Anaesthesia for Liver Transplantation: An Update

Perioperative care in acute liver failure: An anaesthesiologist perspective in the operating theatre

Acute liver failure (ALF) is a life-threatening condition characterized by rapid liver function deterioration, necessitating a multidisciplinary approach for optimal perioperative care. This comprehensive review focuses on the critical role of the anaesthesiologist throughout the preoperative, intraoperative, and postoperative phases, addressing the unique challenges posed by ALF. The article begins with an exploration of ALF, underlining the urgency of timely referral to specialized hepatology centres. Liver transplantation emerges as a life-saving intervention, and the complex decision-making process is discussed, emphasizing the need for a multidisciplinary team to assess transplantation candidacy based on established prognostic criteria. In the preoperative phase, the review stresses the importance of early engagement with tertiary liver centres for timely referrals and identifies patients suitable for transplantation. Safe transport protocols are detailed, highlighting the meticulous planning required for the secure transfer of ALF patients between healthcare facilities. The intraoperative management section delves into the anaesthesiologist's key concerns, including neurological status, sepsis, acute kidney injury, body mass index, and preoperative fasting. Hemodynamic stability, fluid management, and coagulation balance during surgery are emphasized, with insights into anaesthesia techniques, vascular access, monitoring, and hemodynamic management tailored to the challenges posed by ALF patients. The postoperative care is thoroughly examined covering neurological, hemodynamic, metabolic, renal, and nutritional aspects. Management of ALF involves multidisciplinary team, including nephrology for continuous renal replacement therapy, transfusion medicine for plasma exchange, critical care for overall patient care, nutritionists for ensuring adequate nutrition, and hepatologists as the primary guides. In conclusion, the review recognizes the anaesthesiologist as a linchpin in the perioperative care of ALF patients. The integration of safe transport protocols and multidisciplinary approach is deemed crucial for navigating complexities of ALF, contributing to improved patient outcomes. This article serves as an invaluable resource for gastroenterologist and intensivists, enhancing their understanding of the anaesthesiologist's indispensable role in the holistic care of ALF patients in an ever-evolving healthcare landscape.

Effects of Extracellular Calcium Concentration on Hepatic Ischemia-Reperfusion Injury in a Rat Model

OBJECTIVES

Hypocalcemia is frequently identified during liver transplant. However, supplementation of extracellular calcium could induce increased intracellular calcium concentration, as a potential factor for injury to the liver graft. We evaluated the effects of regulating extracellular calcium concentrations on hepatic ischemia-reperfusion injury.

MATERIALS AND METHODS

We randomly divided 24 Sprague-Dawley rats into 3 groups: group C received normal saline (n = 8), group L received citrate to induce hypocalcemia (n = 8), and group L-Co received citrate followed by calcium gluconate to ameliorate hypocalcemia (n = 8). Liver enzyme levels and extracellular calcium were measured before surgery, 1 hour after ischemia, and 2 hours after reperfusion. The primary outcome was liver enzyme levels measured 2 hours after reperfusion. In addition, we evaluated intracellular calcium levels, lactate dehydrogenase activity, and histopathological results in liver tissue.

RESULTS

Three groups demonstrated significant differences in extracellular calcium concentrations, but intracellular calcium concentrations in liver tissue were not significantly different. Group L showed significantly lower mean arterial pressure than other groups at 1 hour after ischemia (93.6 ± 20.8 vs 69.4 ± 14.2 vs 86.6 ± 10.4 mmHg; P = .02, for group C vs L vs L-Co, respectively). At 2 hours after reperfusion, group L showed significantly higher liver enzymes than other groups (aspartate aminotransferase 443.0 ± 353.2 vs 952.3 ± 94.8 vs 502.4 ± 327.3 U/L, P = .01; and alanine aminotransferase 407.9 ± 406.5 vs 860.6 ± 210.9 vs 333.9 ± 304.2 U/L, P = .02; for group C vs L vs L-Co, respectively). However, no significant difference was shown in lactate dehydrogenase and histological liver injury grade.

CONCLUSIONS

Administering calcium to rats with hypocalcemia did not increase intracellular calcium accumulation but instead resulted in less hepatic injury compared with rats with low extracellular calcium concentrations in this rat model study.

Hemodynamic monitoring in liver transplantation 'the hemodynamic system'

PURPOSE OF REVIEW

The purpose of this article is to provide a comprehensive review of hemodynamic monitoring in liver transplantation.

RECENT FINDINGS

Radial arterial blood pressure monitoring underestimates the aortic root arterial blood pressure and causes excessive vasopressor and worse outcomes. Brachial and femoral artery monitoring is well tolerated and should be considered in critically ill patients expected to be on high dose pressors. The pulmonary artery catheter is the gold standard of hemodynamic monitoring and is still widely used in liver transplantation; however, it is a highly invasive monitor with potential for serious complications and most of its data can be obtained by other less invasive monitors. Rescue transesophageal echocardiography relies on few simple views and should be available as a standby to manage sudden hemodynamic instability. Risk of esophageal bleeding from transesophageal echocardiography in liver transplantation is the same as in other patient populations. The arterial pulse waveform analysis based cardiac output devices are minimally invasive and have the advantage of real-time beat to beat monitoring of cardiac output. No hemodynamic monitor can improve clinical outcomes unless integrated into a goal-directed hemodynamic therapy. The hemodynamic monitoring technique should be tailored to the patient's medical status, surgical technique, and the anesthesiologist's level of expertise.

