Blood bank support of a liver transplantation program

Alloimmunization Against RBC Antigens Is Not Associated With Decreased Survival in Liver Transplant Recipients

BACKGROUND

Improvement of liver transplantation (LT) outcomes requires better understanding of factors affecting survival. The presence of RBC alloantibodies (RBCAs) on survival in LT recipients was evaluated.

METHODS

This study was a single-center, retrospective cohort study reviewing transfusion records and all-cause mortality between 2002 and 2021.

RESULTS

Between 2002 and 2021, 2079 LTs were completed, 1,396 of which met inclusion criteria (1,305 RBCA negative; 91 RBCA positive [6.5%]). The cohorts were similar in age (mean [range], 55.8 [17-79] years vs 56.8 [25-73] years; P = .41, respectively) or sex (RBCA negative, 859 [65%] men and 446 [35%] women vs RBCA positive, 51 [56%] men and 40 [44%] women; P = .0684). Of 132 RBCAs detected, 10 were most common were to E (27.27%), Jka (15.91%), K (9.09%), C (8.33%), M (6.06%), D (5.3%), Fya (4.55%), e (2.27%), c (2.27%), and Jkb (2.27%). Twenty-seven patients (29.7%) had more than 1 RBCA; the most common combinations were C with Jka (7.4%) and E with Dia (7.4%). All-cause mortality was increased in men (men, 14.45 years vs women, 17.27 years; P = .0266) and patients 65 years of age and older (≥65 years of age, 10.21 years vs <64 years of age, 17.22 years; P < .0001). The presence of RBCA (≥1) did not affect all-cause mortality (RBCA negative, 14.17 years vs RBCA positive, 15.29 years; P = .4367). The top 5 causes of death were infection (11.9%), primary malignancy (solid) (10.8%), recurrent malignancy (10.5%), cardiovascular arrest (7.1%), and pulmonary insufficiency/respiratory failure (5.7%).

CONCLUSIONS

Survival in RBCA-positive LT recipients is no different from that in RBCA-negative LT recipients.

A brief history of liver transplantation and transplant anesthesia

In this review, we describe the major milestones in the development of organ transplantation with a specific focus on hepatic transplantation. For many years, the barriers preventing successful organ transplantation in humans seemed insurmountable. Although advances in surgical technique provided the technical ability to perform organ transplantation, limited understanding of immunology prevented successful organ transplantation. The breakthrough to success was the result of several significant discoveries between 1950 and 1980 involving improved surgical techniques, the development of effective preservative solutions, and the suppression of cellular immunity to prevent graft rejection. After that, technical innovations and laboratory and clinical research developed rapidly. However, these advances alone could not have led to improved transplant outcomes without parallel advances in anesthesia and critical care. With increasing organ demand, it proved necessary to expand the donor pool, which has been achieved with the use of living donors, split grafts, extended criteria organs, and organs obtained through donation after cardiac death. Given this increased access to organs and organ resources, the number of transplantations performed every year has increased dramatically. New regulatory organizations and transplant societies provide critical oversight to ensure equitable organ distribution and a high standard of care and also perform outcome analyses. Establishing dedicated transplant anesthesia teams results in improved organ transplantation outcomes and provides a foundation for developing new standards for other subspecialties in anesthesiology, critical care, and medicine overall. Through a century of discovery, the success we enjoy at the present time is the result of the work of well-organized multidisciplinary teams following standardized protocols and thereby saving thousands of lives worldwide each year. With continuing innovation, the future is bright.

Association Between Ratio of Fresh Frozen Plasma to Red Blood Cells During Massive Transfusion and Survival Among Patients Without Traumatic Injury

Importance

Hemostatic resuscitation has been shown to be beneficial for patients with trauma, but there is little evidence that it is equally beneficial for bleeding patients without trauma. The practice of a high transfusion ratio of fresh frozen plasma (FFP) to red blood cells (RBCs) has spread to other surgical and medical fields.

Objective

To identify whether ratio-based resuscitation in patients without trauma is associated with improved survival.

Design, Setting, and Participants

This study is a retrospective review of all massive transfusions provided in an urban academic hospital from January 1, 2009, through December 31, 2012. Massive transfusion was defined as the transfusion of at least 10 U of RBCs in the first 24 hours after a patient's admission to the operating room, emergency department, or intensive care unit. All patients who received massive transfusions within the study period and survived more than 30 minutes after hospital arrival were counted (n=865). Patients were grouped into those with trauma and those without trauma. Sources of data included the Research Patient Data Registry, patients' medical records, and blood bank records. All data collection occurred between April 26, 2013, and April 26, 2015. Data analysis took place from April 27, 2015, and June 22, 2016.

Main Outcomes and Measures

Examination of FFP:RBC transfusion ratios for patients without trauma.

