Abstract
Purpose :
To investigate the effect of beta-blockers on physiologic tremor in microsurgery with the EYEsi 3D Simulator. Beta-blockers are believed to be helpful in stressful situations, where the physiological response involves catecholamine release, accentuating physiologic tremor. The tremor’s presence can further increase anxiety, perpetuating this loop. Peripheral B-2 receptor blockade can help prevent this tremor. Using the EYEsi Simulator we can objectively test whether beta-blockers are beneficial in microsurgery.
Methods :
This is a prospective double-blind study that investigates the effect of elevated or suppressed beta-adrenergic activity on microsurgery. Six subjects have completed the study thus far. Subjects are tested under 4 conditions: placebo, agonist (200mg caffeine), or beta blockade (10mg or 40mg propranolol).
Subjects had 4 attempts at each of the surgical tests and the 3 best scores were recorded. This was done 1-hour after administering 1 of the unmarked medications; this was then repeated so each subject was exposed to all 4 pills. The subjects then underwent testing for a second time, thereby attempting to account for the learned effect.
Repeated measures ANOVA was used for comparison and statistically significant values were further analyzed using the Turkey HSD for Post-Hoc Analysis.
Results :
Four subjects had the greatest tremor with the placebo or caffeine pill. Subject 5’s tremor was greatest with 40mg of propranolol, which does not support our theory. Four subjects recorded the lowest tremor averages with propranolol. However, these results are not statistically significant throughout. With regards to instrument handling/lateral movement, higher values indicate worse instrument handling/more lateral movements. Instrument handling scores when using propranolol were significantly better than both the placebo and caffeine in subjects 4 and 6.
Conclusions :
Results-to-date are inconclusive regarding the use of propranolol to dampen physiologic hand tremor, though increased power may demonstrate stronger trends. This study will ideally serve as a stepping-stone for future studies regarding improved surgical performance and training.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.