Transfusion of older red blood cells is associated with decreased graft survival after orthotopic liver transplantation

Transfused Red Blood Cell Characteristics and Kidney Transplant Outcomes Among Patients Receiving Early Posttransplant Transfusion

Importance

Red blood cell transfusion (RBCT) is frequently required in the early post-kidney transplant period, but long-term outcomes associated with RBCT is controversial. Therefore, it may be relevant to investigate the association between RBCT characteristics and transplant outcomes.

Objective

To study the association between RBC storage duration and transplant outcomes.

Design, Setting, and Participants

This was a nationwide retrospective cohort study based on data linking between 2 prospective French nationwide registries. Clinical transplant parameters, outcomes, and RBCT characteristics were extracted from the CRISTAL registry of the Agence de la Biomédecine and the national database of the Etablissement Français du Sang. All 12 559 patients having received a first kidney transplant in France between January 1, 2002, and December 31, 2008, were included. Patients were followed up from transplant to graft loss, death with a functional graft, or data retrieval in June 2016. Data were analyzed from April 2019 to June 2022.

Exposures

Clinical outcomes of transplant recipients who underwent early RBCT were analyzed considering transfusion characteristics.

Main Outcomes and Measures

Cox proportional hazards regression models were fitted to evaluate transplant failure defined as graft loss or death with a functional graft.

Results

Among 12 559 patients who underwent kidney transplant, 3483 received an RBCT during the first 14 days posttransplant. The median (IQR) age of patients was 53.0 (41.5-61.2) years, and 1929 patients (55.4%) were male. Median (IQR) follow-up was 7.8 (7.6-8.0) years. In multivariable analysis, longer (vs shorter) storage duration of transfused RBC was associated with a decrease in risk of transplant failure (hazard ratio, 0.99; 95% CI, 0.98-1.00 for each additional storage day; P = .06). Patients transfused with at least 1 RBC unit stored for more than 20 days had a 5% absolute decrease in transplant failure at 3 years and 7% at 5 years compared with those who received RBC stored for less than 20 days.

Conclusions and Relevance

In this study, longer RBC storage duration was associated with a decreased risk of transplant failure among patients who received kidney transplants and RBC transfusions. Preferential use of RBC with longer storage duration might improve kidney graft survival following transplant and transfusion.

Contribution of Salvaged Blood Red Blood Cell Transfusion During Living Donor Liver Transplantation

BACKGROUND

Transfusion of allogeneic blood products can have adverse effects and profoundly influence postoperative liver transplantation outcomes, including graft survival. To minimize allogeneic red blood cell (RBC) transfusion, salvaged blood can be used during liver transplantation. The aim of this study was to determine the contribution of salvaged blood to allogeneic RBC transfusion in living donor liver transplantation (LDLT) recipients.

METHODS

Data of 311 adult-to-adult LDLT recipients between January 2015 and April 2019 were analyzed. The primary outcome was a change in requirement for allogeneic RBCs due to the use of salvaged blood. Additionally, predictors of intraoperative allogeneic RBC transfusion were investigated.

RESULTS

One hundred fifty-three (49.2%) recipients required allogeneic RBC transfusion. If recipients did not receive salvaged blood, 253 (81.4%) recipients would have needed allogeneic RBC transfusion. The total volume of salvaged blood transfused into recipients during surgery was 269,165 mL, which corresponded to 993 units of allogeneic RBCs and accounted for 76.1% of total RBC transfusion volume. Multivariate analysis showed that male recipients, model for end-stage liver disease score, preoperative hemoglobin level, and volume of salvaged blood used during surgery were independent predictors of the need for intraoperative allogenic RBC transfusion.

CONCLUSIONS

Intraoperative use of salvaged blood significantly reduced allogeneic RBC transfusion in LDLT recipients. It can help transplant teams manage transfusion of allogeneic RBCs during liver transplantation.

