Won-Jung Shin

The supraglottic airway I-gel in comparison with ProSeal laryngeal mask airway and classic laryngeal mask airway in anaesthetized patients.

Background and objective The I-gel is a new single-use supraglottic airway device without an inflatable cuff. This study was designed to investigate the usefulness of the I-gel compared with the classic laryngeal mask airway (cLMA) and ProSeal laryngeal mask airway (pLMA) in anaesthetized, paralysed patients. Methods The American Society of Anesthesiologists physical status I–II patients (n = 167) scheduled for orthopaedic surgery were included in this prospective study. General anaesthesia was achieved with intravenous infusion of propofol, remifentanil and rocuronium. The patients were randomly assigned to I-gel, pLMA and cLMA groups (64, 53 and 50 patients, respectively). Properly sized I-gel (No. 3-4) or LMA (No. 4-5) was inserted. We assessed haemodynamic data, airway leak pressure, leak volume, success rates and postoperative complications. Results There were no differences in the demographic data and haemodynamic data immediately after insertion of devices among the three groups. The airway leak pressures of the I-gel group (27.1 ± 6.4 cmH2O) and pLMA group (29.8 ± 5.7 cmH2O) were significantly higher than that of the cLMA group (24.7 ± 6.2 cmH2O). The success rates for first attempt of insertion were similar among the three groups (P = 0.670). There were no differences in the incidence of adverse events except for the larger incidence of sore throat in the cLMA group. Conclusion I-gel may have a similar airway sealing to that of pLMA, higher than that of cLMA, and is not associated with adverse events. The I-gel might be an effective alternative as a supraglottic airway device.

Lactate and liver function tests after living donor right hepatectomy: a comparison of solutions with and without lactate

Background: Hyperlactatemia can predict the prognosis of patients undergoing liver resection. The effects of lactated Ringers solution on liver function have not been evaluated in patients undergoing major liver resection. We therefore compared the effects of two different crystalloid solutions, with and without lactate, on liver function test data and serum lactate level in living donors undergoing right hepatectomy.

Alterations in QT Interval in Patients Undergoing Living Donor Liver Transplantation

BACKGROUND QT interval prolongation, predisposing to ventricular tachyarrhythmia, has frequently been observed in patients with liver cirrhosis. During liver transplantation (LT) surgery, electrolyte imbalance and hemodynamic instability may affect QT interval changes. We evaluated the alterations in QT parameters at each stage of LT surgery. METHODS We assessed 50 living donor LT recipients without overt heart disease for the corrected QT (QTc) and the interval from peak to the end of the T wave (T(p-e)) automatically using Bazetts formula with LabChart software. QT parameters, laboratory and hemodynamic data were simultaneously collected in the following stages of LT: before anesthetic induction (baseline), pre-anhepatic, anhepatic, 1 hour postreperfusion, and after hepatic artery anastomosis. Recipients were allocated into 2 groups according to their baseline QTc: ≥440 versus <440 msec. RESULTS QTc progressively rose from the pre-anhepatic stage remaining prolonged in each stage of LT surgery compared with the baseline. In the anhepatic stage, 54% of recipients showed marked prolongation of QTc ≥500 msec (522 ± 14), which indicated the potential for a fatal ventricular dysrhythmia: 77% and 36% in groups with QTc ≥440 and <440 msec, respectively. As opposed to changes in QTc, T(p-e) in the anhepatic stage decreased significantly; however, it returned to the baseline level in the neohepatic stage. CONCLUSION A prolonged QTc interval (≥500 msec) was frequently observed throughout the procedure of LT, even among patients with baseline QTc <440 msec, emphasizing the importance of optimizing electrolyte balance and hemodynamic status to reduce greater risk of perioperative arrhythmias.

