Characterization of an andexanet alfa administration protocol guided by drug-specific quantitative anti-Xa assays.

Following FDA approval in 2018, consensus guidelines recommend andexanet alfa as first-line therapy for the management of life-threatening or uncontrollable bleeding in patients taking oral factor Xa (FXa) inhibitors. Dosing is based on the specific FXa inhibitor and dose, and the time elapsed since the patient's last administration of the medication. Additionally, at our institution, anti-FXa screens and drug-specific assays are obtained to guide subsequent dosing based on institution protocol. The objective of this study was to evaluate andexanet alfa utilization based on anti-Xa and FXa-inhibitor-specific assays and assess associated outcomes. This was a retrospective, single-center study aimed to describe the use of anti-FXa and specific direct oral anticoagulant assays to guide the utilization and administration of andexanet alfa. Secondary endpoints evaluated included thrombotic events during index hospitalization, hospital length of stay, hospital mortality, and discharge disposition. Overall, most patients were prescribed apixaban for atrial fibrillation and received andexanet alfa for reversal of intracranial hemorrhage in the emergency department. In general, DOAC-specific assays were concordant with last known times; however, there appears to be minimal correlation with DOAC-specific assay levels and survival. There were 9 thrombotic events (8.7%) in 8 patients. In this cohort, collection of an anti-FXa assay screen was a practical strategy to guide reversal with andexanet alfa; however, the addition of DOAC-specific assay levels may not enhance clinical utility.

Oxidative Stress and Cerebral Vascular Tone: The Role of Reactive Oxygen and Nitrogen Species.

The brain's unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms. This review explores the factors contributing to the brain's vascular tone's vulnerability in the presence of oxidative damage, which can be of clinical interest in critically ill patients or those presenting acute brain injuries. The brain's high metabolic rate and inefficient electron transport chain in mitochondria lead to significant ROS generation. Moreover, non-replicating neuronal cells and low repair capacity increase susceptibility to oxidative insult. ROS can influence cerebral vascular tone and permeability, potentially impacting cerebral autoregulation. Different ROS species, including superoxide and hydrogen peroxide, exhibit vasodilatory or vasoconstrictive effects on cerebral blood vessels. RNS, particularly NO and peroxynitrite, also exert vasoactive effects. This review further investigates the neuroprotective effects of antioxidants, including superoxide dismutase (SOD), vitamin C, vitamin E, and the glutathione redox system. Various studies suggest that these antioxidants could be used as adjunct therapies to protect the cerebral vascular tone under conditions of high oxidative stress. Nevertheless, more extensive research is required to comprehensively grasp the relationship between oxidative stress and cerebrovascular tone, and explore the potential benefits of antioxidants as adjunctive therapies in critical illnesses and acute brain injuries.

Clinical Relevance of Preclinical and Clinical Studies of Four-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Direct Oral Anticoagulants.

Direct oral anticoagulants (DOACs) are widely used for the prevention and treatment of venous thromboembolism and stroke. When emergency reversal of DOAC-related anticoagulation is required, specific DOAC reversal agents are recommended, including idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. However, specific reversal agents are not always available, andexanet alfa has not been approved for urgent surgery, and clinicians need to know the patient's anticoagulant medication before administering these treatments. Four-factor prothrombin complex concentrates (4F-PCCs) are recognized as nonspecific, alternative hemostatic agents for treatment of DOAC-related bleeding. Evidence from preclinical and clinical studies shows that they may reduce the anticoagulant effects of DOACs and may help control DOAC-related bleeding. However, randomized controlled trials are lacking, and most data are from retrospective or single-arm prospective studies in bleeding associated with activated factor X inhibitors. There are no clinical data showing the efficacy of 4F-PCC for the treatment of bleeding in dabigatran-treated patients. This review focuses on the current evidence of 4F-PCC use in controlling bleeding associated with DOACs and provides an expert opinion on the relevance of these data for clinical practice. The current treatment landscape, unmet needs, and future directions are also discussed.

Incidence of Postreperfusion Hyperfibrinolysis in Liver Transplantation by Donor Type and Observed Treatment Strategies.

