Cardiac arrest during adult liver transplantation: a single institution's experience with 1238 deceased donor transplants

Causes of Perioperative Cardiac Arrest: Mnemonic, Classification, Monitoring, and Actions

Perioperative cardiac arrest (POCA) is a catastrophic complication that requires immediate recognition and correction of the underlying cause to improve patient outcomes. While the hypoxia, hypovolemia, hydrogen ions (acidosis), hypo-/hyperkalemia, and hypothermia (Hs) and toxins, tamponade (cardiac), tension pneumothorax, thrombosis (pulmonary), and thrombosis (coronary) (Ts) mnemonic is a valuable tool for rapid differential diagnosis, it does not cover all possible causes leading to POCA. To address this limitation, we propose using the preload-contractility-afterload-rate and rhythm (PCARR) construct to categorize POCA, which is comprehensive, systemic, and physiologically logical. We provide evidence for each component in the PCARR construct and emphasize that it complements the Hs and Ts mnemonic rather than replacing it. Furthermore, we discuss the significance of utilizing monitored variables such as electrocardiography, pulse oxygen saturation, end-tidal carbon dioxide, and blood pressure to identify clues to the underlying cause of POCA. To aid in investigating POCA causes, we suggest the Anesthetic care, Surgery, Echocardiography, Relevant Check and History (A-SERCH) list of actions. We recommend combining the Hs and Ts mnemonic, the PCARR construct, monitoring, and the A-SERCH list of actions in a rational manner to investigate POCA causes. These proposals require real-world testing to assess their feasibility.

Perioperative Considerations in Older Kidney and Liver Transplant Recipients: A Review

With the growth of the older adult population, the number of older adults waitlisted for and undergoing kidney and liver transplantation has increased. Transplantation is an important and definitive treatment for this population. We present a contemporary review of the unique preoperative, intraoperative, and postoperative issues that patients older than 65 y face when they undergo kidney or liver transplantation. We focus on geriatric syndromes that are common in older patients listed for kidney or liver transplantation including frailty, sarcopenia, and cognitive dysfunction; discuss important considerations for older transplant recipients, which may impact preoperative risk stratification; and describe unique challenges in intraoperative and postoperative management for older patients. Intraoperative challenges in the older adult include using evidence-based best anesthetic practices, maintaining adequate perfusion pressure, and using minimally invasive surgical techniques. Postoperative concerns include controlling acute postoperative pain; preventing cardiovascular complications and delirium; optimizing immunosuppression; preventing perioperative kidney injury; and avoiding nephrotoxicity and rehabilitation. Future studies are needed throughout the perioperative period to identify interventions that will improve patients' preoperative physiologic status, prevent postoperative medical complications, and improve medical and patient-centered outcomes in this vulnerable patient population.

Incidence, Outcomes, and Risk Factors of Intraoperative Cardiac Arrest During Orthotopic Liver Transplantation

BACKGROUND

Intraoperative cardiac arrest (ICA) during liver transplantation (LT) is a rare surgical complication that results in devastating outcomes. Moreover, previous worldwide studies have found inconsistencies in the risk factors associated with ICA in LT.

METHODS

This was a retrospective cohort study of adult patients who underwent LT between January and October 2021 at Siriraj Hospital, a tertiary care hospital. The incidence of ICA and outcomes of patients who experienced ICA were examined. Risk factors associated with ICA were investigated as a secondary objective.

RESULTS

Among 342 patients, the incidence of ICA was 3.5% (95% CI 1.8%-6.1%). Of these, 33.3% died intraoperatively. Among patients with ICA, 41.7% died within 30 days, compared with only 7.6% in those without ICA (P = .002). Moreover, the in-hospital mortality rate of those with ICA was 58.3%, which was significantly higher than that of those without ICA (9.7%, P < .001). However, 41.7% of patients with ICA were discharged alive with long-term survival. Because ICA is a rare event, we found only 2 independent factors significantly associated with ICA. These factors include intraoperative temperature below 35°C, with an odds ratio (OR) of 6.07 (95% CI:1.32-27.88, P = .02) and elevated intraoperative serum potassium, with an OR of 4.57 (95% CI:2.15-9.67, P < .001).

CONCLUSIONS

ICA is associated with high perioperative and in-hospital mortality. However, our findings suggest that with effective management of ICA, more than 40% of these patients could be discharged with excellent long-term outcomes. Hypothermia and hyperkalemia were independent risk factors significantly associated with ICA.

