ABSTRACT
Recently, arterial keton body ratio (AKBR) has attracted attention as a new indicator of liver function which is in equibilium with the ratio between oxidized and reduced forms of free nicotinamide-adenine dinucleotides (free NAD<sup>+</sup>/NADH ration) in the mitochondria. There are few reports on whether AKBR contributes to the hepatic energy charge in the open heart surgery with extra corporeal circulation (ECC) or not. This study was undertaken to clarify the contribution of AKBR to the hepatic energy charge during ECC and the relationship between AKBR and hepatic blood flow. AKBR was determined before, during and after ECC in the open heart surgery for 14 patients. Furthermore, the blood flow in hepatic artery, portal vein and liver microcirculation was measured before, during and after ECC in canine models. Finally, the pulsatile perfusion was performed in canine models and compared with the conventional non-pulsatile perfusion for the blood flow and AKBR. In clinical cases, AKBR was decreased in all cases during the ECC. AKBR which was measured at 2 or 3hr after weaning from the ECC was negatively correlated to the total perfusion time with -0.57 as the correlation coefficient. Six patients who were on the ECC over 180min did not show a good recovery of the AKBR after weaning from the ECC. Especially, three patients presented a clinical picture of acute hepatic failure with jaundice, elevation of the serum levels of transaminase and direct hyperbililubinemia, but only one showed hypoglycemia. These patients showed no improvement in clinical data and AKBR. The patient with improved AKBR recovered clinically. In our experiment, the blood flow in the hepatic artery, portal vein was measured by electromagnetic blood flow meter and the liver microcirculation was measured by laserdoppler flowmeter. The blood flow was decreased remakably in the non-pulsatile group at all sites of measurement: it recovered after ECC in hepatic artery and portal vein, but liver microcirculation did not improve well. AKBR was decreased during ECC and did not recover after ECC in the non-pulsatile perfusion. When the pulsatile perfusion was performed, liver circulation was maintained well, and AKBR recovered well after ECC. The above results suggest that AKBR reflects the liver microcirculation and pulsatile perfusion is beneficial to the liver microcirculation. Pulsatile circulation, however, involves several problems, hemolysis, the decrease of platelets, and so on, but these problems have been improved gradually. We think that the pulsatile perfusion will be used in clinical operations to maintain the good hepatic circulation.
ABSTRACT
We tried to evaluate the right ventricular function using a modified Swan-Ganz catheter with a rapid responsive thermistor. Twenty-four dogs comprised this series. Twelve were the model of left heart failure (Group A), and the other twelve were the model of right heart failure (Group B) produced by multiple ligation of coronary arteries. Dogs were studied for some of the circulatory indices before and after ligation with left atrial pressure at 10, 15 and 20mmHg in group A, and right atrial pressure at 10, 15 and 20mmHg in group B by volume loading. In group A, when the left atrial pressure was kept constant, right ventricular ejection fraction (RVEF) and right ventricular stroke work index (RVSWI) were decreased significantly after the ligation of coronary arteries. But there was no significant change in the peak right ventricular pressure-right ventricular endsystolic volume index ratio (peak RVP/RVESVI) associated with ligation. In group B, significant changes were observed in RVEF, RVSWI and peak RVP/RVESVI. Thus, it was found that right ventricular contractility in selective left heart failure was not reduced. <i>E</i><sub>max</sub> was considered to be a valuable index of ventricular contractility not affected by preload and afterload of ventricle, but this index is not easily measured clinically. The index peak RVP/RVESVI which is nearly equivalent to <i>E</i><sub>max</sub>, has an advantage in that it can be determined by the thermodilution method widely used in general. We conclude that this index is very useful to us for post-operative care in cardiac surgery.