BACKGROUND: Hyperfibrinolysis is a possible complication during liver transplantation, particularly immediately after reperfusion. METHODS: We performed a retrospective study to examine the incidence, treatment, and resolution of postreperfusion hyperfibrinolysis in patients undergoing liver transplantation at Duke University Hospital from 2015 to 2020. RESULTS: Out of 535 patients undergoing liver transplantation, 21 or 3.9%, 95% CI (2.5-5.9), had hyperfibrinolysis after reperfusion. Hyperfibrinolysis occurred in 16 of 511 (3.1%) patients receiving livers from DBD donors, 5 of 18 (27.8%) patients receiving livers from donation after circulatory death (DCD) donors, and 0 of 6 (0.0%) patients receiving livers from living donors. Fibrinolysis was treated with cryoprecipitate (12/21), a combination of cryoprecipitate and tranexamic acid (3/21), or neither (6/21) and resolved within several hours in all cases. CONCLUSIONS: Anesthesiologists should be aware of the possibility of postreperfusion hyperfibrinolysis in liver transplantation, particularly with DCD donors, and may consider treatment with cryoprecipitate or tranexamic acid. Further work is needed to identify any potential differences, such as faster resolution of fibrinolysis, between different treatment modalities.

Development of New Donor-Specific and Human Leukocyte Antigen Antibodies After Transfusion in Adult Lung Transplantation.

OBJECTIVES: The development of new human leukocyte antigens (HLAs) and donor-specific antibodies (DSAs) in patients are associated with worse outcomes following lung transplantation. The authors aimed to examine the relationship between blood product transfusion in the first 72 hours after lung transplantation and the development of HLA antibodies, including DSAs. DESIGN: A retrospective observational study. SETTING: At a single academic tertiary center. PARTICIPANTS: Adult lung transplant recipients who underwent transplantation between September 2014 and June 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 380 patients were included in this study, and 87 (23%) developed de novo donor-specific antibodies in the first year after transplantation. Eighty-five patients (22%) developed new HLA antibodies that were not donor-specific, and 208 patients (55%) did not develop new HLA antibodies in the first year after transplantation. Factors associated with increased HLA and DSA development included donor pulmonary infection, non-infectious indication for transplant, increased recipient body mass index, and a preoperative calculated panel reactive antibody value above 0. Multivariate analysis identified platelet transfusion associated with an increased risk of de novo HLA antibody development compared to the negative group (odds ratio [OR; 95% CI] 1.18 [1.02-1.36]; p = 0.025). Cryoprecipitate transfusion was associated with de novo DSA development compared to the negative group (OR [95% CI] 2.21 [1.32-3.69] for 1 v 0 units; p = 0.002). CONCLUSIONS: Increased perioperative transfusion of platelets and cryoprecipitate are associated with de novo HLA and DSA development, respectively, in lung transplant recipients during the first year after transplantation.

Red blood cell microvesicles activate the contact system, leading to factor IX activation via 2 independent pathways.

Storage lesion-induced, red cell-derived microvesicles (RBC-MVs) propagate coagulation by supporting the assembly of the prothrombinase complex. It has also been reported that RBC-MVs initiate coagulation via the intrinsic pathway. To elucidate the mechanism(s) of RBC-MV-induced coagulation activation, the ability of storage lesion-induced RBC-MVs to activate each zymogen of the intrinsic pathway was assessed in a buffer system. Simultaneously, the thrombin generation (TG) assay was used to assess their ability to initiate coagulation in plasma. RBC-MVs directly activated factor XII (FXII) or prekallikrein, but not FXI or FIX. RBC-MVs initiated TG in normal pooled plasma and in FXII- or FXI-deficient plasma, but not in FIX-deficient plasma, suggesting an alternate pathway that bypasses both FXII and FXI. Interestingly, RBC-MVs generated FIXa in a prekallikrein-dependent manner. Similarly, purified kallikrein activated FIX in buffer and initiated TG in normal pooled plasma, as well as FXII- or FXI-deficient plasma, but not FIX-deficient plasma. Dual inhibition of FXIIa by corn trypsin inhibitor and kallikrein by soybean trypsin inhibitor was necessary for abolishing RBC-MV-induced TG in normal pooled plasma, whereas kallikrein inhibition alone was sufficient to abolish TG in FXII- or FXI-deficient plasma. Heating RBC-MVs at 60°C for 15 minutes or pretreatment with trypsin abolished TG, suggesting the presence of MV-associated proteins that are essential for contact activation. In summary, RBC-MVs activate both FXII and prekallikrein, leading to FIX activation by 2 independent pathways: the classic FXIIa-FXI-FIX pathway and direct kallikrein activation of FIX. These data suggest novel mechanisms by which RBC transfusion mediates inflammatory and/or thrombotic outcomes.