Portal hypertension has no role in perioperative bleeding during liver transplantation with systematic porto-caval shunt

BACKGROUND

More than a half of patients undergoing liver transplantation (LT) receive intraoperative transfusion. Portal hypertension (PHT) may contribute to perioperative blood loss. We study the relationship between preoperative hepatic venous pressure gradient (HVPG) values and intraoperative transfusion requirements in adult patients undergoing LT.

METHODS

160 cirrhotic patients undergoing first elective LT (2009-2019) with an HVPG measurement within the previous 6 months were included. Surgical technique was piggyback with portocaval shunt (PCS). The association of HVPG and other variables with transfusion requirements and blood loss were studied.

RESULTS

Blood loss (ml/kg) was positively correlated with HVPG, among other variables, but at multivariable analysis it only remained associated with MELD-Na and HCC indication. Regarding RBC transfusion, MELD-Na and hemoglobin were independently associated with the need and magnitude of RBC transfusion. Subanalysis by surgical stage (hepatectomy, anhepatic, neohepatic) and by serial HVPG cut-offs found no clear associations with either bleeding or transfusion.

DISCUSSION

The severity of PHT plays a minor role on bleeding and transfusion during LT in a contemporary cohort with systematic PCS. Main determinants of transfusion are liver function and baseline hemoglobin, which would seem the suitable goal to optimize transfusion in LT.

Using Rotational Thromboelastometry to Identify Early Allograft Dysfunction after Living Donor Liver Transplantation

Background: Diagnostic tests for early allograft dysfunction (EAD) after living donor liver transplantation (LDLT) vary widely. We aimed to evaluate the predictive value of rotational thromboelastometry (ROTEM)-derived parameters in EAD. Materials and Methods: A total of 121 patients were reviewed. The definition of EAD proposed by Olthoff et al. included the presence of any of the following at postoperative day 7: bilirubin level ≥ 10 mg/dL, INR ≥ 1.6, or serum AST or ALT levels > 2000 IU/L. All patients underwent ROTEM assay, which consisted of an extrinsically activated thromboelastometric test (EXTEM) before and 24 h after LDLT. Results: The 1-year/2-year OS were 68.%8/64.5% and 94.4%/90.8% for the EAD and non-EAD groups, respectively (p = 0.001). Two independent risks were identified for EAD, the postoperative clotting time (CT, p = 0.026) and time to maximum clot firmness (maximum clot firmness (MCF)-t, p = 0.009) on the EXTEM. CT yielded a specificity of 82.0% and negative predictive value of 83.0%, and MCF-t displayed a specificity of 76.4% and negative predictive value of 81.9% in diagnosing EAD. The use of the 24 h post-LDLT ROTEM increased the effectiveness of predicting overall survival (OS) compared to using the Olthoff’s EAD criteria alone (p < 0.001). Conclusion: We conclude that CT and MCF on EXTEM were independent predictors of EAD. The 24 h post-LDLT ROTEM can be used with conventional laboratory tests to diagnose EAD. It increases the effectiveness of predicting OS.

Perioperative Transfusion is Related to the Length of Hospital Stays in Primary Liver Cancer Patients

Purpose

Blood loss may be corrected with red blood cell transfusion, but may ultimately contribute to negative impacts. This study was a retrospective analysis to assess the impact of perioperative blood transfusion on hospital stay days in liver cancer patients.

Methods

We retrospectively examined data from patients with primary liver cancer who underwent curative resection. Patients were divided into perioperative blood transfusion (PBT) and non-PBT groups. Data were given as means and SDs for continuous variables and as counts and percentage for categorical variables. The correlation between blood transfusion and hospital stay days was analyzed by Fisher's exact test. Multivariable logistic regression analyses were used to identify independent predictors of length of hospital stays.

