Kyu Taek Choi

Modified right liver graft from a living donor to prevent congestion.

Background. Right liver grafts without middle hepatic vein (MHV) drainage reconstruction resulted in severe congestion of the anterior segment (AS) in our early experience of adult-to-adult living donor liver transplantation (LDLT). However, a detailed strategy for preventing such congestion or the necessity of MHV reconstruction has not been discussed in LDLT using a right lobe graft. Methods. From July 1997 to February 1998, two of five right lobe grafts without MHV drainage reconstruction were complicated with severe congestion of the AS. Thereafter, 42 adult recipients who received right liver grafts with sizable MHV tributaries underwent the reconstruction of MHV drainage. All sizable (>5 mm in diameter) MHV tributaries were preserved during donor hepatectomy and were reconstructed with the recipient’s autogenous interposition vein grafts at the bench surgery. The reconstructed vein grafts of this modified right lobe graft were anastomosed to the stump of the MHV and/or left hepatic vein of the recipient after graft revascularization. Results. Serial Doppler ultrasonography, which was regularly checked until 30 days posttransplant, revealed the patent interposition vein graft in 38 of 42 recipients (patency rate 90.5%). In these 38 recipients, no evidence of congestion in the AS was recognized on enhanced computed tomography, while providing enough functioning liver mass comparable to an extended right lobe graft. Also, congestion-related graft injury, such as an infarct of the AS, was not observed in these recipients. Conclusions. Our early experience indicated the necessity of MHV drainage reconstruction in right lobe grafts, which do not have MHV trunk in certain instances. However, preoperatively, it is difficult to predict the degree of AS congestion of the right liver graft without MHV drainage reconstruction. We suggest aggressive reconstruction of MHV drainage tributaries of the AS, under the circumstances that sizable MHV tributaries are encountered, to prevent possible congestion-related complications.

Effect of Hypocapnia on Extracellular Glutamate and Glycine Concentrations during the Periischemic Period in Rabbit Hippocampusa

Glutamate (GLU) is a neurotransmitter. Massive release of GLU and glycine (GLY) into the brains extracellular space may be triggered by ischemia, and may result in acute neuronal lysis or delayed neuronal death. The aim of this study was to evaluate the possible relationship between hyperventilation and the level of GLU and GLY during brain ischemia. Rabbits were anesthetized with halothane and oxygen. Group 1 was allowed to hyperventilate (PaCO2 25-35 mmHg). PaCO2 was maintained throughout the study. Group 2 was a normal control group that maintained normocapnia. Two global cerebral ischemic episodes were produced. Microdialysate was collected during the periischemic and reperfusion periods from the dorsal hippocampus. GLU and GLY concentrations were determined using high-performance liquid chromatography. In the control group, GLU and GLY were significantly elevated during each episode of ischemia; these levels returned to baseline within 10 minutes after reperfusion. In contrast, in the hyperventilation group GLU and GLY concentrations increased during ischemia, but they were not statistically significant. Two way ANOVA for the periischemic periods (t = 15,80; p = 0.06) revealed lower GLU values for the hyperventilated animals. A similar analysis for periischemic GLY concentrations revealed significantly lower values in the hyperventilated group (t = 10,15,75,80: p = 0.03) as compared to normal controls. We were able to demonstrate that hypocapnia during periischemic period lowered extracellular GLU and GLY concentrations. These results can explain a part of the protective action of hypocapnia during cerebral ischemia.

Effects of anesthesia on fluid volume kinetics after infusion of colloid solution during blood donation

Background The fluid kinetics of intravenously infused colloid during inhalation anesthesia and hemorrhage have not been investigated. We therefore assessed fluid space changes during infusion of hydroxyethyl starch solution after hemorrhage in conscious and desflurane-anesthetized individuals. Methods Following the donation of 400 ml of blood, 500 ml of hydroxyethyl starch solution was infused over 20 minutes into wakeful and desflurane-anesthetized volunteers. Blood was repeatedly sampled to measure hemoglobin concentration, a marker of plasma dilution, and fluid kinetic analysis was performed to evaluate changes in fluid space. Results Using a fluid kinetic model, we found that the mean volume of fluid space was 7,724 ± 1,788 ml in wakeful volunteers and 6,818 ± 4,221 ml in anesthetized volunteers, and the elimination rate constants were 7.1 ± 3.5 ml/min and 19.4 ± 4.6 ml/min, respectively. Conclusions Infusion of colloid after mild hemorrhage resulted in similar expansions of plasma volume in desflurane-anesthetized and conscious individuals. During anesthesia, however, the expansion of plasma volume by colloid was decreased and of shorter duration than observed in conscious patients.

