The effect of operating lights on laminar flow

AimsThe interaction between surgical lighting and laminar airflow is poorly understood. We undertook an experiment to identify any effect contemporary surgical lights have on laminar flow and recommend practical strategies to limit any negative effects.Materials and MethodsNeutrally buoyant bubbles were introduced into the surgical field of a simulated setup for a routine total knee arthroplasty in a laminar flow theatre. Patterns of airflow were observed and the number of bubbles remaining above the surgical field over time identified. Five different lighting configurations were assessed. Data were analysed using simple linear regression after logarithmic transformation.ResultsIn the absence of surgical lights, laminar airflow was observed, bubbles were cleared rapidly and did not accumulate. If lights were placed above the surgical field laminar airflow was abolished and bubbles rose from the surgical field to the lights then circulated back to the surgical field. The value of the decay parameter (slope...