,44,46,47 reported the proportion of newborn infants with a body temperature between 33.0°C and 34.0°C on admission to a referral centre. Two were judged at critical risk of bias.…”

“…Five studies compared servo-controlled active cooling versus any other cooling method and reported the time to reach target body temperature within the first hours of life. [42][43][44][45]47 One was an RCT 42 (mean difference − 0.32 SD lower (−0.54 lower to −0.10 lower)), one was an NRSI 45 (mean difference − 0.85 SD lower 95% CI (−1.26 lower to −0.44 lower)), and three NRSIs reported the median. 43,44,47 Two studies compared servo-controlled active cooling versus any other cooling and reported the proportion of newborn infants cooled within the first 6 h of life.…”