Kinetics of volume expansion during infusion of Ringer’s solution based on two volume model

In this work mathematical models were developed to represent the kinetics of volume changes of fluid spaces associated with infusion of Ringer’s solution. During infusion of Ringer’s solution, the human body is assumed to be characterized by the two-fluid space model which has second volume space in addition to the first volume so that fluid exchanges between these two spaces are possible. Various infusion types were tested to accommodate different medical situations. Volunteers were given Ringer’s solution and the changes in blood hemoglobin were detected. From the comparison with experimental data, the two-fluid space model was found to represent adequately the kinetics of human volume expansion during infusion of Ringer’s solution.

Efficacy of Pectoral Nerve Block Type II for Breast-Conserving Surgery and Sentinel Lymph Node Biopsy: A Prospective Randomized Controlled Study

Objectives The pectoral nerve block type II (PECS II block) is widely used for postoperative analgesia after breast surgery. This study evaluated the analgesic efficacy of PECS II block in patients undergoing breast-conserving surgery (BCS) and sentinel lymph node biopsy (SNB). Methods Patients were randomized to the control group (n=40) and the PECS II group (n=40). An ultrasound-guided PECS II block was performed after induction of anesthesia. The primary outcome measure was opioid consumption, and the secondary outcome was pain at the breast and axillary measured using the Numerical Rating Scale (NRS) 24 hours after surgery. Opioid requirement was assessed according to tumor location. Results Opioid requirement was lower in the PECS II than in the control group (43.8u2009±u200928.5u2009µg versus 77.0u2009±u200941.9u2009µg, p < 0.001). However, the frequency of rescue analgesics did not differ between these groups. Opioid consumption in the PECS II group was significantly lower in patients with tumors in the outer area than that in patients with tumors in the inner area (32.5u2009±u200923.0u2009µg versus 58.0u2009±u200929.3u2009µg, p=0.007). The axillary NRS was consistently lower through 24u2009hr in the PECS II group. Conclusion Although the PECS II block seemed to reduce pain intensity and opioid requirements for 24u2009h after BCS and SNB, these reductions may not be clinically significant. This trial is registered with Clinical Research Information Service KCT0002509.

Prognostic Impacts of Increases in Amino Transaminases Following Coronary Artery Bypass Grafting on Mortality

OBJECTIVEnTo evaluate the prognostic impacts of postoperative increases in serum amino transaminases on 1-year mortality in patients who underwent coronary artery bypass graft.nnnDESIGNnA retrospective analysis.nnnSETTINGnA tertiary care university hospital.nnnPARTICIPANTSnA total of 1,950 patients who underwent coronary artery bypass graft.nnnINTERVENTIONSnNone.nnnMEASUREMENTS AND MAIN RESULTSnAspartate amino transaminase and alanine amino transaminase ratios were calculated as the ratio between the peak aspartate amino transaminase and alanine amino transaminase within the first 5 post-operative days and their respective upper limit of normal values. A ratio of 2.0 was seen to be the minimum for which a difference in 1-year mortality could be detected in univariate analysis, when considering simultaneously both aspartate amino transaminase and alanine amino transaminase ratios. Multivariable analysis showed an association between an aspartate amino transaminase ratio > 2.0 and increased 1-year mortality (hazard ratio [HR] 2.68, 95% confidence interval [CI] 1.42-5.05, P = 0.002), and also between both an aspartate amino transaminase and alanine amino transaminase ratio > 2.0 and increased 1-year mortality (HR 3.90, 95% CI 1.87-8.14, P < 0.001). However, increases in alanine amino transaminase only above the upper limit of normal were not associated with increased 1-year mortality.nnnCONCLUSIONSnPostoperative increases in aspartate amino transaminase only and increases in both aspartate amino transaminase and alanine amino transaminase greater than twice the upper limit of normal were associated with increased 1-year mortality in patients undergoing coronary artery bypass graft.

