Laboratory predictors of bleeding and the effect of platelet and RBC transfusions on bleeding outcomes in the PLADO trial

Preoperative consultation for determining the appropriate transfusion strategy

Surgical patients are at risk of postoperative complications and mortality, necessitating preoperative patient optimization through the identification and correction of modifiable risk factors. Although preoperative platelet transfusions aim to reduce the risk of bleeding, their efficacy remains uncertain. Similarly, red blood cell transfusion in patients with anemia does not reduce the risk of postoperative mortality and may exacerbate complications. Therefore, developing individualized strategies that focus on correcting preoperative complete blood count abnormalities and minimizing transfusion requirements are essential. This review aimed to examine complete blood count abnormalities and appropriate transfusion strategies to minimize postoperative complications.

Prophylactic versus restrictive platelet transfusion strategy in patients with haematological malignancies in the ICU setting, a propensity-score analysis

PURPOSE

Prophylactic platelet transfusions (PT) aim to reduce bleeding. We assessed whether restrictive PT compared to prophylactic strategy could apply in ICU.

MATERIAL AND METHODS

We conducted a retrospective monocentric study including patients >18 yo with haematological malignancy admitted to the ICU with thrombocytopenia <20 G/L between 2018 and 2021. Patients were classified in 2 groups according transfusion strategy applied during the first 3 days: prophylactic or restrictive transfusion.

RESULTS

180 patients were included, 87 and 93 in the restrictive and prophylactic groups respectively. After propensity-score analysis, 2 groups of 54 matched patients were analyzed. Restrictive strategy led to a significant reduction in PT with incidence rate for 100-ICU-patients-days of 34.9 and 49.9, incidence rate ratio = 0.699 [0.5-0.9], p = 0.006, representing a 31% decrease. Decreased PT persisted until day 28 with platelet concentrates transfusions-free days at day 28 of 21 [13-25] and 16.5 [10.2-21] in the 2 groups (p = 0.04). Restrictive strategy did not result in higher grade ≥ 2 bleeding. Transfusion efficiency was low with similar number of days with platelet <10 or < 20 G/L regardless of strategy. Platelet transfusion strategy was not associated with 28-day mortality. Platelet nadir <5G/L was associated with day-28 mortality with HR = 1.882 [1.011-3.055], p = 0.046.

CONCLUSION

A restrictive PT strategy appears feasible in the ICU.

Restrictive versus liberal red blood cell transfusion strategies for people with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without haematopoietic stem cell support

BACKGROUND

An estimated one-quarter to one-half of people diagnosed with haematological malignancies experience anaemia. There are different strategies for red blood cell (RBC) transfusions to treat anaemia. A restrictive transfusion strategy permits a lower haemoglobin (Hb) level whereas a liberal transfusion strategy aims to maintain a higher Hb. The most effective and safest strategy is unknown.

OBJECTIVES

To determine the efficacy and safety of restrictive versus liberal RBC transfusion strategies for people diagnosed with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without a haematopoietic stem cell transplant (HSCT).

SEARCH METHODS

We searched for randomised controlled trials (RCTs) and non-randomised studies (NRS) in MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1982), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2023, Issue 2), and eight other databases (including three trial registries) to 21 March 2023. We also searched grey literature and contacted experts in transfusion for additional trials. There were no language, date or publication status restrictions.

SELECTION CRITERIA

We included RCTs and prospective NRS that evaluated restrictive versus liberal RBC transfusion strategies in children or adults with malignant haematological disorders receiving intensive chemotherapy or radiotherapy, or both, with or without HSCT.

