Effect of local heating on airflow distribution and the concentration of bacteria-carrying particles in the operating room

Abstract

The concentration and distribution of bacteria-carrying particles (BCPs) in the operating room have an important influence on surgical site infections (SSIs). Local heating is commonly used during surgery to reduce the incidence of perioperative hypothermia (PH). However, the effects of local heating measures on airflow and BCPs have not been thoroughly studied. In order to study the effect of local heating in the operating room on airflow and BCPs, the experiment was carried out in the standard experimental operating room using Bacillus subtilis, and CFD numerical simulation was carried out using k-ε turbulence model and Lagrange particle tracking model. The distribution of airflow and the concentration of BCPs in the operating room was studied in the four cases of no local heating (case 1), heating pad (case 2), warming blanket (case 3), and both heating pad and warming blanket (case 4). The results showed that local heating reduced the airflow rate above the patient's body, which also led to an increase in the concentration of BCPs. At T = 300 s, the concentration of BCPs above the operating table in Case 2, Case 3, and Case 4 was increased by 600 CFU/m3 and 260 CFU/m3 and 670 CFU/m3, respectively, compared with that without local heating. As time goes on, the increment of the concentration of BCPs caused by local heating decreases. It is recommended to use heating pad to keep patients warm from less influence on the concentration of BCPs and airflow distribution. This study provides a reference for reducing patients' SSIs and provides a basis for insulation methods.