Wook-Jong Kim

ABO-Incompatible Adult Living Donor Liver Transplantation Under the Desensitization Protocol With Rituximab

ABO incompatibility is no longer considered a contraindication for adult living donor liver transplantation (ALDLT) due to various strategies to overcome the ABO blood group barrier. We report the largest single‐center experience of ABO‐incompatible (ABOi) ALDLT in 235 adult patients. The desensitization protocol included a single dose of rituximab and total plasma exchange. In addition, local graft infusion therapy, cyclophosphamide, or splenectomy was used for a certain time period, but these treatments were eventually discontinued due to adverse events. There were three cases (1.3%) of in‐hospital mortality. The cumulative 3‐year graft and patient survival rates were 89.2% and 92.3%, respectively, and were comparable to those of the ABO‐compatible group (n = 1301). Despite promising survival outcomes, 17 patients (7.2%) experienced antibody‐mediated rejection that manifested as diffuse intrahepatic biliary stricture; six cases required retransplantation, and three patients died. ABOi ALDLT is a feasible method for expanding a living liver donor pool, but the efficacy of the desensitization protocol in targeting B cell immunity should be optimized.

Effect of Exogenous Albumin on the Incidence of Postoperative Acute Kidney Injury in Patients Undergoing Off-pump Coronary Artery Bypass Surgery with a Preoperative Albumin Level of Less Than 4.0 g/dl.

Background:Hypoalbuminemia may increase the risk of acute kidney injury (AKI). The authors investigated whether the immediate preoperative administration of 20% albumin solution affects the incidence of AKI after off-pump coronary artery bypass surgery. Methods:In this prospective, single-center, randomized, parallel-arm double-blind trial, 220 patients with preoperative serum albumin levels less than 4.0 g/dl were administered 100, 200, or 300 ml of 20% human albumin according to the preoperative serum albumin level (3.5 to 3.9, 3.0 to 3.4, or less than 3.0 g/dl, respectively) or with an equal volume of saline before surgery. The primary outcome measure was AKI incidence after surgery. Postoperative AKI was defined by maximal AKI Network criteria based on creatinine changes. Results:Patient characteristics and perioperative data except urine output during surgery were similar between the two groups studied, the albumin group and the control group. Urine output (median [interquartile range]) during surgery was higher in the albumin group (550 ml [315 to 980]) than in the control group (370 ml [230 to 670]; P = 0.006). The incidence of postoperative AKI in the albumin group was lower than that in the control group (14 [13.7%] vs. 26 [25.7%]; P = 0.048). There were no significant between-group differences in severe AKI, including renal replacement therapy, 30-day mortality, and other clinical outcomes. There were no significant adverse events. Conclusion:Administration of 20% exogenous albumin immediately before surgery increases urine output during surgery and reduces the risk of AKI after off-pump coronary artery bypass surgery in patients with a preoperative serum albumin level of less than 4.0 g/dl.

Association of Preoperative Uric Acid and Acute Kidney Injury Following Cardiovascular Surgery

OBJECTIVE Recent studies suggested that elevated serum uric acid levels may be associated with the risk of acute kidney injury (AKI) in several settings. However, the effect of uric acid on the risk of AKI after cardiovascular surgery remains uncertain. DESIGN A retrospective analysis. SETTING A tertiary care university hospital. PARTICIPANTS All consecutive adult patients (n = 1,019) who underwent cardiovascular surgery between January 2011 and May 2012. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Preoperative and perioperative data were assessed in the study population. AKI was defined and staged as serum creatinine concentration-based Acute Kidney Injury Network criteria. Univariate and multivariate logistic regression analyses were conducted to evaluate the association between preoperative uric acid and postoperative AKI. Preoperative elevated uric acid (≥ 6.5 mg/dL) was associated independently with AKI after cardiovascular surgery (odds ratio 1.46; 95% confidence interval 1.04-2.06, p = 0.030). Results were the same in subgroup analyses. Preoperative elevated uric acid (≥ 6.5 mg/dL) also was associated with a higher incidence of prolonged ICU and hospital stay. CONCLUSIONS Preoperative elevated serum uric acid is an independent risk factor for AKI in patients undergoing cardiovascular surgery. This finding suggests that preoperative measurements of serum uric acid concentration may help stratify risks for AKI in these patients.

Risk Factors of Postoperative Acute Kidney Injury in Patients Undergoing Esophageal Cancer Surgery

OBJECTIVE The purpose of this study was to identify perioperative risk factors for postoperative acute kidney injury (AKI) in patients undergoing esophageal cancer surgery. DESIGN A retrospective analysis of the prospectively collected medical data. SETTING A tertiary care university hospital. PARTICIPANTS All consecutive adult patients (n=595) who underwent elective esophageal surgery for cancer between January 2005 and April 2012. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS AKI was defined by the AKI Network criteria based on serum creatinine changes within the first 48 hours after esophageal cancer surgery. The relationship between perioperative variables and AKI was evaluated using multivariate logistic regression. Postoperative AKI developed in 210 (35.3%) patients. Risk factors for AKI were body mass index (odds ratio [OR] 1.07; 95% confidence interval [CI] 1.01-1.14), preoperative serum albumin level (OR 0.52; 95% CI 0.33-0.84), use of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers (OR 1.35; 95% CI 1.05-1.75), colloid infusion during surgery (OR 1.11; 95% CI 1.06-1.18), and postoperative 2-day C-reactive protein (OR 1.05; 95% CI 1.01-1.09). Postoperative AKI was associated with prolonged length of hospital stay. CONCLUSIONS Postoperative AKI is common in patients undergoing esophageal surgery for cancer. Closer evaluation and monitoring in patients with risk factors for AKI may be warranted.

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.

