Essential hyperhidrosis is caused by an unexplained over activity of the high thoracic sympathetic nervous system. Since the development of video endoscopic surgery, the use of thoracoscopic sympathectomy has gradually increased. However, reports on major anesthetic problems related to bilateral thoracic symathectomy and one lung ventilation (reventilation of a collapsed lung), which are commonly used for this operation are few. The aim of this study was to evaluate changes in cardiovascular function and arterial oxygenation during reventilation of the collapsed lung for bilateral thoracoscopic sympathectomy.

Twenty one patients with essential hyperhidrosis in ASA physical status class 1, undergoing bilateral thoracoscopic T2-3 sympathectomy in the semi-Fowler's position were selected. Mean arterial blood pressure (MBP) of both radial arteries, skin temperature of both palmar area, and heart rate (HR) were recorded just before and after, 5 min and 10 min after sympathectomy. Simultaneously, arterial oxygen tension was obtained 30 min after left lung ventilation (LLV, baseline) and right lung ventilation (RLV, left lung collapse) and 10, 20, 30, 40, 50 and 60 min after LLV (reventilation of the collapsed left lung) under general anesthesia (isoflurane-100% oxygen).

MBPs of bilateral radial arteries were significantly reduced after sympathectomy. However, there were no difference in the percent change of the MBP between both sides. HR was reduced only after right sympathectomy. The skin temperature of ipsilateral thenar area was significantly elevated after sympathectomy. Aterial oxygen tension was markedly reduced after 10 min of reventilation of the collapsed left lung (246.9 ± 11.3 --< 102.3 ± 5.7 mmHg) and then slowly returned to the baseline value after 50 min of reventilation.

Thoracic sympathectomy in patients with essential hyperhidrosis causes a marked decrease of HR and MBP of the bilateral radial arteries and an increase of skin temperature of the ipsilateral palmar area. Reventilation of the collapsed lung for bilateral thoracoscopic T2-3 sympathectomy, causes a marked reduction in the arterial oxygen tension.