Hemostasis and coagulation monitoring and management during liver transplantation

Use of Rotational Thromboelastometry in Liver Transplantation Is Associated With Reduced Transfusion Requirements

OBJECTIVES

Increased transfusion requirements in liver transplantation have been reported to be associated with worsened outcomes, more frequent reinterventions, and higher expenses. Anesthesiologists might counteract this through improved coagulation management. We evaluated the effects of rotational thromboelastometry on transfusion and coagulation product requirements and on outcome measurements.

MATERIALS AND METHODS

Patients who were 14 years or older and who were undergoing liver transplant at Hannover Medical School between January 2005 and December 2009 were included in this retrospective analysis. Demographic, clinical, and laboratory data, use of rotational thromboelastometry, intraoperative need for blood or coagulation products and antifibrinolytic substances, and clinical course were recorded. Correlations were examined using appropriate statistical tests.

RESULTS

Our study included 413 patients. Use of rotational thromboelastometry was associated with less frequent intraoperative administration of red blood cell concentrates, fresh frozen plasma, platelet concentrates, prothrombin complex concentrates, and antithrombin concentrates (all P < .05). In addition, univariate and multivariate tests showed that rotational thromboelastometry was correlated with decreased need for red blood cell concentrates and fresh frozen plasma (all P < .05). Intraoperative administration rates of antifibrinolytic substances and fibrinogen concentrate were significantly increased in patients who received rotational thromboelastometry monitoring (both P < .05). However, use of rotational thromboelastometry was not associated with massive transfusion rates (> 10 units vs less), clinical outcome, or length of stay in the intensive care unit (all P > .05).

CONCLUSIONS

Use of rotational thromboelastometry during liver transplant may reduce the need for intraoperative transfusion and coagulation products. Relevant effects of rotational thromboelastometry on patient outcomes or lengths of stay in the intensive care unit could not be ascertained. However, readjustment of therapeutic thresholds may improve the clinical impact.

Rescue management of early complications after liver transplantation-key for the long-term success

PURPOSE

Postoperative complications may have not only immediate but also long-term effects on the outcomes. Here, we analyzed the effect of postoperative complications requiring a reoperation (grade 3b) within the first 30 days on patients' and graft survival following liver transplantation.

METHODS

Graft and patient survival in relation to donor and recipient variables and the need of reoperation for complications of 277 consecutive liver transplants performed from January 2007 to December 2012 were analyzed.

RESULTS

Two hundred seventy-seven liver transplants were performed in 252 patients. Overall patient and graft survival at 1, 2, and 3 years were significantly reduced in patients requiring a reoperation. The labMELD score was significantly elevated (p = 0.04) and cold ischemia time was prolonged (p = 0.03) in recipients undergoing reoperations. Kaplan-Meier curves indicate that complications impact the outcome primarily within the first 3 months after transplantation. In multivariate analyses, the actual need of reoperation (p < 0.001), the labMELD score (p = 0.05), cold ischemia time (p = 0.02), and the need for hemodialysis pre-transplant (p = 0.05) were the only variables which correlated with the overall survival.

CONCLUSION

Postoperative complications resulting in reoperations have a significant impact on the outcome primarily in the early phase after liver transplantation. Successful management of postoperative complications is key to every successful liver transplant program.

Survey of hemostasis management and transfusion in liver transplantation

OBJECTIVE

To determine the management of haemostasis and transfusion practice in the field of liver transplantation in Spain.

METHODS

A questionnaire was developed for physicians in anaesthesiology of all centres performing liver transplantation in Spain. The information required made reference to the 12 months prior to its distribution, from January 1 to December 31, 2011.

RESULTS

Data were collected from 24 centres in which liver transplantation is performed in Spain. Only 46% reported that they had protocols or practice guidelines for the management of haemostasis, and 83% of hospitals responded that they knew the percentage of transfused patients, but only 57% knew the mean transfusion. Regarding the degree of satisfaction with the management of haemostasis/coagulation, 50% said they were not satisfied. Thromboelastometry was used as an additional method of preoperative monitoring in only 8% of the centres and intra-operatively in one-third. Less than half (46%) of the centres performed preoperative correction of coagulation deficits based on conventional tests. The mean number of packed red cells used was ≤4 in 57% of centres. Consumption of fresh frozen plasma was highly variable, while 100% of centres consumed less than 4 pools of platelets per patient.

CONCLUSIONS

There is a wide variability in the management of haemostasis and transfusion practice among Spanish centres. There are no guidelines or they are not widely used. The mean use of transfused blood products remain high. There was a decrease in centres using new methods of monitoring.

Predicting fluid responsiveness in patients undergoing orthotopic liver transplantation: effects on intraoperative blood transfusion and postoperative complications

OBJECTIVE

To test the hypothesis that the restrictive volume therapy decreases blood transfusion requirement during liver orthotopic transplantation (OLT) without increasing acute renal complications and hospital length stay.

