Accidental Hypothermia: Factors Related to a Prolonged Hospital Stay - Nationwide Observational Study in Japan

Background: Accidental hypothermia (AH) has a low frequency, and the length of hospital stay in patients with AH remains poorly understood. The present study explored which factors were related to long-term hospitalization among patients with AH using Japan’s nationwide registry data.Methods: The data from the Hypothermia STUDY 2018, which included patients ≥ 18 years old with a body temperature ≤ 35°C, were obtained from a multicenter registry for AH conducted at 89 institutions throughout Japan, collected from December 1, 2018, to February 28, 2019. The patients were divided into a “short-stay patients” group (within 7 days) and “long-stay patients” group (more than 7 days). A logistic regression analysis after multiple imputation was performed to obtain odds ratios (ORs) for prolonged hospitalization with age, frailty, cause of hypothermia, mechanism underlying hypothermia, temperature, pH, potassium level, and disseminated intravascular coagulation (DIC) score as independent variables.Results: In total, 656 patients were included in the study, of which 362 were eligible for the analysis. The median length of hospital stay was 17 days. Of the 362 patients, 265 (73.2%) stayed in the hospital for more than 7 days. The factors associated with prolonged hospitalization were frailty (OR, 2.11; 95% confidence interval [CI], 1.09-4.10; p = 0.027), the occurrence of indoor (OR, 3.20; 95% CI, 1.58-6.46; p = 0.001), alcohol intoxication (OR, 0.17; 95% CI, 0.05-0.56; p = 0.004), pH (OR, 0.07; 95% CI, 0.01-0.76; p = 0.029), potassium level (OR, 1.36; 95% CI, 1.00-1.85; p = 0.048), and DIC score (OR, 1.54; 95% CI, 1.13-2.10; p = 0.006). Conclusions: Frailty, indoor situation, alcohol intoxication, pH, potassium level, and DIC score were factors contributing to prolonged hospitalization in patients with AH. These factors can be valuable for the early detection of AH requiring a prolonged hospital stay.