DATA COLLECTION AND ANALYSIS

Two authors independently screened references, full-text reports of potentially relevant studies, extracted data from the studies, and assessed the risk of bias. Any disagreement was discussed and resolved with a third review author. Dichotomous outcomes were presented as a risk ratio (RR) with a 95% confidence interval (CI). Narrative syntheses were used for heterogeneous outcome measures. Review Manager Web was used to meta-analyse the data. Main outcomes of interest included: all-cause mortality at 31 to 100 days, quality of life, number of participants with any bleeding, number of participants with clinically significant bleeding, serious infections, length of hospital admission (days) and hospital readmission at 0 to 3 months. The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

Nine studies met eligibility; eight RCTs and one NRS. Six hundred and forty-four participants were included from six completed RCTs (n = 560) and one completed NRS (n = 84), with two ongoing RCTs consisting of 294 participants (260 adult and 34 paediatric) pending inclusion. Only one completed RCT included children receiving HSCT (n = 6); the other five RCTs only included adults: 239 with acute leukaemia receiving chemotherapy and 315 receiving HSCT (166 allogeneic and 149 autologous). The transfusion threshold ranged from 70 g/L to 80 g/L for restrictive and from 80 g/L to 120 g/L for liberal strategies. Effects were reported in the summary of findings tables only for the trials that included adults to reduce indirectness due to the limited evidence contributed by the prematurely terminated paediatric trial. Evidence from RCTs Overall, there may be little to no difference in the number of participants who die within 31 to 100 days using a restrictive compared to a liberal transfusion strategy, but the evidence is very uncertain (three studies; 451 participants; RR 1.00, 95% CI 0.27 to 3.70, P=0.99; very low-certainty evidence). There may be little to no difference in quality of life at 0 to 3 months using a restrictive compared to a liberal transfusion strategy, but the evidence is very uncertain (three studies; 431 participants; analysis unable to be completed due to heterogeneity; very low-certainty evidence). There may be little to no difference in the number of participants who suffer from any bleeding at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (three studies; 448 participants; RR 0.91, 95% CI 0.78 to 1.06, P = 0.22; low-certainty evidence). There may be little to no difference in the number of participants who suffer from clinically significant bleeding at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (four studies; 511 participants; RR: 0.94, 95% CI 0.74 to 1.19, P = 0.60; low-certainty evidence). There may be little to no difference in the number of participants who experience serious infections at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (three studies, 451 participants; RR: 1.20, 95% CI 0.93 to 1.55, P = 0.17; low-certainty evidence). A restrictive transfusion strategy likely results in little to no difference in the length of hospital admission at 0 to 3 months compared to a liberal strategy (two studies; 388 participants; analysis unable to be completed due to heterogeneity in reporting; moderate-certainty evidence). There may be little to no difference between hospital readmission using a restrictive transfusion strategy compared to a liberal transfusion strategy (one study, 299 participants; RR: 0.89, 95% CI 0.52 to 1.50; P = 0.65; low-certainty evidence). Evidence from NRS The evidence is very uncertain whether a restrictive RBC transfusion strategy: reduces the risk of death within 100 days (one study, 84 participants, restrictive 1 death; liberal 1 death; very low-certainty evidence); or decreases the risk of clinically significant bleeding (one study, 84 participants, restrictive 3; liberal 8; very low-certainty evidence). No NRS reported on the other eligible outcomes.

AUTHORS' CONCLUSIONS

Findings from this review were based on seven studies and 644 participants. Definite conclusions are challenging given the relatively few included studies, low number of included participants, heterogeneity of intervention and outcome reporting, and overall certainty of evidence. To increase the certainty of the true effect of a restrictive RBC transfusion strategy on clinical outcomes, there is a need for rigorously designed and executed studies. The evidence is largely based on two populations: adults with acute leukaemia receiving intensive chemotherapy and adults with haematologic malignancy requiring HSCT. Despite the addition of 405 participants from three RCTs to the previous review's results, there is still insufficient evidence to answer this review's primary outcome. If we assume a mortality rate of 3% within 100 days, we would need a total of 1492 participants to have an 80% chance of detecting, at a 5% level of significance, an increase in all-cause mortality from 3% to 6%. Further RCTs are needed overall, particularly in children.

Risk and adverse clinical outcomes of thrombocytopenia among patients with solid tumors-a Danish population-based cohort study

BACKGROUND

Knowledge about thrombocytopenia among patients with solid tumors is scarce. We examined the risk of thrombocytopenia among patients with solid tumors and its association with adverse outcomes.

