Effects of thoracic epidural analgesia combined with general anesthesia on intraoperative ventilation/oxygenation and postoperative pulmonary complications in robot-assisted laparoscopic radical prostatectomy

Abstract

PURPOSE: The purpose of this study was to evaluate the effects of thoracic epidural analgesia (TEA) on intraoperative ventilation/oxygenation and postoperative pulmonary complications in robot-assisted laparoscopic radical prostatectomy requiring high-pressure pneumoperitoneum and the extreme head-down position.

METHODS: Seventy-two patients (age range, 58-76 years) scheduled for elective robot-assisted laparoscopic radical prostatectomy were randomly assigned to receive either TEA combined with general anesthesia (TEA group, n = 36) or general anesthesia (GA group, n = 36). T4-sensory block using 1% lidocaine was continuously provided during surgery in the TEA group but not in the GA group. The mode of ventilation was volume controlled with a linear ramp in the pressure wave. Maximum peak inspiratory pressure was preset at 35 mm Hg, and no positive end-expiratory pressure was administered to the patients. Minute ventilation was adjusted to maintain end-tidal CO(2) between 30 and 35 mm Hg by changing respiratory rate during surgery. Intraoperative ventilatory parameters and blood gas analyses were checked. Clinical and radiological pulmonary complications were observed for 3 days postoperatively.

RESULTS: Patients in the TEA group showed significantly lower peak inspiratory pressure and higher dynamic compliance with larger expiratory tidal volume during surgery than those in the GA group. They had significantly better oxygenation and lower concentrations of lactate on arterial blood gas analysis than the GA group. Postoperative clinical and radiological complication rates were not significantly different.

CONCLUSIONS: TEA combined with general anesthesia improved intraoperative ventilation/oxygenation. Although clinical and radiologic pulmonary complications were not significantly influenced, TEA can be considered an option for patients with limited reserve capacity or preexisting impairments of visceral blood flow.