Temperature management following cardiac arrest: introducing a protocol improves compliance with targets

Abstract

Introduction We audited the achievement of therapeutic hypothermia (TH) before and after the introduction of a cooling protocol. Instituting TH is recommended following the return of spontaneous circulation (ROSC) for many patients who survive a cardiac arrest [1,2]. The key intervention may be the avoidance of hyperthermia rather than cooling [3]. Methods We conducted a chart review of all patients admitted to the Department of Critical Care (DCC) at our hospital following cardiac arrest over 2 years in 2010 to 2012 (Group 1). We recorded compliance with key recommendations produced by the Royal College of Anaesthetists [4] although we defined post-ROSC hyperthermia as >37.2degreeC rather than >38degreeC. A TH protocol was designed and personnel in the emergency department and DCC educated as to its use. Recommended practice was the infusion of cold i.v. normal saline (1 to 2 l) followed by the use of an intravascular cooling device (Alsius CoolGardTM). Data collection was then undertaken after introduction of the protocol for all patients admitted to the DCC following cardiac arrest in November 2012 to 2013 (Group 2). Results Forty-three patients were admitted in Group 1, 28 in Group 2. Of these, 42% in both groups were following out-of-hospital (OOH) VF arrests. Cooling was attempted in 88% and 82% of OOH VF patients respectively. For patients with either in-hospital or non-VF/ VT cardiac arrests, the numbers cooled were 16% and 12.5%. Cooling initiation within 1 hour increased from 27 to 50%. Achievement of a target temperature of 32 to 34degreeC within 4 hours of ROSC was 55% and 50% respectively. Target maintenance for 12 to 24 hours after ROSC increased 79% to 100%. Avoidance of hypothermia <31degreeC for 48 hours after ROSC improved 95% to 100%. Slow rewarming at 0.25 to 0.5degreeC/ hour to 37degreeC was achieved in 76% and 90%. Avoidance of temperature >37.2degreeC for 48 hours after ROSC increased 84 to 100%. Of the patients cooled, survival with good neurological outcome was achieved in 52% in Group 1 and 88% in Group 2. Conclusion The institution of a temperature management protocol improved compliance with recommended goals, both in achieving hypothermia and in the avoidance of hyperthermia.