Shun-ichi Kimura

EFFECTS OF CONCOMITANT USAGE OF MILRINONE AND CATECHOLAMINE FOR WEANING FROM CARDIOPULMONARY BYPASS

To estimate the effectiveness of concomitant usage of milrinone and catecholamine for weaning from cardiopulmonary bypass (CPB), a clinical study was made, in elective coronary artery bypass grafting (CABG) cases. 24 consecutive patients underwent elective CABG in our institute. In all cases, moderate hypothermia and cardioplegic(St. Thomas solution) cardiac arrest were performed. In 12 cases, continuous intravenous 0.25 microgram/kg/min of milrinone, 3 micrograms/kg/min of dobutamine (DOB) and dopamine (DOA) as the initial doses, were used concomitantly as inotropic agents (Group-I). The same initial doses of catecholamine (DOB and DOA) as the Group-I were administered in another 12 patients (Group-II). When the pump flow of CPB decreased to a half, these drugs were administered in both groups. Hemodynamic data were measured before CPB, just after operation, 3, 6, 12, 24, 48, and 72 hours after operation. There were no significant differences in aortic and pulmonary artery pressure between both groups. However, cardiac index (CI) of the Group-I demonstrated significantly (p < 0.01) higher values than that of Group-II until 24 hours after surgery. Systemic vascular resistance index (SVRI) of the Group-I demonstrated significantly (p < 0.01) lower value than that of Group-II from 3 to 12 hours after operation. There were no significant differences in oxygen delivery (DO2) and oxygen consumption (VO2) between both groups. These results suggested that concomitant usage of milrinone and low dose catecholamine increased CI and decreased SVRI, and made weaning from CPB very easy, demonstrating excellent hemodynamics. This high potential phosphodiesterase inhibitor may be suitable for not only weaning from CPB but also post-cardiotomy cardiogenic shock.

Clinical evaluation of the Gyro Pump C1E3 as a cardiopulmonary bypass pump.

The Gyro Pump C1E3 is a new centrifugal pump with numerous features, including a ceramic pivot bearing system, secondary vanes, and an eccentric inlet port. To evaluate its biocompatibility, antithrombogenicity, and produced hemolysis, we used the Gyro Pump during cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG) cases to compare it with the BioMedicus pump. From September 1998 to February 1999, 30 consecutive patients underwent CABG under conventional CPB. Fifteen patients were supported by the Gyro Pump C1E3 (Group G), and the remaining 15 patients, by a BioMedicus BP-80 pump (Group B). In both groups, flow rate was equivalent. Blood samples were taken as follows: preoperative, 60 minutes after the end of the procedure, and at postoperative days (POD) 0, 1, and 2. We evaluated the plasma free hemoglobin (free Hb) as an indication of hemolysis; beta-thromboglobulin (beta-TG) and platelet factor four (PF-4) as an indication of platelet deterioration; C3, C4, CH50 for complement activation; coagulation parameters, fibrinolytic factor, thrombomodulin, nitric oxide (NO), and endothelin as an indication of endothelial deterioration. This was the first clinical sized Gyro Pump CIE3. De-airing from the pump was easily accomplished via the eccentric oblique inlet port. The system, including its console, was easily and simply controlled. Perioperative laboratory data were not markedly changed in either group with demonstrated equivalence for biocompatibility and hemolysis. After pumping, no thrombus formation or pivot wear were observed inside the pump. This atraumatic, small centrifugal pump appears well suited not only for CPB but also for circulatory support.

Retrospective analysis of the clinical trends and current indications for perioperative intraaortic balloon pumping in high-risk coronary artery bypass surgery

We clinically evaluated the current indications for perioperative intraaortic balloon pumping (IABP) in high-risk patients undergoing coronary artery bypass grafting (CABG). Over the past 22 years, 196 CABG patients received perioperative IABP at our institution. We divided the 22 years into periods I–IV (earliest to latest) and investigated the annual changes in the indications for and mortality from IABP. In periods I and II, IABP was mainly employed for postoperative low-output syndrome (LOS) or perioperative myocardial infarction (PMI). The hospital mortality rate was 13.2%–18.5%. In period III, the mortality rate was markedly reduced by the use of preoperative scheduled IABP. In period IV, however, scheduled IABP was used less often for high-risk CABG, and IABP was mainly employed in patients having emergency CABG for acute coronary syndrome (ACS). The hospital mortality rate was reduced to 3.7%. In the last 2 years, 19 (65.5%) of 29 patients who received preoperative IABP had emergency CABG for ACS, while 27 high-risk CABG patients with poor left ventricular (LV) function or left main trunk (LMT) disease were treated successfully without scheduled IABP. There were no significant differences between the IABP and non-IABP patients in age, sex, number of bypasses, and aortic cross-clamp time. Because of improvements in anesthesia, operative techniques, perioperative management, and cardioplegic solutions, preoperative support with IABP is less often needed for high-risk CABG, except in patients undergoing emergency surgery for ACS.