Study of perioperative extravascular lung water and intrathoracic blood volume in patients undergoing CABG surgery with or without cardiopulmonary bypass

Background
Whether off-pump coronary artery bypass graft (OPCAB) surgery is superior to traditional on-pump coronary artery bypass graft (CABG) surgery still one of the most controversial areas of cardiac surgery and anesthesia. We hypothesized that OPCAB surgery may result in less accumulation of extra-vascular lung water (EVLW) and intra-thoracic blood volume (ITBV) in the peri-operative period.
Patients and Methods
Thirty patients underwent elective CABG surgery were randomized for this study, 15 OPCAB (group 1) and 15 on Pump (group 2). We measured EVLW and ITBV by PiCCO monitor in 8 times; before induction of anesthesia, after induction of anesthesia and before skin incision, before starting revascularization in group 1 or before cardiopulmonary bypass in group 2, at the end of revascularization in group 1 or at the end of CBP in group 2, at the end of surgery (after skin closure), two hours after the end of surgery, six hours after the end of surgery, twelve hours after the end of surgery and finally in the morning of first postoperative period.
Results
Demographic data and the preoperative characteristics were comparable in both patient groups. The intra-operative course was uneventful, and the intra-operative and postoperative characteristics were comparable in both patient groups. In all patients, complete revascularization was achieved. Extra-vascular lung water and intra-thoracic blood volume did not differ between groups in all times of measurements.
Discussion and Conclusion
The clinical advantage of off-pump CABG surgery over standard extracorporeal circulation in regard to lung water content was not found in our study. In conclusion, the presumed superiority of off pump surgery for coronary artery bypass grafting could not be confirmed in our group of patients.