MATERIAL AND METHODS

We conducted a retrospective cohort study (n = 89), randomized into 2 groups: A (liberal fluid strategy) and B (restrictive therapy). We analyzed packed red blood cells (PRBCs) units, transfused units of fresh frozen plasma (FFP), colloids, crystalloids, perioperative renal function, and hospital length stay. For comparison of proportions, we used the χ(2) test and Student t test to compare means (parametric). A logistic regression model was constructed to evaluate the association of all these variables with probability of PRBCs transfusion.

RESULTS

In group A, 88.4% of patients required intraoperative transfusion of PRBCs, with a mean of 8.5 ± 7.02 IU, compared with 82.2% in group B with a mean of 5.02 ± 4.5 IU (P < .001). We also found differences in the following variables: FFP transfusion rate was 95.3% (mean, 15.02 ± 8.2 IU) in group A and 75.6% (mean, 8.7 ± 6.04 IU) in B (P < .001). The amount of colloid was 50% (mean, 692.8 ± 409.6 mL) in group A and 28.9% (mean, 607.6 ± 316.7 mL) in B (P = .032). Platelet concentrates transfusion was 79.1% (mean, 2.05 ± 1.1 IU) in group A and 51.1% (mean, 2.0 ± 1.08 IU) in B (P = .014). As an important effect of restrictive fluid therapy, renal function was assessed; no differences in mean creatinine or acute renal failure in the immediate postoperative period were observed. There was no difference in hospital length stay. Logistic regression modelling identified 3 variables as significant predictors of transfusion: Fluid administration policy, preoperative hemoglobin and FFP units transfused. Furthermore, an increase of preoperative hemoglobin is associated with a lesser probability of transfusion.

CONCLUSIONS

These results show that fluid restriction management for OLT decreased blood products requirements, especially FFP. This could suggest that liberal fluid management may aggravate, rather than prevent, bleeding in these patients. We did observed any no difference in failure of renal function.

Point-of-care haemostasis monitoring during liver transplantation reduces transfusion requirements and improves patient outcome

BACKGROUND

Optimal haemostasis management can improve patient outcomes and reduce blood loss and transfusion volume in orthotopic-liver-transplant (OLT).

METHODS

We performed a prospective study including 200 consecutive OLTs. The first 100 patients were treated according to the clinic's standards and the next 100 patients were treated using the new point-of-care (POC)-based haemostasis management strategy. Transfusion parameters and other outcomes were compared between groups.

RESULTS

Transfusion requirements were reduced in the POC group. The median and IQR of red-blood-cells (RBC) transfusion units were reduced from 5 [2-8] to 3 [0-5] (p < 0.001), plasma from 2 [0-4] to 0 (p < 0.001), and platelets from 1 [0-4] to 0 [0-1] (p < 0.001), into the POC group only four patients received tranexamic acid and fibrinogen transfusion rate was 1.13 ± 1.44 g (p = 0.001). We also improved the incidence of transfusion avoidance, 5% vs. 24% (p < 0.001) and reduced the incidence of massive transfusion (defined as the transfusion of more than 10 RBC units), 13% vs. 2% (p = 0.005). We also observed a relationship between RBC transfusion requirements and preoperative haemoglobin, and between platelet transfusion and preoperative fibrinogen levels. The incidence of postoperative complications, such as, reoperation for bleeding, acute-kidney-failure or haemodynamic instability was significantly lower (13.0% vs. 5%, p = 0.048, 17% vs. 2%, p < 0.001, and 29% vs. 16%, p = 0.028). Overall, blood product transfusion was associated with increased risk of postoperative complications.

CONCLUSIONS

A haemostatic therapy algorithm based on POC monitoring reduced transfusion and improved outcome in OLT.

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.

Monitoring and managing hepatic disease in anaesthesia

Patients with liver disease have multisystem organ dysfunction that leads to physiological perturbations ranging from hyperbilirubinaemia of no clinical consequence to severe coagulopathy and metabolic disarray. Patient-specific risk factors, clinical scoring systems, and surgical procedures stratify perioperative risk for these patients. The anaesthetic management of patients with hepatic dysfunction involves consideration of impaired drug metabolism, hyperdynamic circulation, perioperative hypoxaemia, bleeding, thrombosis, and hepatic encephalopathy.

