Differential effects of plasma and red blood cell transfusions on acute lung injury and infection risk following liver transplantation

Universal antifungal prophylaxis effectively prevents fungal bloodstream infection in pediatric liver transplant recipients: a retrospective real-world study

OBJECTIVES

Fungal bloodstream infection (fBSI) following pediatric liver transplantation presents a significant challenge; however, there remains a paucity of guidance regarding antifungal prophylaxis in this population. This study aimed to evaluate the effectiveness of universal antifungal prophylaxis and propose a desirable strategy.

METHODS

We enrolled 604 pediatric patients who underwent liver transplantation between 2020 and 2023, including 242 patients with empirical prophylaxis and 362 patients with universal prophylaxis. Univariate and multivariate logistic regression analyses were performed to identify independent factors for fBSI.

RESULTS

Eight (2.2%) pediatric recipients in the universal prophylaxis group and 13 (5.4%) in the empirical group developed fBSI (P = 0.038). Universal prophylaxis was a protective factor (P = 0.044), while high-volume intraoperative plasma transfusion and deceased donor liver transplantation were independent risk factors for fBSI (P = 0.035 and 0.008, respectively). Universal antifungal strategy showed an increased overall survival trend after liver transplantation although without significant statistical difference (P = 0.217). Patients with fBSI had poorer survival than those without fBSI (P <0.001).

CONCLUSIONS

Universal prophylaxis strategy for fBSI in pediatrics after liver transplantation is desirable as it could markedly decrease the occurrence of fBSI. Pediatric patients with deceased donors and high-volume intraoperative transfusion should be paid more attention to preventing fBSI.

Multidrug-resistant bacterial infections after liver transplantation: Prevalence, impact, and risk factors

BACKGROUND & AIMS

Infections by multidrug-resistant bacteria (MDRB) are an increasing healthcare problem worldwide. This study analyzes the incidence, burden, and risk factors associated with MDRB infections after liver transplant(ation) (LT).

METHODS

This retrospective, multicenter cohort study included adult patients who underwent LT between January 2017 and January 2020. Risk factors related to pre-LT disease, surgical procedure, and postoperative stay were analyzed. Multivariate logistic regression analysis was performed to identify independent predictors of MDRB infections within the first 90 days after LT.

RESULTS

We included 1,045 LT procedures (960 patients) performed at nine centers across Spain. The mean age of our cohort was 56.8 ± 9.3 years; 75.4% (n = 782) were male. Alcohol-related liver disease was the most prevalent underlying etiology (43.2.%, n = 451). Bacterial infections occurred in 432 patients (41.3%) who presented with a total of 679 episodes of infection (respiratory infections, 19.3%; urinary tract infections, 18.5%; bacteremia, 13.2% and cholangitis 11%, among others). MDRB were isolated in 227 LT cases (21.7%) (348 episodes). Enterococcus faecium (22.1%), Escherichia coli (18.4%), and Pseudomonas aeruginosa (15.2%) were the most frequently isolated microorganisms. In multivariate analysis, previous intensive care unit admission (0-3 months before LT), previous MDRB infections (0-3 months before LT), and an increasing number of packed red blood cell units transfused during surgery were identified as independent predictors of MDRB infections. Mortality at 30, 90, 180, and 365 days was significantly higher in patients with MDRB isolates.

CONCLUSION

MDRB infections are highly prevalent after LT and have a significant impact on prognosis. Enterococcus faecium is the most frequently isolated multi-resistant microorganism. New pharmacological and surveillance strategies aimed at preventing MDRB infections after LT should be considered for patients with risk factors.

IMPACT AND IMPLICATIONS

Multidrug-resistant bacterial infections have a deep impact on morbidity and mortality after liver transplantation. Strategies aimed at improving prophylaxis, early identification, and empirical treatment are paramount. Our study unveiled the prevalence and main risk factors associated with these infections, and demonstrated that gram-positive bacteria, particularly Enterococcus faecium, are frequent in this clinical scenario. These findings provide valuable insights for the development of prophylactic and empirical antibiotic treatment protocols after liver transplantation.

Computer-Aided Diagnosis of Complications After Liver Transplantation Based on Transfer Learning

Liver transplantation is one of the most effective treatments for acute liver failure, cirrhosis, and even liver cancer. The prediction of postoperative complications is of great significance for liver transplantation. However, the existing prediction methods based on traditional machine learning are often unavailable or unreliable due to the insufficient amount of real liver transplantation data. Therefore, we propose a new framework to increase the accuracy of computer-aided diagnosis of complications after liver transplantation with transfer learning, which can handle small-scale but high-dimensional data problems. Furthermore, since data samples are often high dimensional in the real world, capturing key features that influence postoperative complications can help make the correct diagnosis for patients. So, we also introduce the SHapley Additive exPlanation (SHAP) method into our framework for exploring the key features of postoperative complications. We used data obtained from 425 patients with 456 features in our experiments. Experimental results show that our approach outperforms all compared baseline methods in predicting postoperative complications. In our work, the average precision, the mean recall, and the mean F1 score reach 91.22%, 91.70%, and 91.18%, respectively.

Implementation of a Bleeding Management Algorithm in Liver Transplantation: A Pilot Study

Objectives

The aims of the study were to compare the consumption of blood products before and after the implementation of a bleeding management algorithm in patients undergoing liver transplantation and to determine the feasibility of a multicentre, randomized study.

Background

Liver transplantation remains the only curative therapy for patients with end-stage liver disease, but it carries a high risk of surgical bleeding.

Materials and Methods

Retrospective study of patients treated before (group 1) and after (group 2) implementation of a haemostatic algorithm guided by viscoelastic testing, including use of lyophilized coagulation factor concentrates (prothrombin complex and fibrinogen concentrates). Primary outcome was the number of units of blood products transfused in 24 h after surgery. Secondary outcomes included hospital stay, mortality, and cost.

Results

Data from 30 consecutive patients was analysed; 14 in group 1 and 16 in group 2. Baseline data were similar between groups. Median total blood product consumption 24 h after surgery was 33 U (IQR: 11-57) in group 1 and 1.5 (0-23.5) in group 2 (p = 0.028). Significantly fewer units of red blood cells, fresh frozen plasma, and cryoprecipitate were transfused in group 2 versus group 1. There was no significant difference in complications, hospital stay, or in-hospital mortality between groups. The cost of haemostatic therapy was non-significantly lower in group 2 versus group 1 (7,400 vs. 15,500 USD; p = 0.454).

Conclusion

The haemostatic management algorithm was associated with a significant reduction in blood product use during 24 h after liver transplantation. This study demonstrated the feasibility and provided a sample size calculation for a larger, randomized study.

Predictors of intraoperative massive transfusion in orthotopic liver transplantation

BACKGROUND

Although transfusion management has improved during the last decade, orthotopic liver transplantation (OLT) has been associated with considerable blood transfusion requirements which poses some challenges in securing blood bank inventories. Defining the predictors of massive blood transfusion before surgery will allow the blood bank to better manage patients' needs without delays. We evaluated the predictors of intraoperative massive transfusion in OLT.

STUDY DESIGN AND METHODS

Data were collected on patients who underwent OLT between 2007 and 2017. Repeat OLTs were excluded. Analyzed variables included recipients' demographic and pretransplant laboratory variables, donors' data, and intraoperative variables. Massive transfusion was defined as intraoperative transfusion of ≥10 units of packed red blood cells (RBCs). Statistical analysis was performed using SPSS version 17.0.