Use of Transesophageal Echocardiography During Orthotopic Liver Transplantation: Simplifying the Procedure

The intraoperative management of patients undergoing orthotopic liver transplantation (OLT) is influenced by the cardiovascular manifestations typically found in the context of end-stage liver disease, by the presence of concomitant cardiovascular disease, and by the significant hemodynamic changes that occur during surgery. Hypotension and intraoperative blood pressure fluctuations during OLT are associated with liver graft dysfunction, acute kidney failure, and increased risk of 30-d mortality. Patients also frequently present hemodynamic instability due to various causes, including cardiac arrest. Recent evidence has shown transesophageal echocardiography (TEE) to be a useful minimally invasive monitoring tool in patients undergoing OLT that gives valuable real-time information on biventricular function and volume status and can help to detect OLT-specific complications or situations. TEE also facilitates rapid diagnosis of life-threatening conditions in each stage of OLT, which is difficult to identify with other types of monitoring commonly used. Although there is no consensus on the best approach to intraoperative monitoring in these patients, intraoperative TEE is safe and useful and should be recommended during OLT, according to experts, for assessing hemodynamic changes, identifying possible complications, and guiding treatment with fluids and inotropes to achieve optimal patient care.

Management of Intraoperative Cardiac Arrest

Perioperative arrests are both uncommon and heterogeneous and have not been described or studied to the same extent as cardiac arrest in the community. These crises are usually witnessed, frequently anticipated, and involve a rescuer physician with knowledge of the patient's comorbidities and coexisting anesthetic or surgically related pathophysiology ultimately leading to better outcomes. This article reviews the most probable causes of intraoperative arrest and their management.

Intraoperative intracardiac thrombus in liver transplantation: A 9-year retrospective review focusing on treatment and outcomes

This study characterizes incidence and outcomes surrounding intracardiac thrombosis (ICT) during liver transplantation over 9 years at a single center before and after the routine use of transesophageal echocardiography (TEE). Adult liver transplantation patients from 2011 to 2020 were divided into eras based on routine TEE use. ICTs were identified by querying anesthetic records for search terms. Descriptive statistics included counts and proportions for baseline recipient, donor, intraoperative, and postoperative characteristics. Outcome data were based on date of hospital discharge and date of death. The incidence of ICT increased in the TEE era (2016-2020) compared with the pre-TEE era (2011-2015; 3.7% [25/685] vs. 1.9% [9/491]; p < 0.001). Patients with ICT had significantly higher Model for End-Stage Liver Disease-sodium (MELD-Na) scores, pretransplant hospitalization, malignancy, drug-induced liver injury, hypertension, deep vein thrombosis, reperfusion syndrome, transfused platelets and cryoprecipitate, and use of hemostatic medications. A higher proportion of patients in the ICT group underwent simultaneous liver-kidney transplantation. The patients with ICT were similar, except patients in the pre-TEE era had higher MELD-Na scores and incidences of hepatitis C virus and lower incidences of encephalopathy. In the pre-TEE era, all ICTs presented as intraoperative cardiac arrest, and the 30-day mortality in the setting of ICT was 66.7% (6/9). During the TEE era, 80% of ICTs were diagnosed incidentally or attributed to hemodynamic instability (p = 0.002). The 30-day mortality rate was 36% (9/25) in the TEE era (p = 0.25). ICT incidence increased in the TEE era, yet the mortality rate was lower, suggesting that routine intraoperative TEE may lead to the early detection of ICT prior to hemodynamic collapse.

Bleeding Complications from Transesophageal Echocardiography for Liver Transplantation: A Systematic Review

Transesophageal echocardiography (TEE) for liver transplant has historically been avoided due to concern it may cause bleeding from esophageal varices. However, several recent studies, as well as increasing clinical experience, have indicated that it may be safe in many circumstances. We performed a systematic review of the literature to identify and summarize studies reporting complications in patients having TEE during liver transplant. Studies were identified by searching relevant key terms on PubMed as well as citation searching in relevant reviews. We identified 6 studies between 1996 and 2015 which evaluated complications of TEE during liver transplant. They reported an overall bleeding complication rate between .3% and 2.8% and a major bleeding complication rate between .0% and .8%. Most of the major bleeds had identifiable high-risk features such as recent variceal bleeding or banding. Review of the literature suggests that TEE may be safely used in patients undergoing liver transplantation, even with known varices, with a complication rate similar to that of all patients undergoing TEE. However, the risks of TEE may outweigh the potential benefits among patients undergoing liver transplant with particular high-risk features.

