Video-assisted thoracoscopic volume reduction surgery in patients with diffuse pulmonary emphysema: gas exchange and...

Arterial blood gases were studied prospectively using continuous intraarterial blood gas monitoring during thoracoscopic volume reduction surgery (VRS) in 24 patients with advanced diffuse pulmonary emphysema. Additionally, the early postoperative course (48 h) of arterial blood gases was studied retrospectively. Twenty-six operations were performed using a combination of thoracic epidural and general anesthesia with left-sided double-lumen intubation for one-lung ventilation (OLV). Arterial blood gases were determined awake, during two-lung ventilation prior to surgery, during OLV (extreme values), and after tracheal extubation. Additionally, the extremes during the whole procedure were determined: avoiding excessive peak inspiratory pressures (26.4 +/- 7.0 cm H2O), minimum PaO2 was 77 +/- 39 mm Hg (mean +/- SD), maximum PaCO2 65 +/- 14 mm Hg (P < 0.0001 versus preoperative values), and minimum pHa 7.22 +/- 0.08 (P < 0.0001). One tension pneumothorax occurred during OLV. Immediate postoperative extubation was performed in 25 of 26 cases, reintubation was necessary in two cases. One patient with coronary artery disease died 36 h after surgery. Hypercapnia (maximum PaCO2 49 +/- 8 mm Hg, minimum pHa 7.37 +/- 0.04, P < 0.01) was still observed 48 h after surgery. These results demonstrate that adequate oxygenation can be preserved during OLV for VRS, but CO2 elimination is impaired. However, intraoperative hypercapnia and immediate postoperative tracheal extubation are well tolerated.