Results

Totally 206/1031 patients (20.3%) were given perioperative transfusion. The mean length of hospital stay was 17.8 days in PBT and 13.9 days in non-PBT groups. Our multivariable logistic regression showed transfusion, total bilirubin, indirect bilirubin, and the ratio of albumin to bilirubin were all indicators of the length of hospital stay days. Perioperative transfusion was also associated with prolonged length of hospital stays (95% CI: 0.395-0.811, p = 0.002). Transfusion also affected intrinsic coagulation factors (activated partial thromboplastin time, fibrinogen, platelet), inflammatory index (neutrocyte to lymphocyte ratio, monocyte), albumin and bilirubin levels.

Conclusion

Perioperative transfusion of blood was associated with a significantly increased length of hospital stays probably via changing intrinsic coagulation and inflammatory factors and bilirubin levels in plasma.

Early Allograft Dysfunction Following Liver Transplant: Impact of Obesity, Diabetes, and Red Blood Cell Transfusion

PURPOSE

We examined the role of obesity and intraoperative red blood cell (RBC) and platelet transfusion in early allograft dysfunction (EAD) following liver transplantation (LT).

METHODS

This is a retrospective analysis of 239 adult deceased-donor LT recipients over a 10-year period. EAD was defined by Olthoff's criteria. Data collection included donor (D) and recipient (R) age, body mass index (BMI) ≥ 35 kg/m², diabetes mellitus, allograft macrosteatosis, and intraoperative (RBC) and platelet administration. We employed logistic regression to evaluate associations of these factors with EAD. Results are presented as odds ratios (OR) and 95% confidence intervals (CI) with corresponding P values. A P ≤ .05 was considered statistically significant.

RESULTS

EAD occurred in 85 recipients (36%). Macrosteatosis data were available for 199 donors. In the multivariate analyses, BMI-D ≥ 35 kg/m² increased the odds of developing EAD by 156% in the entire cohort (OR 2.56, 95% CI 1.09-6.01) and by 187% in recipients with macrosteatosis data (n = 199, OR 2.87, 95% CI 1.15-7.15). Each unit of RBCs increased the odds for EAD by 8% (OR 1.08, 95% CI 1.02-1.14) and, for the subgroup of 238 recipients with macrosteatosis data, by 9% (OR 1.09, 95% CI 1.02-1.16).

CONCLUSION

We found a significant independent association of donor obesity and intraoperative RBC transfusion with EAD but no such association for platelet administration, MELD score, age, recipient obesity, and diabetes.

Transfusion of Older Red Blood Cells Increases the Risk of Acute Kidney Injury After Orthotopic Liver Transplantation: A Propensity Score Analysis

BACKGROUND

Acute kidney injury (AKI) is a common and serious complication of orthotopic liver transplantation (OLT). Transfusion of older red blood cells (RBCs) has been implicated in poor outcomes in trauma, cardiac surgery, and critically ill patients. However, whether transfusion of older RBCs plays any role in post-OLT AKI remained unknown. The aim of this study was to investigate the effect of the age of transfused RBCs on post-OLT AKI.

METHODS

The clinical data of consecutive adult patients who received donation after cardiac death and underwent OLT from December 2011 to December 2015 were analyzed. These patients were divided into 2 groups: the newer blood group, who received exclusively RBCs that had been stored for <14 days; and the older blood group, who received RBCs that had been stored for 14 days or more. The incidence of post-OLT AKI, severe AKI, lengths of intensive care unit and hospital stay, and in-hospital mortality after OLT were analyzed.

RESULTS

Postoperative AKI occurred in 65.1% of patients in the older blood group and 40.5% of patients in the newer blood group (P < .01). The incidence of severe AKI after OLT was significantly higher, and the duration of intensive care unit stay was significantly longer, in the older blood group. After adjustment by the multivariable regression logistic analysis, transfusion of older blood was independently associated with post-OLT AKI (odds ratio [OR] = 2.47 [95% confidence interval {CI}, 1.13-5.41]; P = .024) and severe AKI (OR = 5.88 [95% CI, 2.06-16.80]; P = .001). After adjustment by the inverse probability of treatment weighting analysis, patients in the older blood group still had significantly higher incidences of postoperative AKI (OR = 2.13 [95% CI, 1.07-4.22]; P = .030) and severe AKI (OR = 3.34 [95% CI, 1.47-7.60]; P = .003) than those in the newer blood group.