Andexanet alfa and four-factor prothrombin complex concentrate for reversal of apixaban and rivaroxaban in patients diagnosed with intracranial hemorrhage.

Limited data exists regarding the clinical outcomes of andexanet alfa and four factor prothrombin complex concentrate (4F-PCC) for reversal of apixaban or rivaroxaban in the setting of intracranial hemorrhage (ICH). The objective of this study was to evaluate clinical outcomes of 4F-PCC and andexanet alfa for reversal of ICH associated with oral factor Xa inhibitors. This was a retrospective, single-center, case series evaluating hemostatic efficacy of patients receiving andexanet alfa) or 4F-PCC for reversal of apixaban or rivaroxaban after ICH. Secondary endpoints included in-hospital mortality, thrombotic complications, timing of reversal agents, intensive care unit and hospital length of stay, patient disposition, and 30-day readmission rate. During the study period, 21 patients received andexanet alfa and 35 received 4F-PCC. Hemostatic efficacy occurred in 64.7% of patients receiving andexanet alfa and 54.8% of receiving 4F-PCC. Thirty-day all-cause mortality was 45.2% for 4F-PCC and 30% for andexanet alfa. Thrombotic events were higher with 4F-PCC (31.4%) compared to andexanet alfa (14.3%). Median time from presentation to administration of reversal agent was 2.67 [1.75-4.13] hours with andexanet alfa and 1.73 [1.21-3.55] hours with 4F-PCC. Discharge to skilled nursing facilities and 30-day readmission were similar between groups. In this cohort, reversal with andexanet alfa and 4F-PCC differed in terms ofhemostatic efficacy and thrombotic events after ICH in patients anticoagulated with apixaban or rivaroxaban.

Heated Humidified Breathing Circuit Rewarming in Hypothermic Patients Post-Cardiopulmonary Bypass-Pilot Study.

OBJECTIVES: Hypothermia on intensive care unit (ICU) admission after cardiac surgery and cardiopulmonary bypass is common. It contributes to postoperative complications including shivering, coagulopathy, increased blood loss and transfusion requirements, morbid cardiac events, metabolic acidosis, increased wound infections, and prolonged hospital length of stay. The current standard of care for rewarming ICU patients is forced air warming blankets. However, high-quality evidence on additional benefit rendered by other warming methods, such as heated humidified breathing circuits (HHBC), is lacking. Therefore, the authors conducted a pilot study to examine whether the addition of HHBC to standard forced air warming blankets in hypothermic patients (≤35°C) admitted to the ICU after cardiac surgery using cardiopulmonary bypass reduced time to normothermia. DESIGN: Prospective study conducted at a single large academic medical center. PARTICIPANTS: The study group was composed of 14 patients who were enrolled prospectively between April 1 and June 14, 2019. The study group was compared with a 2:1 matched retrospective control group. The matched group consisted of 28 patients from a 12-month period from July 1, 2018 June 30, 2019. INTERVENTIONS: Study patients received warming via forced air warming blankets and HHBC and were compared with patients in a control group who received only warming blankets. Time to normothermia, time to extubation, time to normal pH, blood loss, blood transfusions, and coagulation profile laboratory values were compared between the study and control groups. MEASUREMENTS AND MAIN RESULTS: The present study found no statistical difference in time to normothermia, for which the standard-of-care retrospective group achieved normothermia after a median (Q1-Q3) 4.8 (4.0-6.0) hours compared with 4.4 (3.5-5.5) hours in the prospective group receiving HHBC. All secondary outcomes, including time to extubation, time to normal pH, ICU blood product transfusion, chest tube output, and coagulation profile, were similar. CONCLUSIONS: The present pilot study detected a similar time to normothermia, extubation, and normal pH when HHBC were added to standard forced air warming blankets in hypothermic patients (≤35°C) admitted to the ICU after cardiac surgery using cardiopulmonary bypass. A future larger prospective study designed to detect smaller, but clinically meaningful, reductions in the time to key clinical events for patients treated with HHBC is feasible and warranted.

