Particle Tracing: Analysis of Airborne Infection Risks in Operating Theatres

P. Apell[1], S. Hjalmarsson[1], T. Lindberg[1], I. Wernström[1], Y. Tarakonov[1], A. Erichsen Andersson[2], M. Karlsteen[1]
[1]Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden
[2]Sahlgrenska University Hospital, Department of Anesthesia, Surgery and Intensive Care, Göteborg, Sweden
Published in 2012

Patients undergoing surgery are sensitive to infections. The operation staff may spread 10^4 particles per person per minute, of which ten percent are presumed bacteria-carrying. We visualize the influence of the personnel on the air and particle flows for the two most common ventilation systems in Swedish hospitals using Comsol Multiphysics with particle tracing..

The Laminar Air flow-ventilation gives a much more controlled flow where fewer particles reach the patient than with conventional mixed ventilation where it is more likely that the staff unconsciously disrupt the flow. For Laminar Air-flow ventilation it takes more than two minutes for the particles in motion to leave the room having implications for the time preceeding the operation when particles are assumed to settle.