SUMMARY

The current article provides a review of the current hemodynamic monitoring systems and their integration in goal-directed hemodynamic therapy.

The use of simulation in liver transplantation anesthesiology fellowship training: A survey of fellowship program directors in the United States

INTRODUCTION

Liver transplantation surgeries are challenging cases for anesthesiologists. While intra-operative teaching is paramount, simulation has emerged as an educational tool to augment clinical training. A variety of simulation modalities have been described in the literature, but no study has aimed to assess the use of simulation in liver transplantation fellowship training.

METHODS

A 20-question survey detailing the use of simulation, including simulation modalities used and barriers to simulation use, was developed and distributed to 22 program directors for liver transplantation anesthesiology fellowships. An exploratory analysis was performed on multiple-choice and free-text responses.

RESULTS

Thirteen program directors completed the survey and were included in our analysis. Most programs (61.5%) did not report the use of simulation for liver transplantation fellow training. Of the programs that did use simulation, four required it as a mandatory component of their curriculum. Task trainers and screen-based simulators were more commonly used by these programs. Faculty availability and interest, as well as a lack of an established curriculum, were cited as major limitations to simulation use.

CONCLUSIONS

Simulation is an important component of anesthesiology trainee education, as evidenced by the requirement for simulation during residency by the American Council for Graduate Medical Education. Our findings suggest that simulation is an underutilized educational tool that we believe could greatly augment the training of liver transplantation anesthesiology fellows by providing exposure to a wide range of clinical challenges.

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.

Educational Review: Error traps in anesthesia for pediatric liver transplantation

Anesthetic and surgical techniques for the liver transplantation have progressed considerably over the past sixty years; however, this procedure is still fraught with substantial morbidity. To increase the safety culture associated with the liver transplantation, we detail nine error traps associated with anesthesia for pediatric liver transplantation. These potential pitfalls are divided into the operative phases: pre-operative preparation (Failure to have a dedicated anesthesia team for pediatric liver transplantation); pre-anhepatic (Failure to prepare for massive blood loss, Failure to monitor for coagulation abnormalities); anhepatic including reperfusion (Failure to prepare for clamping of the inferior vena cava, Failure to recognize metabolic changes, Failure to maintain homeostasis for reperfusion, Failure to prepare for Post-reperfusion syndrome); and post-anhepatic (Failure to optimize liver perfusion, Failure to maintain hemostatic balance). By offering practical advice on the preparation and treatment of these error traps, we aim to better prepare anesthesiologists to take care of pediatric patients undergoing the liver transplantation.

Perioperative prothrombin complex concentrate and fibrinogen administration are associated with thrombotic complications after liver transplant

BACKGROUND

Use of intraoperative prothrombin complex concentrates (PCC) and fibrinogen concentrate administration has been linked to thrombotic events. However, it is unknown if its use is associated with thrombotic events after liver transplant.

METHODS AND ANALYSIS

We conducted a post hoc analysis of a prospectively conducted registry database study on patients who underwent liver transplant between 2004 and 2017 at Heidelberg University Hospital, Heidelberg, Germany. Univariate and multivariate analyses were used to determine the association between PCC and fibrinogen concentrate administration and thrombotic complications.

RESULTS

Data from 939 transplantations were included in the analysis. Perioperative PCC or fibrinogen administration was independently associated with the primary composite endpoint Hepatic artery thrombosis (HAT), Portal vein thrombosis (PVT), and inferior vena cava thrombosis [adjusted HR: 2.018 (1.174; 3.468), p = 0.011]. PCC or fibrinogen administration was associated with the secondary endpoints 30-day mortality (OR 4.225, p < 0.001), graft failure (OR 3.093, p < 0.001), intraoperative blood loss, red blood cell concentrate, fresh frozen plasma and platelet transfusion, longer hospitalization, and longer length of stay in intensive care units (ICUs) (all p < 0.001). PCC or fibrinogen administration were not associated with pulmonary embolism, myocardial infarction, stroke, or deep vein thrombosis within 30 days after surgery.

CONCLUSION

A critical review of established strategies in coagulation management during liver transplantation is warranted. Perioperative caregivers should exercise caution when administering coagulation factor concentrate during liver transplant surgery. Prospective randomized controlled trials are needed to establish causality for the relationship between coagulation factors and thrombotic events in liver transplantation. Further studies should be tailored to identify patient subgroups that will likely benefit from PCC or fibrinogen administration.

