Intraoperative Management of Liver Transplant Patients Without the Routine Use of Renal Replacement Therapy

Intraoperative hemodialysis with supra- and infradiaphragmatic catheters for liver transplantation

PURPOSE

The benefits of intraoperative dialysis during orthotopic liver transplantation remain controversial. In patients with anuric renal failure and portopulmonary hypertension, maintaining venous return during caval clamping and unclamping along with minimizing fluid overload is critical to avoiding right ventricular strain and failure.

CLINICAL FEATURES

We present the case of a 54-yr-old female who underwent orthotopic liver transplantation for alcohol-related liver disease with acute decompensation including severe hepatorenal syndrome (anuric requiring dialysis), probable hepatopulmonary syndrome, moderate pulmonary hypertension (right ventricular systolic pressure, 44 mm Hg), hepatic encephalopathy (grade 2), and esophageal varices. Prior to incision, pulmonary arterial pressures were 48/28 (mean, 35) mm Hg with a central venous pressure of 30 mm Hg, cardiac output of 7.4 L·min-1, and pulmonary vascular resistance of 98 dynes·sec·cm-5. In the context of right ventricular strain and volume overload observed on transthoracic echocardiography, we inserted an additional dialysis catheter into the right femoral vein. We initiated dialysis using the two catheters as a circuit (femoral line to the dialysis machine; blood was reinjected via the subclavian line) acting as a limited venovenous bypass, allowing right ventricular offloading and hemodialysis throughout the case. We removed 4.5 L via hemodialysis during the surgery, while avoiding acidosis, hyperkalemia, and sodium shifts. The patient tolerated reperfusion adequately despite pre-existing right ventricular dilation and dysfunction.

CONCLUSION

We report on the use two hemodialysis catheters in a patient undergoing orthotopic liver transplantation as a circuit for simultaneous anuric hepatorenal syndrome and moderate pulmonary hypertension with right ventricular dilation and dysfunction. We believe this technique was instrumental in the patient's successful transplant.

Lactate concentration at the end of liver transplant: Early predictor of graft function or just one piece of the puzzle?

BACKGROUND

The post-operative course after Liver Transplantation (LT) can be complicated by early allograft dysfunction (EAD), primary nonfunction (PNF) and death. A lactate concentration at the end of transplant of ≥5 mmol/L was recently proposed as a predictive marker of PNF, EAD, and mortality; this study aimed to validate these previous reports in a large single center cohort.

METHODS

This retrospective cohort study included adult liver transplant recipients who received grafts from deceased donors at our center between June 2012 and May 2021. Receiver operating characteristic (ROC) curves for the lactate concentration at the end of transplantation were computed to determine the AUC for PNF, EAD and mortality at 90 days.

RESULTS

In our cohort of 1137 cases, the AUCs for lactate to predict EAD, PNF and mortality were respectively .56 (95% confidence interval [CI]: .53-.60), .69 (95% CI: .52-.85), and .74 (95% CI: .63-.84).

CONCLUSION

The clinical value of lactate concentration at the end of transplantation to predict PNF, EAD and mortality at 90 days was, at best, modest, as shown by the relatively low AUCs. Our findings cannot validate previous reports that the lactate level alone is a good predictor of poor outcomes after liver transplantation.

Intraoperative Renal Replacement Therapy in Orthotopic Liver Transplantation

Acute kidney injury in patients admitted to the hospital for liver transplantation is common, with up to 80% of pretransplant patients having some form of acute kidney injury. Many of these patients start on dialysis prior to their transplant and have it continued intraoperatively during their surgery. This review discusses the limited existing literature and expert opinion around the indications and outcomes around intraoperative dialysis (intraoperative renal replacement therapy) during liver transplantation. More specifically, we discuss which patients may benefit from intraoperative renal replacement therapy and the impact of hyponatremia and hyperammonemia on the dialysis prescription. Additionally, we discuss the complex interplay between anesthesia and intraoperative renal replacement therapy and how the need for clearance and ultrafiltration changes throughout the different phases of the transplant (preanhepatic, anhepatic, and postanhepatic). Lastly, this review will cover the limited data around patient outcomes following intraoperative renal replacement therapy during liver transplantation as well as the best evidence for when to stop dialysis.

Acute Kidney Injury and Renal Replacement Therapy: A Review and Update for the Perioperative Physician

Post-operative acute kidney injury is a devastating complication with significant morbidity and mortality associated with it. The perioperative anesthesiologist is in a unique position to potentially mitigate the risk of postoperative AKI, however, understanding the pathophysiology, risk factors and preventative strategies is paramount. There are also certain clinical scenarios, where renal replacement therapy may be indicated intraoperatively including severe electrolyte abnormalities, metabolic acidosis and massive volume overload. A multidisciplinary approach including the nephrologist, critical care physician, surgeon and anesthesiologist is necessary to determine the optimal management of these critically ill patients.

