Perioperative monitoring in liver transplant patients

Comparison of tracheal temperature and core temperature measurement in living donor liver transplant recipients: a clinical comparative study

BACKGROUND

Body temperature is a vital sign, and temperature monitoring during liver transplantation is important. Tracheal temperature can be measured via an endotracheal tube with a temperature sensor on the cuff of the tube. This study aimed to investigate the accuracy and trending ability of tracheal temperature measurement compared to those of the core temperature measured at the esophagus and pulmonary artery (PA) in living donor liver transplant recipients.

METHODS

Twenty-two patients who underwent living donor liver transplantation (LDLT) were enrolled. Patients were intubated using an endotracheal tube with a temperature sensor placed on the inner surface of the tube cuff. Tracheal, esophageal, and PA temperatures were recorded at five time points corresponding to the different phases of liver transplantation. The tracheal and esophageal, tracheal and PA, and esophageal and PA temperatures were compared using Bland-Altman analysis, four-quadrant plot/concordance analysis, and polar plot analysis.

RESULTS

Bland-Altman analysis showed an overall mean bias (95% limits of agreement) between tracheal and esophageal temperatures of -0.10 °C (-0.37 °C to 0.18 °C), with a percentage error of 0.27%; between tracheal and PA temperatures, -0.05 °C (-0.91 °C to 0.20 °C), with a percentage error of -0.15%; and between esophageal and PA temperatures, 0.04 °C (-0.27 °C to 0.35 °C), with a percentage error of 0.12%. The concordance rates between tracheal and esophageal temperatures, tracheal and PA temperatures, and esophageal and PA temperatures were 96.2%, 96.2%, and 94.94%, respectively. The polar plot analysis showed a mean angular bias (radial limits of agreement) of 4° (26°), -3° (13°), and 2° (21°).

CONCLUSIONS

Monitoring core temperature at the inner surface of the endotracheal tube cuff is accurate in all phases of LDLT with good trending ability; thus, it can be an excellent alternative for monitoring during LDLTs.

Poor Reliability of Common Measures of Anticoagulation in Pediatric Extracorporeal Membrane Oxygenation

Anticoagulation management in pediatric extracorporeal membrane oxygenation (ECMO) is challenging with multiple laboratory measures utilized across institutions without consensus guidelines. These include partial thromboplastin time (PTT), thromboelastography (TEG), and antifactor Xa (aXa). We aimed to evaluate the consistency of TEG R-time, PTT, and aXa correlation to bivalirudin and heparin dosing. We conducted a single-center restrospective review of pediatric ECMO cases from 2018 to 2020 anticoagulated with bivalirudin or heparin. We collected up to 14 serial simultaneous TEG R-time, PTT, and aXa measurements over a 7 day ECMO course with corresponding bivalirudin or heparin dosing. We analyzed the correlation between bivalirudin, heparin, and the three measurements of anticoagulation. A total of 67 ECMO runs, 32 bivalirudin, and 35 heparin, and more than 1,500 laboratory values, of which >80% simultaneous, were analyzed. When assessing correlations at the individual patient level, there was no consistent correlation between dosing and at least one laboratory parameter in the majority of patients. Furthermore, 44% of the bivalirudin cohort and 37% of the heparin cohort exhibited no correlation with any parameters. There were statistically significant correlations only between bivalirudin and heparin dosing and the sum total of the different laboratory tests. These inconsistencies highlight the importance of multimodality testing of anticoagulation in the management of pediatric ECMO anticoagulation and cannot be relied on in isolation from bedside clinical judgment.

Lateral-Apical Approach to Pericardiocentesis for Treatment of Cardiac Tamponade Immediately Post-orthotopic Liver Transplantation

Cardiac tamponade is a rare complication following orthotopic liver transplantation (OLT). The incidence and treatment specific to the immediate postoperative OLT patient have never been reported. Here, we describe a case of OLT complicated by coagulopathy and difficult intraoperative pulmonary artery catheter placement with subsequent postoperative hemopericardium resulting in tamponade. An emergent, ultrasound-guided, lateral-apical pericardiocentesis was successfully performed, suggesting a possible procedural technique for pericardiocentesis in the immediate postoperative period for liver transplant patients.

