Convective Warming Therapy Does Not Increase the Risk of Wound Contamination in the Operating Room

Abstract

Although convective warming therapy is effective in preventing hypothermia in anesthetized patients, little is known concerning the potential risks of its use. Hence, this balanced cross-over study was designed to determine if the use of convective warming therapy increased the risk of wound contamination. For 4 h, eight healthy male volunteers (aged 20-25 yr) lay supine on an operating room table with their lower bodies and legs covered with a warming cover and sterile surgical drape. The convective warming therapy was administered for 2 h. The other 2 h served as the control. In each session, culture plates were placed directly on the subject's abdomen through an opening in the drape. Tympanic membrane and leg skin temperatures were significantly higher with active warming. No significant differences in the number of bacterial colonies were observed between the two study periods. It was concluded that convective warming therapy, when appropriately applied, does not increase the risk for airborne bacterial wound contamination in the operating room.

Forced-Air Warming and Resistive Heating Devices. Updated Perspectives on Safety and Surgical Site Infections

“…The effect of FAW on contaminant counts in the sterile OR environment ( 12 , 25 , 26 , 31 ) generated different opinions among different authors. Studies conducted by Albrecht et al found an increased bacterial load in OR room with ultra clean ventilation (UCV) when FAW is used, and attributed this effect to the floor level location of FAW blowers and their intake, where most of the contaminants originated ( 4 , 6 , 10 ).…”

Forced-air warming and ultra-clean ventilation do not mix

“…25 In addition, we were unable to consider all factors that have been associated with SSI, as the details of blood transfusion, obesity, incontinence and fitness for surgery, which have been identified elsewhere as important predictors for deep infection, 4,18 were not sufficiently detailed in the medical record. Moreover, prior research is limited to a handful of studies that have either looked at the disruption in ventilation due to forced-air warming in conventional operating theatres 26,27 or evaluated accumulation microbial contamination and emission issues. [28][29][30][31][32] Research in ultra-clean operating theatres is limited to a single orthopaedic study in which forcedair warming resulted in elevated microbial counts over the surgical site.…”

The potential for increased risk of infection due to the reuse of convective air‐warming/cooling coverlets

“…It was previously reported that a singular use of warming coverlets does not increase the potential for airborne bacterial wound infection (7). Nevertheless in some institutions convective air coverlets are being reused, although not recommended by any of the manufacturers.…”

“…In a previous study it was shown that a single use of a convective air-warming coverlet did not increase the potential for wound contamination (7). Yet, in some instances these coverlets may come in direct contact with the surgical site perioperatively and in some institutions covers are being reused on several different patients (which is not in accordance with use recommended by manufacturers).…”