Modulation of red blood cell oxygen affinity with a novel allosteric modifier of hemoglobin is additive to the Bohr effect.

PURPOSE: The Bohr effect describes hemoglobin's affinity for oxygen dependent on solution pH. Within pH range 6.0-8.5, hemoglobin's oxygen affinity decreases with decreasing pH. This results in increased oxygen delivery to metabolically active, acidic tissues and improved oxygen uptake in basic regions including lung tissue. Myo-Inositol tripyrophosphate (ITPP) translocates the erythrocyte membrane and allosterically modifies hemoglobin (Hb). We tested the hypothesis that ITPP does not abrogate the Bohr effect. METHODS: Experiments were conducted to determine the effect of increasing concentrations of ITPP on P50 with varying pH. We incubated 10 mL red blood cells at 37 °C for 1 h with ITPP concentrations from 0 to 240 mM. The Clark oxygen electrode (Hemox-Analyzer; TCS Scientific, New Hope, PA) determined oxygen affinity of each sample, in triplicate, using buffers pH 6.8, 7.4, and 7.6. A mixed linear regression model with fixed effects for ITPP concentration and pH was used. RESULTS: Increasing ITPP concentration and decreasing pH increased P50 (p < 0.0001 for ITPP concentration, p < 0.0001 for pH). ITPP modulated increased P50 in normal pH (7.4) and acidic condition pH (6.8); with no effect at alkaline pH (7.6). CONCLUSION: The Bohr effect is conserved, with ITPP augmenting the decreased oxygen affinity seen with tissue acidosis, while not affecting oxygen affinity in conditions similar to a pulmonary microenvironment.

Fatty acid desaturase activity in mature red blood cells and implications for blood storage quality.

BACKGROUND: Increases in the red blood cell (RBC) degree of fatty acid desaturation are reported in response to exercise, aging, or diseases associated with systemic oxidant stress. However, no studies have focused on the presence and activity of fatty acid desaturases (FADS) in the mature RBC. STUDY DESIGN AND METHODS: Steady state metabolomics and isotope-labeled tracing experiments, immunofluorescence approaches, and pharmacological interventions were used to determine the degree of fatty acid unsaturation, FADS activity as a function of storage, oxidant stress, and G6PD deficiency in human and mouse RBCs. RESULTS: In 250 blood units from the REDS III RBC Omics recalled donor population, we report a storage-dependent accumulation of free mono-, poly-(PUFAs), and highly unsaturated fatty acids (HUFAs), which occur at a faster rate than saturated fatty acid accumulation. Through a combination of immunofluorescence, pharmacological inhibition, tracing experiments with stable isotope-labeled fatty acids, and oxidant challenge with hydrogen peroxide, we demonstrate the presence and redox-sensitive activity of FADS2, FADS1, and FADS5 in the mature RBC. Increases in PUFAs and HUFAs in human and mouse RBCs correlate negatively with storage hemolysis and positively with posttransfusion recovery. Inhibition of these enzymes decreases accumulation of free PUFAs and HUFAs in stored RBCs, concomitant to increases in pyruvate/lactate ratios. Alterations of this ratio in G6PD deficient patients or units supplemented with pyruvate-rich rejuvenation solutions corresponded to decreased PUFA and HUFA accumulation. CONCLUSION: Fatty acid desaturases are present and active in mature RBCs. Their activity is sensitive to oxidant stress, storage duration, and alterations of the pyruvate/lactate ratio.

Bedside Allogeneic Erythrocyte Washing with a Cell Saver to Remove Cytokines, Chemokines, and Cell-derived Microvesicles.

