REDUCTION IN PULMONARY MICROVASCULAR PRESSURE FOLLOWING CARDIOPULMONARY BYPASS - BENEFICIAL-EFFECTS OF DOBUTAMINE

Pulmonary microvascular pressures (PMVP) have important diagnostic and therapeutic implications when utilized to monitor pulmonary dysfuncti on after cardiopulmonary bypass, Elevations in PMVP may lead to inters titial pulmonary edema and right ventricular failure, This study evalu ated the influence of Dobutamine on PMVP in a trial of 80 consecutive patients undergoing isolated coronary artery bypass grafting (CABG), F orty patients were randomized to the Dobutamine study group and receiv ed 5 mu g/kg/min of Dobutamine for 24 hours, starting at the completio n of bypass, In the control group, patients received postoperative ino tropic support as indicated (dopamine [n=10] or amrinone [n=6]) by the clinical situation, PMVP values were computed based on continuous hem odynamic monitoring at 6, 12, 18 and 24 hours, Preoperative demographi c descriptors and operative variables were comparable between the two groups, Postoperative fluid requirements and nonpulmonary complication s were also similar between groups, Upon completion of cardiopulmonary bypass, PMVP (mean+/-SD) were PMVP decreased over time in the Dobutam ine group, while it did not change in the control group, Clinically me an time to extubation was reduced from 18 to 12 hours (p<0.06) in the Dobutamine group, We conclude that in patients undergoing cardiopulmon ary bypass, the postoperative administration of Dobutamine significant ly reduces the PMVP. This may reduce pulmonary interstitial edema and pulmonary complications, Upon completion of cardiopulmonary bypass, PM VP (mean+/-SD) were measured at 6 hours, 12 hours, 18 hours and 24 hou rs, The control group measured 25+/-5 mmHg, 26+/-2 mmHg, 27+/-3 mmHg a nd 28+/-3 mmHg. The Dobutamine group measured 25+/-6 mmHg, 24+/-3 mmHg , 22+/-2 mmHg and 18+/-5 mmHg. PMVP decreased over time in the Dobutam ine group (p<0.001), while it did not change in the control group, Cli nically mean time to extubation was reduced from 18 to 12 hours (p<0.0 6) in the Dobutamine group, We conclude that in patients undergoing ca rdiopulmonary bypass, the post-operative administration of Dobutamine significantly reduced PMVP. This may reduce pulmonary interstitial ede ma and pulmonary complications post cardiopulmonary bypass.