Understanding the role of intraoperative hypothermia in perioperative opioid requirements in immediate implant-based breast reconstruction.

Abstract

The relationship between perioperative temperatures and postoperative pain is unknown. The present study investigated the relationship of intraoperative hypothermia and perioperative opioid requirements after immediate implant-based breast reconstruction. A retrospective chart review was conducted on patients undergoing immediate implant-based breast reconstruction from 2019-2023. Patients were classified into the hypothermic group (majority of procedure <36.0 °C) or normothermic group (majority of procedure ≥36.0 °C). Cumulative inpatient opioid requirements (morphine milli-equivalents [MMEs]) and frequency of patients requiring "high-dose opioids" (≥100 MMEs) were collected and compared between the groups. In total, 536 patients (835 breasts) were included, among whom 135 (25.1%) were hypothermic. The hypothermic group had lower mean intraoperative (88.4 vs. 99.1 MMEs, P = 0.007) and postoperative (45.6 vs. 56.8 MMEs, P = 0.006) than the normothermic group. Mean (B = 14.6, P = 0.004) and nadir (B = 10.4, P = 0.038) intraoperative temperatures directly predicted higher opioid requirements while higher percentages of the procedure time spent under 36 °C (B = -27.6, P = 0.004) predicted lower opioid requirements. The hypothermic group was associated with 66% decreased odds of requiring high-dose opioids after adjusting for differences in patient and operative characteristics (P = 0.007). Hypothermia is associated with decreased perioperative opioid requirements. Future studies should further investigate ideal temperature thresholds for warming protocols to minimize postoperative pain.