CONCLUSIONS

Transfusion of older RBCs significantly increased the risk of postoperative AKI in liver transplant recipients.

Rotational thromboelastometry (ROTEM) 24 hours post liver transplantation predicts early allograft dysfunction

Early allograft dysfunction (EAD) represents one of the most common and serious complications after liver transplantation (LT).

Methods

One hundred sixty-four patients who underwent LT were prospectively included in the present study. Patient demographics, intraoperative blood loss and transfusion were recorded at the time of LT. Lactate levels were recorded during surgery and daily for the first 3 postoperative days. Standard and derived rotational thromboelastometry (ROTEM) parameters were recorded 24 hours after LT. EAD was diagnosed according to Nanashima criteria and post anaesthesia care unit length of stay was recorded.

Results

Forty-seven patients (28.6%) developed EAD. Intraoperative blood loss (p = 0.01), packed red blood cells (p = 0.04) and fresh frozen plasma (p = 0.01) transfusion represented intraoperative risk factors for EAD. Lactate levels were significantly higher in patients with EAD at all time points. Patients with EAD demonstrated an increased clot formation time and decreased maximum clot firmness in both intrinsically (p < 0.01) and extrinsically (p < 0.01) activated assay, a decreased thrombin potential index (p < 0.01), area under the curve (p < 0.01) and clot elasticity (p < 0.01) on ROTEM assay.

Conclusion

Our results show that both standard and derived ROTEM parameters may indicate early signs of graft failure and can aid in the diagnosis of EAD.

Longer storage of red blood cells does not affect mortality in transfused liver transplant recipients

BACKGROUND

The characteristics of red blood cell (RBC) products change after 2 weeks of cold storage. It is unclear whether older RBCs affect mortality after liver transplantation. This retrospective cohort study aimed to evaluate the association between the age of transfused RBCs and death after living donor liver transplantation (LDLT).

STUDY DESIGN AND METHODS

Of 200 recipients who underwent LDLT, 118 who received RBCs with a mean storage duration of less than 10 days (shorter storage group) were compared with 82 with an RBC mean storage duration of more than 14 days (longer storage group). Key exclusion criteria were transfusion of very fresh RBCs stored for less than 4 days and transfusion of old RBCs in recipients of the shorter storage group. The primary outcome was posttransplant overall death. Survival analysis was performed using the Cox model.

RESULTS

Mean RBC storage duration was 7 days in the shorter storage group and 17 days in the longer storage group. Death probability at 1, 2, and 5 years posttransplant was 5.1%, 7.6%, and 13.6% in the shorter storage group, respectively, and 6.1%, 8.5%, and 13.5% in the longer storage group. Death risk was comparable between the two groups in univariable (hazard ratio [HR] 1.00, 95% confidence interval [CI], 0.47-2.16, p = 0.991) and multivariable (HR 1.07, 95% CI, 0.46-2.50, p = 0.882) analyses. Graft failure risk was also comparable (HR 1.04, 95% CI, 0.50-2.18, p = 0.916). Hepatocellular carcinoma recurrence probability at 1, 2, and 5 years was 10.8%, 15.4%, and 23.1%, respectively, in the shorter storage group and 11.4%, 15.9%, and 20.7% in the longer storage group (HR 0.84, 95% CI, 0.37-1.89, p = 0.670). No significant differences were observed regarding graft regeneration/function, vascular/biliary complications, acute kidney injury, surgical site infection, or rejection (p > 0.05).

