Effect of Propranolol on Hyperthermia Secondary to Paroxysmal Sympathetic Hyperactivity in Critically Ill Patients...

Patients with traumatic brain injury (TBI) may develop paroxysmal sympathetic hyperactivity (PSH), a syndrome manifesting as cyclic increases in vital signs and motor activity. Previous studies show propranolol mitigating sympathetic symptoms and negative outcomes, but few reports assess its effect on body temperature.

The purpose of this study was to determine if propranolol attenuates hyperthermia secondary to PSH in patients with TBI.

This study evaluated febrile patients with TBI treated with propranolol. The primary outcome was the difference in maximum (Tmax), minimum (Tmin), and average (Tavg) daily temperatures and temperature variability (Tvar). Secondary outcomes included similar evaluation of heart rate (HR) and mean arterial pressure (MAP), differences in a modified clinical features scale (mCFS), and number of infectious work-ups before and after propranolol initiation. Data were collected one day before, the day of, and 3 days after propranolol initiation. Repeated measures analysis of variance (ANOVA) was used to evaluate vital sign differences among days of therapy. Post-hoc Tukey's tests were performed to identify between-day differences if they existed.

Fifty-nine patients were included. The majority were male (76.3%) and had a severe TBI (78.0%). Tmax, Tmin, Tavg, and Tvar were all not different between Day -1 and Day 3. Tmax decreased from 38.6 ± 0.11°C on Day 0 (the day of propranolol initiation) to 38.3 ± 0.14°C on Day 3 (P = 0.22). Maximum and average HRs were significantly decreased after propranolol initiation on Day 3 (P < 0.001) and on Days 2 (P = 0.04) and 3 (P = 0.01), respectively. Changes in MAP were not statistically significant. The mCFS and number of infectious work-ups were significantly lower after propranolol initiation.

Temperature was not significantly decreased after propranolol initiation in patients with TBI and hyperthermia; however, HR and mCFS were significantly lower. Larger studies are needed to characterize the effect of propranolol on temperature in patients with PSH.