A comparative evaluation of intrapleural and thoracic epidural analgesia for postoperative pain relief after minimally invasive direct coronary artery bypass surgery.

OBJECTIVE

To compare the efficacy of thoracic epidural analgesia (TEA) and intrapleural analgesia (IPA) after minimally invasive direct coronary artery bypass (MIDCAB) surgery with regard to quality of analgesia and complications.

DESIGN

A prospective, randomized study.

SETTING

A specialty research hospital.

PARTICIPANTS

Fifty consenting adults scheduled for MIDCAB surgery.

INTERVENTIONS

All patients underwent elective MIDCAB surgery. Patients in the TEA group (n=25) had an epidural catheter inserted in the fourth to fifth thoracic interspace and those in the IPA group (n=25) had an intrapleural catheter inserted in the sixth to seventh intercostal space intraoperatively under vision.

MEASUREMENTS AND MAIN RESULTS

Parameters evaluated after administration of bupivacaine (8 mL of 0.25% in the TEA group and 20 mL of 0.25% in the IPA group) on first demand included visual analog scale (VAS) pain scores, cardiovascular and respiratory (clinical, blood gases) function, wakefulness, supplemental analgesic requirement, and complications. Measurements were made at 2-hour intervals for the next 12 hours. VAS scores were significantly lower at 2, 6, 8, and 12 hours in the IPA group (TEA = 3.5, 4.5, 4.9, 4.6; IPA = 2.2, 3.6, 3.5, 3.7). There were no significant differences in hemodynamic or respiratory parameters or postoperative requirement for supplemental analgesia. In the TEA group, three patients had catheter migration and four had severe backache.

CONCLUSION

IPA is a safe and effective technique for postoperative analgesia after MIDCAB surgery and has a low complication rate compared with TEA. Careful positioning, chest tube clamping, and anchoring of the catheter are mandatory for IPA to be effective.