Comparative Study of Heparinase Treated Activated Clotting Time with Hephrinase Treated Thromboelastography for Detecting Residual Heparin Effects Following Cardiopulmonary Bypass / 대한마취과학회지

Residual heparin effects after protamine reversal is a potential bleeding disorder associated with cardiopulmonary bypass(CPB). To differentiate this from the other multiple factors causing coagulopathy should be initialized in the setting of management. The purpose of this study was to compare simple activated clotting time(ACT) and thromboelastography(TEG) with heparinase treated ACT and TEG for detecting residual heparin effects to distinguish rapidly the presence of heparin from the effects of other factors because the enzyme heparinase specifically neutralized heparin. After institution approval, 20 patients who required open heart surgery were studied. Baseline kaoline ACT, heparinase ACT, TEG and heparinase TEG(Haemoscope) were obtained before CPB on the same blood sample. The repeated tests were performed on the same blood samples 20 minutes after protamine reversal following CPB. Differences between heparinase treated tests and untreated tests were also evaluated at the same time. Wilcoxon signed ranked test was used to compare the results between before and after bypass. None of patients had significant postoperative bleeding complication. All tests before bypass were normal. Twenty minutes after protamine reversal, 3 patients showed kaoline ACT were extended above 10% of the value of heparinase ACT but all of them remained within normal range. However, nearly all patients showed heparin effects on TEG. The heparin effects on TEG were defined as significant differences in all of parameters, especially in alpha angle and R+K time between simple TEG and heparinase TEG. In Conclusion, heparinase treated ACT and native ACT are not sensitive to residual heparin effects after CPB. Their normal results did not preclude residual heparin effects on heparinase modified TEG. However, it might be further investigated to need additional protamine in the case of residual heparin effects on TEG.

Two Cases of Postoperative Bleeding Monitored by Thromboelastography in Reoperation of Open Heart Surgery / 대한마취과학회지

The excessive postoperative hemorrhage increases the mortality and morbidity after surgery. The longer expracorporeal circulation time, the worse the patient's blood coagulation disorder. And it makes the possibility of bleeding tendency predictable. We have two clinical experiences of reoperation due to postoperative hemorrhage after open-heart surgery. As with the heparin independent thromboelastography(TEG) following Cardiopulmonary Bypass(CPB) and postbypass TEG, we could distinguish expectantly surgical bleeding from medical bleeding relating with open heart surgery.

The Assessment of Change in Total Oxygenation by Continuous Monitoring of Mixed Venous Oxygen Saturation during Canine Orthotopic Liver Transplantation / 대한마취과학회지

There are many hemodynamic and physiologic changes during liver transplantation much more than other surgical interventions. The oxygen delivery and oxygen consumption are af- fected by depressed hemodynamic and metabolic status during the operation. At the lower levels of oxygen present in venous blood, a linear relationship exists between saturation and tension. The use of fiberoptic oximetry system in conventional pulmonary artery flotation catheters has made the bedside application of this relationship of practical value in the continuous assessment of mixed venous oxygen saturation. This study was performed to determine changes in SvO2 and other variables of oxygen kinetics during canine OLT and study the correlation between SvO2 and cardiac output, SvO2 and oxygen consumption and oxygen utilization ratio. The continuous rnixed venous oxygen saturation and cardiac output by SO2/CO computer were monitored and the oxygen delivery, oxygen consumption and oxygen utilization ratio were calculated by arterial and venous blood gas analysis and modified Fick's equation during orthotopic liver transplantation in 20 dogs. The results were as follow as ; 1. There was no significant difference in tissue oxygen extraction between preoperative control and anhepatic phase, while cardiac output were decreased during anhepatic phase. 2. By utilizing centrifugal pump(venovenous bypass) oxygen delivery and oxygen utilization ratio were well maintained even though suppressed the change of oxygen delivery and oxygen consumption during anhepatic phase. 3. There was a significant decrease in SvO2 immediately after declamping the suprahepatic vena cava, whereas the oxygen utilization rate and oxygen consumption following reperfusion were significantly increased than just prior to reperfusion of transplanted liver. 4. A Statistically significant correlation was found between SvO2 and cardiac output, oxygen consumption in all surgical stages except reperfusion(CO;r=0.478, p<0.001, VO2,r=-0. 272, p=0.004), but their correlations were relatively poor. However, there was highly significant correlation among SvO2 and oxygen utilization ratio in all surgical stages(O2UR; r=- 0.834, P<0.001). In conclusion, continuous monitoring mixed venous oxygen via a fiberoptic pulmonary catheter could be used as the index for evaluation of hemodynamics and oxygen kinetics during canine OLT, but further research should be performed to determine whether these measurements indicate viability of the grafted liver.