CONCLUSIONS

No evidence was found that transfusion of old RBCs contributes to death after LDLT.

Storage injury and blood transfusions in trauma patients

PURPOSE OF REVIEW

The aim of the present review was to concisely summarize recent studies and current knowledge about effects of red blood cell storage injury in trauma patients.

RECENT FINDINGS

Despite a pathophysiological rationale for older packed red blood cells (PRBCs) being associated with adverse events in the host organism, recent large clinical trials failed to show negative effects of transfusion with older PRBCs on clinically relevant outcomes in mixed patient population. However, there is a lack of well-designed randomized controlled trials focusing on the effects of storage lesion of PRBCs in trauma patients.

SUMMARY

In the absence of specific evidence for trauma patients, we recommend to continue with a conservative transfusion regime and standard of care blood banking practice of using older PRBCs first.

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.

Transfusion of packed red blood cells at the end of shelf life is associated with increased risk of mortality - a pooled patient data analysis of 16 observational trials

Observational studies address packed red blood cell effects at the end of shelf life and have larger sample sizes compared to randomized control trials. Meta-analyses combining data from observational studies have been complicated by differences in aggregate transfused packed red blood cell age and outcome reporting. This study abrogated these issues by taking a pooled patient data approach. Observational studies reporting packed red blood cell age and clinical outcomes were identified and patient-level data sets were sought from investigators. Odds ratios and 95% confidence intervals for binary outcomes were calculated for each study, with mean packed red blood cell age or maximum packed red blood cell age acting as independent variables. The relationship between mean packed red blood cell age and hospital length of stay for each paper was analyzed using zero-inflated Poisson regression. Random effects models combined paper-level effect estimates. Extremes analyses were completed by comparing patients transfused with mean packed red blood cell aged less than ten days to those transfused with mean packed red blood cell aged at least 30 days. sixteen datasets were available for pooled patient data analysis. Mean packed red blood cell age of at least 30 days was associated with an increased risk of in-hospital mortality compared to mean packed red blood cell of less than ten days (odds ratio: 3.25, 95% confidence interval: 1.27–8.29). Packed red blood cell age was not correlated to increased risks of nosocomial infection or prolonged length of hospital stay.

Preischemic transfusion of old packed RBCs exacerbates early-phase warm hepatic ischemia reperfusion injury in rats

BACKGROUND

Hepatic innate immune cells are considered to play a central role in the early phase of hepatic ischemia reperfusion (IR) injury. Transfusion of old red blood cells (RBCs) is known to prime immune cells, and transfusion before IR may exacerbate liver injury because of the expected hyperresponsiveness of immune cells.

MATERIALS AND METHODS

Twenty-four Sprague-Dawley rats were divided into four groups: sham operation (Sham); hepatic IR only (IR Control); and two transfusion groups, preischemic (Pre-T) and postischemic (Post-T), in which allogeneic RBCs stored for 2 weeks were transfused before hepatic IR or after reperfusion, respectively. Partial hepatic ischemia was induced for 90 min, and reperfusion was allowed for 120 min. Serum alanine transaminase levels, area of necrosis, and apoptotic cells were then assessed. Inflammatory (tumor necrosis factor alpha, interleukin 1 beta [IL-1β], IL-6, IL-10, and cyclooxygenase 2) and oxidative mediators (heme oxygenase 1, superoxide dismutase, and glutathione peroxidase 1) were assessed for elucidating the relevant mechanisms underlying the hepatic injury.

RESULTS

Pre-T, but not Post-T, showed increased serum alanine transaminase levels than IR Control (P < 0.05). Area of necrosis was more severe in Pre-T than in IR Control or Post-T (P < 0.01), and apoptotic cells were also more abundant in Pre-T than in IR Control (P < 0.01). tumor necrosis factor alpha and IL-6 levels were higher in Pre-T than in IR Control or Post-T (P < 0.05), with no significant difference in cytoprotective protein levels.