Minimal Surgical Manpower for Living Donor Liver Transplantation

Background: Living donor liver transplantation (LDLT) is widely performed with good outcomes in the current era of improved surgical techniques. However, few studies have addressed how many human resources are required in the surgery itself. This study aimed to introduce how to perform LDLT with minimal manpower and evaluate the outcomes in adult patients. Methods: The main surgical procedures of donor and recipient operations of LDLT were performed by a single specialist surgeon who led a team of minimal manpower that only included one fellow, one resident, one intern, and three nurses. He also provided postsurgical care and followed up all the patients as a primary care physician. The outcomes were analyzed from the standpoints of the feasibility and acceptability. Results: Between November 2018 and February 2020, a total of 47 patients underwent LDLT. Ten patients had ABO-incompatible donors. The median age of the overall recipients was 57 years old (36–71); 37 patients (78.7%) were male. The MELD score was 10 (6–40), and the main etiologies were hepatic malignancy (38 patients or 80.9%) and liver failure (9 patients or 19.1%). The median age of the overall donors was 34 years old (19–62); 22 patients (46.8%) were male. All the graft types were right liver except for one case of extended right liver with middle hepatic vein. All donors had an uneventful recovery with no complications. There was one intraoperative mortality due to cardiac arrest after reperfusion in one recipient. Hepatic artery thrombosis was developed in 5 (10.6%) recipients. An acute rejection episode occurred in one patient. The median follow-up period for all the patients was 32.9 months (range, 24.7–39.8). Biliary complications were developed in 11 (23.4%) recipients. In total, 7 (15%) patients died, including 1 intraoperative mortality, 5 from cancer recurrence, and 1 from intracranial hemorrhage. The 1-, 2-, and 3-year overall survival rates in the recipient group were 91.5%, 87.2%, and 85.1%, respectively. Conclusions: LDLT with minimal surgical manpower is feasible under the supervision of a single expert surgeon who has the capacity for all the main surgical procedures in both donor and recipient operations without compromising the outcomes in the present era of advanced surgical management.

Elevated effluent potassium concentrations predict the development of postreperfusion hyperkalemia in deceased liver transplantation: a retrospective cohort study

BACKGROUND

Postreperfusion hyperkalemia (PRHK) has garnered increasing attention in regard to deceased liver transplantation (LT), especially for LT using the expanded criteria donor grafts. However, the impact of the effluent potassium (eK⁺) concentration on PRHK has been largely overlooked. We evaluated whether elevated eK⁺ concentrations are associated with PRHK in deceased LT.

METHODS

In this single-institution, retrospective cohort study, we included all adults who underwent deceased LT with intraoperative eK⁺ concentration monitoring between November 2016 and December 2018. The eK⁺ concentrations were obtained from the effluent samples collected following a standard portal vein flush. PRHK was defined as any serum potassium (sK⁺) level of > 5.5 mmol/L following reperfusion. Logistic regression was performed to identify predictors for PRHK, and linear regression was used to examine predictors of the maximum percentage increase in the sK⁺ level following reperfusion.

RESULTS

Of the 86 patients who met the inclusion criteria, 54 (62.8%) developed PRHK. Independent predictors for PRHK included greater graft weight (OR 1.283 [95% CI 1.029-1.599] per 100 g, P = 0.027), an elevated eK⁺ concentration (OR 1.291 [95% CI 1.068-1.561] per mol/L, P = 0.008), and a higher sK⁺ level before reperfusion (OR 4.459 [95% CI 1.543-12.884] per mol/L, P = 0.006). An eK⁺ concentration of more than 6.9 mmol/L had a sensitivity of 59.26% and a specificity of 78.12% for predicting PRHK (area under the receiver operating characteristic curve, 0.694). Multiple linear regression analyses indicated that the eK⁺ and sK⁺ levels before reperfusion were significant predictors of the maximum percentage increase in the sK⁺ level following reperfusion. In addition, PRHK was associated with an increased risk of postreperfusion significant arrhythmias, severe postreperfusion syndrome, and postoperative early allograft dysfunction.

CONCLUSIONS

This study shows that the eK⁺ concentration could predict the risk of PRHK in deceased LT. Further prospective studies are warranted to clarify these associations.

Perioperative management of adult living donor liver transplantation: Part 1 - recipients

Living donor liver transplantation was first developed to mitigate the limited access to deceased donor organs in Asia in the 1990s. This alternative liver transplantation option has become an established and widely practiced transplantation method for adult patients suffering from end-stage liver disease. It has successfully addressed the shortage of deceased donors. The Society for the Advancement of Transplant Anesthesia and the Korean Society of Transplant Anesthesia jointly reviewed published studies on the perioperative management of live donor liver transplant recipients. The review aims to offer transplant anesthesiologists and critical care physicians a comprehensive overview of the perioperative management of adult live liver transplantation recipients. We feature the status, outcomes, surgical procedure, portal venous decompression, anesthetic management, prevention of acute kidney injury, avoidance of blood transfusion, monitoring and therapeutic strategies of hemodynamic derangements, and Enhanced Recovery After Surgery protocols for liver transplant recipients. This article is protected by copyright. All rights reserved.

