Influence of pleurotomy on pulmonary function after off-pump coronary artery bypass grafting

This study evaluated the influence of pleurotomy on pulmonary function after off-pump coronary artery bypass grafting (CABG) using the left internal thoracic artery (LITA).

Thirty patients were prospectively allocated into two groups: 15 patients with an opened left pleural cavity (OP group) and 15 patients with an intact pleural cavity (IP group). Bedside pulmonary function tests were recorded preoperatively and on postoperative days 1, 3, and 5. Arterial blood gas analyses and ratio of partial pressure of arterial oxygen (PaO2/fraction of inspired oxygen (FiO2) ratio were evaluated preoperatively and on postoperative day 1.

A significant decrease of pulmonary function was observed in both groups until postoperative day 5. When compared with the percentage of the preoperative value, the forced vital capacity was significantly lower in the OP group than in the IP group on postoperative days 1 (33.3% +/- 8.3% versus 49.1% +/- 8.4%, p < 0.001), 3 (45.4% +/- 7.0% versus 62.1% +/- 8.6%, p < 0.001), and 5 (56.1% +/- 8.7% versus 77.5% +/- 11.6%, p < 0.001). Similar results were found for forced expiratory volume in 1 second on postoperative days 1 (35.7% +/- 8.6% versus 50.0% +/- 9.8%, p < 0.001), 3 (48.4% +/- 7.0% versus 61.5% +/- 9.02%, p < 0.001) and 5 (58.8% +/- 8.5% versus 75.9% +/- 10.2%, p < 0.001). The PaO2 value and the PaO2/FiO2 ratio dropped on postoperative day 1 in both groups (p < 0.05), with a higher fall in the OP group (p < 0.05). Orotracheal intubation time (p = 0.012) and hospital stay (p = 0.002) were lower in the IP group.

Off-pump CABG using the LITA, independently of pleural opening, induced a significant reduction in early postoperative pulmonary function. However, the patients undergoing pleurotomy demonstrated more pronounced pulmonary dysfunction.