Comparison of Stroke Volume Variations Derived From Radial and Femoral Arterial Pressure Waveforms During Liver Transplantation

BACKGROUND Stroke volume variation (SVV) is being increasingly used to predict fluid responsiveness. Since radial arterial pressure (RAP) and femoral arterial pressure (FAP) frequently showing discrepancies during liver transplantation (LT), we sought to investigate the effect of differing arterial waveforms on SVV and cardiac output (CO) derived from the Vigileo device, by comparing SVV and CO values derived from RAP (SVV(RAP), CO(RAP)) and FAP (SVV(FAP), CO(FAP)) during LT. METHODS The linear associations and agreements between SVV(RAP) and SVV(FAP) and between CO(RAP) and CO(FAP) were assessed during LT. Hemodynamic variables were measured at nine predefined time points in all 32 recipients, resulting in 288 data pairs. RESULTS Correlations were observed between SVV(RAP) and SVV(FAP) (r = .961) and between CO(RAP) and CO(FAP) (r = .848) at all time points. These correlations between SVV(RAP) and SVV(FAP) (r = .923) and between CO(RAP) and CO(FAP) (r = .902) existed even during the period when mean RAP and FAP values differed (10 minutes after reperfusion). Bland-Altman analysis for SVV(RAP) versus SVV(FAP) and for CO(RAP) versus CO(FAP) showed weak biases (-0.2% and -0.5 L/min) and reasonable limits of agreement (-2.2 to 1.8% and -1.9 to 0.9 L/min). The percentage errors for SVV and CO values were 27.0% and 22.2%. CONCLUSIONS There was no significant difference between SVV(RAP) and SVV(FAP) when measured using the Vigileo device during LT. This finding indicated that SVV obtained using the Vigileo device offered relatively consistent information regardless of the catheterization site.

Laboratory Variables Associated with Low Near-Infrared Cerebral Oxygen Saturation in Icteric Patients Before Liver Transplantation Surgery

BACKGROUND: Although regional cerebral oxygen saturation (rSO2) measurements can detect disturbances in cerebral oxygenation, their usefulness is limited in patients with hyperbilirubinemia. We examined the relationship between rSO2 and other laboratory variables that may affect interpretation of low rSO2 in awake patients with end-stage liver disease before liver transplantation surgery. METHODS: Before induction of general anesthesia, rSO2 was measured in 164 patients with liver cirrhosis (Child class A/B/C = 19/41/104) and 8 with fulminant hepatic failure. Patients with West Haven hepatic encephalopathy of grade 3 or 4 were excluded. Relationships between rSO2 and laboratory variables were evaluated by correlation and multivariate regression, and by receiver operating characteristic curve analysis. RESULTS: Univariate analyses showed that rSO2 (median 58.5%, range 15% to 82%) correlated with serum total bilirubin, hemoglobin (Hb), creatinine, sodium, and magnesium concentrations, and prothrombin time (P < 0.001 each), but not with serum concentrations of glucose, albumin, potassium, and ammonia. Multiple logistic regression analysis showed that only elevated total bilirubin (range 0.4 to 66 mg/dL; odds ratio [OR] = 1.31; 95% confidence interval [CI] = 1.18 to 1.45) and low Hb (range 5.3 to 15.7 g/dL; OR = 0.21; 95% CI = 0.11 to 0.43) were independently related to rSO2 <50%. The optimum cutoff points for observing an rSO2 <50% were total bilirubin >7.2 mg/dL (sensitivity 89%, specificity 90%) and Hb <9.6 g/dL (sensitivity 70%, specificity 82%). CONCLUSIONS: High total bilirubin and low Hb concentrations were independently associated with rSO2 values below 50% in end-stage liver disease patients awaiting liver transplantation. The results of this study identify patients in whom a low rSO2 may be an artifact rather than cerebral ischemia.