CONCLUSIONS

Preischemic transfusion of old RBCs aggravated hepatic injury. Inflammatory cytokines seemed to play a crucial role in liver injury exacerbation. Our results indicate that transfusion before hepatic ischemia may be detrimental.

Prolonged EVLP Using OCS Lung: Cellular and Acellular Perfusates

BACKGROUND

We report the ability to extend lung preservation up to 24 hours (24H) by using autologous whole donor blood circulating within an ex vivo lung perfusion (EVLP) system. This approach facilitates donor lung reconditioning in a model of extended normothermic EVLP. We analyzed comparative responses to cellular and acellular perfusates to identify these benefits.

METHODS

Twelve pairs of swine lungs were retrieved after cardiac arrest and studied for 24H on the Organ Care System (OCS) Lung EVLP platform. Three groups (n = 4 each) were differentiated by perfusate: (1) isolated red blood cells (RBCs) (current clinical standard for OCS); (2) whole blood (WB); and (3) acellular buffered dextran-albumin solution (analogous to STEEN solution).

RESULTS

Only the RBC and WB groups met clinical standards for transplantation at 8 hours; our primary analysis at 24H focused on perfusion with WB versus RBC. The WB perfusate was superior (vs RBC) for maintaining stability of all monitored parameters, including the following mean 24H measures: pulmonary artery pressure (6.8 vs 9.0 mm Hg), reservoir volume replacement (85 vs 1607 mL), and PaO2:FiO2 ratio (541 vs 223). Acellular perfusion was limited to 6 hours on the OCS system due to prohibitively high vascular resistance, edema, and worsening compliance.

CONCLUSIONS

The use of an autologous whole donor blood perfusate allowed 24H of preservation without functional deterioration and was superior to both RBC and buffered dextran-albumin solution for extended lung preservation in a swine model using OCS Lung. This finding represents a potentially significant advance in donor lung preservation and reconditioning.

Pediatric liver transplantation: a North American perspective

Liver transplantation (LT) is an important component in the therapeutic armamentarium of managing end-stage liver disease. In North American children, biliary atresia remains the most common indication for LT compared to hepatitis C in adults, while hepatoblastoma is the most common liver tumor requiring LT, versus Hepatocellular carcinoma in adults. Rejection, lymphoproliferative disease, renal insufficiency, metabolic syndrome, recurrent disease, 'de novo' autoimmune hepatitis and malignancy require careful surveillance and prompt action in adults and children after LT. In children, specific attention to EBV viremia, growth, development, adherence and transition to the adult services is also required. Antibody mediated rejection and screening for donor specific antibodies is becoming important in managing liver graft dysfunction. Biomarkers to identify and predict tolerance are being developed. Machine perfusion and stem cells (iPS) to synthesize organs are generating interest and are a focus for research.

Past, present and forecast of transfusion medicine: What has changed and what is expected to change?

Blood transfusion is the second most used medical procedures in health care systems worldwide. Over the last few decades, significant changes have been evolved in transfusion medicine practices. These changes were mainly needed to increase safety, efficacy, and availability of blood products as well as reduce recipients' unnecessary exposure to allogeneic blood. Blood products collection, processing, and storage as well as transfusion practices throughout all patient populations were the main stream of these changes. Health care systems across the world have adopted some or most of these changes to reduce transfusion risks, to improve overall patients' outcome, and to reduce health care costs. In this article, we are going to present and discuss some of these recent modifications and their impact on patients' safety.

Massive haemorrhage in liver transplantation: Consequences, prediction and management

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.

Transfusion of recently donated (fresh) red blood cells (RBCs) does not improve survival in comparison with current practice, while safety of the oldest stored units is yet to be established: a meta-analysis

BACKGROUND AND OBJECTIVES

Preclinical studies generated the hypothesis that older stored red blood cells (RBCs) can increase transfusion risks. To examine the most updated and complete clinical evidence and compare results between two trial designs, we assessed both observational studies and randomized controlled trials (RCTs) studying the effect of RBC storage age on mortality.