RESULTS

The study included 970 OLT patients. The median age of patients was 57 (range: 16-74) years; 609 (62.7%) were male. RBCs, thawed plasma, and platelets were transfused intraoperatively to 782 (80.6%) patients, 831 (85.7%) patients, and 422 (43.5%) patients, respectively. Massive transfusion was documented in 119 (12.3%) patients. In multivariate analysis, previous right abdominal surgery, the recipient's hemoglobin, Model for End Stage Liver Disease (MELD) score, cold ischemia time, warm ischemia time, and operation time were predictive of massive transfusion. There was a direct significant correlation between the number of RBC units transfused and plasma (Pearson correlation coefficient r = .794) and platelets (r = .65).

DISCUSSION

Previous abdominal surgery, the recipient's hemoglobin, MELD score, cold ischemia time, warm ischemia time, and operation time were predictive of intraoperative massive transfusion in OLT.

Patient Blood Management in Liver Transplant—A Concise Review

Transfusion of blood products in orthotopic liver transplantation (OLT) significantly increases post-transplant morbidity and mortality and is associated with reduced graft survival. Based on these results, an active effort to prevent and minimize blood transfusion is required. Patient blood management is a revolutionary approach defined as a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient’s own blood while promoting patient safety and empowerment. This approach is based on three pillars of treatment: (1) detecting and correcting anemia and thrombocytopenia, (2) minimizing iatrogenic blood loss, detecting, and correcting coagulopathy, and (3) harnessing and increasing anemia tolerance. This review emphasizes the importance of the three-pillar nine-field matrix of patient blood management to improve patient outcomes in liver transplant recipients.

How do I/we forecast tomorrow's transfusion? A focus on recipients' profiles

Red blood cell (RBC) transfusion is a life-saving medical intervention and has an essential role in the management of surgical patients. However, blood donations and supply levels are decreasing, therefore there is an unmet need for the accurate prediction of the transfusion probability for surgical patients. Multiple methods have been established to predict the need for RBC transfusion. Maximum surgical blood order schedules are widely used in the clinical setting. However, these lists are not designed to accurately predict RBC utilization for an individual case as factors such as preoperative haemoglobin level, total body blood volume, comedications are not considered. Artificial intelligence and related technologies based on machine learning modelling are valuable alternatives to predict transfusion probability taking into account patient individual risk factors including among others comorbidities, laboratory parameters, use of oral anticoagulation, ASA score, surgeon's ID or applied blood saving measures. Overall, forecasting the need for a RBC transfusion can facilitate personalized medicine, quality assurance, decrease blood wastage, decrease costs, and increase patient safety. Furthermore, transfusion prediction models could facilitate blood management strategies before surgery.

Association of red blood cell transfusion volume with postoperative complications and mortality in neonatal surgery

INTRODUCTION

Red blood cell transfusion (RBCT) is commonly administered in neonatal surgical care in the absence of clear clinical indications such as active bleeding or anemia. We hypothesized that higher RBCT volumes are associated with worse postoperative outcomes.

METHODS

Neonates within the National Surgical Quality Improvement Program-Pediatric database who underwent inpatient surgery (2012-2016) were stratified by weight-based RBCT volume: <20cc/kg, 20-40cc/kg, and >40cc/kg. Postoperative complications were categorized as wound, systemic infection, central nervous system (CNS), renal, pulmonary, and cardiovascular. Multivariable logistic regression and cubic spline analysis were used to evaluate the association between RBCT volume, postoperative complications, and 30-day mortality. Sensitivity analysis was conducted by performing propensity score matching.

RESULTS

Among 9,877 neonates, 1,024 (10%) received RBCTs. Of those who received RBCT, 53% received <20cc/kg, 27% received 20-40cc/kg, and 20% received >40cc/kg. Relative to neonates who were not transfused, RBCT volume was associated with a dose-dependent increase in renal complications, CNS complications, cardiovascular complications, and 30-day mortality. With cubic spline analysis, a lone inflection point for 30-day mortality was identified at a RBCT volume of 30 - 35 cc/kg. After propensity score matching, the dose-dependent relationship was still present for 30-day mortality.

CONCLUSION

Total RBCT volume is associated with worse postoperative outcomes in neonates with a significant increase in 30-day mortality at a RBCT volume of 30 - 35 cc/kg. Future prospective studies are needed to better understand the association between large RBCT volumes and poor outcomes after neonatal surgery.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

Perioperative Pediatric Erythrocyte Transfusions: Incorporating Hemoglobin Thresholds and Physiologic Parameters in Decision-making

This article presents current literature and scientific evidence on hemoglobin thresholds and physiologic parameters to guide decisions regarding perioperative erythrocyte transfusions in pediatric patients based on the most up-to-date studies and expert consensus recommendations.

Validation of 5 models predicting transfusion, bleeding, and mortality in liver transplantation: an observational cohort study

BACKGROUND

Historically, orthotopic liver transplantation (OLT) has been associated with massive blood loss, blood transfusion and morbidity. In order to predict such outcomes five nomograms have been published relating to transfusions and morbidity associated with OLTs. These nomograms, developed on the basis of three cohorts of patients consisting of 406, 750, and 800 having undergone OLTs, aimed to predict a transfusion of ≥1 red blood cell unit (RBC), a transfusion of >2 RBC units, a blood loss of >900 ml, as well as one-month and one-year survival rates. The aim of this study was to validate these five nomograms in a contemporary, independent cohort of patients.

METHODS

Five nomograms were previously developed based on 406, 750, and 800 OLTs. In this study we performed a temporal validation of these nomograms on contemporary patients that consisted of three cohorts of 800, 250, and 200 OLTs. Logistic regression coefficients from the historic development cohorts were applied to the three contemporary temporal validation cohorts.

RESULTS

The most accurate nomogram was able to predict transfusion of ≥1 RBC units with an area under the curve (AUC) was 0.91. The second-best nomogram was able to predict bleeding of >900 ml with an AUC of 0.70. T he AUC of the third nomogram (transfusion of >2 RBC units) was 0.70. However, is temporal validation was suboptimal, due to a low prevalence of OLTs transfused with >2 RBC units. The last 2 nomograms exhibited clearly suboptimal AUC values of 0.54 and 0.61.

CONCLUSION

Two of the five nomograms predict blood transfusion and blood loss with excellent accuracy. Transfusion of ≥1 RBC unit and blood loss of >900 ml can be predicted on the basis of these nomograms. However, these nomograms are not accurate to predict one-month and one-year survival rates. These results should be further cross-validated, ideally prospectively, in additional external independent cohorts.

Outcomes following formation of a dedicated pediatric liver transplant anesthesia team

BACKGROUND

Given the complex nature of liver transplant surgery, adult centers typically use a dedicated liver transplant anesthesia team, which has improved patient outcomes.

AIMS

Our goal was to determine whether a dedicated pediatric liver transplant anesthesia team was associated with improved patient outcomes.

METHODS

This retrospective cohort study analyzed patients who underwent liver transplantation from April 2013 to September 2020 at St. Louis Children's Hospital. The general group (April 2013-December 2016) was compared with the liver group (January 2017-September 2020). Outcomes measured included cases per anesthesiologist, early extubation, ventilator days, fluid and blood administration, postoperative events, and intensive care unit and hospital length of stay (LOS).

RESULTS

Patients in both groups had similar demographics. The average number of cases/anesthesiologist/year was 2.9 times higher in the liver group (mean (SD) general 0.7 (0.5), liver 2.0 (0.6), and difference in mean [95% CI] 1.3 [0.8, 1.8]). The rate of extubation in the operating room was higher for patients in the liver group (general 56%, liver 80%, and difference in proportion [95% CI] 24.7 [7.0, 42.4]), while the number of ventilator days was lower (mean (SD) general 2.1 (4.4), liver 1.1 (3.6), and difference in proportion [95%CI] -0.9 [-2.6, 0.7]). Colloid administration was higher in the liver group (mean (SD) general 23.9 (14.5) ml/kg, liver 48.4 (37.7) ml/kg, and difference in mean [95% CI] 24.6 [12.7, 36.4]), while fresh frozen plasma administration was lower in the liver group (mean (SD) general 15.3 (23.9) ml/kg, liver 6.2 (14) ml/kg, and difference in mean [95% CI] -9.0 [-16.8, -1.3]). There were no significant differences between the groups in postoperative events including blood product transfusions, vasopressor use, and thromboses, or in the intensive care unit and hospital LOS.

