Small amount of alcohol did not deteriorate microsurgical dexterity: a prospective laboratory study

Background Alcohol consumption has been reported to deteriorate surgical performance both immediately after consumption as well as on the next day. We studied the early effects of alcohol consumption on microsurgical manual dexterity in a laboratory setting. Method Six neurosurgeons or neurosurgical residents (all male) performed micro- and macro suturing tasks after consuming variable amounts of alcohol. Each participant drank 0–4 doses of alcohol (14 g ethanol). After a delay of 60–157 min, he performed a macrosurgical and microsurgical task (with a surgical microscope). The tasks consisted of cutting and re-attaching a circular latex flap (diameter: 50 mm macrosuturing, 4 mm microsuturing) with eight interrupted sutures (4–0 multifilament macrosutures, 9–0 monofilament microsutures). We measured the time required to complete the sutures, and the amplitude and the frequency of physiological tremor during the suturing. In addition, we used a four-point ordinal scale to rank the quality of the sutures for each task. Each participant repeated the tasks several times on separate days varying the pre-task alcohol consumption (including one sober task at the end of the data collection). Results A total of 93 surgical tasks (47 macrosurgical, 46 microsurgical) were performed. The fastest microsurgical suturing (median 11 min 49 s, [interquartile range (IQR) 654 to 761 s]) was recorded after three doses of alcohol (median blood alcohol level 0.32‰). The slowest microsurgical suturing (median 15 min 19 s, [IQR 666 to 1121 s]) was observed after one dose (median blood alcohol level 0‰). The quality of sutures was the worst (mean 0.70 [standard deviation (SD) 0.48] quality points lost) after three doses of alcohol and the best (mean 0.33 [SD 0.52] quality points lost) after four doses (median blood alcohol level 0.44‰). Conclusions Consuming small amount of alcohol did not deteriorate microsurgical performance in our study. An observed reduction in physiological tremor may partially explain this.