Intercostal versus subxiphoid approach for pleural drainage post coronary artery bypass grafting

Background: Pleurotomy increases pulmonary dysfunction in coronary artery bypass graft (CABG) patients. It is not known whether subxiphoid approach is associated with better pulmonary function and less pain compared to the intercostal approach. The objective of this study is to compare postoperative pain and pulmonary function in patients with subxiphoid versus intercostal pleural drains post CABG. Methods: 71 patients had CABG with left internal thoracic artery harvested and left pleurotomy. According to left pleural drain site, patients were grouped into group I (intercostal drain, n = 38) and group II (subxiphoid drain, n = 33). Preoperative FEV1/FVC was 81.5 ± 8.17 versus 78.72 ± 8.1 and PO2/FiO2 was 388.2 ± 38.9 versus 374.9 ± 38.6 in group I and II respectively. These differences between the two groups were not significant as well as the other preoperative patients' characteristics and operative variables. Results: There was no difference between groups with respect to residual left pleural effusion detected by postoperative CT. Analgesic use was significantly higher in patients with intercostal pleural drain (p-value = 0.014). No significant difference in pulmonary function postoperatively between groups. Intercostal pleural drain was a significant predictor of postoperative analgesic dose by multivariable regression analysis (p-value = 0.016). By instrumental variable analysis according to surgeons' preference, intercostal pleural drains were not associated with residual pleural effusion (p-value = 0.11) nor deterioration of pulmonary functions (p-value = 0.09) but were associated with increased postoperative analgesic dose (p-value = 0.03). Conclusions: Both approaches for pleural drains post CABG are effective without compromising pulmonary functions. More analgesia is required for patients with intercostal pleural drain