CONCLUSIONS

The liver group was associated with increased early extubations, decreased ventilator days, and decreased fresh frozen plasma use.

Subjective Difficulty Scale in Liver Transplantation: A Prospective Observational Study

The predictive value of a subjective difficulty scale (DS) after surgical procedures is unknown. The objective of this study was to evaluate the prognostic value of a DS after liver transplantation (LT) and to identify predictors of difficulty. Surgeons prospectively evaluated the difficulty of 441 consecutive liver transplantations from donation after brain death at the end of the surgery by using a DS from 0 to 10 (“the easiest to the hardest you can imagine”). DS was associated with severe morbidity. The risk of graft loss at 1 year remained unchanged from 0 to 6 but increased beyond 6. Graft survival and patient survival of group with DS 7–10 was significantly impaired compared to groups with DS: 0–3 or DS: 4–6 but were significantly impaired for the group with DS: 7–10. Independent predictors of difficult LT (DS ≥ 7) were annular segment 1, transjugular intrahepatic portosystemic shunt, retransplantation beyond 30 days, portal vein thrombosis, and ascites. Of them, ascites was a borderline non-significant covariate (p = .04). Vascular complications occurred more often after difficult LT (20.5% vs. 5.9%), whereas there was no difference in the other types of complications. DS can be used to tailor monitoring and anticipate early complications. External validation is needed.

Association of acidosis with coagulopathy and transfusion requirements in liver transplantation

The relationship between acidosis and coagulopathy has long been described in vitro and in trauma patients, but not yet in orthotopic liver transplantation (OLT). The association of metabolic acidosis with coagulopathy and with transfusion requirements was evaluated in patients submitted to OLT. Changes in acid-base and coagulation parameters were analyzed by repeated measures. Regression analyses [adjusted for sex, age, model for end stage liver disease (MELD) score, and baseline values of hemoglobin, fibrinogen, international normalized ratio, platelets] determined the association of acid-base parameters with coagulation markers and transfusion requirement. We included 95 patients, 66% were male, 49.5% of the patients had hepatocellular carcinoma and the mean MELD score was 20.4 (SD 8.9). The values of all the coagulation and acid-base parameters significantly changed during OLT, particularly in the reperfusion phase. After adjustments for baseline parameters, the decrease in pH and base excess (BE) values were associated with a decrease in fibrinogen levels (mean decrease of fibrinogen level = 14.88 mg/dL per 0.1 unit reduction of pH values and 3.6 mg/dL per 1 mmol/L reduction of BE levels) and an increase in red blood cells transfusion (2.16 units of RBC per 0.1 unit reduction of pH and 0.38 units of RBC per 1 mmol/L reduction of BE levels). Among multiple factors potentially associated with adverse outcomes, decreasing pH levels were independently associated with the length of hospitalization but not with in-hospital mortality. Metabolic acidosis is independently associated with decreased fibrinogen levels and increased intraoperative transfusion requirement during OLT. Awareness of that association may improve treatment strategies to reduce intraoperative bleeding risk in OLT.

The effect of a viscoelastic-guided bleeding algorithm implementation on blood products use in adult liver transplant patients. A propensity score-matched before-after study

BACKGROUND

Perioperative blood products transfusion is correlated with increased morbidity and mortality in liver transplantation (LTx). The objectives of our study are to assess the effect of a standardized viscoelastic test (VET)-guided bleeding management algorithm implementation on intraoperative bleeding, allogenic blood products and factor concentrates requirements and on early postoperative complications in LTx.

METHODS

Retrospective before-after study comparing two matched cohorts of patients undergoing LTx before (control cohort) and after (intervention cohort) the implementation of a VET-based bleeding algorithm in a single center academic hospital.

RESULTS

After propensity score matching, we included 94 patients in each cohort. Patients in intervention cohort received significantly less blood products, fresh frozen plasma (FFP), and cryoprecipitate (p < 0.001 for each), while the amount of fibrinogen concentrate used was significantly higher (p < 0.001). Postoperatively, intervention cohort patients had significantly lower postoperative hemoglobin and fibrinogen levels and longer prothrombin time compared to control cohort. There were no significant differences in red blood cells transfusions, intraoperative bleeding, early postoperative complications, and short term survival.

CONCLUSIONS

The implementation of a VET-guided bleeding algorithm decreases allogenic blood products requirements, mainly FFP use and allows a more restrictive management of coagulopathy in patients with chronic liver disease undergoing LTx.

Association between perioperative allogeneic red blood cell transfusion and infection after clean-contaminated surgery: a retrospective cohort study

BACKGROUND

Allogeneic red blood cell (RBC) transfusion can induce immunosuppression, which can then increase the susceptibility to postoperative infection. However, studies in different types of surgery show conflicting results regarding this effect.

METHODS

In this retrospective cohort study conducted in a tertiary referral centre, we included adult patients undergoing clean-contaminated surgery from 2014 to 2018. Patients who received allogeneic RBC transfusion from preoperative Day 30 to postoperative Day 30 were included into the transfusion group. The control group was matched for the type of surgery in a 1:1 ratio. The primary outcome was infection within 30 days after surgery, which was defined by healthcare-associated infection, and identified mainly based on antibiotic regimens, microbiology tests, and medical notes.

RESULTS

Among the 8098 included patients, 1525 (18.8%) developed 1904 episodes of postoperative infection. Perioperative RBC transfusion was associated with an increased risk of postoperative infection after controlling for 27 confounders by multivariable regression analysis (odds ratio [OR]: 1.60; 95% confidence interval [CI]: 1.39-1.84; P<0.001) and propensity score weighing (OR: 1.64; 95% CI: 1.45-1.85; P<0.001) and matching (OR: 1.70; 95% CI: 1.43-2.01; P<0.001), and a dose-response relationship was observed. The transfusion group also showed higher risks of surgical site infection, pneumonia, bloodstream infection, multiple infections, intensive care admission, unplanned reoperation, prolonged postoperative length of hospital stay, and all-cause death.

CONCLUSIONS

Perioperative allogeneic RBC transfusion is associated with an increased risk of infection after clean-contaminated surgery in a dose-response manner. Close monitoring of infections and enhanced prophylactic strategies should be considered after transfusion.

Hemoderivative Transfusion in Liver Transplantation: Comparison Between Recipients of Grafts From Brain Death Donors and Recipients of Uncontrolled Donors After Circulatory Death

INTRODUCTION

Intraoperative bleeding during liver transplantation has been correlated with a higher risk of morbidity and mortality and decrease in patient and graft survival.

MATERIALS AND METHODS

Between January 2006 and December 2016 we performed 783 orthotopic liver transplants. After applying exclusion criteria, we found liver grafts from donors after circulatory death (DCD, group A) were used in 69 patients and liver grafts from donors after brain death (group B) were used in 265 patients.

RESULTS

No difference was found in terms of sex, body mass index, Model for End-Stage Liver Disease score, indication for transplantation, intensive care unit stay, and Child-Pugh score. The mean transfusion of hemoderivates was as follows: red blood cell 9 (0-28) units in group A vs 6 (0-20) units in group B (P = .004) and fresh frozen plasma 10 (0-29) units in group A vs 9.5 (0-23) in group B (P = .000). The only 2 factors related to massive blood transfusion (>6 units of red blood cell) were uncontrolled DCD condition (odds ratio = 2.38; 95% confidence interval, 1.32-4.31; P = .004), and higher Model for End-Stage Liver Disease score (odds ratio = 2.63; 95% confidence interval, 1.53-4.55; P = .001). Survival at 1, 3, and 5 years was 81.3%, 70.2%, and 68.9% in group A vs 89%, 83.7%, and 78% in group B (P = .070).

