FABRIC BALACLAVAS VS SURGEONS HOODS- DO THEY MAKE A DIFFERENCE TO BACTERIAL SHEDDING IN LAMINAR FLOW THEATRES?

Abstract

Aim: To determine the effects of the different types of headgear on bacterial shedding in laminar flow theatres.

Material and Methods: Sham experiments were carried out using standard theatre clothing, sterile gowns and face masks with visors. Three experimental groups were utilised; no headgear (control), surgeons hoods or fabric balaclavas (known colloquially as “chicken hats”). The sham experiments consisted of two surgeons, scrubbed and gowned, both wearing the same headgear, talking and moving hands for 30 minutes over a sterile mock operating field. 5 bacterial plates were placed on the sterile sheets to capture shed bacteria. An additional 5 plates were placed above head height in the laminar flow enclosure. An air sampler was positioned within the laminar flow and set off for the middle 5 mins of the experiment. Plates were then incubated for 48hrs at 37oC and the number of colony forming units at head and waist height as well as in the air sampler were counted. Each experiment was repeated 5 times.

Results: The bacterial shedding rate at waist height was 0.2 CFUs/plate (314 CFUs/m2/hr) for the control experiment, 0 CFUs/plate (0 CFUs/m2/hr) for the surgeons hoods and 0.08 CFUs/plate (126 CFUs/m2/hr) for the fabric balaclavas.

Conclusion: These experiments show very low bacterial shedding rates with standard clothing and headgear in laminar flow theatres. Although these results demonstrate worse bacterial shedding with fabric balaclavas (which contradicts conventional thinking), the low rate of shedding rates means the results are not statistically significant. It therefore raises the question as to whether we should be using the more expensive fabric balaclavas without proven benefit, and the possibility of increased bacterial shedding.