Factors associated with severity of accidental hypothermia: A cohort retrospective multi-institutional study

Frequently it is difficult to determine illness severity in hypothermic patients. Our goal was to determine if there are factors associated with illness severity of hypothermic emergency department (ED) patients.

Multi-hospital retrospective cohort. Consecutive patients in 24 EDs (1-1-2012 to 4-30-2015). Hypothermic patients (≤35 °C) were identified using ICD codes. We used hospital admission as marker of illness severity. Student's t-test was used for differences between mean age and temperature for admitted and discharged patients. We calculated the percent of patients admitted by factor, the difference from overall admission rate and 95% confidence interval (CI) of difference.

There were 2094 visits with hypothermia ICD code. Of these, 132 patients had initial rectal temperatures ≤35 °C. Females comprised 42%; the mean age was 55 ± 23 years, and overall admission rate was 62%. The percent of patients with alcohol, trauma and found indoors were 39%, 27% and 27%, respectively. For admitted and discharged patients the mean ages were 60 and 48 years, respectively (p = 0.01), and initial mean temperature 32.3 °C vs. 33 °C, respectively (p = 0.07). Found indoors was associated with an 86% admission rate, a 22% increase (95% CI, 3%-34%) compared to overall admission rate. There was no statistically significant difference in admission rates from overall admission rate based on gender, alcohol or trauma.

For hypothermic ED patients increased severity of illness was associated with older age and found indoors but not associated with initial temperature, gender, alcohol or trauma. These findings may assist physicians in treatment and disposition decisions.