CONCLUSION

The use of liver grafts from DCDs is associated with increased necessity of transfusion of hemoderivates in comparison with the use of liver grafts from donors after brain death.

Transfusion-Related Acute Lung Injury During Liver Transplantation: A Scoping Review

Liver transplantation is associated with significant blood loss, often requiring massive blood product transfusion. Transfusion-related acute lung injury (TRALI) is a devastating cause of transfusion-related deaths. While reports have investigated the general incidence of TRALI, the incidence of TRALI specifically following transfusion during liver transplant remains unclear. This scoping review summarizes existing literature regarding TRALI during the liver transplantation perioperative period. Databases were searched for all articles and abstracts reporting on TRALI after liver transplantation. Data collected included number of patients studied, patient characteristics, incidences of TRALI, TRALI characteristics, and patient outcomes. The primary outcome investigated was the incidence of TRALI in the setting of liver transplantation. Thirteen full-text citations were included in this review. The incidence of TRALI post-liver transplant was 0.68% (65 of 9,554). Based on reported transfusion data, patients diagnosed with TRALI received an average of 10.92 ± 10.81 units of packed red blood cells (pRBC), 20.05 ± 15.72 units of fresh frozen plasma, and 5.75 ± 10.00 units of platelets. Common interventions following TRALI diagnosis included mechanical ventilation with positive end-expiratory pressure, inhaled high-flow oxygen, inhaled pulmonary vasodilator, and pharmacologic treatment using pressors or inotropes, corticosteroids, or diuretics. Based on reported mortality data, 26.67% of patients (12 of 45) diagnosed with TRALI died during the postoperative period. This scoping review underscores the importance of better understanding the incidence and presentation of TRALI after liver transplant surgery. The clinical implications of these results warrant the development of identification and management strategies for liver transplant patients at increased risk for developing TRALI.

Perioperative blood transfusion decreases long-term survival in pediatric living donor liver transplantation

BACKGROUND

The impact of perioperative blood transfusion on short- and long-term outcomes in pediatric living donor liver transplantation (PLDLT) must still be ascertained, mainly among young children. Clinical and surgical postoperative complications related to perioperative blood transfusion are well described up to three months after adult liver transplantation.

AIM

To determine whether transfusion is associated with early and late postoperative complications and mortality in small patients undergoing PLDLT.

METHODS

We evaluated the effects of perioperative transfusion on postoperative complications in recipients up to 20 kg of body weight, submitted to PLDLT. A total of 240 patients were retrospectively allocated into two groups according to postoperative complications: Minor complications (n = 109) and major complications (n = 131). Multiple logistic regression analysis identified the volume of perioperative packed red blood cells (RBC) transfusion as the only independent risk factor for major postoperative complications. The receiver operating characteristic curve was drawn to identify the optimal volume of the perioperative RBC transfusion related to the presence of major postoperative complications, defining a cutoff point of 27.5 mL/kg. Subsequently, patients were reallocated to a low-volume transfusion group (LTr; n = 103, RBC ≤ 27.5 mL/kg) and a high-volume transfusion group (HTr; n = 137, RBC > 27.5 mL/kg) so that the outcome could be analyzed.

RESULTS

High-volume transfusion was associated with an increased number of major complications and mortality during hospitalization up to a 10-year follow-up period. During a short-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and bleeding complications, with a decrease in rejection complications compared to the LTr. Over a long-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and minor neoplastic complications, with a decrease in rejection complications. Additionally, Cox hazard regression found that high-volume RBC transfusion increased the mortality risk by 3.031-fold compared to low-volume transfusion. The Kaplan-Meier survival curves of the studied groups were compared using log-rank tests and the analysis showed significantly decreased graft survival, but with no impact in patient survival related to major complications. On the other hand, there was a significant decrease in both graft and patient survival, with high-volume RBC transfusion.

CONCLUSION

Transfusion of RBC volume higher than 27.5 mL/kg during the perioperative period is associated with a significant increase in short- and long-term postoperative morbidity and mortality after PLDLT.

Machine Learning for the Prediction of Red Blood Cell Transfusion in Patients During or After Liver Transplantation Surgery

Aim: This study aimed to use machine learning algorithms to identify critical preoperative variables and predict the red blood cell (RBC) transfusion during or after liver transplantation surgery. Study Design and Methods: A total of 1,193 patients undergoing liver transplantation in three large tertiary hospitals in China were examined. Twenty-four preoperative variables were collected, including essential population characteristics, diagnosis, symptoms, and laboratory parameters. The cohort was randomly split into a train set (70%) and a validation set (30%). The Recursive Feature Elimination and eXtreme Gradient Boosting algorithms (XGBOOST) were used to select variables and build machine learning prediction models, respectively. Besides, seven other machine learning models and logistic regression were developed. The area under the receiver operating characteristic (AUROC) was used to compare the prediction performance of different models. The SHapley Additive exPlanations package was applied to interpret the XGBOOST model. Data from 31 patients at one of the hospitals were prospectively collected for model validation. Results: In this study, 72.1% of patients in the training set and 73.2% in the validation set underwent RBC transfusion during or after the surgery. Nine vital preoperative variables were finally selected, including the presence of portal hypertension, age, hemoglobin, diagnosis, direct bilirubin, activated partial thromboplastin time, globulin, aspartate aminotransferase, and alanine aminotransferase. The XGBOOST model presented significantly better predictive performance (AUROC: 0.813) than other models and also performed well in the prospective dataset (accuracy: 76.9%). Discussion: A model for predicting RBC transfusion during or after liver transplantation was successfully developed using a machine learning algorithm based on nine preoperative variables, which could guide high-risk patients to take appropriate preventive measures.

Risk Factors and Impact of Perioperative Prophylaxis on the Risk of Extended-spectrum β-Lactamase-producing Enterobacteriaceae-related Infection Among Carriers Following Liver Transplantation

BACKGROUND

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) carriage is frequent among liver transplant (LT) recipients, thereby fostering a large empirical carbapenem prescription. However, ESBL-E infections occur in only 10%-25% of critically ill patients with rectal colonization. Our aim was to identify risk factors for post-LT ESBL-E infection in colonized patients. The effect of perioperative antimicrobial prophylaxis (AP) was also analyzed in patients with prophylaxis lasting <48 hours and without proven intraoperative infection.

METHODS

Retrospective study from a prospective database including patients with a positive ESBL-E rectal screening transplanted between 2010 and 2016.

RESULTS

Among the 749 patients transplanted, 100 (13.3%) were colonized with an ESBL-E strain. Thirty-nine (39%) patients developed an infection related to the same ESBL-E (10 pulmonary, 11 surgical site, 13 urinary, 5 bloodstream) within 11 postoperative days in median. Klebsiella pneumoniae carriage, model for end-stage liver disease ≥25, preoperative spontaneous bacterial peritonitis prophylaxis, and antimicrobial exposure during the previous month were independent predictors of ESBL-E infection. We propose a colonization to infection risk score built on these variables. The prevalence of infection for colonization to infection score of 0, 1, 2, and ≥3 were 7.4%, 26.3%, 61.9%, and 91.3%, respectively. Of note, the incidence of post-LT ESBL-E infection was lower in case of perioperative AP targeting colonizing ESBL-E (P = 0.04).

