Purpose: Our purpose was to examine perioperative alterations in hemodynamic changes with head-up tilt (HUT) in patients undergoing endoscopic thoracic sympathectomy (ETS).
Methods: The subjects were 11 patients with essential hyperhidrosis scheduled to undergo ETS (ETS group) and 9 age-matched volunteers undergoing minor surgery (control group). HUT was performed (40 degrees; 5 min) before and after the surgery, under nitrous oxide anesthesia. Orthostatic hypertension and hypotension in response to HUT were defined as changes of 10% or greater in systolic blood pressure.
Results: The increase in heart rate in response to HUT was significantly reduced after surgery in the ETS group (from 34 +/- 18 to 14 +/- 11 beats.min(-1); P < 0.001), but not in the control group (from 23 +/- 18 to 22 +/- 12 beats.min(-1); P = 0.911). Orthostatic hypertension disappeared completely after ETS (from 5 of 11 to none of 11 patients; P = 0.035), whereas the prevalence of orthostatic hypotension increased significantly after ETS (from 3 of 11 to 9 of 11 patients; P = 0.030). In the control group, the prevalence of neither orthostatic hypertension nor orthostatic hypotension changed after surgery.
Conclusions: ETS attenuates autonomic circulatory response under nitrous oxide anesthesia.