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°; 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.
Key words Endoscopic thoracic sympathectomy - Baroreflex - Essential palmar hyperhidrosis - Head-up tilt - Orthostatic change
Received: February 16, 2001 / Accepted: October 24, 2001