BACKGROUND: Removal of cytokines, chemokines, and microvesicles from the supernatant of allogeneic erythrocytes may help mitigate adverse transfusion reactions. Blood bank-based washing procedures present logistical difficulties; therefore, we tested the hypothesis that on-demand bedside washing of allogeneic erythrocyte units is capable of removing soluble factors and is feasible in a clinical setting. METHODS: There were in vitro and prospective, observation cohort components to this a priori planned substudy evaluating bedside allogeneic erythrocyte washing, with a cell saver, during cardiac surgery. Laboratory data were collected from the first 75 washed units given to a subset of patients nested in the intervention arm of a parent clinical trial. Paired pre- and postwash samples from the blood unit bags were centrifuged. The supernatant was aspirated and frozen at -70°C, then batch-tested for cell-derived microvesicles, soluble CD40 ligand, chemokine ligand 5, and neutral lipids (all previously associated with transfusion reactions) and cell-free hemoglobin (possibly increased by washing). From the entire cohort randomized to the intervention arm of the trial, bedside washing was defined as feasible if at least 75% of prescribed units were washed per protocol. RESULTS: Paired data were available for 74 units. Washing reduced soluble CD40 ligand (median [interquartile range]; from 143 [1 to 338] ng/ml to zero), chemokine ligand 5 (from 1,314 [715 to 2,551] to 305 [179 to 488] ng/ml), and microvesicle numbers (from 6.90 [4.10 to 20.0] to 0.83 [0.33 to 2.80] × 106), while cell-free hemoglobin concentration increased from 72.6 (53.6 to 171.6) mg/dl to 210.5 (126.6 to 479.6) mg/dl (P < 0.0001 for each). There was no effect on neutral lipids. Bedside washing was determined as feasible for 80 of 81 patients (99%); overall, 293 of 314 (93%) units were washed per protocol. CONCLUSIONS: Bedside erythrocyte washing was clinically feasible and greatly reduced concentrations of soluble factors thought to be associated with transfusion-related adverse reactions, increasing concentrations of cell-free hemoglobin while maintaining acceptable (less than 0.8%) hemolysis.

Clinical outcomes of cardiac surgery patients undergoing therapeutic plasma exchange for heparin-induced thrombocytopenia.

BACKGROUND AND OBJECTIVES: Heparin-induced thrombocytopenia (HIT) is an antibody-mediated condition that leads to thrombocytopenia and possible thrombosis. Patients with HIT who require cardiac surgery pose a challenge as high doses of heparin or heparin alternatives are required to permit cardiopulmonary bypass (CPB). Intraoperative therapeutic plasma exchange (TPE) is a valuable adjunct in the management of antibody-mediated syndromes including HIT. The clinical impact of TPE on thromboembolic events, bleeding and mortality after heparin re-exposure is not well established. We hypothesized that TPE with heparin re-exposure will not lead to HIT-related thromboembolic events, bleeding or increased mortality after cardiac surgery with CPB. MATERIALS AND METHODS: We reviewed 330 patients who received perioperative TPE between September 2012 and September 2017. RESULTS: Twenty four patients received TPE for HIT before anticipated heparin use for CPB. Most patients were males (79%) scheduled for advanced heart failure therapies. Three patients (12·5%) died within 30 days after surgery but none of the deaths were considered HIT-related. Thromboembolic events (TE) occurred in 3 patients within 7 days of surgery; of those, two were possibly HIT-related. CONCLUSION: Therapeutic plasma exchange with heparin re-exposure was not strongly associated with HIT-related thrombosis/death after cardiac surgery with CPB.

Blood product transfusion and lung transplant outcomes: A systematic review.

The perioperative transfusion of blood products has long been linked to development of acute lung injury and associated with mortality across both medical and surgical patient populations.1,2 The need for blood product transfusion during and after lung transplantation is common and, in many instances, unavoidable. However, this practice may potentially be modifiable.3 In this systematic review, we explore and summarize what is known regarding the impact of blood product transfusion on outcomes following lung transplantation, highlighting the most recent work in this area. Overall, the majority of the literature consists of single center retrospective analyses or the work of multicenter working groups referencing the same database. In the end, there are a number of remaining questions regarding blood product transfusion and their downstream effects on graft function and survival.

