The RCT and meta-analytic evidence supporting hypothermia for comatose survivors of resuscitation from ventricular fibrillation cardiac arrest is characterized by some writers as “compelling”. Others (SBU, 2006; CEDIT, 2004; ANZHSN, 2005; all in Table 1) are more circumspect, citing heterogeneity among trials, relatively small numbers, technical or organizational impediments to wide implementation, and the need for continuing research.
While agreeing on the relatively small body of eligible research and need for more studies to close knowledge gaps, the most recent high-quality review [Arrich (Cochrane; 2009) in Appendix Table 1] finds available evidence consistent for positive effects of hypothermia on survival and neurologic outcome. In this context, we note the addition of hypothermia to complex interventions for improvement of resuscitation protocols (Appendix Table 4) and the corresponding difficulties of isolating its effects from those of other interventions.
Of particular note, studies covered here provide evidence that simple “low-tech” methods (cold IV fluids, blankets, ice packs) for inducing hypothermia are effective: Arrich (2009) pooled comparable studies using standard cooling, and the single inadequate-quality trial comparing outcomes with simple methods directly to one device (Heard, 2010; Appendix Table 2.) found no significant differences.