Changes in NSE and S-100β during the perioperative period and effects on brain injury in infants with biliary atresia undergoing parent donor liver transplantation

The present study aimed to investigate the effects of parental donor liver transplantation on the perioperative changes of serum calcium-binding protein β (S-100β) and neuron-specific enolase (NSE) levels, two markers of brain injury, and on postoperative cognitive function. The present study was a prospective observational study of infants with congenital biliary atresia who underwent selective liver transplantation in 2017 at Tianjin First Central Hospital (Tianjin, China). Blood samples were collected prior to, during and following surgery, and S-100β and NSE levels were measured using ELISA. The pediatric patients were assessed using the Bayley Scales of Infant Development 1 day prior to and 3 months after surgery. Additionally, the pediatric anesthesia emergence delirium scores were evaluated. The results demonstrated that serum NSE and S100β were increased during and after surgery compared with prior to surgery (P<0.05). Furthermore, serum S-100β and NSE levels peaked 1 h after the neohepatic phase compared with prior to surgery (P<0.05). Compared with 1 day before surgery, mental development index (MDI) and psychomotor development index (PDI) were decreased 3 months after surgery (MDI, 87.7±8.4 vs. 84.5±8.5, P=0.015; PDI, 82.9±8.7 vs. 79.6±8.8, P=0.016). In conclusion, parental donor liver transplantation may cause a certain degree of brain injury in pediatric patients with end-stage liver disease, as revealed by increased serum NSE and S100β levels.

Anesthesia for Combined Heart and Liver Transplantation

A heart or liver transplantation procedure performed in isolation itself presents multiple challenges for the perioperative team. Accordingly, combining both transplants yields a vastly more complicated surgery, with many unique multisystem and multidisciplinary considerations. Although combined heart and liver transplantations are being performed with increasing frequency, nationwide experience is relatively limited at most institutions. The aim of this review is to discuss the perioperative challenges presented to the anesthesiology teams and provide evidence-based guidance for the management of these daunting procedures.

Preoperative Evaluation and Anesthetic Management of Patients With Liver Cirrhosis Undergoing Cardiac Surgery

Preoperative evaluation and anesthetic management of patients with liver cirrhosis undergoing cardiac surgery remain a clinical challenge because of its high risk for perioperative complications. This narrative review article summarizes the pathophysiology and anesthetic implication of liver cirrhosis on each organ system. It will help physicians to evaluate surgical candidates, to optimize intraoperative management, and to anticipate complications in liver cirrhosis patients undergoing cardiac surgery. Morbidity typically results from bleeding, sepsis, multisystem organ failure, or hepatic insufficiency. These complications occur as a result of the presence of coagulopathy, poor nutritional status, immune dysfunction, cirrhotic cardiomyopathy, and renal and pulmonary dysfunction that occur with liver cirrhosis. Therefore, liver cirrhosis should not be seen as a single disease, but one that manifests with multiorgan dysfunction. Cardiac surgery in patients with liver cirrhosis increases the risk of perioperative complications, and it presents a particular challenge to the anesthesiologist in that nearly every aspect of normally functioning physiology may be jeopardized in a unique way. Accurately classifying the extent of liver disease, preoperative optimization, and surgical risk communication with the patient are crucial. In addition, all teams involved in the surgery should communicate openly and coordinate in order to ensure optimal care. To reduce perioperative complications, consider using off-pump cardiopulmonary bypass techniques and optimal perfusion modalities to mimic current physiologic conditions.

Dynamic Metabolomics Study of the Bile Acid Pathway During Perioperative Primary Hepatic Carcinoma Following Liver Transplantation

Background

There are many situations of abnormal metabolism influencing liver graft function. This study aims to provide data for the development of liver function recovery after liver transplantation by dynamically analyzing metabolites of bile acids pathway in serum.

