Changes in Renal Blood Flow and Real-time Renal Cortical Perfusion According to Low-dose Nitroglycerin and Dopamine Administration Following the Occlusion and Reperfusion of Liver Blood Flow in Experimental Dogs / 대한마취과학회지

BACKGROUND: Pringle maneuver and nitroglycerin (NTG) administration to reduce hemorrhage during hepatectomy may affect renal blood flow (RBF) and renal cortical perfusion (RCP) by reducing blood pressure (BP), perload and others. However, so far there have been no studies on RBF and RCP changes during and after hepatic vascular maneuver in hepatectomy. The purpose of this study was to evaluate the changes in RBF and RCP along with low dose (2 microgram/kg/min) NTG with or without low dose (3 microgram/kg/min) dopamine after the occlusion and reperfusion of hepatic blood flow. METHODS: Eighteen mongrel dogs were divided into three groups according to drug administration after hepatic reperfusion; control group (group C, n = 6), NTG group (group N, n = 6), and NTG with dopamine group (group N-D, n = 6). After femoral arterial and central venous catheterization, a midline abdominal incision was made, and the hepatic artery (HA) and the portal vein (PV) were exposed for clamping and declamping. Thereafter, the right renal artery was exposed, and a doppler probe for measuring RBF was placed around the right renal artery, and a thermal diffusion microprobe was inserted in the renal outer cortex to measure RCP. Hemodynamics, RBF and RCP, were repeatedly measured before and after HA and PV reperfusion. RESULTS: No significant change in heart rate was observed in any group. The BP decreased in all the groups after HA and PV occlusion. In group C, the BP recovered to the baseline level after hepatic reperfusion but not in groups N and N-D. The RBF and RCP decreased in all groups after HA andPV occlusion. The RBF increased compared to baseline in N-D after hepatic reperfusion, and the RCP increased versus baseline in N-D, 10 minutes after hepatic reperfusion. CONCLUSIONS: In conclusion, it was observed that the RBF and RCP increased compared to baseline by administering dopamine during HA and PV reperfusion. Therefore, the prophylactic administration of low dose dopamine during hepatectomy offers an effective method of protecting renal function.

The Effect of Preventive Antihypertensive Medication with Nicardipine or Nitroglycerin during Off-pump Coronary Artery Bypass Graft / 대한마취과학회지

BACKGROUND: Tight control of blood pressure in patients with coronary artery disease is critical, especially in the setting of long-standing hypertension and left ventricular dysfunction. With off-pump coronary artery bypass graft (CABG), hypertension usually occurs after the sternotomy, along with an increase in heart rate and filling pressure. In order to minimize hypertension during this period, nitroglycerin or nicardipine was prophylactically infused. METHODS: Twenty patients scheduled to undergo an off-pump CABG from April to August, 2001, were selected and divided into two groups. Group I (n = 10) received nicardipine and Group II (n = 10) received nitroglycerin. Before the skin incision, nicardipine (0.5 - 1.0ng/kg/min) or nitroglycerin (0.5 - 1.0ng/kg/min) was continuously infused. Mean arterial pressure (MAP), heart rate (HR), mean pulmonary artery pressure (mPAP), pulmonary artery occlusion pressure (PAOP), cardiac index (CI), and the systemic vascular resistance index (SVRI) were repeatedly measured at the stages of preincision, postincision, poststernotomy, pericardium open, and 10 min after reperfusion. RESULTS: Although MAP after the sternotomy was increased compared with preincision, it remained within a normal range. Similarly, HR, mPAP, and PAOP were all within a normal range despite increases. The CI was within a normal range at all stages in both groups, and there were no significant difference between the two groups. In group I, the SVRI was significantly decreased compared with group II when pericardium was opened. CONCLUSIONS: Both nicardipine and nitroglycerin were effective in preventing or attenuating hypertension after sternotomy with the hemodynamic stability.