An alternative approach to delivering safe, sustainable surgical theatre environments

Abstract

Outcomes are reported from an antimicrobial-resistance research initiative into the infection control offered by downward laminar-flow ventilation in hospital operating theatres. Pre-cooled air is forced down onto the patient with the intention of diverting airborne pathogens from the surgical wound. The concept was commercialised in the early 1970s as the Ultra Clean Ventilation (UCV) system, a commonly applied contemporary solution. Data collected by the authors in unoccupied UCV theatres in a recently completed acute hospital indicate that as the warming air descends into the occupied zone, it may be subject to recirculation within the suite of spaces. This phenomenon is confirmed by the authors’ experimental modelling. Increasing the residence time of microorganisms will increase the probability of surgical site infection (SSI). An alternative is proposed: an upflow displacement ventilation scheme in combination with a localised source of filtered air to ventilate the wound as required. Likely ventilation flows are modelled experimentally and compared with those of the downdraught-ventilated UCV type. The alternative arrangement appears to provide comparable risk of SSI, while requiring less energy to drive the ventilation system. The concept is developed into a novel surgical theatre proposal in which background airflows are driven