Newly published papers find no evidence that 3M™ Bair Hugger™ system causes infections

Four new medical papers published this year debunk claims that forced-air warming systems cause surgical site infections.

The papers – all published in respected medical journals – reinforce the long-held contention by medical experts that the 3M™ Bair Hugger™ patient warming system does not lead to an increase in surgical site infections.

The Bair Hugger system has been used more than 200 million times in the past three decades and continues to be used thousands of times a day. Numerous scientific studies indicate that keeping patients warm before, during and after surgery can provide valuable benefits, including reduced risk of surgical site infections, fewer post-operative heart attacks, reduced blood loss and faster recovery times.

Plaintiffs’ lawyers are suing 3M, claiming that their clients developed infections during surgeries in which the Bair Hugger system was used. The lawyers cite a handful of studies that suggest the Bair Hugger systems’ use of warm air may disturb the airflow in the operating room.

Yet, no studies have ever found that the Bair Hugger system causes an increase in bacterial counts in the surgical area. Even the studies cited by plaintiffs’ lawyers acknowledge there is no proof that the Bair Hugger system leads to more bacteria.

The new papers further strengthen the existing science (and lack of a credible large-sample study), while bolstering 3M’s position that there is no merit to the claims of plaintiffs’ lawyers.  

Here is a synopsis of the papers:

  • Airborne bacterial contamination during orthopedic surgery: A randomized controlled pilot trial. This study measured bacterial counts in six locations in the operating room, with a group of 80 different patients. The study found that “it was not possible to detect any higher bacterial counts on any plate in the forced-air warming group (the Bair Hugger system) versus the resistive warming group (the HotDog blanket).” Results of this well-designed study were published in the Journal of Clinical Anesthesia in February 2017. 
  • Prevention of Periprosthetic Joint Infection: New Guidelines. This paper, published in the The Bone & Joint Journal in March 2017, discusses new guidelines from the World Health Organization and Center for Disease Control in preventing infections in total knee and hip replacement surgeries. On the issue of patient warming, the study notes: “Concerns regarding the use of air warming and the potential for contamination have been raised by a few authors although this has not been proven ... The guidelines agree on the importance of maintaining normothermia of the patient during surgery.’’  
  • Forced-Air warmers and Surgical Site Infections in Patients Undergoing Knee or Hip Arthroplasty. This paper, published in January 2017 in the Annual Review of Nursing Research, reviewed the existing science. Its conclusion: “Current evidence does not support forced-air warmers causing surgical site infections in patients undergoing total knee or hip arthroplasty.’’ The paper called for more study of the alleged issues. 
  • Normothermia in Arthroplasty. This comprehensive study was published in January 2017 the Journal of Arthroplasty. Its finding: “Based on the available evidence present at this point, there is no scientific proof that the use of forced-air warming leads to an increase in surgical site infections regardless of the type of surgical procedure and the type of operating room.’’