AORN Journal, noting concerns about infection risk from forced-air warmers, called for multi-center, randomized, controlled trials. Evidence of bacteria in the air-flow paths of forced-air warmers; authors ask manufacturers to consider redesign.

In a continuing-education review article in the October issue of AORN Journal,published by the Association of Operating Room Nurses, the authors examined 192 sources.  Their conclusions included the following:

  • “Clinicians should take steps to prevent health care–associated infections from the use of forced-air warmers….”  Such steps include “routinely and meticulously” cleaning the devices.
  •  Forced-air warmers may interrupt the flow of filtered air toward the area of the wound and may allow dust particles containing pathogenic organisms to come into contact with the wound.
  •  Five separate studies suggested that forced-air warmers could be harboring bacteria or bacteria-containing particles.

Among the research considered by the authors was “Forced-air warming and ultra-clean ventilation do not mix: an investigation of theatre ventilation, patient warming and joint replacement infection in orthopaedics,” by UK orthopedic surgeon PD McGovern et al and published in the Journal of Bone & Joint Surgery.  The research included 1,437 patients undergoing hip or knee replacement.  The “Finding and comments” of the AORN Journal authors included:

“High risk of developing deep infections for subjects warmed with forced-air warming systems (odds ratio, 3.8; P=.024).”07

Because of “methodological problems” in the published investigations, however, the authors stated, “the evidence we reviewed does not conclusively indicate that forced-air warmers are the cause of SSIs [surgical-site infections].”  Clinicians might continue to use forced-air warming systems, they said, “so long as they are meticulously maintained.”

At least one lawsuit already has been filed against 3M, the manufacturer of Bair Hugger forced-air warming. The plaintiff, a 70-year-old man from Houston, underwent 15 revisions after the Bair Hugger system allegedly caused an infection during total hip replacement surgery.  Although the plaintiff avoided amputation, he remains severely disabled.  The Petition claims damages in excess of $1 million.

More than 50,000 forced-air warming units are currently in use across the country, and the technology is used in almost all total joint replacement surgeries.  According to the Houston plaintiff’s attorney, many more cases are likely to be filed.  Several plaintiffs’ firms have begun advertising for patients potentially injured by Bair Hugger.

Dr. Scott Augustine, inventor of Bair Hugger warming, defends the device, claiming that it is “probably safe in soft-tissue surgeries. The risk to patients only occurs with implanted devices,” he says, “like artificial joints. In those surgeries, a single bacteria landing on the device can secrete a biofilm, making it impervious to antibiotics and antibodies.  The infection can erupt weeks later.  In those cases, the pathogen usually arrives through the air.

“In soft tissue surgeries,” Dr. Augustine concluded, “the risk of infection from FAW is much less.”