METHODS

Using Danish health registries, we identified all patients with incident solid tumors from 2015-2018 (n = 52,380) and a platelet count measurement within 2 weeks prior to or on their cancer diagnosis date. The risk of thrombocytopenia was categorized as grades 0 (any platelet count × 109/L): <150; 1: <100; 2: <75; 3: <50; 4: <25, and 5: <10. To study the outcomes, each patient with thrombocytopenia was matched with up to five cancer patients without thrombocytopenia by age, sex, cancer type, and stage. Cox regression was used to compute hazard ratios (HRs) of bleeding, transfusion, or death, adjusting for confounding factors.

RESULTS

The 1-year risk of thrombocytopenia was 23%, increasing to 30% at 4 years. This risk was higher in patients receiving chemotherapy (43% at 1 year and 49% at 4 years). Overall, patients with thrombocytopenia had higher 30-days rates of bleeding (HR = 1.72 [95% confidence interval, CI: 1.41-2.11]). Thrombocytopenia was also associated with an increased rate of transfusion, and death, but some of the risk estimates were imprecise.

CONCLUSIONS

The risk of thrombocytopenia was substantial among patients with solid tumors and associated with adverse outcomes.

Scenario Decision-Making About Plasma and Platelet Transfusion for Intracranial Monitor Placement: Cross-Sectional Survey of Pediatric Intensivists and Neurosurgeons

OBJECTIVES

To report pediatric intensivists' and pediatric neurosurgeons' responses to case-based scenarios about plasma and platelet transfusions before intracranial pressure (ICP) monitor placement in children with severe traumatic brain injury (TBI).

DESIGN

Cross-sectional, electronic survey to evaluate reported plasma and platelet transfusion decisions in eight scenarios of TBI in which ICP monitor placement was indicated.

SETTING

Survey administered through the Pediatric Acute Lung Injury and Sepsis Investigators and the American Association of Neurologic Surgeons.

SUBJECTS

Pediatric intensivists and pediatric neurosurgeons.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 184 participants responded (85 identified as pediatric intensivists and 54 as pediatric neurosurgeons). In all eight scenarios, the majority of respondents reported that they would base their decision-making about plasma transfusion on international normalized ratio (INR) alone (60-69%), or platelet transfusion on platelet count alone (83-86%). Pediatric intensivists, as opposed to pediatric neurosurgeons, more frequently reported that they would have used viscoelastic testing in their consideration of plasma transfusion (32% vs. 7%, p < 0.001), as well as to guide platelet transfusions (29 vs. 8%, p < 0.001), for the case-based scenarios. For all relevant case-based scenarios, pediatric neurosurgeons in comparison with pediatric reported that they would use a lower median (interquartile range [IQR]) INR threshold for plasma transfusion (1.5 [IQR 1.4-1.7] vs. 2.0 [IQR 1.5-2.0], p < 0.001). Overall, in all respondents, the reported median platelet count threshold for platelet transfusion in the case-based scenario was 100 (IQR 50-100) ×10 9 /L, with no difference between specialties.

CONCLUSIONS

Despite little evidence showing efficacy, when we tested specialists' decision-making, we found that they reported using INR and platelet count in pediatric case-based scenarios of TBI undergoing ICP monitor placement. We also found that pediatric intensivists and pediatric neurosurgeons had differences in decision-making about the scenarios.

Venous thromboembolism in critically ill adult patients with hematologic malignancy: a population-based cohort study

PURPOSE

The aim of this study was to describe the incidence of venous thromboembolism (VTE) and major bleeding among hospitalized patients with hematologic malignancy, assessing its association with critical illness and other baseline characteristics.

METHODS

We conducted a population-based cohort study of hospitalized adults with a new diagnosis of hematologic malignancy in Ontario, Canada, between 2006 and 2017. The primary outcome was VTE (pulmonary embolism or deep venous thrombosis). Secondary outcomes were major bleeding and in-hospital mortality. We compared the incidence of VTE between intensive care unit (ICU) and non-ICU patients and described the association of other baseline characteristics and VTE.