CONCLUSIONS

Thirty-nine percentage of ESBL-E carriers develop a related infection after LT. We identified predictors for ESBL-E infection in carriers that may help in rationalizing carbapenem prescription. Perioperative AP targeting colonizing ESBL-E may be associated with a reduced risk of post-LT ESBL-E infections.

Association between intraoperative rotational thromboelastometry or conventional coagulation tests and bleeding in liver transplantation: an observational exploratory study

INTRODUCTION

Liver transplantation is associated with major blood loss and transfusions. Our objective was to evaluate the association between coagulation results (rotational thromboelastometry (ROTEM) and conventional coagulation tests) and intraoperative bleeding or perioperative red blood cell (RBC) transfusions in liver transplantation.

METHODS

We measured ROTEM values and conventional coagulation tests at the beginning of surgery, after graft reperfusion and at the end of surgery. We did bivariate correlation and multivariable regression analyses to explore the association between test results and either intraoperative bleeding or perioperative RBC transfusions.

RESULTS

We enrolled 75 consecutive patients. Median [Q1-Q3] intraoperative blood loss was 1400 mL [675-2300] and 59% of patients did not receive any RBC transfusion either intraoperatively or postoperatively. In multivariable analyses, FIBTEM maximal clot firmness (MCF) measured at the beginning of surgery was associated with lower intraoperative blood loss (ß = -106 mL for each mm; 95% CI, -203 to -9 mL). Both a higher haemoglobin concentration (multiplicative factor = 0.89 for each g/L; 95% CI, 0.84 to 0.95) and FIBTEM MCF measured at the end of surgery (multiplicative factor = 0.68 for each mm; 95% CI, 0.48 to 0.95) were associated with fewer postoperative RBC transfusions.

CONCLUSION

FIBTEM MCF was strongly associated with intraoperative blood loss and postoperative transfusions while other coagulation results were not. This study might inform future clinical trials on ROTEM-based interventions in liver transplantation.

STUDY REGISTRATION

Clinical Trials.gov: NCT02356068.

Infection deteriorating hepatitis B virus related acute-on-chronic liver failure: a retrospective cohort study

Background

Infection is common in acute-on-chronic liver failure (ACLF), which may worsen the clinical condition and prognosis. However, the characteristics of infection and its influence on prognosis in hepatitis B virus related ACLF (HBV-ACLF) as defined by the European Association for the Study of the Liver (EASL) have not been clarified. We aimed to investigate the characteristics of infection and its influence on mortality in patients with HBV-ACLF defined by EASL in China.

Methods

We performed a retrospective cohort study in patients with HBV-ACLF defined by EASL in a single center from January 2015 to December 2017. These patients were divided into two groups with and without infection. The incidence, sites of infection, isolated strains, and risk factors associated with mortality were evaluated.

Results

A total of 289 patients were included, among them 185 (64.0%) were diagnosed with an infection. The most common type of infection was pneumonia (55.7%), followed by spontaneous bacterial peritonitis (47.6%) and others. The gram-negative bacteria were the most frequent (58.3%). Patients with one, two, and three or more infection sites had a gradually increasing incidence of sepsis (P < 0.01), septic shock (P < 0.001), and ACLF-3 (P < 0.05). Also, patients with infection isolated one, two, and three or more strains showed a growing incidence of sepsis (P < 0.01) and septic shock (P < 0.001). Patients with infection showed a significantly higher 28-day mortality than those without (P < 0.01), especially in patients with ACLF-3. Infection was identified as an independent risk factor for 28-day mortality in all HBV-ACLF patients. Pneumonia and sepsis were identified as independent predictors of 28-day mortality for patients with infection.

Conclusions

Infection is associated with severe clinical course and high mortality in HBV-ACLF defined by EASL. The increased number of infection sites or isolated strains was associated with the occurrence of sepsis and septic shock. Pneumonia and sepsis were independent predictors for mortality in HBV-ACLF patients with infection.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

A systematic literature review on the use of platelet transfusions in patients with thrombocytopenia

Objective: Investigate globally, current treatment patterns, benefit-risk assessments, humanistic, societal and economic burden of platelet transfusion (PT). Methods: Publications from 1998 to June 27, 2018 were identified, based on databases searches including MEDLINE®; Embase and Cochrane Database of Systematic Reviews. Data from studies meeting pre-specified criteria were extracted and validated by independent reviewers. Data were obtained for efficacy and safety from randomized controlled trials (RCTs); data for epidemiology, treatment patterns, effectiveness, safety, humanistic and societal burden from real-world evidence (RWE) studies; and economic data from both. Results: A total of 3425 abstracts, 194 publications (190 studies) were included. PT use varied widely, from 0%-100% of TCP patients; 1.7%-24.5% in large studies (>1000 patients). Most were used prophylactically rather than therapeutically. 5 of 43 RCTs compared prophylactic PT with no intervention, with mixed results. In RWE studies PT generally increased platelet count (PC). This increase varied by patient characteristics and hence did not always translate into a clinically significant reduction in bleeding risk. Safety concerns included infection risk, alloimmunization and refractoriness with associated cost burden. Discussion: In RCTs and RWE studies there was significant heterogeneity in study design and outcome measures. In RWE studies, patients receiving PT may have been at higher risk than those not receiving PT creating potential bias. There were limited data on humanistic and societal burden. Conclusion: Although PTs are used widely for increasing PC in TCP, it is important to understand the limitations of PTs, and to explore the use of alternative treatment options where available.

Eliminating international normalized ratio threshold for transfusion in pediatric patients with acute liver failure

INTRODUCTION

Transfusion protocols are not well-studied for pediatric patients with acute liver failure (ALF). This study evaluates the utility of an international normalized ratio (INR)-based transfusion threshold for these patients.

METHODS

Forty-four ALF pediatric patients from 2009 to 2018 were reviewed and divided into two groups: (a) a threshold group including patients between 2009 and 2015 who were transfused for an INR above 3.0, per institutional policy (n = 30), and (b) a post-threshold group including patients after 2015 through 2018 who were transfused based on clinical judgment (n = 14). Preoperative INRs, preoperative transfusions, intraoperative transfusions, early reoperation, renal function, graft function and deaths were compared.

RESULTS

Liver failure severity was similar between threshold and post-threshold groups. Threshold patients had a lower average INR prior to transplantation, 2.8 (range 1.8-3.8) vs 4.4 (range 2.1-9.0), respectively (P = .01). Twenty-six threshold patients (87%) received preoperative FFP compared with seven post-threshold patients (50%, P = .0088). Two threshold patients (7%) received preoperative cryoprecipitate compared with five post-threshold patients (36%, P = .014). The incidence of pre-transplant bleeding, operative transfusions, and 1-year patient and graft survival did not differ significantly.

CONCLUSION

Clinical judgment vs an INR-based threshold for transfusions did not increase perioperative complications in children with ALF.

Association of Perioperative Variables and the Acute Respiratory Distress Syndrome in Liver Transplant Recipients

Background

The assessment of perioperative risk factors for the development of acute respiratory distress syndrome (ARDS) has been described in various surgical populations. However, there are only limited data among patients undergoing liver transplantation (LT), particularly regarding the influence of intraoperative ventilation parameters. We sought to identify the perioperative risk factors associated with the development of ARDS in LT recipients.

Methods

This is a single-center, retrospective cohort study of adult patients who underwent LT at a tertiary academic medical center between January 1, 2006, and January 31, 2016. Postoperative ARDS was identified using the Berlin definition. Multivariable logistic regression analysis was used to identify perioperative risk factors for ARDS.

