Abstract
BACKGROUND: Pediatric patients undergoing cardiovascular interventions outside the operating room are at high risk of perioperative hypothermia. We aimed to compare the effects of upper body and full underbody forced-air warming blankets on the time-weighted deviation of esophageal temperature outside the target range (36.5-37.5 °C) during general anesthesia. METHODS: In this randomized controlled study, 88 children (age < 15 years) scheduled for elective cardiovascular interventions under general anesthesia were randomly assigned to the upper body (n = 44) or full underbody (n = 44) group. After the induction of anesthesia, warming blankets were applied and heated using a forced-air warmer to maintain an esophageal temperature of 36.5-37.5 °C. The primary outcome was the time-weighted average deviation of esophageal temperature outside the desired range, defined as the total deviation in temperature divided by the duration spent outside the target range. Secondary outcomes included use of additional warming or cooling methods, temperature trends, thermal comfort, and adverse events. Statistical comparisons were performed using t-tests or chi-square tests, with p < 0.05 considered significant. RESULTS: The time-weighted averages of periods out of the desired temperature range were comparable between the two groups (upper body vs. full underbody, 0.213 ± 0.212 °C vs. 0.265 ± 0.277 °C; mean difference, 0.053; 95% confidence interval [CI], - 0.052 to 0.157; p = 0.318). The incidence of hyperthermia (> 37.5 °C) was 9.09% (upper body) and 0% (full underbody, p = 0.125). The duration of hypothermia (< 36.5 °C) was 58.82 ± 48.83 min (upper body) and 70.03 ± 53.20 min (full underbody; mean difference, 11.20 min; 95% CI, - 10.44 to 32.85; p = 0.318). The incidence rates of adverse events were 4.55% (upper body) and 15.91% (full underbody, p = 0.159). CONCLUSIONS: Both warming methods showed comparable time-weighted averages of temperatures outside the desired range, suggesting similar effectiveness. However, careful monitoring is essential to mitigate the risks of hyperthermia and skin-related complications and ensure patient safety during pediatric cardiovascular interventions. TRIAL REGISTRATION NUMBER: NCT05349734 (registered at clinicaltrials, principal investigator: Hee-Soo Kim, registration date: April 26,2022).