Cardiovascular manifestation of end-stage liver disease and perioperative echocardiography for liver transplantation: anesthesiologist’s view

Liver transplantation (LT) is the curative therapy for decompensated cirrhosis. However, anesthesiologists can find it challenging to manage patients undergoing LT due to the underlying pathologic conditions of patients with end-stage liver disease and the high invasiveness of the procedure, which is frequently accompanied by massive blood loss. Echocardiography is a non-invasive or semi-invasive imaging tool that provides real-time information about the structural and functional status of the heart and is considered to be able to improve outcomes by enabling accurate and detailed assessments. This article reviews the pathophysiologic changes of the heart accompanied by cirrhosis that mainly affect hemodynamics. We also present a comparative review of the diagnostic criteria for cirrhotic cardiomyopathy published by the World Congress of Gastroenterology in 2005 and the Cirrhotic Cardiomyopathy Consortium in 2019. This article discusses the conditions that could affect hemodynamic stability and postoperative outcomes, such as coronary artery disease, left ventricular outflow tract obstruction, portopulmonary hypertension, hepatopulmonary syndrome, pericardial effusion, cardiac tamponade, patent foramen ovale, and ascites. Finally, we cover a number of intraoperative factors that should be considered, including intraoperative blood loss, rapid reaccumulation of ascites, manipulation of the inferior vena cava, post-reperfusion syndrome, and adverse effects of excessive fluid infusion and transfusion. This article aimed to summarize the cardiovascular manifestations of cirrhosis that can affect hemodynamics and can be evaluated using perioperative echocardiography. We hope that this article will provide information about the hemodynamic characteristics of LT recipients and stimulate more active use of perioperative echocardiography.

Research Priorities in Liver Transplant Anesthesiology: Results of a Survey of Liver Transplant Anesthesiologists

Optimal perioperative care contributes to improved patient outcomes, as demonstrated in the field of liver transplant (LT). The evolution in perioperative care over the past two decades has been driven by research in areas such as preoperative testing, coagulation management, and intraoperative monitoring. However, much of this research is driven by local institutional pressures and practices with a dearth of studies emanating from research consortia or other groups of experts within the field. To better characterize the top research questions in the field, we queried a group of 128 LT anesthesiologists representing 87 international liver transplant centers with a response from 71 practitioners (59.2%). Three experts then codified the responses into the top 20 questions, which were sent to the survey recipients as a second survey to rank order. Seventy-five respondents (61.5%) provided responses which were merged into a weighted ranked priority list and analyzed by respondent location and center size. The highest ranked question was, "What intraoperative anesthetic management/interventions affect graft outcome?" Most of the top research questions focused on preoperative risk factor management or optimization and intraoperative management techniques. In general, this priorities list may serve as a guide for transplant anesthesiology researchers to focus future research endeavors on shared interests that improve patient care. This article is protected by copyright. All rights reserved.

Uncommon Occurrence of an Air Embolism during the Preanhepatic Phase of an Orthotopic Liver Transplant

Vascular air embolism (VAE) during liver transplantation usually occurs during the dissection phase of the procedure or during liver reperfusion. If this phenomenon occurs, it can cause significant cardiovascular, pulmonary, and neurological complications. Prompt identification of VAE is essential, and the surgeon should be immediately notified. The mainstay treatment is identification and rectification of the source of the air embolus, hemodynamic support, and prevention of further air entrainment. This case report describes the occurrence of a pulmonary air embolism during the preanhepatic phase of an orthotopic liver transplant.

Simultaneous right-sided nephrectomy with orthotopic liver and kidney transplantation-An alternative method for patients with autosomal dominant polycystic liver and kidney disease

Purpose

In patients suffering from autosomal dominant polycystic liver and kidney disease (ADPLKD), combined organ transplantation often poses a technical challenge due to the large volume of both organs. To simplify the transplantation procedure by improving the exposure of anatomical structures, we introduce a novel surgical technique of orthotopic liver and kidney transplantation.

Methods

The modified simultaneous liver and kidney transplantation technique via a right-sided L-incision included three steps: (1) right-sided nephrectomy in the recipient followed by (2) orthotopic liver transplantation in cava replacement technique and (3) the orthotopic kidney transplantation with arterial reconstruction to the right common iliac artery.

Results

In total, seven patients with ADPLKD were transplanted by using the modified transplantation technique. The mean operation time was 342.43 min (±68.77). Postoperative patients were treated for 6.28 days (±2.50) in the intensive care unit and were discharged from the surgical ward approximately 28 days (±5.66) after the operation with normal graft function. Complications associated with the use of the modified technique, such as bleeding, anastomotic stenosis, biloma, or urinoma, did not occur.

Conclusion

Modified simultaneous liver and kidney transplantation is a safe alternative for patients with ADPLKD. By combining right-sided nephrectomy and orthotopic graft transplantation, the approach optimizes the exposure of anatomical structures and simplifies the transplantation procedure. Additionally, the modified transplantation technique does not require a particular organ explantation procedure and can be applied for all liver and kidney grafts.