Results

Of 817 eligible patients who underwent an LT during the study period, 20 (2.45%) developed postoperative ARDS. In the preoperative model, ongoing dialysis (odds ratio, 6.41; P < 0.01) was identified as an independent risk factor of ARDS post-LT. A higher mean peak inspiratory pressure per increase of 1 cm H₂O (odds ratio, 1.31; P < 0.01) was the only independent risk factor in the intraoperative model. Patients who developed ARDS postoperatively had significantly greater intensive care unit and hospital stay compared to non-ARDS patients (P < 0.001). There were no significant differences in the 30-day (P = 0.16) and 1-year (P = 0.51) mortality between the groups.

Conclusions

Dialysis at the time of transplant and elevated intraoperative mean peak inspiratory pressure were associated with the development of ARDS. ARDS post LT was associated with increased intensive care unit and hospital length of stay, but not increased mortality.

Circadian Rhythms Have Effects on Surgical Outcomes of Liver Transplantation for Patients With Hepatocellular Carcinoma: A Retrospective Analysis of 147 Cases in a Single Center

AIM

To investigate the impact of circadian rhythms on the outcomes of liver transplantation on patients suffering from hepatocellular carcinoma (HCC).

METHODS

We retrospectively reviewed data of patients who underwent liver transplantation from 2012 to 2017 in our center. Based on the begin time of transplantation, these patients were separated into 2 groups: day group and night group. The intraoperative and postoperative clinical variables were analyzed to find out the impact of the circadian rhythms. Multivariate analysis was performed to examine strength associations between the begin time of operation and surgical outcomes.

RESULTS

A total of 147 patients were included in this study: 102 patients in the day group and 45 patients in the night group. Compared with the day group, patients in the night group had higher incidence of intraoperative massive hemorrhage (11.1% vs 2.0%, P = .048), more intraoperative blood loss (2168.00 ± 2324.20 mL vs 1405.88 ± 1037.69 mL, P = .040), and more requirement of red blood cells (RBC) suspension (8.59 ± 7.11 u vs 6.37 ± 5.78 u, P = .048). In addition, total operation time in the night group was longer than that in the day group (8.90 ± 1.65 hours vs 8.26 ± 1.69 hours, P = .034), as well as the cold ischemia time (9.35 ± 5.03 hours vs 7.21 ± 3.93 hours, P = .014). Furthermore, the night group had higher incidence of other intraoperative complications (13.3% vs 2.9%, P = .038), postoperative abdominal infection (20.0% vs 6.9%, P = .038), and more hospital cost (37,357.96 ± 6779.96 dollars vs 33,551.75 ± 11,683.38 dollars, P = .045). Moreover, patients in the night group needed longer time to restore hepatic function to normal (21.77 ± 10.91 days vs 17.54 ± 10.80 days, P = .033). Multivariate analysis showed that begin time of operation was the independent risk factor of longer operation time, more blood loss during operation, higher incidence of massive hemorrhage and other intraoperative complications, longer time for restoration of hepatic function to normal, higher incidence of abdominal infection at the early stage after transplantation, and more hospital cost (all P value ≤ .05).

CONCLUSION

Liver transplantation performed at night was associated with higher incidence of intraoperative and early postoperative complications, as well as higher hospital cost. And these worsened outcomes all could be explained by the influence that circadian rhythms had on patients or medical workers.

Analysis of the postoperative hemostatic profile of colorectal cancer patients subjected to liver metastasis resection surgery

BACKGROUND

Liver resection surgery has advanced greatly in recent years, and the adoption of fasttrack programs has yielded good results. Combination anesthesia (general anesthesia associated to epidural analgesia) is an anesthetic-analgesic strategy commonly used for the perioperative management of patients undergoing surgery of this kind, though there is controversy regarding the coagulation alterations it may cause and which can favor the development of spinal hematomas.

AIM

To study the postoperative course of liver resection surgery, an analysis was made of the outcomes of liver resection surgery due to colorectal cancer metastases in our centre in terms of morbiditymortality and hospital stay according to the anesthetic technique used (general vs combination anesthesia).

METHODS

A prospective study was made of 61 colorectal cancer patients undergoing surgery due to liver metastases under general and combination anesthesia between January 2014 and October 2015. The patient characteristics, intraoperative variables, postoperative complications, evolution of hemostatic parameters, and stay in intensive care and in hospital were analyzed.

RESULTS

A total of 61 patients were included in two homogeneous groups: general anesthesia (n = 30) and combination anesthesia (general anesthesia associated to epidural analgesia) (n = 31). All patients had normal coagulation values before surgery. The international normalized ratio (INR) in both the general and combination anesthesia groups reached maximum values at 2448 h (mean 1.37 and 1.45 vs 1.39 and 1.41, respectively), followed by a gradual decrease. There was less intraoperative bleeding in the combination anesthesia group (769 mL) than in the general anesthesia group (1200 mL) (P < 0.05). Of the 61 patients, 38.8% in the general anesthesia group experienced some respiratory complication vs 6.6% in the combination anesthesia group (P < 0.001). The time to gastrointestinal tolerance was significantly correlated to the type of anesthesia, though not so the stay in critical care or the time to hospital discharge.

CONCLUSION

Epidural analgesia in liver resection surgery was seen to be safe, with good results in terms of pain control and respiratory complications, and with no associated increase in complications secondary to altered hemostasis.

Transfusion-related Acute Lung Injury in the Perioperative Patient

Transfusion-related acute lung injury is a leading cause of death associated with the use of blood products. Transfusion-related acute lung injury is a diagnosis of exclusion which can be difficult to identify during surgery amid the various physiologic and pathophysiologic changes associated with the perioperative period. As anesthesiologists supervise delivery of a large portion of inpatient prescribed blood products, and since the incidence of transfusion-related acute lung injury in the perioperative patient is higher than in nonsurgical patients, anesthesiologists need to consider transfusion-related acute lung injury in the perioperative setting, identify at-risk patients, recognize early signs of transfusion-related acute lung injury, and have established strategies for its prevention and treatment.

Risk factors, management and prevention of transfusion-related acute lung injury: a comprehensive update

Introduction: Despite mitigation strategies that include the exclusion of females from plasma donation or the exclusion of females with a history of pregnancy or known anti-leukocyte antibody, transfusion-related acute lung injury (TRALI) remains a leading cause of transfusion-related morbidity and mortality. Areas covered: The definition of TRALI is discussed and re-aligned with the new Berlin Diagnostic Criteria for the acute respiratory distress syndrome (ARDS). The risk factors associated with TRALI are summarized as are the mitigation strategies to further reduce TRALI. The emerging basic research studies that may translate to clinical therapeutics for the prevention or treatment of TRALI are discussed. Expert opinion: At risk patients, including the genetic factors that may predispose patients to TRALI are summarized and discussed. The re-definition of TRALI employing the Berlin Criteria for ARDS will allow for increased recognition and improved research into pathophysiology and mitigation to reduce this fatal complication of hemotherapy.

Association between Early Acute Respiratory Distress Syndrome after Living-Donor Liver Transplantation and Perioperative Serum Biomarkers: The Role of Club Cell Protein 16

Background

Acute respiratory distress syndrome (ARDS) after living-donor liver transplantation (LDLT) is not uncommon, but it lacks the biomarkers for early detection. Club cell protein 16 (CC16), high-motility group box 1 protein (HMGB1), interleukin-1β (IL-1β), and IL-10 have been reported as relevant to the development of ARDS. However, they have not been investigated during LDLT.

Methods

Seventy-three consecutive recipients undergoing LDLT were enrolled and received the same perioperative care plan. Perioperative serum CC16, HMGB1, IL-1β, and IL-10 levels were measured at the pretransplant state, 30 minutes after reperfusion, postoperative day 1 (POD1), and POD3. ARDS was diagnosed according to the 2012 Berlin definition.