Factors Associated With Changes in Coagulation Profiles After Living Donor Hepatectomy

BACKGROUND Hepatic resection may be associated with postoperative coagulopathy. However, there is limited information about the predictors affecting coagulopathy after donor hepatectomy. We evaluated the contributors of maximal changes in prothrombin time (PT), activated thromboplastin time (aPTT), and platelet count in the development of postoperative coagulopathy. METHODS We retrospectively analyzed 864 living donors, all of whom received general anesthesia using desflurane, isoflurane, or sevoflurane. A coagulation derangement was defined as one or more of the following events postoperatively: peak PT >1.5 international normalized ratio (INR; highest quartile of PT), peak aPTT >46 seconds (highest quartile of aPTT), or nadir platelet count <100 × 10(9)/L. Factors were evaluated by univariate and multivariate logistic regression analysis to identify predictors of coagulopathy. RESULTS Mean postoperative peak PT, peak aPTT, and nadir platelet count were 1.4 ± 0.2 INR, 43.8 ± 23.7 seconds, and 155.9 ± 37.3 × 10(9)/L, respectively, with 39.4% of donors being at the risk for coagulation derangement. Multivariate logistic regression analysis revealed that predictors of such derangement included anesthesia duration, remnant liver volume, and body mass index (BMI). However, coagulation derangement was not independently associated with age, gender, volatile anesthetics, central venous pressure, fatty change in the liver, estimated blood loss, or intraoperative hypotensive episodes. CONCLUSION We found that long anesthesia duration, low BMI, and small remnant liver volume were predictors of coagulation derangement. These results provide a better understanding of risk factors affecting changes in coagulation profiles after living donor hepatectomy.

Evaluation of Intraoperative Brain Natriuretic Peptide as a Predictor of 1-Year Mortality After Liver Transplantation

BACKGROUND Although brain natriuretic peptide (BNP), a marker of cardiac dysfunction, has been known to predict postoperative mortality, little is known about the postoperative prognostic ability of BNP in liver transplantation (OLT) recipients. We aimed to determine whether intraoperative BNP level can predict 1-year all-cause mortality after OLT. METHODS We retrospectively investigated 525 OLT recipients. BNP and hemodynamic parameters were simultaneously measured 1 hour after induction of anesthesia. Cox regression analysis and receiver operating characteristic curve analysis were performed to determine clinical predictors and optimal cutoff values of post-OLT mortality. RESULTS The 1-year all-cause mortality rate was 9.7% (51/525). Median BNP concentration was significantly higher in nonsurvivors than in survivors (114 vs 56 pg/mL, P < .001). Significant factors in univariate Cox regression analysis were Child-Pugh score, model for end-stage liver disease (MELD) score, logBNP, hemoglobin, creatinine, heart rate, systolic pulmonary arterial pressure, and central venous pressure. In multivariate Cox regression analysis, independent predictors of posttransplant mortality were MELD score and logBNP. However, simultaneously measured hemodynamic parameters did not remain predictors. BNP levels greater than a cutoff of 136 pg/mL (specificity = 83.5%, negative predictive value = 93.6%) were associated with increased post-OLT mortality (log-rank test P < .001). CONCLUSIONS Intraoperative BNP level is an independent predictor of 1-year all-cause mortality after OLT with a high negative predictive value, suggesting that its measurement appears useful in identifying patients at low risk of post-OLT mortality.

Does Stroke Volume Variation Predict Intraoperative Blood Loss in Living Right Donor Hepatectomy

BACKGROUND Although stroke volume variation (SVV) is a valuable index of preload responsiveness, there is limited information about the association between low SVV and increased hepatectomy-related bleeding. We therefore evaluated whether SVV predicts blood loss during living donor hepatectomy. METHODS We evaluated 93 adult liver donors undergoing right hepatectomy for transplantation. Arterial blood pressure, heart rate, body temperature, central venous pressure, SVV, cardiac output, and systemic vascular resistance were measured. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to determine independent factors and optimal cutoff values of hemodynamic parameters for predicting intraoperative blood loss ≥ 700 mL. RESULTS Of these 93 donors, 36 (38.7%) had blood loss ≥ 700 mL. Univariate logistic regression analysis showed that factors associated with blood loss ≥ 700 mL included heart rate, SVV, cardiac output, and systemic vascular resistance. Multivariate logistic regression analysis revealed that only SVV was an independent predictor of blood loss ≥ 700 mL. ROC curve analysis showed that the optimal cutoff value for SVV predicting blood loss ≥ 700 mL was 6% (area under the curve = 0.64). CONCLUSIONS SVV is a significant independent predictor of blood loss ≥ 700 mL during donor hepatectomy, suggesting that low SVV may provide useful information on intraoperative bleeding in donors undergoing right hepatectomy.

