An ergonomic task analysis of spinal anaesthesia

Ergonomics is the study of physical interaction between humans and their working environment. The objective of this study was to characterize the performance of spinal anaesthesia in an acute hospital setting, applying ergonomic task analysis.

A data capture sheet was developed using a series of multidisciplinary expert discussions and piloted on: five procedures. The final version of this sheet was applied to 24 further procedures. Data were acquired using direct observations, video recordings and application of a questionnaire. The domains of interest were patient, operator and environmental factors related to ergonomic performance.

At least one important deficit in ergonomic performance was identified during each of the 24 procedures. None of the 24 assistants who helped to position the patients had specific training for this purpose. Eleven out of 24 operators exhibited marked (>/=60 degrees ) thoracolumbar flexion for at least a part of the procedure. Seven out of 24 operators positioned the instrument tray to their nondominant side prior to commencing the procedure. All studied patients were exposed during at least a part of the procedure at a relatively low temperature [17.5 +/- 1 degrees C (16-20.7) (mean +/- SD (range)].

In the setting described, spinal anaesthesia is usually performed in a manner which is clearly suboptimal in terms of ergonomics. This underrecognized problem needs to be addressed through education and training.