Can forced-air warming lead to surgical site infections, as a flood of recent patient lawsuits contend, or is it just a bunch of hot air?

Fifteen total joint replacement patients have filed lawsuits against 3M Health Care, the manufacturer of the popular Bair Hugger forced-air patient warming device, and the number is expected to rise. The patients allege that forced-air warming devices circulate more than just hot air. They say the blowers stir up contaminated air from the OR floor and deposit it in the surgical site, causing deep joint infections that resulted in the need for repeated surgeries, amputation and other complications.

Details of the 2 most recent lawsuits are harrowing. A patient's leg was amputated after he became infected with Methicillin-resistant Staphylococcus aureus during a knee replacement surgery. An artificial hip patient who suffered an SSI needed 15 additional surgeries, including one to remove the implanted joint.

While attorneys work to have these cases consolidated in a single federal court, more suits could be coming. One law firm has set up a website, trolling for patients.

3M launched its own website, The Facts About Forced-Air Warming, to refute such claims, which a company official calls "baseless."

"There is no evidence that forced-air warming increases the risk of infection," says 3M attorney Christiana Jacxsens of Greenberg Traurig in Atlanta, Ga. "In its entire history, not one hospital, doctor, or medical provider has reported a single confirmed incidence of infection believed to be caused by the Bair Hugger device."

Many of the allegations linking surgical site infections to forced-air warming were started by a surprising source — the inventor of the Bair Hugger, Scott Augustine, MD, who after a contentious split from the company that sold the Bair Hugger to 3M, invented the HotDog patient warming system, an air-free device that works similar to an electric blanket, warming the patient from above and below simultaneously. Dr. Augustine claims in an article in the The New York Times that the company selling the Bair Hugger knew of the infection risk as far back as 2010 and was covering up this danger to keep sales strong.

3M vehemently denies the allegation, and several independent researchers, including the Association of PeriOperative Registered Nurses (AORN) note that studies showing evidence of a link are limited or use flawed methodologies. In a 2013 review, AORN says that "given the efficacy of these devices in preventing inadvertent perioperative hypothermia" facilities can continue using forced-air warming "until well-conducted, large-scale trials can further examine the issue."

The Bair Hugger is the nation's best-selling surgical warming device. Since its inception in 1987, the device has been used to safely warm more than 200 million patients in hospitals around the world, says the company. More than 170 clinical studies support the safety and efficacy of Bair Hugger therapy, including more than 60 randomized controlled trials, adds 3M. "3M remains confident in the safety and efficacy of the Bair Hugger forced-air warming system," says Ms. Jacxsens. "3M stands behind the Bair Hugger every day and will continue to stand behind it, its customers and their patients."

Kendal Gapinski