Successful use of intra-operative continuous renal replacement therapy in pediatric liver transplant recipients: Single center case series

BACKGROUND

Acute kidney injury (AKI) is common in pediatric patients undergoing liver transplantation (LT), with an incidence 17%-55%. Fluid, metabolic, and acid-base aberrancies are often pronounced pre-operatively and further worsened by events during LT, making intra-operative continuous renal replacement therapy (CRRT) an option for critically ill LT recipients.

METHODS

All pediatric LT performed at our institution who underwent intra-operative CRRT between January 2017 and August 2021 were included. Patient demographics and clinical data including graft outcomes, intra-operative findings, and timing and indications for CRRT were collected from the electronic medical record.

RESULTS

CRRT was used in nine of the 76 (12%) pediatric LT performed at our center during the study period. Ages at LT ranged from 39 to 17.7 years. Recipients requiring CRRT were more likely to have acute liver failure, status 1A, and higher calculated MELD/PELD scores. CRRT was initiated pre-transplant in three recipients and continued post-transplant in six recipients. Median duration of CRRT was two (range 0-14) days. Indications included hyperammonemia (3/9), acidosis (3/9), fluid overload (6/9), and hyperkalemia (2/9). The CRRT group had a significantly longer post-transplant intensive care unit length of stay in comparison to those that did not require CRRT (median 6, range 3-40 days vs. median 3, range 0-121 days, p = .02], but there were no significant differences in reoperations, hospital length of stay, or recipient or graft survival.

CONCLUSIONS

We demonstrate that CRRT can be safely performed in pediatric LT recipients, including young infants through adolescents.

Intraoperative dialysis with the use of a mobile dialysis system during liver transplantation

PURPOSE

Over the last few years, transplant centers have started to use various intraoperative renal replacement therapy (ioRRT) modalities during liver transplantation (LT) in patients with pre-existing renal impairment. Here, we present a study on the safety and clinical outcomes of intraoperative hemodialysis (ioHD) performed using a mobile dialysis system during LT.

PATIENTS AND METHODS

We retrospectively analyzed 102 adult patients undergoing LT with ioHD; pre-existing renal failure and/or intraoperative metabolic derangement were ioHD treatment indications.

RESULTS

Our study cohort consisted of three groups: LT with preoperative serum creatinine (sCr) ​< ​2 ​mg/dL (Group 1:n ​= ​22), LT with preoperative sCr ≥2 ​mg/dL (Group 2:n ​= ​73), and simultaneous liver-kidney transplantation (Group 3:n ​= ​7). Among the procedures, 30% were re-transplantations. The mean calculated Model for End-stage Liver Disease score in Group 2 was 39.2, and 67% of patients were hospitalized in the intensive care unit. Patients in Group 1 were less acutely ill but developed severe intraoperative derangements and, therefore, underwent urgent ioHD intraoperatively. However, it was delayed when compared to Group 2. All groups achieved post-reperfusion potassium levels <4 ​mmol/L and a decrease in central venous pressure. No serious procedural complications occurred. Post-reperfusion syndrome occurred in 12.7% of patients. Elevated mortality was likely due to the high illness severity in the cohort.

CONCLUSIONS

Performing ioHD with a mobile dialysis system during LT was safe and effective, while being easier to perform than continuous techniques. Its effect on intra- and postoperative outcomes should be addressed in a study with a control group.

Adult liver transplant anesthesiology practice patterns and resource utilization in the United States: Survey results from the society for the advancement of transplant anesthesia

INTRODUCTION

Liver transplant anesthesiology is an evolving and expanding subspecialty, and programs have, in the past, exhibited significant variations of practice at transplant centers across the United States. In order to explore current practice patterns, the Quality & Standards Committee from the Society for the Advancement of Transplant Anesthesia (SATA) undertook a survey of liver transplant anesthesiology program directors.

METHODS

Program directors were invited to participate in an online questionnaire. A total of 110 program directors were identified from the 2018 Scientific Registry of Transplant Recipients (SRTR) database. Replies were received from 65 programs (response rate of 59%).

RESULTS

Our results indicate an increase in transplant anesthesia fellowship training and advanced training in transesophageal echocardiography (TEE). We also find that the use of intraoperative TEE and viscoelastic testing is more common. However, there has been a reduction in the use of veno-venous bypass, routine placement of pulmonary artery catheters and the intraoperative use of anti-fibrinolytics when compared to prior surveys.

CONCLUSION

The results show considerable heterogeneity in practice patterns across the country that continues to evolve. However, there appears to be a movement towards the adoption of specific structural and clinical practices.

Intraoperative Renal Replacement Therapy: Practical Information for Anesthesiologists

Previous publications regarding perioperative renal replacement therapy (RRT) have focused on the general care of the RRT-dependent patient and provided a broad overview of the various RRT modalities. The goal of this review article is to provide anesthesiologists with specific practical information regarding the possible intraoperative advantages and limitations of each modality, mandatory equipment to institute intraoperative therapy, and background knowledge necessary to communicate effectively with nephrologists and/or support staff regarding the intraoperative RRT goals.

