Significance of temperature in antimuscarinic toxicity: a case-control study

Introduction Antimuscarinic toxicity can result in temperature dysregulation, but the clinical significance of this is unclear. The objective of this study was to compare peak temperatures between antimuscarinic patients with and without severe clinical outcomes. Methods This was a case-control analysis at two large, urban, academic medical centers from January 1, 2016, through December 31, 2021. We compared peak temperature (T-max) amongst antimuscarinic patients who experienced severe outcomes with those who did not. Severe outcome was defined as seizure, ventricular dysrhythmia, hypotension, or intubation. Results Fifty-six patients met inclusion criteria of which 23 developed severe outcomes: 16 seizures, 9 cases with hypotension, 5 intubations, and 2 ventricular dysrhythmias. Tmax amongst all patients ranged from 36.4-39.2 degrees C. There were no fatalities. There was no difference in Tmax in the emergency department or throughout hospitalization between groups, and Tmax was not predictive for the development of severe outcomes. Discussion Maximum temperatures did not differ between patients with and without severe outcomes in the setting of antimuscarinic toxicity, and temperature was poorly predictive of outcomes. Our findings suggest that mild temperature dysregulation in antimuscarinic toxicity is not a key prognostic indicator for severe outcome. Further study is needed to assess implication of severe hyperthermia.