Changes in Blood Potassium after Reperfusion during Living-Donor Liver Transplantation: An Exploratory Study

The incidence of hyperkalemia (>5.5 mEq/L) or high blood potassium (5–5.5 mEq/L) during living-donor liver transplantation (LDLT) is reported to be more than 10%. It occurs more frequently in the early post-reperfusion period and is a major cause of post-reperfusion arrhythmia and cardiac arrest. Unlike deceased-donor liver transplantation, the pattern of blood potassium changes immediately after reperfusion has not been described in LDLT. From January 2021 to March 2021, fifteen consecutive patients were enrolled. Baseline blood potassium was measured from blood samples obtained 10-min (T_-10) and immediately before (T₀) reperfusion. During the first 5 min after reperfusion, blood potassium measurements were conducted every one minute (T₁–T₅). The blood potassium levels at T_-10 and T₀ were 3.8 ± 0.4 and 3.9 ± 0.4 mEq/L, respectively. After reperfusion, mean increases (95% CI) in blood potassium from T_-10 and T₀ were 0.5 (0.4–0.6) and 0.4 (0.3–0.5) mEq/L, respectively. Blood potassium peaked at T₁, returned to baseline at T₃, and fell below the baseline at T₅. Peak blood potassium after reperfusion showed strong correlations with blood potassium measured at T_-10 (p < 0.001) and T₀ (p < 0.0001). These findings can support the establishment of future research plans and perioperative management of blood potassium in LDLT.

Association between surgical volumes and hospital mortality in patients: a living donor liver transplantation single center experience

Background

Many factors cause hospital mortality (HM) after liver transplantation (LT).

Methods

We performed a retrospective research in a single center from October 2005 to June 2019. The study included 463 living donor LT patients. They were divided into a no-HM group (n = 433, 93.52%) and an HM group (n = 30, 6.48%). We used logistic regression analysis to determine how clinical features and surgical volume affected HM. We regrouped patients based on periods of surgical volume and analyzed the clinical features.

Results

Multivariate analysis revealed that donor age (OR = 1.050, 95% CI 1.011–1.091, p = 0.012), blood loss (OR = 1.000, 95% CI 1.000–1.000, p = 0.004), and annual surgical volumes being < 30 LTs (OR = 2.540, 95% CI 1.011–6.381, p = 0.047) were significant risk factors. A comparison of years based on surgical volume found that when the annual surgical volumes were at least 30 the recipient age (p = 0.023), donor age (p = 0.026), and ABO-incompatible operations (p < 0.001) were significantly higher and blood loss (p < 0.001), operative time (p < 0.001), intensive care unit days (p < 0.001), length of stay (p = 0.011), rate of re-operation (p < 0.001), and HM (p = 0.030) were significantly lower compared to when the annual surgical volumes were less than 30.

Conclusions

Donor age, blood loss and an annual surgical volume < 30 LTs were significant pre- and peri-operative risk factors. Hospital mortality and annual surgical volume were associated with statistically significant differences; surgical volume may impact quality of care and transplant outcomes.

Inducible Left Ventricular Outflow Tract Obstruction in Patients Undergoing Liver Transplantation: Prevalence, Predictors, and Association With Cardiovascular Events

BACKGROUND

Inducible left ventricular outflow tract obstruction (LVOTO) is often encountered in liver transplantation (LT) candidates during cardiac workup. While the impact of LVOTO on adverse cardiovascular hemodynamics is well reported, it is unclear whether it predisposes to perioperative cardiovascular complications.

METHODS

Consecutive patients with end-stage liver disease undergoing dobutamine stress echocardiography (DSE) were evaluated at an LT center between 2010 and 2017. Perioperative major adverse cardiovascular events (MACEs) at 30 days and all-cause death were recorded from a prospectively maintained LT database.