Results

Of the 73 recipients, 13 developed ARDS with significantly longer durations of mechanical ventilation and intensive care unit stay. Serum CC16 levels on POD1 increased significantly from the pretransplant state in the ARDS group but not in the non-ARDS group. Pretransplant serum CC16 levels were also higher in the ARDS group. The area under the receiver operating characteristic curves for POD1 serum CC16 levels used to discriminate ARDS was 0.803 (95% confidence interval: 0.679 to 0.895; p < 0.001). By comparison, HMGB1, IL-1β, and IL-10 were not associated with ARDS after LDLT.

Conclusion

The higher pretransplant serum CC16 level and its increased level on POD1 were associated with the development of early ARDS after LDLT. This trial is registered with NCT01936545, 27 August 2013.

A consensus redefinition of transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a serious complication of blood transfusion and is among the leading causes of transfusion-related morbidity and mortality in most developed countries. In the past decade, the pathophysiology of this potentially life-threatening syndrome has been increasingly elucidated, large cohort studies have identified associated patient conditions and transfusion risk factors, and preventive strategies have been successfully implemented. These new insights provide a rationale for updating the 2004 consensus definition of TRALI.

STUDY DESIGN AND METHODS

An international expert panel used the Delphi methodology to develop a redefinition of TRALI by modifying and updating the 2004 definition. Additionally, the panel reviewed issues related to TRALI nomenclature, patient conditions associated with acute respiratory distress syndrome (ARDS) and TRALI, TRALI pathophysiology, and standardization of reporting of TRALI cases.

RESULTS

In the redefinition, the term "possible TRALI" has been dropped. The terminology of TRALI Type I (without an ARDS risk factor) and TRALI Type II (with an ARDS risk factor or with mild existing ARDS) is proposed. Cases with an ARDS risk factor that meet ARDS diagnostic criteria and where respiratory deterioration over the 12 hours before transfusion implicates the risk factor as causative should be classified as ARDS. TRALI remains a clinical diagnosis and does not require detection of cognate white blood cell antibodies.

CONCLUSIONS

Clinicians should report all cases of posttransfusion pulmonary edema to the transfusion service so that further investigation can allow for classification of such cases as TRALI (Type I or Type II), ARDS, transfusion-associated circulatory overload (TACO), or TRALI or TACO cannot distinguish or an alternate diagnosis.

Risk Factors for Transfusion after Orthotopic Liver Transplantation

Background

Transfusion of blood products during orthotopic liver transplantation (OLT) is associated with increased morbidity and mortality. Although risk factors associated with intraoperative transfusion requirements have been widely assessed, published data on the prediction of postoperative transfusion requirements are sparse.

Objectives

The aim of this study was to evaluate risk factors for postoperative allogeneic transfusion requirements in OLT.

Methods

Clinical characteristics and intraoperative parameters of 645 consecutive adult patients undergoing OLT were retrospectively reviewed. Multivariate logistic regression was used to determine the main determinants for postoperative transfusion requirements.

Results

Determinants of postoperative transfusion requirements of any blood product in the postoperative period were the number of blood products transfused in the intraoperative period (OR 1.17, 95% CI 1.08-1.28), warm ischemia time (OR 1.05, 95% CI 1.02-1.08), MELD score (OR 1.05, 95% CI 1.01-1.08) and hepatocellular carcinoma (OR 0.45, 95% CI 0.28-0.72). A dose-dependent effect between the number of units transfused in the intraoperative period and transfusion requirements in the postoperative period was also observed. The relative risk of postoperative allogeneic transfusion of any blood component was 5.9 (95% CI 3.4-10.4) for patients who received 1-2 units in the intraoperative period, 7.3 (95% CI 3.6-14.7) for those who received 3-5 units in the intraoperative period, and 11.1 (95% CI 4.7-26.4) for those who received 6 or more units, when compared to no intraoperative blood transfusion.

Conclusion

Our study demonstrated an association between intraoperative transfusion and warm ischemia time with postoperative transfusion requirements. The identification of risk factors for transfusion in the postoperative period may improve management of these patients by increasing awareness to bleeding complications in this high-risk population and by expanding hemostasis monitoring to the postoperative period.

Impact of MELD Score-Based Organ Allocation on Mortality, Bleeding, and Transfusion in Liver Transplantation: A Before-and-After Observational Cohort Study

OBJECTIVE

The goal of this study was to evaluate the effect of the Model for End-Stage Liver Disease (MELD)-based allocation system on mortality, bleeding, and transfusion requirement in orthotopic liver transplantation (OLT).

DESIGN

OLTs were studied for this observational study (before-and-after observational cohort study).

SETTING

One community hospital.

PARTICIPANTS

The study comprised 686 patients who underwent 750 consecutive OLTs.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Patients who underwent OLT in the MELD era had an adjusted lower 1-year mortality (adjusted odds ratio 0.45 [0.24-0.83]) compared with patients who underwent OLT the pre-MELD era. No significant difference in 1-month mortality was observed. Other variables with a significant effect on 1-year mortality in multivariate analysis were preoperative international normalized ratio, intraoperative use of a phlebotomy, total intraoperative volume of crystalloid infused, and retransplantation. Blood loss was greater in the MELD era (median difference 200 mL; p < 0.001), as were red blood cell, fresh frozen plasma, and cryoprecipitate transfusions. More patients in the MELD era received at least 1 transfusion (27% v 20%; p = 0.024).

CONCLUSION

The MELD allocation system did not affect 1-month mortality, but a decrease in 1-year mortality was demonstrated. Blood loss and transfusions increased during OLTs performed in the MELD era. The role of other variables should be explored further to explain postoperative morbidity and mortality.

Quality Improvement in Transfusion Practice of Orthotopic Liver Transplantation Reduces Blood Utilization, Length of Hospital Stay, and Cost

OBJECTIVES

Orthotopic liver transplantation (OLT) can require substantial usage of blood products. Higher rates of transfusion have been associated with increased length of hospital stay, higher rates of infection, graft failure, and mortality. This study was a retrospective analysis to assess the impact of quality improvement interventions in OLT.

METHODS

Data collection included demographics, preoperative and intraoperative data, blood utilization, and cost data. Statistical analysis was performed using R software.

RESULTS

Total blood product utilization was reduced by approximately 50%. Statistically significant decreases were noted in blood product usage in the intraoperative and first 48-hour postoperative utilization, the number of OLTs using fewer than five RBC units, length of hospital stay, and cost.

CONCLUSIONS

This study showed successful implementation of quality improvement team interventions to reduce blood utilization during OLT. Reduced transfusion significantly correlated with decreased length of hospital stay and cost.

Utility of prothrombin complex concentrate as first-line treatment modality of coagulopathy in patients undergoing liver transplantation: A propensity score-matched study

BACKGROUND

Transfusion management during liver transplantation (LT) is aimed at reducing blood loss and allogeneic transfusion requirements. Although prothrombin complex concentrate (PCC) has been used satisfactorily in various bleeding disorders, studies on its safety, and efficacy during LT are limited.

METHODS

A retrospective chart review of adult patients who underwent living donor LT at a single institute between October 2016 and January 2018 was carried out. The safety and efficacy of PCC in reducing transfusion requirements intraoperatively in patients who received PCC were compared with patients who did not receive PCC. A propensity score-matching technique was used, at a 1:1 ratio, to remove selection bias.

RESULTS

After completing the 1:1 propensity score-matched analysis, 60 pairs of patients were identified. The use of PCC was associated with significantly decreased red blood cell transfusion requirements (6.2 ± 4.1 vs 8.23 ± 5.18, P < 0.001) and fresh frozen plasma transfusion requirements (2.6 ± 2 vs 6.18 ± 4.1, P < 0.001). The number of patients developing postoperative hemorrhagic complications was higher in the non-PCC group.

CONCLUSIONS

During LT, the use of PCC led to decreased transfusion requirements. No thromboembolic complications related to PCC were noted in this series.