Results

There were 865 massive transfusion events that occurred within 4 years, transfusing 16 569 U of RBCs, 13 933 U of FFP, 5228 U of cryoprecipitate, and 22 635 U of platelets. Most of these transfusions were received by patients without trauma (767 [88.7%]), by men (582 [67.3%]), and for intraoperative bleeding (544 [62.9%]). The FFP:RBC ratios of survivors and nonsurvivors were nearly identical: the ratio for survivors was 1:1.5 (interquartile range [IQR], 1:1.1-1:2.2) and for nonsurvivors was 1:1.4 (IQR, 1:1.1-1:1.9; P = .43). Among the 767 patients without trauma, there was no difference in the adjusted odds ratio (aOR) for 30-day mortality when comparing the high FFP:RBC ratio vs the low FFP:RBC ratio subgroups (aOR, 1.10; 95% CI, 0.72-1.70; P = .65). In vascular surgery, the aOR for death favored the high FFP:RBC ratio subgroup (aOR, 0.16; 95% CI, 0.03-0.79; P = .02). However, in general surgery and medicine, the aOR for death favored the low FFP:RBC ratio subgroup; general surgery: aOR, 4.27 (95% CI, 1.28-14.22; P = .02); medicine: aOR, 8.48 (95% CI, 1.50-47.75; P = .02).

Conclusions and Relevance

High FFP:RBC transfusion ratios are applied mostly to patients without trauma, who account for nearly 90% of all massive transfusion events. Thirty-day survival was not significantly different in patients who received a high FFP:RBC ratio compared with those who received a low ratio.

Changing trends in transfusion practice in liver transplantation

PURPOSE OF REVIEW

Prevention of excessive blood loss is an important issue in the perioperative management of liver transplantation. This review describes changing trends in blood products use, risk predicting of blood transfusion, variability in use and practices, as well as transfusion safety during liver transplantation.

RECENT FINDINGS

Over the last 20 years, the average use of blood products per case has considerably decreased. There are marked interinstitutional differences in blood use. Differences in patient population characteristics and surgical techniques are a partial explanation, but differences in transfusion practices probably account for a substantial part of the variability. Recent data have sparked off ongoing controversy relating to volume replacement therapy and its impact on blood loss. New studies emphasize the risks associated with transfusion in liver transplantation.

SUMMARY

Recent studies call for continuing every reasonable effort to minimize the use of blood components and can guide us in new approaches to this vital problem.

Alloimmunization to Red Cell Antigens in Liver and Multivisceral Transplant Patients

BACKGROUND

Alloimmunization to red blood cell (RBC) antigens can significantly impact transfusion support of patients undergoing solid-organ transplantation. This study evaluated the incidence of clinically significant RBC alloantibodies (abs) in 2000 consecutive adults receiving liver (OLTX), intestinal (ITX) or multivisceral (MVT) transplants.

METHODS

From January 1991 to May 2006, 2000 patients underwent OLTX (n=1892), MVT (n=74), or ITX (n=34). Blood sample for serologic investigation was submitted to the transfusion service no later than 4 hr before surgery. The presence of clinically significant RBC abs before transplant with subsequent transfusion requirements, the incidence of delayed transfusion reactions, and de novo abs after transplant were evaluated.

RESULTS

One hundred fifteen patients (5.75%) had clinically significant RBC abs before transplant, with 56.7% directed against Rh system antigens. Forty-six (40%) had multiple abs. A mean of 18 packed RBC units (U) were transfused per patient. Patients requiring >20 U (n=34) or those with multiple abs received antigen-negative units for the first 5-10 U when antibody was still present, switched to antigen-unscreened units during massive blood loss and returned to antigen-negative units for the last 5-10 U transfused. Twelve patients (0.6%) developed de novo abs posttransplant. Twenty-two (1.1%) had delayed serologic transfusion reaction. All patients were successfully managed without delay in initiation of surgery or hemolytic complications.

CONCLUSION

RBC alloimmunization can present a special challenge to solid-organ transplantation. Early serologic testing of the recipient pretransplant and prompt communication between the transfusion service and transplant team facilitates successful transfusion management of these patients.

The effect of aprotinin on renal function in orthotopic liver transplantation

BACKGROUND

In the European Multicenter Study on the Use of Aprotinin in Liver Transplantation (EMSALT), a randomized, double-blind, placebo-controlled, prospective study, we demonstrated that aprotinin significantly reduces intraoperative blood loss during orthotopic liver transplantation (OLT). Aprotinin is metabolized in the kidney and potentially nephrotoxic at high concentrations. Renal insufficiency is a common and serious complication after OLT. It is unknown whether aprotinin increases the risk of renal failure after OLT.