RESULTS

We evaluated 560 patients who underwent DSE during LT workup, with LVOTO identified in 24.3% (n = 136). Of these, 309 patients progressed to transplant. Patients with LVOTO demonstrated a lower peak systolic blood pressure (SBP) and an overall reduction in SBP on DSE. A total of 85 MACEs were recorded in 72 patients (23.3%) including 3 deaths, 19 cases of heart failure, 11 cardiac arrests, 8 acute coronary syndromes, and 44 arrhythmias. MACE occurred in 15/64 patients (23.4%) with LVOTO and 57/245 (23.3%) without (P = 0.92). There was an increased risk of perioperative cardiac arrest in patients with LVOTO (7.4% versus 2.4%, P = 0.04). Intraoperatively, patients with LVOTO required higher doses of vasopressors (P = 0.01) and received greater volumes of fluid (10.5 ± 8.1 versus 8.4 ± 6.4 L, P = 0.03).

CONCLUSIONS

Patients with end-stage liver disease and LVOTO demonstrate a reduction in SBP during physiological stress that may translate to hemodynamic instability during LT. LVOTO was not associated with an increased rate of perioperative MACE or death.

Effect of QT interval prolongation on cardiac arrest following liver transplantation and derivation of a risk index

Liver transplantation (LT) has a 4-fold higher risk of periprocedural cardiac arrest and ventricular arrhythmias (CA/VAs) compared with other noncardiac surgeries. Prolongation of the corrected QT interval (QTc) is common in patients with liver cirrhosis. Whether it is associated with an increased risk of CA/VAs following LT is unclear. Rates of 30-day CA/VAs post-LT were assessed in consecutive adults undergoing LT between 2010 and 2017. Pretransplant QTc was measured by a cardiologist blinded to clinical outcomes. Among 408 patients included, CA/VAs occurred in 26 patients (6.4%). QTc was significantly longer in CA/VA patients (475 ± 34 vs 450 ± 34 ms, P < .001). Optimal QTc cut-off for prediction of CA/VAs was ≥480 ms. After adjustment, QTc ≥480 ms remained the strongest predictor for the occurrence of CA/VAs (odds ratio [OR] 5.2, 95% confidence interval [CI] 2.2-12.6). A point-based cardiac arrest risk index (CARI) was derived with the bootstrap method for yielding optimism-corrected coefficients (2 points: QTc ≥480, 1 point: Model for End-Stage Liver Disease [MELD] ≥30, 1 point: age ≥65, and 1 point: male). CARI score ≥3 demonstrated moderate discrimination (c-statistic 0.79, optimism-corrected c-statistic 0.77) with appropriate calibration. QTc ≥480 ms was associated with a 5-fold increase in the risk of CA/VAs. The CARI score may identify patients at higher risk of these events. Whether heightened perioperative cardiac surveillance, avoidance of QT prolonging medications, or beta blockers could mitigate the risk of CA/VAs in this population merits further study.

Intraoperative Cardiac Arrest During Adult Liver Transplantation: Incidence and Risk Factor Analysis From 7 Academic Centers in the United States

BACKGROUND

Intraoperative cardiac arrest (ICA) has a reported frequency of 1 in 10,000 anesthetics but has a much higher estimated incidence in orthotopic liver transplantation (OLT). Single-center studies of ICA in OLT are limited by small sample size that prohibits multivariable regression analysis of risks.

METHODS

Utilizing data from 7 academic medical centers, we performed a retrospective, observational study of 5296 adult liver transplant recipients (18-80 years old) between 2000 and 2017 to identify the rate of ICA, associated risk factors, and outcomes.

RESULTS

ICA occurred in 196 cases (3.7% 95% confidence interval [CI], 3.2-4.2) and mortality occurred in 62 patients (1.2%). The intraoperative mortality rate was 31.6% in patients who experienced ICA. In a multivariable generalized linear mixed model, ICA was associated with body mass index (BMI) <20 (odds ratio [OR]: 2.04, 95% CI, 1.05-3.98; P = .0386), BMI ≥40 (2.16 [1.12-4.19]; P = .022), Model for End-Stage Liver Disease (MELD) score: (MELD 30-39: 1.75 [1.09-2.79], P = .02; MELD ≥40: 2.73 [1.53-4.85], P = .001), postreperfusion syndrome (PRS) (3.83 [2.75-5.34], P < .001), living donors (2.13 [1.16-3.89], P = .014), and reoperation (1.87 [1.13-3.11], P = .015). Overall 30-day and 1-year mortality were 4.18% and 11.0%, respectively. After ICA, 30-day and 1-year mortality were 43.9% and 52%, respectively, compared to 2.6% and 9.3% without ICA.

CONCLUSIONS

We established a 3.7% incidence of ICA and a 1.2% incidence of intraoperative mortality in liver transplantation and confirmed previously identified risk factors for ICA including BMI, MELD score, PRS, and reoperation and identified new risk factors including living donor and length of surgery in this multicenter retrospective cohort. ICA, while rare, is associated with high intraoperative mortality, and future research must focus on therapy to reduce the incidence of ICA.