Liver Transplantation without Perioperative Transfusions Single-Center Experience Showing Better Early Outcome and Shorter Hospital Stay

Background. Significant amounts of red blood cells (RBCs) transfusions are associated with poor outcome after liver transplantation (LT). We report our series of LT without perioperative RBC (P-RBC) transfusions to evaluate its influence on early and long-term outcomes following LT. Methods. A consecutive series of LT between 2006 and 2011 was analyzed. P-RBC transfusion was defined as one or more RBC units administrated during or ≤48 hours after LT. We divided the cohort in “No-Transfusion” and “Yes-Transfusion.” Preoperative status, graft quality, and intra- and postoperative variables were compared to assess P-RBC transfusion risk factors and postoperative outcome. Results. LT was performed in 127 patients (“No-Transfusion” = 39 versus “Yes-Transfusion” = 88). While median MELD was significantly higher in Yes-Transfusion (11 versus 21; P = 0.0001) group, platelet count, prothrombin time, and hemoglobin were significantly lower. On multivariate analysis, the unique independent risk factor associated with P-RBC transfusions was preoperative hemoglobin (P < 0.001). Incidence of postoperative bacterial infections (10 versus 27%; P = 0.03), median ICU (2 versus 3 days; P = 0.03), and hospital stay (7.5 versus 9 days; P = 0.01) were negatively influenced by P-RBC transfusions. However, 30-day mortality (10 versus 15%) and one- (86 versus 70%) and 3-year (77 versus 66%) survival were equivalent in both groups. Conclusions. Recipient MELD score was not a predictive factor for P-RBC transfusion. Patients requiring P-RBC transfusions had worse postoperative outcome. Therefore, maximum efforts must be focused on improving hemoglobin levels during waiting list time to prevent using P-RBC in LT recipients.

Liver transplantation: Advances and perioperative care

Liver transplantation is one of the treatments for many-life threatening liver diseases. Numerous advances in liver transplant surgery, anaesthesia and perioperative care have allowed for an increasing number of these procedures. The purpose of this review is to consider some of the important advances in perioperative care of liver transplant patients such as pre-operative evaluation, intraoperative monitoring and management and early extubation. A PubMed and EMBASE search of terms “Anaesthesia” and “Liver Transplantation” were performed with filters of articles in “English”, “Adult” and relevant recent publications of randomised control trial, editorial, systemic review and non-systemic review were selected and synthesized according to the author's personal and professional perspective in the field of liver transplantation and anaesthesia. The article outlines strategies in organ preservation, training and transplant database for further research.

[Anesthesia in the patient with impaired liver function]

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.

Antifibrinolytics in liver surgery

Hyperfibrinolysis, a known complication of liver surgery and orthotopic liver transplantation (OLT), plays a significant role in blood loss. This fact justifies the use of antifibrinolytic drugs during these procedures. Two groups of drug namely lysine analogues [epsilon aminocaproic acid (EACA) and tranexamic acid (TA)] and serine-protease-inhibitors (aprotinin) are frequently used for this purpose. But uniform data or guidelines on the type of antifibrinolytic drugs to be used, their indications and correct dose, is still insufficient. Antifibrinolytics behave like a double-edged sword. On one hand, there are benefits of less transfusion requirements but on the other hand there is potential complication like thromboembolism, which has been reported in several studies. We performed a systematic search in PubMed and Cochrane Library, and we included studies wherein antifibrinolytic drugs (EACA, TA, or aprotinin) were compared with each other or with controls/placebo. We analysed factors like intraoperative red blood cell and fresh frozen plasma requirements, the perioperative incidence of hepatic artery thrombosis, venous thromboembolic events and mortality. Among the three drugs, EACA is least studied. Use of extensively studied drug like aprotinin has been restricted because of its side effects. Haemostatic effect of aprotinin and tranexamic acid has been comparable. However, proper patient selection and individualized treatment for each of them is required. Purpose of this review is to study various clinical trials on antifibrinolytic drugs and address the related issues like benefits claimed and associated potential complications.

[Proposed experimental model to provide training in the management of anesthesia in liver transplantation]

OBJECTIVE

To propose and evaluate the use of a porcine model for training in how to manage and improve the quality of anesthesia during liver transplantation.

MATERIAL AND METHODS

Five trained anesthesiologists who had no previous experience in managing anesthesia during liver transplantation and who did not work in hospitals where the procedure was performed volunteered for the training course and evaluated it. Each trainee anesthetized 5 animals. Surgery was performed under total balanced anesthesia with monitoring of hemodynamics, ventilation, biochemistry, arterial blood gases, and coagulation. Previously set criteria were used to evaluate the trainees' skill in maintaining patient stability. Their work was assessed 7 times: at baseline, 15 minutes into the preanhepatic phase, at the end of the preanhepatic stage, 15 minutes into the anhepatic phase, at the end of the anhepatic phase, 15 minutes into the postanhepatic phase, and at the end of the postanhepatic phase. After completing the course, the trainees filled in a questionnaire to evaluate its usefulness. Analysis of variance was applied to score changes in anesthetic quality criteria.

RESULTS

After implantation, changes in metabolic (acidosis) and cardiac (hypotension and bradycardia) status were the most critical abnormalities the trainees faced. Their skill in coping with hemodynamic and metabolic changes improved significantly (P<.05). All participants expressed a preference for receiving training in a porcine model before providing anesthesia in this surgical setting.

CONCLUSIONS

Under this training model, the anesthesiologists understood and were able to manage the hemodynamic and physiologic changes that develop during a liver transplant procedure. We believe that training using a porcine model allows an anesthesiologist to acquire experience and skill in this setting.