Presented at the Neonatal Society 2010 Spring Meeting.
O’Reilly K, Winterbottom S, Tooley J
Neonatal Unit, St Michael’s Hospital, Southwell St, Bristol, BS2 8EG, UK
Background: Therapeutic hypothermia as a treatment for hypoxic ischaemic encephalopathy after perinatal asphyxia has been the standard of care for all infants born within our neonatal network since April 2008. Our 24 hour neonatal transport team takes referrals from the six level 1 / 2 units within our network and offers initial advice on management before retrieving all the infants to one of the two level 3 centres. It is recommended that therapeutic hypothermia should commence as soon as the criteria for cooling is recognised. Cooling is therefore initiated in the referring units and continued during the retrieval process. Over the last 18 months we have used various methods of achieving therapeutic hypothermia during retrievals. Initially passive hypothermia only, followed by active cooling using adjuncts and subsequently active cooling using cooling machines already used in clinical practice (Tecotherm (Inspiration healthcare),Criticool (Kontron)). The aim of this study was to evaluate the effectiveness of different cooling methods during transport.
Methods: Transport data for all infants centralised for therapeutic hypothermia was retrospectively reviewed over an 18 month period. The method of cooling during transfer was noted in addition to rectal temperature prior to, during and on completion of transfer.
Results: 10 babies were transferred after turning off all active forms of warming (passive cooling). 17 babies were transferred using active cooling with adjuncts e.g. gloves filled with tap water .19 were transferred with a commercially available cooling machine safely secured and plugged into the ambulance 240V electricity supply.
Conclusion: Therapeutic hypothermia can only be reliably achieved during transport using a purpose built machine that allows changes in temperature (both up and down) as necessary. The use of passive cooling methods or adjuncts such as gloves filled with cold water frequently do not achieve the therapeutic target temperature required resulting in inadequate neuroprotection. They also lead to potentially dangerous low temperatures. We recommend that cooling during transport should only be undertaken using a purpose built cooling machine.
References
Anderson ME, Longhofer TA, Philips W, McRay DE. Passive cooling to initiate hypothermia for transported encephalopathic newborns. Journal of Perinatology (2007) 27, 592-593
Hallberg B, Olson L, Bartocci M, Edqvist I, Blennow M. Passive induction of hypothermia during transport of asphyxiated infants: a risk of excessive cooling. Acta Paediatrica 2009;98(6):942-6