Forced-Air Warmers and Surgical Site Infections in Patients Undergoing Knee or Hip Arthroplasty

The majority of the evidence indicates preventing inadvertent perioperative hypothermia reduces the incidence of many perioperative complications. Among the results of inadvertent perioperative hypothermia are increased bleeding, myocardial events, impaired wound healing, and diminished renal function. Most researchers agree there is an increased incidence of surgical site infections in patients who experience inadvertent perioperative hypothermia. Forced-air warming is effective in preventing inadvertent perioperative hypothermia. Paradoxically, forced-air warmers have been implicated in causing surgical site infections in patients undergoing total knee or hip arthroplasty. The results of investigations suggest these devices harbor pathogens and cause unwanted airflow disturbances. However, no significant increases in bacterial counts were found when forced-air warmers were used according to the manufacturer's directions. The results of one study suggested the incidence of surgical site infections in patients undergoing total joint arthroplasty was increased when using a forced-air warmer. However these researchers did not control for other factors affecting the incidence of surgical site infections in these patients. Current evidence does not support forced-air warmers causing surgical site infections in patients undergoing total knee or hip arthroplasty. Clinicians must use and maintain these devices as per the manufacturer's directions. They may consider using alternative warming methods. Well-conducted studies are needed to help determine the role of forced-air warmers in causing infections in these patients.