The Effects of Active Warming on Patient Temperature and Pain After Total Knee Arthroplasty

Background: Total knee arthroplasty (TKA) is a procedure with associated risks of inadvertent perioperative hypothermia and significant postoperative pain. Hypothermia may affect patients' experience of postoperative pain, although the link is not well understood. Objective: The aim of this prospective, randomized controlled trial was to determine the efficacy of a patient-controlled active warming gown in optimizing patients' perioperative body temperature and in diminishing postoperative pain after TKA. Methods: Thirty patients who would be undergoing TKA received either a standard hospital gown and prewarmed standard cotton blanket (n = 15) or a patient-controlled, forced-air warming gown (n = 15). Results: Although pain scores were not significantly different in the two groups (P = 0.08), patients who received warming gowns had higher temperatures (P < 0.001) in the postanesthesia care unit, used less opioid (P = 0.05) after surgery, and reported more satisfaction (P = 0.004) with their thermal comfort than did patients who received standard blankets. These findings indicate that patient-controlled, forced-air warming gowns can enhance perioperative body temperature and improve patient satisfaction. Patients who use warming gowns may also need less opioid to manage their postoperative pain. Conclusions: Nurses should ensure that effective patient warming methods are employed in all patients, particularly in patients with compromised thermoregulatory systems (such as older adults), and in surgeries considered to be exceptionally painful (such as TKA).