Intraoperative Continuous Renal Replacement Therapy During Liver Transplantation: A Meta-Analysis

Continuous renal replacement therapy (CRRT) is frequently used to treat recipients with renal failure before or after liver transplantation (LT), though evidence supporting its use during surgery remains unclear. Therefore, we conducted a quantitative meta-analysis to evaluate the effect of intraoperative continuous renal replacement therapy (IORRT) in recipients with pretransplant severe renal dysfunction. We searched PubMed, Embase, and the Cochrane database for trials focusing on LT recipients supported with or without IORRT. Outcomes assessed were mortality, preoperative characteristics, intraoperative data, and predefined postoperative outcomes. Seven trials with 1051 recipients were eligible. Preoperatively, the IORRT group recipients had higher Model for End-Stage Liver Disease scores (weighted mean difference [WMD], 6.19; 95% confidence interval [CI], 2.51-9.87), Charlson scores (WMD, 0.45; 95% CI, 0.09-0.80), acute liver failure (odds ratio [OR], 1.82; 95% CI, 1.27-2.61), serum creatinine (WMD, 71.33 μmol/L; 95% CI, 1.98-140.69 μmol/L), total bilirubin level (WMD, 5.05 μmol/L; 95% CI, 1.75-8.35 μmol/L), intensive care unit admission (OR, 3.53; 95% CI, 1.23-10.13), vasoactive therapy (OR, 3.80; 95% CI, 2.64-5.46), ventilator care (OR, 2.52; 95% CI, 1.18-5.35), and renal replacement therapy (RRT) (OR, 29.37; 95% CI, 7.66-112.54) compared with control patients. IORRT patients also required more intraoperative blood product transfusion and had more post-LT RRT (OR, 25.67; 95% CI, 4.92-133.85). However, there were no significant differences in short-term mortality (OR, 2.12; 95% CI, 0.82-5.44) between the groups. In addition, worse longterm mortality was seen in the IORRT group. In conclusion, IORRT is feasible and safe and may help sicker recipients tolerate the LT procedure to achieve short-term clinical outcomes comparable with less ill patients without IORRT. More high-quality evidence is needed to verify our conclusion in the future.

Intraoperative Dialysis During Liver Transplantation

BACKGROUND

Orthotopic liver transplantation (LT) is a technically complex surgical procedure associated with a major risk of hemodynamic instability and metabolic derangement, especially in patients with coexisting renal dysfunction. Some centers have applied intraoperative renal replacement therapy (ioRRT) to support patients with preoperative renal failure and prevent critical complications. Although there is a strong theoretical rationale for this treatment, there remains a paucity of definite data demonstrating its benefits.

METHODS

This was a retrospective observational study of all adult patients undergoing intraoperative dialysis in our center from January 2010 till December 2016.

RESULTS

The study group consisted of 88 patients with a mean MELD score of 31.4. Six patients underwent simultaneous liver and kidney transplantation. Forty-four (50%) recipients were admitted to the intensive care unit before transplantation, and 19 (21.6%) needed mechanical ventilation. Twenty-eight (31.8%) of the procedures were retransplantations, and 40 (45.4%) patients had been undergoing renal replacement therapy before LT. The mean preoperative serum creatinine was 2.82 ± 1.13 mg/dL. The majority of patients (54.5%) was operated on using the veno-venous bypass technique. The mean arterial blood pH and potassium levels after reperfusion were 7.2 ± 0.12 and 4.04 ± 0.95 mmol/L, respectively. Postreperfusion syndrome (PRS) occurred in 11 (13.9%) patients in whom dialysis started at least 15 minutes before reperfusion. Dialysis circuit clotting occurred in 9.1% of cases. There were no other adverse events of ioRRT.

CONCLUSION

Our data suggests that intraoperative dialysis in severely ill patients with a high MELD score is safe and effective. Lower than expected PRS occurrence needs to be confirmed in a study with a control group.

2019 Clinical Update in Liver Transplantation

Liver transplantation continues be the standard for treatment of end-stage liver disease, and even with recent advances in organ preservation, the anesthetic management continues to require understanding of multiple organ systems beyond the liver. Multiple factors contribute to hemodynamic changes after reperfusion of the liver graft that anesthesiologists should be aware of before unclamping. Concomitant renal dysfunction in end-stage liver disease is not uncommon, and preparation for continuous renal replacement therapy may need to be considered in certain cases. Cardiac evaluation of liver transplantation patients with an emphasis on arrhythmias, including atrial fibrillation, can help prevent both intraoperative and postoperative complications detrimental to the patient and graft. Finally, combined liver and thoracic organ transplantations may be indicated for certain disease processes that affect multiple organs. These cases require an understanding of the surgical technique and acknowledgment that some goals of the procedures may be in direct opposition to each other.

Abdominal Organ Transplantation: Noteworthy Literature in 2018

A PubMed search revealed 1382 articles on pancreatic transplantation, 781 on intestinal transplantation, more than 7200 on kidney transplantation, and more than 5500 on liver transplantation published between January 1, 2018, and December 31, 2018. After narrowing the list down to human studies, 436 pancreatic, 302 intestinal, 1920 liver, and more than 2000 kidney transplantation studies were screened for inclusion in this review.