Activated Coagulation Time and Hepcon Protamine Titration Device to Manage Unfractionated Heparin During Cardiopulmonary Bypass in a Hemophilia A Patient on Emicizumab.

In the perioperative management of patients with hemophilia A, emicizumab prevents the accurate measurement of common clotting assays, including the activated clotting time (ACT), which is essential for high-dose heparin monitoring during cardiopulmonary bypass surgery. The authors describe the successful perioperative management of a hemophilia A patient on maintenance emicizumab who, following a non-ST myocardial infarction, underwent cardiopulmonary bypass grafting surgery with heparin monitoring using both the ACT and heparin levels from the Hepcon protamine titration device. Postoperatively, the patient was transitioned to recombinant factor VIII replacement therapy. In hemophilia A patients on emicizumab who require heparin titration on cardiopulmonary bypass surgery, the ACT, combined with Hepcon heparin levels, may be used to complete the surgery successfully without excessive bleeding or morbidity.

Conventional Ultrafiltration During Elective Cardiac Surgery and Postoperative Acute Kidney Injury.

OBJECTIVE: Conventional ultrafiltration (CUF) during cardiopulmonary bypass (CPB) serves to hemoconcentrate blood volume to avoid allogeneic blood transfusions. Previous studies have determined CUF volumes as a continuous variable are associated with postoperative acute kidney injury (AKI) after cardiac surgery, but optimal weight-indexed volumes that predict AKI have not been described. DESIGN: Retrospective cohort. SETTING: Single-center university hospital. PARTICIPANTS: A total of 1,641 consecutive patients who underwent elective cardiac surgery between June 2013 and December 2015. INTERVENTIONS: The CUF volume was removed during CPB in all participants as part of routine practice. The authors investigated the association of dichotomized weight-indexed CUF volume removal with postoperative AKI development to provide pragmatic guidance for clinical practice at the authors' institution. MEASUREMENTS AND MAIN RESULTS: Primary outcomes of postoperative AKI were defined by the Kidney Disease: Improving Global Outcomes staging criteria and dichotomized, weight-indexed CUF volumes (mL/kg) were defined by (1) extreme quartiles (Q3) and (2) Youden's criterion that best predicted AKI development. Multivariate logistic regression models were developed to test the association of these dichotomized indices with AKI status. Postoperative AKI occurred in 827 patients (50.4%). Higher CUF volumes were associated with AKI development by quartiles (CUF >Q3 = 32.6 v CUF < Q1 = 10.4 mL/kg; odds ratio [OR] = 1.68, 95% CI: 1.19-2.3) and Youden's criterion (CUF ≥ 32.9 v CUF <32.9 mL/kg; OR = 1.60, 95% CI: 1.21-2.13). Despite similar intraoperative nadir hematocrits among groups (p = 0.8), higher CUF volumes were associated with more allogeneic blood transfusions (p = 0.002) and longer lengths of stay (p < 0.001). CONCLUSIONS: Removal of weight-indexed CUF volumes > 32 mL/kg increased the risk for postoperative AKI development. Importantly, CUF volume removal of any amount did not mitigate allogeneic blood transfusion during elective cardiac surgery. Prospective studies are needed to validate these findings.

Rejuvenation solution as an adjunct cold storage solution maintains physiological haemoglobin oxygen affinity during early-storage period of red blood cells.