METHODS

We analyzed intraoperative urine output, need for postoperative dialysis, perioperative serum creatinine levels, and creatinine clearance in 93 patients enrolled in EMSALT, receiving a high dose of aprotinin, a regular dose, or placebo.

RESULTS

Peak increase in serum creatinine exceeding 0.5 mg/dl during one of the postoperative days occurred in 11 (35%) patients in the placebo group, in 11 (34%) patients in the high-dose group, but only in 1 (3%) patient in the regular-dose group (P=0.007). Furthermore, a perioperative decrease in creatinine clearance was seen in the placebo group (-23.9+/-10.1 ml/min) but not in both high-dose (-1.6+/-13.3 ml/min) and regular-dose (9.7+/-10.3 ml/min) groups (P<0.02 comparing regular-dose and placebo group).

CONCLUSIONS

Despite its potential nephrotoxicity, the use of aprotinin for reducing blood loss during OLT does not lead to a higher incidence of postoperative renal insufficiency. In combination with the observed reduction in blood loss, these findings support the prophylactic use of regular-dose aprotinin during OLT.

Poor prediction of blood transfusion requirements in adult liver transplantations from preoperative variables

STUDY OBJECTIVE

To assess the ability of preoperative information to predict intraoperative blood transfusion requirements in adult orthotopic liver transplantation.

DESIGN

Retrospective review.

SETTING

Liver transplantation program in a referral center.

PATIENTS

583 sequential adult patients undergoing orthotopic liver transplantation.

MEASUREMENTS

Preoperative variables with a previously demonstrated relationship to intraoperative transfusion were identified from the literature. These variables were then collected retrospectively from 583 consecutive liver transplantations. Relationships between these and intraoperative blood transfusion requirements were examined by both univariate analyses and multiple linear regression analysis.

RESULTS

Univariate analysis revealed significant associations between blood transfused and the following preoperative variables: age, gender, diagnosis, presence of grade 3 or 4 encephalopathy, pseudocholinesterase, creatinine, bilirubin, mean pulmonary artery pressure, activated partial thromboplastin time, and platelet count. Multiple linear regression analysis with correction for diagnosis identified age, creatinine, bilirubin, and pseudocholinesterase as independent predictors; for the final model r(2) = 0.22.

CONCLUSION

Preoperative variables are poor predictors of intraoperative transfusion requirements even when significant associations exist, identifying a small proportion of the variability observed. A predictive approach based on this method would be too inaccurate to be of clinical use. The majority of the variability in transfusion requirements during liver transplantation most likely results from intraoperative and donor organ factors.

Coagulation defects in liver disease

A normally functioning hemostasis system is closely related to liver function. The liver parenchymal cells produce most of the factors and inhibitors of the clotting and fibrinolytic systems, and the RES of the liver greatly aids in the clearance of activation products. Hemostasis defects thus depend on the extent of liver damage. A wide spectrum of defects is found in patients with liver cirrhosis. Owing to impaired protein synthesis, most factors and inhibitors of the clotting and the fibrinolytic systems are markedly reduced. Additionally, abnormal vitamin K-dependent factor and fibrinogen molecules have been encountered. Most patients have hyperfibrinolysis that could be DIC in nature. Thrombocytopenia and thrombocytopathy are also found. Acute or chronic hepatocellular disease may display decreased vitamin K-dependent factor levels, especially factor VII and protein C, with other factors still being normal. If patients go into hepatic failure, the abnormalities resemble those found in liver cirrhosis. Vitamin K deficiency is associated with the production of poorly functioning vitamin K-dependent factors. All other hemostasis parameters are normal. Disturbances associated with liver surgeries again depend on the underlying liver problem. Peritoneovenous shunts (LeVeen) may lead to DIC; bleeding from partially resected liver surfaces is usually a mechanical problem. Severe bleeding is encountered with orthotopic liver transplantation. It is greatly influenced by the activation of the fibrinolytic system. This occurs during the anhepatic phase and during the reperfusion phase. The hyperfibrinolysis is mediated by an intense release of t-PA. Antifibrinolytic drugs, if used cautiously, have markedly reduced bleeding and thus reduced need for blood and blood product substitution.

Selection criteria for liver donation: a review

An overview of the criteria that are currently being used for the selection of liver donors is presented. The validity of the different criteria is discussed. The potential benefits of introducing other modalities is dealt with.