RESULTS

Among 76,803 eligible patients (mean age 67 years [standard deviation, SD, 15]), 20,524 had at least one ICU admission. The incidence of VTE was 3.7% in ICU patients compared to 1.2% in non-ICU patients (odds ratio [OR] 3.08; 95% confidence interval [CI] 2.77-3.42). The incidence of major bleeding was 7.6% and 2.4% (OR 3.33; 95% CI 3.09-3.58), respectively. The association of critical illness and VTE remained significant after adjusting for potential confounders (OR 2.92; 95% CI 2.62-3.25). We observed a higher incidence of VTE among specific subtypes of hematologic malignancy and patients with prior VTE (OR 6.64; 95% CI 5.42-8.14). Admission more than 1 year after diagnosis of hematologic malignancy (OR 0.64; 95% CI 0.56-0.74) and platelet count ≤ 50 × 109/L at the time of hospitalization (OR 0.63; 95% CI 0.48-0.84) were associated with a lower incidence of VTE.

CONCLUSION

Among patients with hematologic malignancy, critical illness and certain baseline characteristics were associated with a higher incidence of VTE.

Bleeding risk assessment in immune thrombocytopenia

The bleeding risk in immune thrombocytopenia (ITP) is related not only to low platelet count but also to the presence of platelet dysfunction. However, diagnosing a concomitant platelet dysfunction is challenging as most of the available platelet function assays (PFAs) require a platelet count of greater than 100,000/μL. Sonoclot coagulation and platelet function analyzer works on the principle of viscoelastometry, and results remain unaffected by the platelet counts. To assess the platelet function in adult acute ITP patients with the help of sonoclot coagulation and platelet function analyzer and correlate it with the risk of bleeding. Newly diagnosed acute ITP patients with a platelet count less than 20,000/μL were divided into two groups based on WHO bleeding grade: ITP non-bleeder (ITP-NB) group (WHO bleeding grade ≤1) and ITP bleeder (ITP-B) group (WHO bleeding grade ≥2). Platelet function was assessed by sonoclot in both groups. The patients without significant bleeding (ITP-NB) were followed up monthly for six months with the assessment of platelet function during each contact. Eighty patients (30 ITP-B and 50 ITP-NB) were prospectively included in this study. The median age of patients in the two groups was 37 years and 30 years, respectively. The female-to-male ratio was 4:1 and 1:1 in ITP-B and ITP-NB groups. The median platelet count in ITP-B and ITP-NB was 12000/μL (range 1000-19000/μL) and 8000/μL (range 1000-19000/μL), respectively. Mean platelet functions by sonoclot in both groups were lower than the normal cut-off (>1.6). However, the mean platelet function in the ITP-B group (0.2 + 0.17) was significantly lower than the ITP-NB group (1.2 ± 0.52) (p = 0.01). During the follow-up period of 6 months, patients in ITP-NB with a normal platelet function (>1.6) on sonoclot had lesser episodes (one episode) of clinically significant bleeding than patients with a low platelet function (4 episodes). Patients with acute severe thrombocytopenia and bleeding phenotype have a greater abnormality on platelet function by sonoclot than patients with non-bleeding phenotype. This information may help in taking therapeutic decisions in patients with acute ITP.

Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation

Diffuse alveolar hemorrhage (DAH) is a morbid syndrome that occurs after autologous and allogeneic hematopoietic cell transplantation in children and adults. DAH manifests most often in the first few weeks following transplantation. It presents with pneumonia-like symptoms and acute respiratory failure, often requiring high levels of oxygen supplementation or mechanical ventilatory support. Hemoptysis is variably present. Chest radiographs typically feature widespread alveolar filling, sometimes with peripheral sparing and pleural effusions. The diagnosis is suspected when serial bronchoalveolar lavages return increasingly bloody fluid. DAH is differentiated from infectious causes of alveolar hemorrhage when extensive microbiological testing reveals no pulmonary pathogens. The cause is poorly understood, though preclinical and clinical studies implicate pretransplant conditioning regimens, particularly those using high doses of total-body-irradiation, acute graft-versus-host disease (GVHD), medications used to prevent GVHD, and other factors. Treatment consists of supportive care, systemic corticosteroids, platelet transfusions, and sometimes includes antifibrinolytic drugs and topical procoagulant factors. Therapeutic blockade of tumor necrosis factor-α showed promise in observational studies, but its benefit for DAH remains uncertain after small clinical trials. Even with these treatments, mortality from progression and relapse is high. Future investigational therapies could target the vascular endothelial cell biology theorized to contribute to alveolar bleeding and pathways that contribute to susceptibility, inflammation, cellular resilience, and tissue repair. This review will help clinicians navigate through the limited evidence to diagnose and treat DAH, counsel patients and families, and plan for future research.

