Thoracic epidural anesthesia combined with general anesthesia: The preferred anesthetic technique for thoracic surgery

Abstract

Thoracic epidural anesthesia (TEA) combined with general anesthesia (GA) as well as total-IV anesthesia (TIVA) are both established anesthetic managements for thoracic surgery. We compared them with respect to hypoxic pulmonary vasoconstriction, shunt fraction and oxygenation during one-lung ventilation. Fifty patients, ASA physical status II-III undergoing pulmonary resection were randomly allocated to two groups. In the TIVA group, anesthesia was maintained with propofol and fentanyl. In the TEA group, anesthesia was maintained with TEA (bupivacaine 0.5%) combined with low-dose concentration 0.3-0.5 vol% of isoflurane (end-tidal). Changing from two-lung ventilation to one-lung ventilation caused a significant increase in cardiac output (CO) in the TIVA group, whereas no change was observed in the TEA group. One-lung ventilation caused significant increases in shunt fraction in both groups which was associated per definition with a significant decrease in PaO2 in both groups but Pao2 remained significantly increased in the TEA group (P < 0.05). We conclude that both anesthetic regimens are safe intraoperatively. However, TEA in combination with GA did not impair arterial oxygenation to the same extent as TIVA, which might be a result of the changes in CO. Therefore, patients with preexisting cardiopulmonary disease and impaired oxygenation before one-lung ventilation might benefit from TEA combined with GA.