Perioperative Single-Donor Platelet Apheresis and Red Blood Cell Transfusion Impact on 90-Day and Overall Survival in Living Donor Liver Transplantation

Background:

Although many previous studies have confirmed that perioperative blood transfusion is associated with poor outcomes after liver transplantation (LT), few studies described the influence of single-donor platelet apheresis transfusion in living donor LT (LDLT). This study aimed to assess the effect of blood products on outcomes for LDLT recipients, focusing on apheresis platelets.

Methods:

This retrospective study included 126 recipients who underwent their first adult-to-adult LDLT. Twenty-four variables including consumption of blood products of 126 LDLT recipients were assessed for their link to short-term outcomes and overall survival. Kaplan-Meier survival curve and the log-rank test were used for recipient survival analysis. A multivariate Cox proportional-hazard model and a propensity score analysis were applied to adjust confounders after potential risk factors were identified by a univariate Cox analysis.

Results:

Patients who received apheresis platelet transfusion had a lower 90-day cumulative survival (78.9% vs. 94.2%, P = 0.009), but had no significant difference in overall survival in the Cox model, compared with those without apheresis platelet transfusion. Units of apheresis platelet transfusion (hazard ratio [HR] = 3.103, 95% confidence interval [CI]: 1.720–5.600, P < 0.001) and preoperative platelet count (HR = 0.170, 95% CI: 0.040–0.730, P = 0.017) impacted 90-day survival independently. Multivariate Cox regression analysis also found that units of red blood cell (RBC) transfusion (HR = 1.036, 95% CI: 1.006–1.067, P = 0.018), recipient's age (HR = 1.045, 95% CI: 1.005–1.086, P = 0.025), and ABO blood group comparison (HR = 2.990, 95% CI: 1.341–6.669, P = 0.007) were independent risk factors for overall survival after LDLT.

Conclusions:

This study suggested that apheresis platelets were only associated with early mortality but had no impact on overall survival in LDLT. Units of RBC, recipient's age, and ABO group comparison were independent predictors of long-term outcomes.

Strategies to avoid empiric blood product administration in liver transplant surgery

Massive blood loss has been a dreaded complication of liver transplantation, and the accompanying transfusion is associated with adverse outcomes in the form of decreased patient and graft survival. With advances in both surgical techniques and anesthetic management during transplantation, blood and blood products requirements reduced significantly. However, transfusion practices vary among different centers. The altered coagulation parameters in patients with liver cirrhosis results in a state of “rebalanced hemostasis” and patients are just as likely to clot as they are to bleed. Commonly used coagulation tests do not always reflect this new state and can, therefore, be misleading. Transfusion of blood products solely to correct abnormal parameters may worsen the coagulation status, thus adversely affecting patient outcome. Point-of-care tests such as thromboelastometry more reliably predict the risk of bleeding in these patients and in addition may provide quicker turnaround times compared to routine tests. Perioperative management should also include the possibility of thrombosis in these patients, and the use of low-molecular-weight heparin correlates with better patient survival. This review article aims to highlight the concept of rebalanced hemostasis, limitation of routine coagulation tests, and harmful effect of empiric transfusion of blood products.

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.

The Coagulation Profile of End-Stage Liver Disease and Considerations for Intraoperative Management

The coagulopathy of end-stage liver disease results from a complex derangement in both anticoagulant and procoagulant processes. With even minor insults, cirrhotic patients experience either inappropriate bleeding or clotting, or even both simultaneously. The various phases of liver transplantation along with fluid and blood product administration may contribute to additional disturbances in coagulation. Thus, anesthetic management of patients undergoing liver transplantation to improve hemostasis and avoid inappropriate thrombosis in the perioperative environment can be challenging. To add to this challenge, traditional laboratory tests of coagulation are difficult to interpret in patients with end-stage liver disease. Viscoelastic coagulation tests such as thromboelastography (Haemonetics Corporation, Braintree, MA) and rotational thromboelastometry (TEM International, Munich, Germany) have helped to reduce transfusion of allogeneic blood products, especially fresh frozen plasma, but have also lead to the increased use of fibrinogen-containing products. In general, advancements in surgical techniques and anesthetic management have led to significant reduction in blood transfusion requirements during liver transplantation. Targeted transfusion protocols and pharmacologic prevention of fibrinolysis may further aid in the management of the complex coagulopathy of end-stage liver disease.

Transfusion-Related Acute Lung Injury (TRALI) and Transfusion-Associated Circulatory Overload (TACO) in Liver Transplantation: A Case Report and Focused Review

Liver transplantation (LT) is a complex procedure in a patient with multi-organ system dysfunction and coagulation defects. The surgical procedure involves dissection, major vessel manipulation, and pathophysiologic effects of graft storage and reperfusion. As a result, LT frequently involves significant hemorrhage. Subsequent massive transfusion carries high risk of transfusion-associated complications. Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion associated mortality. In this case report and focused review, we present data that suggest that patients undergoing liver transplantation may be at higher risk for TRALI and TACO than the general population. Anesthesiologists can play a role in decreasing these risks by increasing recognition and reporting of TRALI and TACO, using point of care testing with thromboelastography to guide and decrease transfusion, and considering alternatives to traditional blood products like solvent/detergent plasma.

Development of a Predictive Model for Blood Transfusions and Bleeding During Liver Transplantation: An Observational Cohort Study

OBJECTIVE

Orthotopic liver transplantation (OLT) frequently is associated with major blood loss and considerable transfusion requirements. The goal of this study was to define the risk factors for multiple transfusions and major bleeding during OLT and to help identify higher risk patients that could benefit from targeted interventions.

DESIGN

OLTs were studied for this observational cohort study.

SETTING

Community hospital.

PARTICIPANTS

A total of 800 consecutive OLTs were studied.

INTERVENTION

No intervention.

MEASUREMENTS AND MAIN RESULTS

Baseline and intraoperative data were gathered. Multivariate logistic regression analyses were performed to find variables associated with 2 outcomes: transfusion of more than 2 units of red blood cells (RBC) and bleeding ≥900 mL. Two nomograms were developed to predict individual risks. The overall intraoperative RBC transfusion was 0.6 ± 1.4 units on average, and 61 surgeries (7.6%) received more than 2 units of RBC (4.5 ± 1.9). Some variables were associated with the outcomes: 5 were associated with transfusion of more than 2 units of RBC (patient's height, starting hemoglobin concentration, starting bilirubin value, the use of a phlebotomy, and central venous pressure [CVP] at the time of vena cava clamping) and 3 with blood loss of ≥900 mL (starting hemoglobin value, Child-Turcotte-Pugh score, and CVP at the time of vena cava clamping). Preclamping CVP showed the strongest association with both outcomes. Nomograms were developed to predict the individual OLT recipients' risk of requiring more than 2 units RBC and suffering from major bleeding. Among the variables associated with multiple RBC transfusions and major bleeding, 3 can lead to interventions: baseline hemoglobin value, the use of a phlebotomy, and the preclamping CVP.

CONCLUSION

Some variables were able to predict the risk of multiple transfusions and major bleeding in this low bleeding liver transplantation population. Further studies based on these variables should be done to better define the role of targeted interventions in higher risk liver transplant recipients.

Transfusion Medicine and Coagulation Management in Organ Transplantation

Organ transplantation recipients present unusual challenges with regard to blood transfusion. Although this patient population requires a larger proportion of blood product resources, liberal transfusion of allogeneic blood products can lead to a plethora of complications. Recent trends suggest that efforts to minimize bleeding, conserve products, and target transfusion to specific deficits and needs are increasingly becoming the standard practice; these must all occur with optimization of graft function and preservation in mind. With newer monitoring modalities and factor concentrates, the approach toward transfusion and bleeding in organ transplantation has rapidly improved in recent years.