BACKGROUND: Red blood cell (RBC) units accumulate morphologic and metabolic lesions during storage before transfusion. Pyruvate-inosine-phosphate-adenine (PIPA) solutions (Rejuvesol, Biomet, Warsaw, IN) can be incubated with RBC units to mitigate storage lesions. This study proposes a PIPA treatment process, termed cold 'rejuvenation', using Rejuvesol as an adjunct additive solution, to prevent biomechanical storage lesions while avoiding the 1 h PIPA incubation required with standard PIPA treatment. We compared the efficacy of cold to standard 'rejuvenation' in improving metabolic lesions that occur during cold storage of RBCs, without altering function. METHODS: Twelve leucoreduced, A-positive RBC units were obtained. Each unit was aliquoted into either control (standard storage), washed (W), standard rejuvenation (SR) or cold rejuvenation (CR) groups, the latter two requiring washing. A volume-adjusted dose of Rejuvesol was instilled into the CR group upon receipt (Day 3). After 15 days of storage, p50, RBC deformability, in-bag haemolysis and mechanical fragility were analysed. 'Any treatment' is defined as W, SR and CR, with comparisons in reference to control. RESULTS: Higher p50s were seen in rejuvenated groups (>30 mmHg vs. <19 mmHg; P < 0·0001). Any treatment significantly increased elongation index (P = 0·034) but did not significantly increase in-bag haemolysis (P = 0·062). Mechanical fragility was not significantly different between groups (P = 0·055) at baseline, but the control (CTL) group was more fragile after 2 h in a cardiac bypass simulation than any treatment (P < 0·0001). CONCLUSIONS: This study demonstrates that rejuvenation (standard or cold) prevents the leftward p50 shift of storage lesions without detrimental effect on RBC deformity, in-bag haemolysis or mechanical fragility.

Multicenter Evaluation of the Quantra QPlus System in Adult Patients Undergoing Major Surgical Procedures.

BACKGROUND: The management of perioperative bleeding and the optimization of the available therapies are subjects of significant clinical interest. Clinical guidelines recommend the use of whole blood viscoelastic testing devices to target the utilization of blood products during major surgical procedures. The Quantra QPlus System is a new cartridge-based viscoelastic testing device based on an innovative ultrasound technology. The aim of this study was to evaluate this new system in a surgical population. METHODS: Two hundred seventy-seven adult subjects were enrolled in a multicenter, prospective observational study consisting primarily of patients undergoing cardiac and major orthopedic surgeries. Samples were obtained at multiple time points for testing on the Quantra QPlus System, the rotational thromboelastometry (ROTEM) delta, and standard coagulation tests. Quantra measurements included Clot Time (CT), Heparinase Clot Time (CTH), Clot Time Ratio (CTR), Clot Stiffness (CS), Fibrinogen (FCS), and Platelet (PCS) Contributions to CS. Data analyses included assessment of the concordance of Quantra parameters with a series of clinical composite indexes formed on the basis of standard coagulation tests in 3 domains representing increased, decreased, and normal/subclinical coagulation function. Linear regression and receiver operator characteristic (ROC) analyses of Quantra parameters with corresponding parameters from ROTEM assays were also performed. RESULTS: The accuracy (overall percent agreement or ratio of true positives and true negatives over the entire population) between the Quantra and the composite indexes was between 72% and 98% depending on the specific parameter. Linear regression analysis indicated that the correlation between ROTEM delta and Quantra was very strong with r values ranging between 0.84 and 0.89. Results from ROC analysis demonstrated sensitivities and specificities in the 80%-90% range when QPlus parameters were used to discriminate ROTEM threshold values currently used in goal-directed treatment algorithms. CONCLUSIONS: This study demonstrated that the Quantra QPlus System is strongly correlated with a well-established viscoelastic testing device and its parameters effectively represent the results from multiple standard laboratory assays. The Quantra has been designed to operate at the point of care with the potential to provide rapid and comprehensive results to aid in the management of coagulopathic patients.

ABO Blood Group and Transfusions In the Intraoperative and Postoperative Period After LVAD Implantation.