Consensus report on flow cytometry for platelet function testing in thrombocytopenic patients: communication from the SSC of the ISTH

BACKGROUND

Platelet count alone does not reliably predict bleeding risk, suggesting platelet function is important to monitor in patients with thrombocytopenia. There is still an unmet need for improved platelet function diagnostics in patients with low platelet count in many clinical situations. Flow cytometry is a promising tool allowing reliable platelet function study in this setting.

OBJECTIVES

The goal of this joint project between the International Society on Thrombosis and Haemostasis (ISTH) Scientific Standardization Committee (SSC) Subcommittees on Platelet Physiology and Platelet Immunology is to provide expert consensus guidance on the use of flow cytometry for the evaluation of platelet function, particularly activation, in patients with low platelet counts.

METHODS

A literature review was performed to identify relevant questions and areas of interest. An electronic expression of interest form was thereafter announced on the ISTH webpage, followed by a survey encompassing 37 issues regarding preanalytical, analytical, postanalytical, and performance aspects. Areas of disagreement or uncertainty were identified and formed the basis for 2 focus group discussions.

RESULTS

Consensus recommendations relative to patient sample collection, preanalytical variables, sample type, platelet-count cutoff, any potential specific modification of the standard flow cytometry protocol, and results expression and reporting are proposed based on the current practices of experts in the field as well as on literature review.

CONCLUSION

The proposed consensus recommendations would allow standardization of protocols in upcoming clinical studies. The clinical utility of platelet function testing using flow cytometry to predict bleeding risk still needs rigorous multicenter outcome studies in patients with thrombocytopenia.

Platelet transfusion in critical care: A new method to analyze transfusion practice based on decision time intervals

BACKGROUND

While prior studies of platelet transfusion in critical care have focused on transfusions given, proper analysis of clinical transfusion practice also requires consideration of the decision not to transfuse.

STUDY DESIGN AND METHODS

We introduce a new method to assess transfusion practice based on decision time intervals (DTIs). Each patient's intensive care (ICU) stay was segmented into a series of DTIs defined by a time interval following results of a complete blood count (CBC). We studied the presence of 17 clinical factors during each DTI whether transfusion was given or not. We used a generalized linear mixed model to assess the most influential clinical triggers for platelet transfusion.

RESULTS

Among 6125 ICU patients treated between October 2016 and October 2021, we analyzed 39,745 DTIs among patients (n = 2921) who had at least one DTI with thrombocytopenia (≤150,000/μL). We found no association between platelet count and two markers of bleeding: drop in hemoglobin and chest tube drainage. We found that the majority of DTIs were associated with no platelet transfusion regardless of the platelet count; that no specific platelet value triggered transfusion; but rather that multiple clinical factors in conjunction with the platelet count influenced the decision to transfuse.

DISCUSSION

DTI analysis represents a new method to assess transfusion practice that considers both transfusions given and not given, and that analyzes clinical circumstances present when decisions regarding transfusion are made. The method is easily adapted to blood components other than platelet transfusions and is easily extended to other ICU and other hospital settings.

The Coagulopathy of Acute Promyelocytic Leukemia: An Updated Review of Pathophysiology, Risk Stratification, and Clinical Management

Acute promyelocytic leukemia (APL) has a well-established mechanism and a long-term prognosis that exceeds that of any other acute leukemia. These improving outcomes are due, in part, to all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), two targeted and highly active agents in this disease. However, there remains a considerable morbidity and mortality risk in APL secondary to clinically significant hemorrhagic and/or thrombotic events. Prevention and treatment of these coagulopathic complications remain significant impediments to further progress in optimizing outcomes for patients with APL. Moreover, the relative rarity of APL hinders adequately powered randomized controlled trials for evaluating APL coagulopathy management strategies. This review draws from peer-reviewed works falling between initial descriptions of APL in 1957 and work published prior to January 2023 and provides an updated overview of the pathophysiology of hemorrhagic and thrombotic complications in APL, outlines risk stratification parameters, and compiles current clinical best practices. An improved understanding of the pathophysiologic mechanisms driving hemorrhage and thrombosis along with the completion of well-designed trials of management strategies will assist clinicians in developing interventions that mitigate these devastating complications in an otherwise largely curable disease.