Material/Methods

A comprehensive metabolomics profiling of serum of 9 liver transplantation patients before transplantation, on the 1^st, 3^rd, and 7^th days after liver transplantation, and healthy individuals were performed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Multivariate data and dynamic analysis were used to search for biomarkers between the metabolomics profiles present in perioperative liver transplantation and normal controls.

Results

Thirty-three differential endogenous metabolites were screened by the threshold of variable importance in the projection (VIP) from an orthogonal partial least square discriminant analysis (OPLS-DA) greater than 1.0, q-value <0.05, and fold change (FC) ≤0.8 or ≥1.2 between the preoperative group and the normal controls in negative mode. The metabolite intensities of taurocholic acid, taurochenodeoxycholic acid, chenodeoxycholic acid glycine conjugate, and glycocholic acid pre-transplantation were significantly higher than those of normal controls. The average metabolite intensities of taurocholic acid and taurochenodesoxycholic acid on the first day after liver transplantation were lower than those observed pre-transplantation. The average metabolite intensities on day 3 after liver transplantation showed a sudden increase and then decreased after 7 postoperative days. The average metabolite intensities of glycocholic acid and chenodeoxycholic acid glycine conjugate showed an increasing trend on the 1^st, 3^rd, and 7^th days after liver transplantation.

Conclusions

Use of taurocholic acid and taurochenodeoxycholic acid-related bile secretion, liver regeneration, and de novo bile acid synthesis may help clinical evaluation and provide data for the development of liver function recovery after liver transplantation.

Anaesthesia for Liver Transplantation: An Update

Liver transplantation (LT) is a challenging surgery performed on patients with complex physiology profiles, complicated by multi-system dysfunction. It represents the treatment of choice for end-stage liver disease. The procedure is performed under general anaesthesia, and a successful procedure requires an excellent understanding of the patho-physiology of liver failure and its implications. Despite advances in knowledge and technical skills and innovations in immunosuppression, the anaesthetic management for LT can be complicated and represent a real challenge. Monitoring devices offer crucial information for the successful management of patients. Hemodynamic instability is typical during surgery, requiring sophisticated invasive monitoring. Arterial pulse contour analysis and thermo-dilution techniques (PiCCO), rotational thromboelastometry (RO-TEM), transcranial doppler (TCD), trans-oesophageal echocardiography (TEE) and bispectral index (BIS) have been proven to be reliable monitoring techniques playing a significant role in decision making. Anaesthetic management is specific according to the three critical phases of surgery: pre-anhepatic, anhepatic and neo-hepatic phase. Surgical techniques such as total or partial clamping of the inferior vena cava (IVC), use of venovenous bypass (VVBP) or portocaval shunts have a significant impact on cardiovascular stability. Post reperfusion syndrome (PRS) is a significant event and can lead to arrhythmias and even cardiac arrest.

Bleeding and Thrombosis With Pediatric Extracorporeal Life Support: A Roadmap for Management, Research, and the Future From the Pediatric Cardiac Intensive Care Society: Part 2

OBJECTIVES

To make recommendations on improving understanding of bleeding and thrombosis with pediatric extracorporeal life support including future research directions.

DATA SOURCES

Evaluation of literature and consensus conferences of pediatric critical care and extracorporeal life support experts.

STUDY SELECTION

A team of 10 experts with pediatric cardiac and extracorporeal membrane oxygenation experience and expertise met through the Pediatric Cardiac Intensive Care Society to review current knowledge and make recommendations for future research to establish "best practice" for anticoagulation management related to extracorporeal life support.

DATA EXTRACTION/DATA SYNTHESIS

This white paper focuses on clinical understanding and limitations of current strategies to monitor anticoagulation. For each test of anticoagulation, limitations of current knowledge are addressed and future research directions suggested.

CONCLUSIONS

No consensus on best practice for anticoagulation monitoring exists. Structured scientific evaluation to answer questions regarding anticoagulation monitoring and bleeding and thrombotic events should occur in multicenter studies using standardized approaches and well-defined endpoints. Outcomes related to need for component change, blood product administration, healthcare outcome, and economic assessment should be incorporated into studies. All centers should report data on patient receiving extracorporeal life support to a registry.

