Prehospital therapeutic hypothermia after out-of-hospital cardiac arrest: a systematic review and meta-analysis

BackgroundThe effectiveness and safety of the infusion of ice-cold fluids for prehospital hypothermia in cardiac arrest victims are unclear. This study assessed its effects in adult victims of out-of-hospital cardiac arrest.MethodsAn online search of PubMed and Cochrane Library databases was performed. Cooling methods were limited to ice-cold fluid perfusion. Randomized controlled trials were included in this review. The main outcomes were body temperature at hospital arrival, survival to hospital discharge, neurological recovery, incidence of pulmonary edema, and the rate of rearrest.ResultsAmong 1155 citations, 5 studies were included in this meta-analysis. The pooled analysis of these studies revealed no differences in survival to hospital discharge, favorable neurological outcomes, and incidence of pulmonary edema between the treatment group and control group. There were significant differences in body temperature at hospital arrival (I2 = 0.0%, χ2 = 2.58, MD = −0.760, 95% confidence interval = −0.938 to −0.581, P < .001) and the rate of rearrest (I2 = 0.0%, χ2 = 0.69, 95% confidence interval = 1.109 to 1.479, P = .031).ConclusionsPrehospital therapeutic hypothermia induced by intravenous infusion of ice-cold fluids in patients with out-of-hospital cardiac arrest decreased body temperature at hospital arrival but did not improve survival to hospital discharge and favorable neurological outcomes. Ice-cold fluid infusion did not increase the incidence of pulmonary edema but increased the incidence of rearrests.