Intraoperative Renal Regional Oxygen Desaturation Can Be a Predictor for Acute Kidney Injury after Cardiac Surgery

OBJECTIVE To evaluate the usefulness of renal regional oxygen saturation (renal rSO2) in predicting the risk of acute kidney injury (AKI) after cardiac surgery. DESIGN A prospective observational study. SETTING Tertiary care university hospital. PARTICIPANTS One hundred patients undergoing cardiac surgery. INTERVENTIONS Renal rSO2 was monitored continuously by near-infrared spectroscopy (NIRS) throughout the anesthetic period. MEASUREMENTS AND MAIN RESULTS Postoperative AKI was defined using the Risk, Injury, Failure, Loss, and End-stage (RIFLE) criteria. Of 95 patients who were included in the final analysis, 34 patients developed AKI after surgery. Recorded renal rSO2 data were used to calculate the total duration of the time when renal rSO2 was below the threshold values of 70%, 65%, 60%, 55%, and 50%. The total periods when the renal rSO2 level was below each of the threshold values were significantly longer in patients with AKI than in those without AKI (p = 0.001 or p<0.001). Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive power of renal rSO2 for AKI. The ROC curve analysis showed that renal rSO2 could predict the risk of AKI with statistical significance and that a renal rSO2<55% had the best performance (area under the curve-ROC, 0.777; 95% CI, 0.669-0.885; p<0.001). Multivariate logistic regression analysis revealed that AKI significantly correlated with the duration of renal rSO2<55% (p = 0.002) and logistic EuroSCORE (p = 0.007). CONCLUSIONS Intraoperative renal regional oxygen desaturation can be a good predictor of AKI in adult patients undergoing cardiac surgery.

Adult Living Donor Liver Transplantation for Acute-on-Chronic Liver Failure in High–Model for End-Stage Liver Disease Score Patients

The large volume of adult living donor liver transplantations (ALDLTs) at our center affords a unique opportunity to examine the impact of acute‐on‐chronic liver failure (ACLF) among high–Model for End‐Stage Liver Disease MELD score patients. From February 1998 to March 2010, 1958 cirrhotic recipients were analyzed to study the relationship between MELD scores and ALDLT outcomes. A total of 327 high‐MELD score recipients were categorized into ACLF and non‐ACLF groups, and their outcomes were compared. The 5‐year graft and patient survival in the high‐MELD group were 75.2% and 76.4%, respectively, which were significantly worse than the low and intermediate MELD groups. The presence of ACLF associated with higher MELD scores appeared to be the dominant factor responsible for the inferior results of patients with MELD score of 30–34 points. The 5‐year graft survivals in the ACLF group was 70.5% and in the non‐ACLF group it was 81.0% (p = 0.035). Therefore, ALDLT should be performed as soon as possible in high‐MELD score patients prior to ACLF development. Moreover, ACLF patients should be separately categorized when analyzing the outcomes of ALDLT. ALDLT for ACLF patients should not be discouraged because favorable outcomes can be expected through timely ALDLT and comprehensive management.

The analgesic efficacy and safety of nefopam in patient-controlled analgesia after cardiac surgery: A randomized, double-blind, prospective study

Objective The efficacy and side-effects of nefopam were prospectively compared with those of fentanyl for patient-controlled analgesia (PCA) following cardiac surgery. Methods Patients scheduled to undergo cardiac surgery were randomly assigned between three PCA groups (nefopam, fentanyl or nefopam + fentanyl). Pain was assessed at rest and during movement at 12, 24, 36, 48 and 72 h after surgery using a visual analogue scale (VAS). Total infused PCA volume, number of rescue drug injections, duration of intubation and length of stay in the intensive care unit were recorded. The incidence of adverse effects was noted at 48 h postoperatively. Results There were no significant between-group differences in VAS score, total PCA infusion volume or number of rescue injections (n = 92 per group). Nausea was significantly more common in the fentanyl group compared with both other groups. Conclusions PCA with nefopam alone provides suitable postoperative analgesia after cardiac surgery.

Effect of remote ischemic preconditioning on cognitive function after off-pump coronary artery bypass graft: a pilot study

Background Several studies have shown in animal models that remote ischemic preconditioning (rIPC) has a neuroprotective effect. However, a randomized controlled trial in human subjects to investigate the neuroprotective effect of rIPC after cardiac surgery has not yet been reported. Therefore, we performed this pilot study to determine whether rIPC reduced the occurrence of postoperative cognitive dysfunction in patients who underwent off-pump coronary artery bypass graft (OPCAB) surgery. Methods Seventy patients who underwent OPCAB surgery were assigned to either the control or the rIPC group using a computer-generated randomization table. The application of rIPC consisted of four cycles of 5 min ischemia and 5 min reperfusion on an upper limb using a blood pressure cuff inflating 200 mmHg before coronary artery anastomosis. The cognitive function tests were performed one day before surgery and again on postoperative day 7. We defined postoperative cognitive dysfunction as decreased postoperative test values more than 20% of the baseline values in more than two of the six cognitive function tests that were performed. Results In the cognitive function tests, there were no significant differences in the results obtained during the preoperative and postoperative periods for all tests and there were no mean differences observed in the preoperative and postoperative scores. The incidences of postoperative cognitive dysfunction in the control and rIPC groups were 28.6% (10 patients) and 31.4% (11 patients), respectively. Conclusions rIPC did not reduce the incidence of postoperative cognitive dysfunction after OPCAB surgery during the immediate postoperative period.

Preoperative treatment with an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker has no beneficial effect on the development of new-onset atrial fibrillation after off-pump coronary artery bypass graft surgery.

The present study investigated whether preoperative angiotensin‐converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) use affected the incidence of postoperative atrial fibrillation (POAF) in patients undergoing off‐pump coronary artery bypass graft (OPCAB).