Changes in Pulmonary Arterial Pressure and Pulmonary Vascular Resistance after Mitral Valve Replacement / 대한마취과학회지

As the mitral valve disease becomes long-standing, the patient may develop pulmonary hypertension. It was reported that after surgical correction, the elevated pulmonary vascular resistance(PVR) would fall quickly in association with the fall in left atrial pressure(LAP). This study was performed to evaluate the changes in mean pulmonary artery pressure(PAP) and PVR immediately after mitral valve replacement(MVR). Fifty six patients undergoing mitral valve replacement(MVR) were divided into two groups on the basis of the presence or absence of significant pulmonary hypertension, defined as a resting mean pulmonary arterial pressure greater than 30mmHg. After induction of anesthesia, PAP, PVR, cardiac output(CO) were measured and compared with values in postbypass period. PAP and PVR were significantly decreased(PAP from 39.64+/-1.88 to 29.18+/-1.65 mmHg, P 0.001, PVR from 6.16+/-1.14 to 3.53+/-0.62 units, P or = 30mmHg, n=23), whereas not changed in Group I(PAP30 mmHg, n=33)(P<0.05). Persistance of an elevated PVR may cause right ventricular failure and low-output syndrome, so that an attempt to reduce the PVR is needed postoperatiavely. This study demonstrated that the PAP and PVR fall significantly after MVR especially in patients with severe pulmonary hypertension.

Effects of Perioperative Colliction of Blood and Acute Normovolemic Hemodilution on Requirement of Homologous Transfusion During Open Heart Surgery / 대한마취과학회지

This study was designed to investigate the effect of preoperative collection of blaod and acute normovolemic hemodilution(ANH) on the requirement of homologous transfusion, perioperative blood loss and hematological parameters in patients undergoing open heart surgery. Ninety two adult patients for elective open heart surgery were randomly assigned to one of three groups. Group I, ANH group, had blood withdrawn to a hematocrit of 33%o after induction of anesthesia(n =54). In Group II preoperative collection of blood in accordance with hospital protocol and ANH were performed(n=16). Ciroup III was control group(n=22). Autologous blood was replaced post bypass. The patients whose hematocrit fell below 25% were transfused with homologous blood. The use of homologous transfusion was 2.2+/-0.4 units in group I, 0.1+/-0.1 units in group II and 4.1+/-0.8 units in group III. Requirement of homologous transfusion in group II was reduced compared with group II and III with statistical significance(P<0.05). There was statistical significance between group I and group III(P<0.05) in homologous transfusion. Postoperative blood loss was 760.7+/-74.6 ml in group I, 675.6+101.5 ml in group II and 819.3+/-91.3 rnl in group III. There was no statistical significance among 3 groups. There was no difference in hematocrit or platelet count, and total blood loss on immediately post surgery or on day 1. Our data show that preoperative collection of blood and ANH can reduce the amount of homologous transfusion.