Accuracy and Efficacy of Impedance Cardiography as a Non-Invasive Cardiac Function Monitor

PURPOSE

The most common method of monitoring cardiac output (CO) is thermodilution using pulmonary artery catheter (PAC), but this method is associated with complications. Impedance cardiography (ICG) is a non-invasive CO monitoring technique. This study compared the accuracy and efficacy of ICG as a non-invasive cardiac function monitoring technique to those of thermodilution and arterial pressure contour.

MATERIALS AND METHODS

Sixteen patients undergoing liver transplantation were included. Cardiac index (CI) was measured by thermodilution using PAC, arterial waveform analysis, and ICG simultaneously in each patient. Statistical analysis was performed using intraclass correlation coefficient (ICC) and Bland-Altman analysis to assess the degree of agreement.

RESULTS

The difference by thermodilution and ICG was 1.13 L/min/m², and the limits of agreement were -0.93 and 3.20 L/min/m². The difference by thermodilution and arterial pressure contour was 0.62 L/min/m², and the limits of agreement were -1.43 and 2.67 L/min/m². The difference by arterial pressure contour and ICG was 0.50 L/min/m², and the limits of agreement were -1.32 and 2.32 L/min/m². All three percentage errors exceeded the 30% limit of acceptance. Substantial agreement was observed between CI of thermodilution with PAC and ICG at preanhepatic and anhepatic phases, as well as between CI of thermodilution and arterial waveform analysis at preanhepatic phase. Others showed moderate agreement.

CONCLUSION

Although neither method was clinically equivalent to thermodilution, ICG showed more substantial correlation with thermodilution method than with arterial waveform analysis. As a non-invasive cardiac function monitor, ICG would likely require further studies in other settings.

Upper Extremity Compartment Syndrome Following Radial Artery Puncture in a Patient Undergoing Orthotopic Liver Transplant

Acute compartment syndrome is the physiologic consequence of increasing pressures within an enclosed anatomic space; if left untreated, it can subsequently cause irreversible necrosis, nerve injury, and tissue damage. A number of iatrogenic causes have been reported in the literature; however, to the best of our knowledge, there are no prior reports of upper extremity compartment syndrome in orthotopic liver transplant following arterial line placement. Here, we report a 52-year-old male with a history of end-stage liver disease secondary to primary sclerosing cho-langitis who presented for orthotopic liver transplant. A radial arterial line with 20-gauge catheter was placed atraumatically without complication. Intraoperatively, the patient developed severe coagulopathy. The cause was likely multifactorial, including dilution of factors from the massive blood loss during the dissection phase, a prolonged anhepatic period, and delayed graft function, resulting in decreased production of coagulation factors. This consumptive process likely subjected minor vascular injury to potential bleeding and caused a slow cumulative bleed into the right forearm, resulting in compartment syndrome. This case exemplifies the complications that can occur from arterial line placement in a liver transplant recipient who develops severe intraoperative coagulopathy. This can arguably be extrapolated to any situation caused by significant dilutional coagulopathy or a consumptive process, such as disseminated intra-vascular coagulation. As such, when large-volume blood transfusions are anticipated, we recommend that all central venous and arterial accesses be obtained under ultraso-nographic guidance and that frequent extremity physical examinations should be performed at a minimum of every hour. Correcting the underlying coagulopathy is imperative to resolve ongoing bleeding, a high index of suspicion is warranted, and immediate diagnosis and therapy are integral to improving patient outcomes.

Intensive Care of Pulmonary Complications Following Liver Transplantation

Chronic liver disease has been associated with pulmonary dysfunction both before and after liver transplantation. Post-liver transplantation pulmonary complications can affect both morbidity and mortality often necessitating intensive care during the immediate postoperative period. The major pulmonary complications include pneumonia, pleural effusions, pulmonary edema, and atelectasis. Poor clinical outcomes have been known to be associated with age, severity of liver dysfunction, and preexisting lung disease as well as perioperative events related to fluid balance, particularly transfusion and fluid volumes. Delineating each and every one of these pulmonary complications and their associated risk factors becomes paramount in guiding specific therapeutic strategies.