In August 2013 research was published in the American Association of Nurse Anesthetists which revealed 96 percent of 3M Bair Hugger forced-air warming blowers generated significant levels of contamination.1 Up to 110,000 contaminated particles per cubic foot were found when the Bair Huggers were used, and more than 70 percent of the blowers attached to the Bair Huggers registered higher contaminant levels in the hose-end airflows than in the intake airflows. This led researchers to conclude the contaminants were incubated insidethe Bair Hugger blowers. While the original design of the Bair Hugger claimed 93.8 percent efficiency in the intake filtration system, in practice, the filters performed at only 63.8 percent efficiency.1
This level of reduced filtration caused substantial buildup of internal contamination among the forced-air blowers tested. One of the members of 3M’s Advisory Board, Dr. Daniel Sessler, has often been quoted as saying the filters on the Bair Hugger largely eliminate bacteria in the heated air. The AANA research definitely challenges that statement. The authors of the AANA article urged 3M to redesign the Bair Hugger in order to allow decontamination, to increase inlet filter efficiency and to add a filter at the distal end of the hose. The goal would be to reach HEPA quality standards—99.97 percent efficiency.1
Filtration System on the Bair Hugger May Be Inadequate
In order to reduce the risks of emission contamination, forced-air warming devices are equipped with an intake filter, however minimal evidence exists which supports the performance of that intake filter in the prevention of airborne contamination, including microbial-laden dust, respiratory droplets and skin cells. The typical location for forced-air warming blowers tend to be close to the floor, by the head of the operating table. Movements of surgical staff and the patient generate significant quantities of skin cells, and as many as 10 percent of those skin cells have been found to carry viable microorganisms. The skin cells are affected by a trio of circumstances: the downward nature of airflow, gravity and the forced-air warming blower.
Doctor Who Invented the Bair Hugger Vocal about the Potential Risks
Forced-air warming blankets are extremely effective in preventing surgical hypothermia, resulting in less bleeding and shorter recovery times. The Bair Hugger was the first forced-air warming blanket, developed by Dr. Scott Augustine in 1988. In the last few years, however, Dr. Augustine has been very vocal about the potential dangers associated with the Bair Hugger. The risks include deep joint infection, most likely to occur during an artificial knee or hip replacement or the implantation of an artificial heart valve.
Dr. Augustine theorizes that during a joint surgery, bacteria landing on the artificial device secretes a biofilm, making the joint impervious to antibodies or antibiotics. Dr. Augustine believes the Bair Hugger is probably safe when used in soft joint surgeries, but notes the law of physics dictates heat will rise. In the case of the Bair Hugger forced-air warming blanket, that rising heat has been found to mobilize contaminants on the operating floor, sending them into the surgical site.
Amputation from Deep Joint Infection
A deep joint infection can be extremely serious, requiring the removal of the artificial joint, IV antibiotics for six to eight weeks and an extended hospital stay. In more serious cases of deep joint infection the patient can lose a limb. Amputation is an extremely tragic consequence of a Bair Hugger forced-air warming blanket infection, and can alter a patient’s life forever. Even when the limb is saved, the patient will have to have the artificial joint re-implanted, and can expect the entire deep joint infection to cost more than $100,000 and take them away from their normal life for as long as three months.