Effects of Intrapleural Analgesia on Pulmonary Function and Postoperative Pain in Patients With Chronic Obstructive Pulmonary Disease Undergoing Coronary Artery Bypass Graft Surgery

Objective: Pain after coronary artery bypass graft (CABG) surgery remains a significant problem and may cause serious complications because of restricted breathing and limited early mobilization. The aim of this study was to assess the effects of intrapleural analgesia on the relief of postoperative pain in patients undergoing CABG surgery.

Design: Postoperative pain, pulmonary function tests, and outcomes were compared with a placebo group after CABG surgery in a double-blind randomized clinical trial.

Settings: Cardiovascular surgery clinic.

Participants: One hundred twenty-five patients with decreased lung function were studied.

Interventions: Group A (62 patients) received 20 mL of 0.5% bupivacaine bilaterally in the intrapleural spaces every 6 hours for 4 days, and group B (63 placebo patients) received sterile saline solution.

Measurements and Main Results: Group A had a significantly shorter extubation time than the placebo group (8 ± 1 h v 10 ± 4 hours, p < 0.001). Blood gas analysis showed higher PaO₂ and lower PaCO₂ levels in group A. The patients receiving bupivicaine had significantly higher FEV₁, FCV, VC, MVV, PEF, and FEF 25-75% values postoperatively when compared with the placebo group. Postoperative analgesic requirements and visual analog pain scales were significantly lower in group A. The intensive care unit stay in group A was shorter (1.2 ± 0.7 v 1.4 ± 0.6 days, p = 0.04); however, the hospital stay did not differ between groups.

Conclusions: Improvement in lung function parameters correlating with decreased postoperative pain with intrapleural bupivacaine was observed. Intrapleural analgesia provided a good level of analgesia, improved respiratory performance, and allowed rapid mobilization, which led to a reduction of postoperative respiratory complications.

Key Words: intrapleural analgesia, bupivacaine, pulmonary complications, cardiopulmonary bypass, pulmonary function tests