BACKGROUND: Thoracoscopic Sympathicotomy (TS) is widely accepted as an effective method for the treatment of palmar hyperhidrosis. Single lumen endotracheal tube using CO₂ insufflation is a simple and safe method for thoracoscopic surgery. However, there are chances of CO₂ embolism during CO₂ insufflation and nerve dissection. The object of this study were to assess the incidence of embolic events using transesophageal echocardiography (TEE) and to evaluate the related cardiorespiratory consequence during TS.

METHODS: Thirty-two patients undergoing TS were studied. The long axis four chamber view was obtained continuously, except for predetermined intervals (after induction, CO₂ insufflation in left thoracic cavity, left sympathicotomy, CO₂ insufflation in right thoracic cavity, and right sympathicotomy) where the transgastric short axis view was obtained to derive ejection fraction (EF). Heart rate, mean arterial pressure (MAP), O₂ saturation, and end tidal CO₂ were monitored. Statistical analysis was performed using multivariated ANOVA and unpaired Student's t-test. P < 0.05 was considered significant.

RESULTS: We observed CO₂ embolism in 28/32 patients during CO₂ insufflation (left or right) and in 32/32 patients during nerve dissection (left or right). There was no significant difference in cardiorespiratory variables between patients who presented embolism and who did not, during four distinct periods of events. Meanwhile, MAP decrease (P = 0.002) and EF increased significantly (P = 0.007) after sympathicotomy. This can be explained by decrease in systemic vascular resistance (SVR) by sympathicotomy.

CONCLUSIONS: Embolic events commonly occur during CO₂ insufflation and nerve dissection without cardiorespiratory instability during TS. However, we should pay attention when administrating N₂O.