Reduced plasma coagulation factor XIII in patients with acute leukemia in remission during consolidation chemotherapy cycles

Acute leukemia (AL) is a malignancy from hematologic stem cells (HSC). Consolidation with intensive chemotherapy is required after induced remission and repeatedly causes treatment-related bleeding that is usually attributed to chemotherapy-induced thrombocytopenia (CIT). However, our previous study demonstrated that severe deficiency of plasma coagulation factor XIII (pFXIII) also participated in the bleeding of CIT in AL. However, the relationship between pFXIII deficiency and consolidation chemotherapy was unknown. Here, we observed the concentration of pFXIII in patients with AL before and after consolidation chemotherapy and reevaluated the correlation to bleeding in myelosuppression. Thus, we found that the concentration of pFXIII before chemotherapy in all patients was markedly lower than in the control data and was further decreased by chemotherapy, related to bleeding in myelosuppression. These findings indicated that chemotherapy-induced pFXIII deficiency should be of concern and explored in depth.

First description of atrial fibrillation and congenital thrombotic thrombocytopenic purpura treated by left atrial appendage occlusion

Given an increased risk of both thrombosis and bleeding, thrombotic thrombocytopenic purpura (TTP) presents a unique challenge when anticoagulation is required for comorbid disease, particularly in the setting of major bleeding events. We present for the first time a patient with TTP and atrial fibrillation, presenting with recurrent stroke, but unable to tolerate anticoagulation due to prior intra-cerebral hemorrhage. To address both issues concomitantly, we describe the successful application of a novel management approach to facilitate left atrial appendage occlusion, there by offering a non-pharmacologic means of stroke prevention without added bleeding risk.

Primary hemostasis dysfunctions and bleeding risk in newly diagnosed acute myeloid leukemia

BACKGROUND

Acute myeloid leukaemia carries the risk of complications associated with dysfunctions in haemostasis system. The purpose of this study was to investigate the factors associated with the risk of bleeding in patients with newly diagnosed acute myeloid leukaemia (AML).

METHODS

This study involved the methods of immunoenzymatic analysis and classical coagulation studies. The number of biochemical parameters important for establishing coagulative dysfunction in acute myeloid leukaemia was determined, the main ones being the level of von Willebrand factor, the Ristocetin-cofactor activity of von Willebrand factor and factor VIII activity, prothrombin time, platelet count, and fibrinogen concentration.

RESULTS

According to the results of the present study, the reduced activity of von Willebrand factor in patients with AML was associated with severe bleeding. The authors observed an increase in the number of platelets count in patients with AML who experienced haemorrhages compared to patients with no bleeding signs. The study also established an increase in the concentration of fibrinogen in cancer patients, compared to the control sample. Symptoms and quantitative indicators for diagnosing the severity of haemorrhagic syndrome were grouped. The authors considered the advantages and disadvantages of many therapeutic preparations and focussed on specific markers of activated haemorrhage-predicting platelets.

CONCLUSION

Further studies concern the search for effective markers and therapeutic approaches to minimize haemorrhagic syndrome. The results were statistically processed using the functions ANOVA, t test, CORREL, determination of the value of reliability, and mean square deviation.