The predictive performance of infusion strategy nomogram based on a fluid kinetic model

Background In a previous study, fluid kinetic models were applied to describe the volume expansion of the fluid space by administration of crystalloid and colloid solutions. However, validation of the models were not performed, it is necessary to evaluate the predictive performance of these models in another population. Methods Ninety five consenting patients undergoing elective spinal surgery under general anesthesia were enrolled in this study. These patients were randomly assigned to three fluid groups i.e. Hartmanns solution (H group, n = 28), Voluven® (V group, n = 34), and Hextend® (X group, n = 33). After completion of their preparation for surgery, the patients received a loading and maintenance volume of each fluid predetermined by nomograms based on fluid pharmacokinetic models during the 60-minute use of an infusion pump. Arterial samples were obtained at preset intervals of 0, 10, 20, and 30 min after fluid administration. The predictive performances of the fluid kinetic modes were evaluated using the fractional change of arterial hemoglobin. The relationship between blood-volume dilution and target dilution of body fluid space was also evaluated using regression analysis. Results A total of 194 hemoglobin measurements were used. The bias and inaccuracy of these models were -2.69 and 35.62 for the H group, -1.53 and 43.21 for the V group, and 9.05 and 41.82 for the X group, respectively. The blood-volume dilution and target dilution of body-fluid space showed a significant linear relationship in each group (P < 0.05). Conclusions Based on the inaccuracy of predictive performance, the fluid-kinetic model for Hartmanns solution showed better performance than the other models.

The effects of inspiratory to expiratory ratio on ventilation and oxygenation during high frequency partial liquid ventilation in a rabbit model of acute lung injury

BACKGROUNDnWe examined the effects of varying inspiratory to expiratory (I : E) ratio on gas exchange and hemodynamics during high frequency partial liquid ventilation (HFPLV), a combination of high frequency ventilation (HFV) and partial liquid ventilation (PLV), in a rabbit model of acute lung injury.nnnMETHODSnTwelve rabbits treated with repeated saline lavage were divided into two groups. In the HFPL group (n = 6), 6 ml/kg of perfluorodecaline was administered through the endotracheal tube. Rabbits in this group and in the HFJ group (n = 6) were treated with high frequency jet ventilation (HFJV) at I : E ratios of 1 : 1, 1 : 2, and 1 : 3 for 15 minutes, and arterial blood gas, mixed venous blood gas and hemodynamic parameters were measured.nnnRESULTSnWe observed no significant respiratory and hemodynamic differences between the two groups. At an I : E ratio of 1 : 1, the PaO2 was significantly higher, and the shunt rate and PaCO2 were significantly lower in both groups, compared with I : E ratios of 1 : 2 and 1 : 3. Cardiac output at the 1 : 3 I : E ratio was significantly higher than at 1 : 1.nnnCONCLUSIONSnThese findings indicate that, in this model, a 1 : 1 I : E ratio was superior for oxygenation and ventilation than I : E ratios of 1 : 2 or 1 : 3, while having no detrimental effects on hemodynamics.

Hemodynamic Changes during the Pringle Maneuver in Patients with Abnormal Liver Function

Background: During the Pringle maneuver (PM), the increase of systemic vascular resistance (SVR) and the active constriction of the intrahepatic capacitance vessels could minimize arterial blood pressure change. Pressor reactivity to sympathetic agonists is impaired and blood volume buffering capability is less efficient in a cirrhotic liver . Accordingly, we evaluated the relations between hemodynamics during PM and preoperative liver function test (LFT) by serum aminotransferase and Indocyanine Green (ICG) clearance. Methods: Twenty-seven patients undergoing hepatectomy with PM were classified into two groups according to the liver function state assigned by serum aminotransferases and ICG clearance test. Sequential changes of hemodynamics were measured with Doppler flowmeter during PM. Hemodynamic data were analyzed by using ANOVA for repeated measurement. Correlation between LFTs were sought using Pearson correlation and logistic regression. Results: During the PM, cardiac output decreased significantly compared to the preclamping period in the abnormal LFT group. There were no significant changes in any other hemodynamic variables in the normal LFT group. When comparing the two groups during PM, mean arterial blood pressures and cardiac output were significantly lower in the abnormal LFT groups compared to the normal LFT groups (P < 0.05). Conclusions: These differences may suggest that cardiovascular responsiveness to reflex autonomic stimulation during the PM is significantly impaired in patients with abnormal LFT compared with normal LFT subjects. (Korean J Anesthesiol 1999; 37: 1020∼ 1026)