Effect of forced-air warming blankets on indoor air quality in unidirectional flow operating theatres

Perioperative hypothermia increases the likelihood that a patient will get a surgical site infection, which is one of the biggest public health problems. Controversy exists regarding the effect of forced-air warming systems on the disruption of unidirectional discharge of ultra-clean air in operating theaters. However, researchers agree that thermal blankets are indeed useful to prevent hypothermia. This work aims to analyze the effect of a forced-air warming blanket on the indoor air quality in the surgical field of a high-performance operating theater as a function of the supply velocity employing Computational Fluid Dynamics. An operating theater, its facilities, medical staff, and patient covered with a drape were modeled. Ten cases with driving speeds between 0.20 and 0.40 m/s at 0.05 m/s intervals, with thermal blankets ON and OFF, were simulated. Both air renewal and particle dispersion results in the breathing zone were analyzed. The results show that the use of thermal blankets to avoid patient hypothermia is acceptable at discharge velocities of 0.30 m/s because both the decontamination kinetics and air renewal are improved by 45.6% and 37.6%, respectively. Unfavorable results were obtained for the rest of the case studies with different supply velocities.