Predictors of cardiac arrest in severe accidental hypothermia

STUDY OBJECTIVE

To indicate predictors of witnessed hypothermic cardiac arrest.

METHODS

We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome.

RESULTS

Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO2, and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO2 of 72 mmHg, and uncorrected PaO2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction.

CONCLUSIONS

In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities.

[Anaesthesiology in the Polish Armed Forces in the West during World War II]

Until the outbreak of WW II, anaesthesiology, as a separate specialty, did not exist in Poland. After the fall of Poland, a large section of the Polish Armed Forces was evacuated to France and after that, to the UK, where Polish military physicians had a unique opportunity to obtain training in modern anaesthesia. The first regular courses were established at the University of Edinburgh. After WW II, doctor Stanisław Pokrzywnicki, a pioneer of Polish anaesthesiology, who was trained by Sir Robert Macintosh, and doctor Bolesław Rutkowski, an anaesthesiologist in London, returned to Poland and started regular services. This led to the registering of anaesthesiology as a separate specialty in 1951. In the article, the wartime and post-war stories of the first Polish anaesthesiologists are presented.