Laminar airflow and the prevention of surgical site infection. More harm than good?

Abstract

Introduction: Laminar airflow (LAF) systems are thought to minimise contamination of the surgical field with airborne microbes and thus to contribute to reducing surgical site infections (SSI). However recent publications have questioned whether LAF ventilation confers any significant benefit and may indeed be harmful.

Methods: A detailed literature review was undertaken through www.Pubmed.com and Google scholar (http://scholar.google.com). Search terms used included "laminar flow". "laminar airflow", "surgical site infection prevention", "theatre ventilation" and "operating room ventilation", "orthopaedic theatre" and "ultra-clean ventilation". Peer-reviewed publications in the English language over the last 50 years were included, up to and including March 2014.

Results: Laminar airflow systems are predominantly used in clean prosthetic implant surgery. Several studies have demonstrated decreased air bacterial contamination with LAF using bacterial sedimentation plates placed in key areas of the operating room. However, apart from the initial Medical Research Council study, there are few clinical studies demonstrating a convincing correlation between decreased SSI rates and LAF. Moreover, recent analyses suggest increased post-operative SSI rates.

Conclusion: It is premature to dispense with LAF as a measure to improve air quality in operating rooms where prosthetic joint surgery is being carried out. However, new multi-centre trials to assess this or the use of national prospective surveillance systems to explore other variables that might explain these findings such as poor operating room discipline are needed, to resolve this important surgical issue.

Keywords: Laminar airflow; SSI; Surgical infection; Theatre ventilation.