Pulmonary complications of orthotopic liver transplantation

We retrospectively reviewed the pulmonary complications and associated morbidity and mortality of 44 consecutive patients who underwent 52 orthotopic liver transplantations (OLTs) at the Mayo Clinic during 1987. All survivors participated in follow-up for 1 year after OLT. Of the five deaths in the study group, three were associated with pulmonary infections. On postoperative chest roentgenograms, 24 cases of pulmonary infiltrates were noted; 12 were caused by infections. Ten opportunistic pulmonary infections developed in nine patients: four cytomegalovirus, three Pneumocystis carinii pneumonia, and one each of Cryptococcus, Aspergillus, and Candida. All except one of the opportunistic infections were diagnosed after the sixth postoperative week. Fiberoptic bronchoscopy was helpful for diagnosing opportunistic pulmonary infections in six patients. One Aspergillus pulmonary infection was diagnosed by transthoracic needle aspiration. Bacterial pneumonia occurred in five patients. Preoperative pulmonary function tests, performed in 40 patients, revealed a restrictive ventilatory defect in 28% and impaired gas transfer in 52%. Pleural effusion was present in 18% of patients preoperatively and in 77% during the first week after OLT. Preoperative severity of liver disease and results of arterial blood gas determinations, pulmonary function tests, and chest roentgenography were not associated with postoperative mortality and pulmonary infections. Infectious and noninfectious pulmonary complications are common in liver transplant recipients. Attempts to decrease the frequency and severity of pulmonary complications by early diagnosis and effective treatment may diminish the morbidity and mortality associated with OLT.

An evaluation of the Rapid Infusion System

The performance of the Rapid Infusion System was evaluated in the laboratory. Using a conventional mixture of two units of packed red cells, two units of fresh frozen plasma and 500 ml crystalloid, a single line and a driving pressure of 300 mmHg, the highest flow in our study was 970 ml.min-1 (2.8 mm catheter, no stopcock). With a 1.6 mm venous cannula the measured flow was 640 ml.min-1. Additional diluting of the standard 'blood cocktail' did not add much to the performance of the system. When primed with tap water 21 degrees C (12 degrees C respectively), the fluid at the outlet of the system reached a maximum temperature of 37.8 degrees C (37.4 degrees C) after 6 min at a flow of 400 ml.min-1. At flows higher than 1150 ml.min-1 (priming with 12 degrees C tap water: 800 ml.min-1), the system slowed down to flows of 700 to 1000 ml.min-1 in order to maintain an adequate temperature. We conclude, that the Rapid Infusion System is a valuable tool for situations where a rapid but controlled replacement with warmed blood at rates up to at least 1100 ml.min-1 is needed. The use of large bore intravenous catheters and avoiding additional resistors such as standard 3-way stopcocks is highly recommended.

Intraoperative autologous transfusion: its role in orthotopic liver transplantation

In our orthotopic liver transplantation program, intraoperative autologous transfusion was used in 89 of the first 100 procedures. In these 89 cases, intraoperative autologous transfusion provided a mean of 6.2 erythrocyte units per case or 32% of the total intraoperative erythrocyte requirements. The maximal number of erythrocyte units administered to any patient was 36.6 units (and 51% of the erythrocyte requirements). The most rapid rate of reinfusion of intraoperatively salvaged blood (11.8 units/h) occurred during reperfusion. No coagulopathy, infectious sequelae, or other complications were attributable to intraoperative autologous transfusion. In patients with large volumes of blood loss, intraoperative autologous transfusion is cost-effective, apart from the consideration of its medical benefits. Use of intraoperative autologous transfusion in liver transplantation resulted in conservation of erythrocytes and reduction in exposure to homologous blood and blood components.

Intraoperative blood loss and patient and graft survival in orthotopic liver transplantation: their relationship to clinical and laboratory data

We reviewed the records of 83 patients who underwent 100 orthotopic liver transplantations in order to determine the following: (1) the methods to predict blood usage, (2) the consequences of an ABO-incompatible transplant, (3) the benefit of providing cytomegalovirus (CMV)-negative blood products to CMV-negative patients receiving a liver from a CMV-negative donor, (4) the association of donor anti-hepatitis B core antigens and subsequent hepatitis B, and (5) the prognostic consequences of rouleaux observed in pretransplant blood compatibility testing. Patient diagnosis, the presence of ascites, a preoperative prothrombin time greater than 15 seconds, and a multifactorial "risk category" were all predictive of intraoperative blood loss. A history of previous gastrointestinal bleeding or an operation that involved the right upper abdominal quadrant was not predictive of intraoperative blood loss. Although CMV infection is common after liver transplantation, the prophylactic use of CMV antibody-negative blood products in CMV-negative recipients receiving a liver from a CMV-negative donor in our series was not associated with postoperative CMV infection. The transplantation of a liver positive for anti-hepatitis B core antigen was associated with subsequent hepatitis B surface antigen seroconversion in two of four cases. Transplantation of an ABO-incompatible liver and the presence of rouleaux observed in pretransplant blood compatibility testing were both associated with a significantly higher mortality. A careful review of laboratory data and medical records of patients undergoing liver transplantation should enhance the ability to modify the approach to the allocation of limited blood resources and the care and management of these patients.