Perioperative hypothermia prevention using forced-air warming blankets versus resistive polymer mattresses in geriatric hip fracture surgery

Unplanned perioperative hypothermia is not a minor inconvenience it is a preventable complication that worsens outcomes in frail elderly patients. This randomised controlled trial compared Forced-Air Warming (FAW) blankets with Resistive Polymer (RP) mattresses for maintaining normothermia during hip fracture surgery in 110 patients aged 65 years and older at the Calgary Research Institute of Perioperative Medicine between February 2024 and October 2024. Patients were randomly assigned to FAW (n = 55) or RP (n = 55). Core temperature was measured via oesophageal probe at baseline, 30, 60, 90, and 120 minutes intraoperatively, and at Post-Anesthesia Care Unit (PACU) arrival. The primary outcome was the incidence of perioperative hypothermia, defined as core temperature below 36.0 degrees Celsius at any measurement point. Secondary outcomes included mean core temperature at each time point, shivering incidence, blood loss, transfusion requirements, and thermal comfort scores. Hypothermia occurred in 16.4% of FAW patients versus 38.2% of RP patients (relative risk 0.43, 95% CI 0.23-0.79, p = 0.006). Mean core temperature was significantly higher in the FAW group from 60 minutes onward (p<0.01 at each time point). Shivering in the PACU was observed in 9.1% of FAW patients versus 23.6% of RP patients (p = 0.04). Estimated blood loss and transfusion rates did not differ between groups. These results confirm that forced-air warming blankets provide better hypothermia prevention than resistive polymer mattresses in geriatric hip fracture patients and should be considered the preferred warming method in this high-risk population.