Influence of a local ventilation system on patient and personnel protection in operating rooms

To reduce the surgical site infection risk in operating rooms, great effort is done exchanging the room air. However, the effect of the conventional ventilation systems laminar air flow and mixing ventilation on the removal of airborne germs is limited. In this study, a concept that introduces additional air inlets for local horizontal ventilation in the vicinity of the operation table is tested in experiments. The impact of this pioneer system on the removal of bacteria originating from the surgical staff and surgical smoke that is emitted during electrosurgical procedures was tested with surrogate particles in a full-scale research operating room. Moreover, thermal comfort of the surgical staff according to standard DIN EN ISO 7730 and heat flux of the patient where measured, too. It was shown that the concentrations of contaminations were reduced by more than one order of magnitude for surgical smoke and two orders of magnitude for airborne germs in the proximity of the local air inlet, compared to reference cases without local ventilation. The heating system of the patient simulators surface consumed significantly more power when using the local ventilation system, increasing the risk of perioperative hypothermia. The thermal comfort of the surgical staff was only slightly affected by the local ventilation system and in an acceptable range. It was also observed that a risk of cross-contamination from the surgical micro-environment to the peripherical area was formed due to the horizontal airflow.