Successful resuscitation after hyperkalemic cardiac arrest during liver transplantation by converting veno-venous bypass to veno-arterial ECMO

INTRODUCTION

Intraoperative cardiac arrest (ICA) is a feared complication during liver transplantation (LTx), typically occurring during reperfusion. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used for post-reperfusion cardiac arrest.

CASE REPORT

We present a case of successful resuscitation after hyperkalemic ICA during the pre-anhepatic phase of a second liver transplantation by converting veno-venous bypass (VVB) to VA-ECMO.

DISCUSSION

While this technique has been recommended for ICA during reperfusion, it has never been reported during the pre-anhepatic phase. VA-ECMO can be a lifesaving extension to cardiopulmonary resuscitation for ICA during LTx with beneficial neurological outcome by providing perfusion while the cause of ICA is reversed.

CONCLUSION

Conversion of VVB to VA-ECMO should be considered in all patients who suffer from ICA during LTx with use of VVB. With VVB installed, conversion to VA-ECMO is fast and effective. If VVB is not used, early VA-ECMO should be considered for ICA.

Expanded Criteria Donor-Related Hyperkalemia and Postreperfusion Cardiac Arrest During Liver Transplantation: A Case Report and Literature Review

Background

Liver transplantation (LT) using extended criteria donor (ECD) grafts is frequently associated with a high flush fluid potassium concentration (FFK) and acute hyperkalemia after reperfusion, which puts patients at greater risk of postreperfusion cardiac arrest (PRCA).

Case Report

Herein, we present a case with an extremely high FFK that was successfully pretreated to avoid the risk of PRCA. A 3-year-old boy with biliary atresia underwent LT from a 623-g donation after brain death liver graft with localized frostbite on the right lobe surface. The FFK was 18.8 mmol/L after flushing with 1000 mL of 5% albumin. To prevent PRCA due to acute hyperkalemia, further portal vein (PV) flush, retrograde reperfusion via the inferior vena cava, and antegrade reperfusion via the PV were adopted to remove the excessive potassium ions. Ultimately, the liver graft was reperfused when the perfused blood potassium concentration was 7.5 mmol/L without subsequent development of PRCA during the immediate reperfusion period. Nevertheless, the patient still experienced vasoplegic syndrome during the late reperfusion period.

Conclusions

Our case illustrates that the FFK measurement is helpful for identifying ECD-related hyperkalemia and for providing advance warning of PRCA. Future investigations are warranted to confirm the relationship between high FFK and PRCA and to observe the effectiveness of other interventions to prevent PRCA due to ECD-related hyperkalemia.

Perioperative Stress-Induced (Takotsubo) Cardiomyopathy in Liver Transplant Recipients

A comprehensive analysis of published cases of Takotsubo cardiomyopathy, occurred in liver transplant recipients in the perioperative period, has been attempted in this review. Predisposing factors, precipitating events, potential physiological mechanisms, acute and post-event management have been discussed.

Postreperfusion hyperkalemia in liver transplantation using donation after cardiac death grafts with pathological changes

BACKGROUND

With the increasing use of donation after cardiac death (DCD), especially of the graft liver with steatosis or other pathological changes, the frequency of postreperfusion hyperkalemia in liver transplantation has increased significantly. The present study aimed to determine the factors associated with developing postreperfusion hyperkalemia in liver transplantation from DCD.

METHODS

One hundred thirty-one consecutive adult patients who underwent orthotopic liver transplantation from DCD were retrospectively studied. Based on serum potassium within 5 minutes after reperfusion, recipients were divided into two groups: hyperkalemia and normokalemia. According to preoperative biopsy results, the DCD graft livers were classified into five categories. Univariate analysis was performed using Chi-square test to identify variables that were significantly different between two groups. Multivariate logistic regression was used to confirm the risk factors of developing hyperkalemia and postreperfusion syndrome. Correlation analysis was used to identify the relationship between the serum concentration of potassium within 5 minutes after reperfusion and the difference in mean arterial pressure values before and within 5 minutes after reperfusion.

