Recent study rebuts airflow claims; 3M™ Bair Hugger™ Patient Warming System did not disrupt operating room airflow

It’s worth reading this November 2015 study and watching the accompanying videos, available here. They do a great job of explaining how airflow works in an operating room, and use science to show that the Bair Hugger Warming System did not disrupt clean operating room airflow and did not move air from the floor to the surgical site.

Operation Room Air Flow Study with 3M™  Bair Hugger™ Warming System in Simulated Hip Replacement Surgery
John P. Abraham, Ph. D., University of St. Thomas and Jennifer A. Wagner, Ph. D., Prism Environmental Health and Safety Solutions

The Bair Hugger Warming System provides a safe and effective way to maintain normal body temperature during surgery.  When used properly the Bair Hugger Warming System lowers the risk of hypothermia and improves patient recovery and surgery outcomes (i.e. reduces risk of surgical site infection, blood loss and transfusion requirement, prolonged recovery, and fatal heart attack).  A scientific research project was undertaken to assess whether the Bair Hugger System disturbed the clean-air flow in an operating room in the vicinity of a sterile surgical site.  The investigation showed that the Bair Hugger Warming System did not disrupt the normal airflow patterns of an operating room, and did not move air from the floor to the surgical site in a simulated hip replacement procedure.

The investigation had three separate components. One part of the investigation incorporated advanced mathematical calculations based upon the fundamental laws of physics to track the paths of airflow in the operating room. The calculations demonstrated that the air from the Bair Hugger System avoided the surgical site. The air flow that emerged from the Bair Hugger System traveled away from the surgical table and migrated toward the room exhaust vents along with the air beneath the operating table– not toward the surgical site.

A second part of the investigation involved experiments performed in an operating room with flow visualization studies that purposely injected visible fog into multiple locations in the room: 1) behind the anesthesia screen where the Bair Hugger air would exit near the patient’s head; 2) underneath the surgical table; and 3) next to the surgical table, near the surgical team, and near the surgical site. This investigation found that downward clean moving air from ceiling supply ducts in an operating room inhibited air from other sources from intruding into the surgical region. The downward flow of clean air worked irrespective of whether the Bair Hugger Warming System was used or not.

The third part of the investigation included a review of the scientific literature. The best scientific work did not show any causal link between the use of a Bair Hugger Warming System and surgical site infections. Even contrary research, which was largely funded by a competitive company, failed to show any causal link. More than 170 clinical studies have utilized the Bair Hugger system, and studies have demonstrated forced-air warming’s clinical effectiveness. Studies have demonstrated perioperative temperature management with forced-air warming actually reduces the risk of surgical site infections, surgical bleeding and risk of heart attack.

The findings of the three components of this investigation mutually reinforce one another. All of these studies showed that the Bair Hugger Warming System is safe when used according to manufacturer directions, providing an effective way to maintain patient temperature.

Outpatient Surgery : Answering questions about warming and lawsuits

Of all the questions surrounding patient warming, the most burning is this: Do forced-air warmers circulate contaminants that can cause wound infections, as a spate of recent lawsuits alleges? Read on as we tackle this and other hot topics surrounding your quest to maintain normothermia.

1. Does forced-air warming cause SSIs?
Of the many proven benefits of maintaining normothermia, perhaps the greatest is that it staves off surgical wound infections. But what if the very act of forced-air warming causes SSIs? 

You've no doubt heard the claims or seen the ads from law firms trolling for clients: Besides blowing hot air, forced-air warming units stir up the germs from the floor and cause them to go airborne. The jetstream of germs, the notion goes, rises alongside the table and settles over the surface of knee or hip implants in the sterile field. The germs can take root in the wounds and cause debilitating infections, especially in patients undergoing deep joint surgery. Not everyone is buying this (Bunch of) Hot Air Theory.

"Commercially driven junk science that has no basis in reality whatsoever," says an observer.

3M's lawyers say no reputable study has proven that forced-air warmers contaminate the air when they vent their waste heat. Just the opposite is true, they say. Decades of research and clinical experience show that using forced-air to maintain normal body temperature helps reduce the risk of infections and improves surgical outcomes.

"Forced air is highly effective, easy to use, inexpensive and remarkably safe," says anesthesiologist Daniel Sessler, MD, who has researched forced-air warming extensively as chair of the department of outcomes research at the Cleveland Clinic.

Continue reading here.

3M responds to website claims on 3M Bair Hugger warming system

Top Class Actions has invited 3M to respond to recent coverage of lawsuits filed against 3M regarding its Bair Hugger Surgical Warming System.

3M believes strongly that none of these cases have merit and is eager to prove that in court. There is no valid evidence that anyone has ever contracted a surgical site infection from the Bair Hugger system. Likewise, there is no scientific study that has demonstrated a causal link between the use of Bair Hugger therapy and an increase in surgical site infections. The recent Proceedings of the International Consensus Meeting on Periprosthetic Joint Infections determined that “no studies have shown an increase in SSI related to the use of” forced-air warming devices such as Bair Hugger.

There is, however, ample evidence that Bair Hugger warming therapy helps patients. Many clinical and quality studies have shown that maintaining normal body temperature during surgery reduces the risk of surgical-site infections. Patient warming is a recommended practice by leading health care institutions and professional societies – and the Bair Hugger system is a safe, effective and efficient method of doing so.

Continue reading here.