The following is a summary of “Predictors of cardiac arrest in severe accidental hypothermia,” published in the April 2024 issue of Emergency Medicine by Podsiadło, et al.

For a study, researchers sought to identify predictors of witnessed hypothermic cardiac arrest (HCA) in patients with severe accidental hypothermia.

A retrospective analysis was conducted on 182 patients presenting with severe accidental hypothermia (core body temperature ≤28 °C) and preserved spontaneous circulation at initial contact with medical services. Patients were divided into two groups: those who experienced HCA between medical encounter and restoration of normothermia and those who did not. Hemodynamic and biochemical parameters were analyzed for their association with HCA.

Among the patients, 52 (29%) experienced HCA. Univariable analysis revealed significant associations between HCA and heart rate (P < 0.001), systolic blood pressure (P = 0.03), ventricular arrhythmia (P = 0.001), and arterial oxygen partial pressure (PaO₂) (P = 0.002). The multivariable logistic regression identified heart rate, PaO₂, and Base Excess (BE) as predictors of HCA (AUROC = 0.78). An alternative model, applicable in prehospital settings without blood gas analysis, included heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74). Threshold values of heart rate (43/min), temperature-corrected PaO₂ (72 mmHg), and uncorrected PaO₂ (109 mmHg) showed satisfactory sensitivity and specificity for predicting HCA.

Lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure were associated with HCA in patients with severe accidental hypothermia. These parameters could aid in the early identification of high-risk patients and their allocation to extracorporeal rewarming facilities.

Reference: sciencedirect.com/science/article/abs/pii/S0735675724000329