RESULTS

Twenty-two of 131 liver recipients had hyperkalemia episodes within 5 minutes after reperfusion. The rate of hyperkalemia was significantly higher in recipients of macrosteatotic DCD graft liver (78.6%, P<0.001) than that in recipients of non-macrosteatotic DCD graft liver. The odds ratio of developing postreperfusion hyperkalemia in recipients of macrosteatotic DCD graft liver was 51.3 (P<0.001). Macrosteatosis in the DCD graft liver was an independent risk factor of developing hyperkalemia within 5 minutes after reperfusion. The highest rate of postreperfusion syndrome also occurred in the recipients with macrosteatotic DCD graft liver (71.4%, P<0.001). A strong relationship existed between the serum potassium within 5 minutes after reperfusion and the difference in mean arterial pressure values before and within 5 minutes after reperfusion in macrosteatotic DCD graft liver recipients.

CONCLUSION

Macrosteatosis in the DCD graft liver was an independent risk factor of developing hyperkalemia and postreperfusion syndrome in the recipients.

Atrioventricular conduction disturbances immediately after hepatic graft reperfusion and their outcomes in patients undergoing liver transplantation

Hemodynamic perturbation during hepatic graft reperfusion in patients undergoing liver transplantation (LT) is challenging and is frequently accompanied by bradyarrhythmia and even asystole. However, detailed data on electrocardiographic (ECG) changes during reperfusion are almost nonexistent, although the correct diagnosis by record is important for the treatment. We aimed to identify ECG rhythm disturbances during graft reperfusion and to investigate risk factors and outcomes. Data from 1065 consecutive patients who underwent adult LT were analyzed. The incidence, type, and detailed characteristics of ECG changes immediately after graft reperfusion were assessed using an electronically archived intraoperative ECG database. We analyzed risk factors, postoperative outcomes including major cardiovascular events, 30-day and 1-year mortalities of recipients based on the occurrence of atrioventricular (AV) block, and asystole during reperfusion. The typical pattern of postreperfusion bradyarrhythmia was progressive PR interval prolongation until a Mobitz type 1 AV block occurred. The overall incidence of AV block was 5.0% (53/1065), and 30.2% of them (16/53) had initiated as AV block and then progressed into ventricular asystole. Fulminant hepatic failure was a significant predictor for occurrence of AV block (odds ratio [OR], 7.20; 95% confidence interval, 3.38-15.32; P < 0.001). Patients with AV block showed significantly higher incidence of postoperative major cardiovascular events (P < 0.001) and 30-day mortality (P = 0.002) than those without AV block, whereas the 1-year mortality was not different between the 2 groups (P = 0.10). The postreperfusion asystole was consistently preceded by a Mobitz type 1 AV block. The occurrence of AV block and asystole appears to be an important prognosticator. Therefore, maintaining an optimal range of physiological status and gradual unclamping of the vena cava to avoid sudden atrial distension are recommended in high-risk patients during reperfusion period. Liver Transplantation 22 956-967 2016 AASLD.

Postperfusion Syndrome in Cadaveric Liver Transplantations: A Retrospective Study

OBJECTIVE

To evaluate the factors that affects the postperfusion syndrome in cadaveric liver transplantations and the effect of the postperfusion syndrome on discharge from the hospital.

METHODS

Patients who underwent cadaveric liver transplantations between 2007 and 2013 were scanned retrospectively. Intraoperative anaesthesia records, intensive care unit follow-up forms and discharge reports were examined from patient files. Overall, 43 patients having complete data were included in the study. The postperfusion syndrome is defined as asystoli or a decrease in mean arterial pressure of more than 30%, which occurred in the first 5 min of reperfusion and continued for 1 min. Patients were divided into two groups: those who had the postperfusion syndrome and those who did not.

RESULTS

The number of patients who had the postperfusion syndrome was 25 of 43 (58.1%). The MELD score of patients without the postperfusion syndrome was calculated as 16.9±3.2 and that of patients with the postperfusion syndrome was 19.7±3.6. A statistically significant relationship was detected between the postperfusion syndrome occurrence and a high MELD score (p=0.013). The diastolic blood pressure just before reperfusion was statistically lower in the group with the postperfusion syndrome than in the other group (p=0.023, 50±8 vs. 58±11). According to the logistic regression analysis, the MELD score and the decrease in diastolic blood pressure before reperfusion were defined as independent predictive factors.

CONCLUSION

According to the study, the ratio for having the postperfusion syndrome was found to be 58.1%. The independent predictor factors affecting the postperfusion syndrome were detected as the MELD score and the decrease in diastolic blood pressure before reperfusion. The postperfusion syndrome during orthotropic liver transplantation is an important issue for anaesthesiologists. The awareness of the related factors with the postperfusion syndrome may help in the development of various preventive strategies.

