A systematic review of safety and adverse effects in the practice of therapeutic hypothermia

Objective

To carry out a systematic review to estimate the rate and magnitude of adverse effects following therapeutic hypothermia (TH) procedure in patients resuscitated from out-of-hospital cardiac arrest (OHCA) and highlight the specific complications seen after the procedure.

Methods

A systematic review of currently published studies was performed following standard guidelines. Online database searches were performed for controlled trials for the last twenty years. Papers were examined for methodological soundness before being included. Data were independently extracted by two blinded reviewers. Studies were also assessed for bias using the Cochrane criteria. The adverse effects attributed to TH in the literature were appraised critically.

Results

The initial data search yielded 78 potentially relevant studies; of these, 59 were excluded for some reason. The main reason for exclusion (n?=?43, 55.8%) was that irrelevance to adverse effects of TH. Finally, 19 underwent full-text review. Studies were of high-to-moderate (n?=?12, 63%) to low-to-very low (n?=?7, 37%) quality. Five studies (27.7%) were found to have high risk of bias, while 8 (42.1%) had low risk of bias.

Interpretation

Although adverse effects related to the practice of TH have been studied extensively, there is substantial heterogeneity between study populations and methodologies. There is a considerable incidence of side effects attributed to the procedure, e.g., from life-threatening ventricular arrhythmias to self-limited consequences. Most studies analyzed in this systematic review indicated that the procedure of TH has not caused severe adverse effects leading to significant alterations in the outcomes following resuscitation from OHCA.PROSPERO, registration number is: CRD42018075026.