MATERIALS AND METHODS

Five databases were searched through December 2014 for studies comparing mortality using transfused RBCs having longer and shorter storage times.

RESULTS

Analysis of six RCTs found no significant differences in survival comparing current practice (average storage age of 2 to 3 weeks) to transfusion of 1- to 10-day-old RBCs (OR 0·91, 95% CI 0·77-1·07). RBC storage age was lower in RCTs vs. observational studies (P = 0·01). The 31 observational studies found an increased risk of death (OR 1·13, 95% CI 1·03-1·24) (P = 0·01) with increasing age of RBCs, a different mortality effect than RCTs (P = 0·02).

CONCLUSION

RCTs established that transfusion of 1- to 10-day-old stored RBCs is not superior to current practice. The apparent discrepancy in mortality between analyses of RCTs and observational studies may in part relate to differences in hypotheses tested and ages of stored RBCs studied. Further trials investigating 1- to 10-day-old stored RBC benefits would seem of lower priority than studies to determine whether 4- to 6-week stored units have safety and efficacy equivalent to the 2- to 3-week-old stored RBCs commonly transfused today.

In a canine pneumonia model of exchange transfusion, altering the age but not the volume of older red blood cells markedly alters outcome

BACKGROUND

Massive exchange transfusion of 42-day-old red blood cells (RBCs) in a canine model of Staphylococcus aureus pneumonia resulted in in vivo hemolysis with increases in cell-free hemoglobin (CFH), transferrin-bound iron (TBI), non-transferrin-bound iron (NTBI), and mortality. We have previously shown that washing 42-day-old RBCs before transfusion significantly decreased NTBI levels and mortality, but washing 7-day-old RBCs increased mortality and CFH levels. We now report the results of altering volume, washing, and age of RBCs.

STUDY DESIGN AND METHODS

Two-year-old purpose-bred infected beagles were transfused with increasing volumes (5-10, 20-40, or 60-80 mL/kg) of either 42- or 7-day-old RBCs (n = 36) or 80 mL/kg of either unwashed or washed RBCs with increasing storage age (14, 21, 28, or 35 days; n = 40).

RESULTS

All volumes transfused (5-80 mL/kg) of 42-day-old RBCs resulted in alike (i.e., not significantly different) increases in TBI during transfusion as well as in CFH, lung injury, and mortality rates after transfusion. Transfusion of 80 mL/kg RBCs stored for 14, 21, 28, and 35 days resulted in increased CFH and NTBI in between levels found at 7 and 42 days of storage. However, washing RBCs of intermediate ages (14-35 days) does not alter NTBI and CFH levels or mortality rates.

CONCLUSIONS

Preclinical data suggest that any volume of 42-day-old blood potentially increases risks during established infection. In contrast, even massive volumes of 7-day-old blood result in minimal CFH and NTBI levels and risks. In contrast to the extremes of storage, washing blood stored for intermediate ages does not alter risks of transfusion or NTBI and CFH clearance.

Clinical effects of red blood cell storage

BACKGROUND

Well-characterized biochemical, structural, and physiological changes occur when red blood cells (RBCs) are stored for a period of time and are collectively called the storage lesion.

METHODS

Key study results are summarized and contrasted and new data from recently completed randomized controlled trials will be discussed.

RESULTS

It is unclear whether in vitro changes to RBCs that occur during storage are clinically relevant. The clinical effects of RBC storage have been the focus of observational studies in recent years. However, these studies lack any consensus, possibly because of methodological limitations.

CONCLUSIONS

The clinical significance of storing RBCs is controversial, although new data from randomized controlled trials of neonates and patients undergoing cardiac surgery suggest that the duration of RBC storage is not associated with adverse clinical outcomes in these patient populations.