Prolonged Intraoperative Cardiac Resuscitation Complicated by Intracardiac Thrombus in a Patient Undergoing Orthotopic Liver Transplantation

We report the case of successful resuscitation after prolonged cardiac arrest during orthotopic liver transplantation. After reperfusion, the patient developed ventricular tachycardia, complicated by intracardiac clot formation and massive hemorrhage. Transesophageal echocardiography demonstrated stunned and nonfunctioning right and left ventricles, with developing intracardiac clots. Treatment with heparin, massive transfusion and prolonged cardiopulmonary resuscitation ensued for 51 minutes. Serial arterial blood gases demonstrated adequate oxygenation and ventilation during cardiopulmonary resuscitation. Cardiothoracic surgery was consulted for potential use of extracorporeal membrane oxygenation, however, the myocardial function improved and the surgery was completed without further intervention. On postoperative day 6, the patient was extubated without neurologic or cardiac impairment. The patient continues to do well 2 years posttransplant, able to perform independent daily activities of living and his previous job. This case underscores the potential for positive outcomes with profoundly prolonged, effective advanced cardiovascular life support in patients who experience postreperfusion syndrome.

Serum acidosis prior to reperfusion facilitates hemodynamic recovery following liver transplantation

INTRODUCTION

Reperfusion is the most critical event during liver transplantation, and sustained leakage of acidic preservation solution from the liver graft contributes to marked hemodynamic instability. Recent laboratory studies with hepatocyte cultures have revealed that low pH may protect hepatocyte mitochondria against ischemia-reperfusion injury by inhibiting the mitochondrial permeability transition (MPT), the so-called "pH paradox." However, the clinical significance of this pH paradox theory remains largely unknown. In this study, we sought to determine whether there is an association between serum pH immediately prior to reperfusion and hemodynamic recovery after reperfusion and graft survival.

METHODS

We analyzed retrospective data from 527 patients who underwent Orthotopic liver transplantation between 2003 and 2008. All patients were allocated to one of two groups: pH ≤ 7.32 or pH > 7.32, as measured 5 min before reperfusion. Case-control matching was performed using the propensity score to adjust for background differences between the two groups. Data were analyzed using Student's t-test and the χ (2) test.

RESULTS

There were 85 patients in the pH ≤ 7.32 group and 385 patients in the pH > 7.32 group. The recovery of mean arterial pressure after hepatic artery reperfusion was significantly faster in the pH ≤ 7.32 group (slope of recovery: 0.0004 % vs. 0.0002 %/min, p = 0.041). Other parameters studied, including vasopressor dosage after reperfusion, did not show any statistically significant difference between groups.

CONCLUSIONS

Our findings suggest that less aggressive treatment of acidosis with a slower rate of normalization of serum pH (from low to normal) after reperfusion promotes faster hemodynamic stabilization. These findings provide evidence to support the concept of the pH paradox, and may also substantiate the argument against the usage of alkalizing agents before reperfusion unless acidosis becomes clinically significant.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

Reversible non-ischaemic cardiomyopathy and left ventricular dysfunction after liver transplantation: a single-centre experience

BACKGROUND & AIMS

Non-ischaemic cardiomyopathy (NIC) is an early complication of liver transplantation (LT). Our aims were to define the prevalence, associated clinical factors, and prognosis of this condition.

METHODS

A retrospective study was performed on patients undergoing LT at our institution from January 2005 to December 2012. Patients who developed NIC were identified. Data collected included demographic and clinical data.

RESULTS

A total 1460 transplants were performed in this period and seventeen patients developed NIC. Pretransplant median QTc interval was 459 (range, 405-530), and median E/A ratio was 1 (range, 0.71-1.67). Fourteen patients (82%) were severely malnourished and required nutritional support. Thirteen patients (76%) had renal insufficiency. Median time to onset was 2 days post-transplant (range, 0-20). Echocardiograms showed global left ventricular hypokinesis and a decrease in ejection fraction (EF) from a median of 65% (range, 50-81) pretransplant to a median of 21% (range, 15-32). Median raw model for end-stage liver disease (MELD) score was 29 in patients with NIC vs. 18 in patients without cardiomyopathy (P = 0.01). There was no significant difference between recipients with NIC vs. recipients without cardiomyopathy regarding donor age, donor risk index, and cold and warm ischaemia time. Recovery of cardiac function occurred in 16 patients, with a median EF of 44% (range, 25-65%) at the time of discharge. The last echocardiogram available showed a median EF of 59% (range, 49-73%). One-year survival of NIC patients was 94.1%.

CONCLUSION

Non-ischaemic cardiomyopathy is a rare complication after LT. Patients with NIC are critically ill, with high MELD score, and severe malnutrition.