OBJECTIVES: To assess whether blood group O patients undergoing left ventricular assist device (LVAD) insertion have higher perioperative transfusion requirements, postoperative chest tube output, and postoperative changes in hematocrit. DESIGN: Retrospective review of 116 LVAD patients from August 2015 to May 2018. SETTING: Single-institution, urban academic medical center. PARTICIPANTS: One hundred sixteen LVAD patients analyzed by blood group: group O (n = 49) versus non-O (n = 67). INTERVENTIONS: Transfusions in the combined intraoperative and postoperative period at 7 days and 90 days after LVAD implantation, chest tube output in the first 24 hours, and hematocrit change in the first 48 hours postoperatively. RESULTS: There was no difference between group O and non-O within the univariable analysis for both 7-day and 90-day transfusion rates. Adjusting for covariables, blood type O was not associated with packed red blood cells transfusion after accounting for multiple comparisons (odds ratio 1.33 [1.07-1.66], p = 0.01, where p < 0.005 was considered statistically significant as a Bonferroni correction was performed to control the familywise error rate). Additionally, there was no difference in chest tube output over the first 24 hours (1,129 v 1,057 mL, p = 0.47) or hematocrit change in the first 48 hours postoperatively (3.49 v 4.53%, p = 0.15). CONCLUSION: O blood group is not a significant predictor of transfusion requirements in the combined intraoperative and postoperative period up to 90 days after LVAD implantation.

Metabolic impact of red blood cell exchange with rejuvenated red blood cells in sickle cell patients.

BACKGROUND: Red blood cell exchange (RCE) transfusions are a mainstay in the treatment of sickle cell anemia (SCA), and allow a temporary restoration of physiological parameters with respect to erythrocyte oxygen carrying capacity and systems metabolism. Recently, we noted that 1) RCE significantly impacts recipients' metabolism in SCA; 2) fresh and end-of-storage red blood cell (RBC) units differently impact systems of metabolism in healthy autologous recipients; and 3) phosphate/inosine/pyruvate/adenine (PIPA) solution reverses the metabolic age of stored RBCs. Therefore, we hypothesized that RCE with PIPA-treated RBC units could further increase the metabolic benefits of RCE in SCA patients. STUDY DESIGN AND METHODS: Circulating plasma and erythrocytes were collected from patients with SCA before and after RCE, with either conventional or PIPA-treated RBC units, prior to metabolomics analyses. RESULTS: Consistent with prior work, RCE significantly decreased circulating levels of markers of systemic hypoxemia (lactate, succinate) and decreased plasma levels of acyl-carnitines and amino acids. However, PIPA-treated exchanges were superior to untreated RCEs, with a higher energy state and an increased capacity to activate the pentose phosphate pathway and glutamine metabolism. In addition, RBCs and plasma from recipients of PIPA-treated RBC units resulted in significantly decreased levels of post-transfusion plasticizers, though at the expense of higher circulating levels of oxidized purines (hypoxanthine, xanthine, and the antioxidant urate). CONCLUSION: Transfusion of PIPA-treated RBCs further increases the metabolic benefits of RCE to patients with SCA, significantly reducing the levels of post-transfusion plasticizers.

Interval decline in hemoglobin A is associated with annual clinical event rate in sickle cell anemia patients receiving maintenance apheresis RBC exchange.

BACKGROUND: Apheresis red blood cell (RBC) exchange (RCE) is a standard intervention for patients with sickle cell anemia (SCA) who have had previous thromboembolic stroke or intractable chronic pain. Replacing sickling cells with those containing hemoglobin A (HbA) minimizes microvascular pathophysiology that produces clinical crises. Limited data exist regarding the interval changes in HbA between transfusions. We sought to describe the HbA decrement between RCE procedures and its relationship to clinical status. STUDY DESIGN AND METHODS: SCA patients (all hemoglobin SS disease) treated with maintenance RCE (n = 21) over a 15-month period at two neighboring institutions were retrospectively reviewed. Time-normalized daily HbA decrement was calculated to reflect loss of transfused RBCs, and annual events of either emergency department or hospital admissions for SCA complications were noted. Associations between HbA decrement and laboratory measures were calculated using mixed linear regression models and unpaired t test was used to compare HbA decrement between high and low event rate groups. RESULTS: A total of 31 events were recorded, and mean HbA decrement per day was 0.77 ± 0.16%. The mean interval between RCEs was 36 ± 12 days. Patients with more annual events exhibited a significantly greater daily HbA decrement (p = 0.007). No significant association between RBC unit age and HbA decrement or annual event rate was observed. CONCLUSIONS: Patients exhibiting greater daily HbA decrement were more likely to have multiple emergency department visits or admissions for sickling crises. Modulating HbA decrement may merit study as an intermediate metric for interventions to improve outcomes in hemoglobin SS disease.