Effect of Right Ventricular Dysfunction on Dynamic Preload Indices to Predict a Decrease in Cardiac Output After Inferior Vena Cava Clamping During Liver Transplantation

BACKGROUND Dynamic preload indices such as stroke volume variation (SVV) and pulse pressure variation (PPV) have yielded false-positive results in patients with right ventricular (RV) dysfunction. We therefore assessed the effect of RV dysfunction on dynamic indices to predict the decrease in cardiac output (CO) during liver transplantation. METHODS Hemodynamic parameters were measured before and after inferior vena cava (IVC) clamping in 52 recipients. The RV dysfunction was defined as an RV ejection fraction (RVEF) ≤ 30%. The area under the receiver operating characteristic curve (AUC) sufficient to detect changes in CO (ΔCO) ≥ 20% after IVC clamping in recipients was calculated. RESULTS Recipients with RVEF ≤ 30% did not show significant increases in SVV or PPV despite having ΔCO ≥ 20%. In recipients with RVEF > 30%, the threshold value and AUC of SVV predicting a decrease in CO were 10% and 0.755 (compared with an AUC of 0.5, P = .011), respectively, whereas those for PPV were 10% and 0.767 (P = .007), respectively. However, in recipients with RVEF ≤ 30%, the threshold value and AUC of SVV were 10% and 0.638 (P = .305), respectively, whereas those for PPV were 12% and 0.684 (P = .159), respectively. CONCLUSIONS These results suggest that dynamic preload indices may not be sufficiently sensitive to detect a CO decrease in liver transplant recipients with RV dysfunction, emphasizing the importance of evaluating RV function when determining the predictability of dynamic indices.

Effect of Propranolol on the Relationship Between QT Interval and Vagal Modulation of Heart Rate Variability in Cirrhotic Patients Awaiting Liver Transplantation

BACKGROUND Prolonged corrected QT (QT(c)) interval and vagal dysfunction are common occurrences in liver cirrhosis and are determinants of mortality in patients with chronic liver disease. We evaluated whether propranolol can affect the relationship between QT(c) interval and cardiac vagal control of heart rate variability (HRV) in cirrhotic patients awaiting liver transplantation. METHODS We compared 50 cirrhotic patients (M/F = 43/7, 52.6 ± 8.4 years, Child-Pugh class A/B/C: 9/24/17) receiving propranolol with a sex-, age-, and liver disease severity-matched control group of 50 patients (M/F = 43/7, 52.0 ± 8.3 year, Child-Pugh class A/B/C: 9/24/17) not receiving propranolol. Among the parameters evaluated were QT(c) interval and cardiac vagal indices of HRV, including the root mean square of successive differences in R-R intervals (RMSSD); spectral power in the high-frequency range (HF); standard deviation (SD)1 in Poincare plot; and sample entropy. Correlations between QT(c) interval and vagal indices of HRV were analyzed. RESULTS The mean duration of preoperative propranolol treatment in the propranolol group was 19.4 ± 24.7 months. QT(c) interval was significantly lower, whereas RMSSD, HF, SD1, and sample entropy were significantly higher in the propranolol group than in the control group. Correlation coefficients between QT(c) interval and RMSSD, HF, SD1, and sample entropy were higher in the propranolol group than in the control group. CONCLUSIONS The prolonged QT(c) interval observed in cirrhotic patients may be reduced by propranolol administration, an effect attributable to improved vagal cardiac modulation. These findings suggest that propranolol may have a beneficial effect on perioperative mortality in cirrhotic patients awaiting liver transplantation.