Extracorporeal membrane oxygenation in adults receiving haematopoietic cell transplantation: an international expert statement

Combined advances in haematopoietic cell transplantation (HCT) and intensive care management have improved the survival of patients with haematological malignancies admitted to the intensive care unit. In cases of refractory respiratory failure or refractory cardiac failure, these advances have led to a renewed interest in advanced life support therapies, such as extracorporeal membrane oxygenation (ECMO), previously considered inappropriate for these patients due to their poor prognosis. Given the scarcity of evidence-based guidelines on the use of ECMO in patients receiving HCT and the need to provide equitable and sustainable access to ECMO, the European Society of Intensive Care Medicine, the Extracorporeal Life Support Organization, and the International ECMO Network aimed to develop an expert consensus statement on the use of ECMO in adult patients receiving HCT. A steering committee with expertise in ECMO and HCT searched the literature for relevant articles on ECMO, HCT, and immune effector cell therapy, and developed opinion statements through discussions following a Quaker-based consensus approach. An international panel of experts was convened to vote on these expert opinion statements following the Research and Development/University of California, Los Angeles Appropriateness Method. The Appraisal of Guidelines for Research and Evaluation statement was followed to prepare this Position Paper. 36 statements were drafted by the steering committee, 33 of which reached strong agreement after the first voting round. The remaining three statements were discussed by all members of the steering committee and expert panel, and rephrased before an additional round of voting. At the conclusion of the process, 33 statements received strong agreement and three weak agreement. This Position Paper could help to guide intensivists and haematologists during the difficult decision-making process regarding ECMO candidacy in adult patients receiving HCT. The statements could also serve as a basis for future research focused on ECMO selection criteria and bedside management.

The impact of thrombocytopenia on variceal bleeding in cirrhotic patients with transjugular intrahepatic portosystemic shunt

Thrombocytopenia is the most frequent haematologic disorder in patients with cirrhosis, and it is perceived as a contributory factor for bleeding events. Cirrhosis patients with portal hypertension (PHT) is often accompanied with mild to moderate thrombocytopenia when they treated with transjugular intrahepatic portosystemic shunt (TIPS). To address whether the risk of variceal hemorrhage after TIPS varies with different platelet count in patients with normal platelet count and thrombocytopenia, we conducted the retrospective controlled study to evaluate the association of platelet count with the risk of variceal bleeding after TIPS. 304 patients were selected to the study. Propensity score matching was performed to adjust for potential selection bias. 63 patients from each group could be paired. Cox proportional hazards models were used to evaluate the association between platelet and variceal bleeding after TIPS. Platelet counts of two groups are 185.0 ± 98.7 × 10⁹/L (normal platelet count) and 70.6 ± 39.3 × 10⁹/L (thrombocytopenia) respectively. The bleeding rates of two groups in overall cohort are 10.9% (normal platelet count) and 12.9% (thrombocytopenia). After matched, the bleeding rates of two groups are 11.1% (normal platelet count) and 14.3% (thrombocytopenia) There was no statistically significant difference in bleeding rates between the two groups, either in the whole cohort (P = 0.671) or in the matched cohort (P = 0.593). Platelet count was not associated with bleeding events after TIPS (hazard ratio (HR) 95% confidence interval: 0.986-1.005, P = 0.397 in normal platelet count and 95% confidence interval: 0.968-1.020, P = 0.648 in thrombocytopenia). Thrombocytopenia in patients with cirrhosis was not associated with the risk of variceal bleeding episodes post-TIPS. Thrombocytopenia should not be viewed as an absolute contraindication for TIPS.

Impact of anemia and thrombocytopenia on postpartum hemorrhage risk among women with term singleton pregnancy

Both thrombocytopenia (platelet count < 150 × 10³/µL) and anemia have been associated with postpartum hemorrhage (PPH). However, the impact of thrombocytopenia on PPH risk among women with mild and severe anemia is unknown. We sought to evaluate the association between thrombocytopenia and anemia in increasing risk of PPH. We performed a secondary analysis of a retrospective cohort of pregnant women from 19 hospitals across the United States from 2016 to 2021. Women who had a term singleton pregnancy and hematocrit (Hct) ≤ 33% at delivery were included in the study. The primary outcome was PPH (defined as blood loss ≥ 1000 mL or blood transfusion). We also analyzed the effect of severe anemia (Hct < 28%) on the association between PPH and thrombocytopenia. Chi-squared tests and Fisher's exact tests were used for categorical variables and an independent t-test was used for continuous variables. There were 20,808 women who met our inclusion criteria, of which 1793 (8.6%) had platelet count < 150 × 10³/µL. The prevalence of PPH was 6.4%. Compared with women with normal platelet count, those with thrombocytopenia had 1.3-fold higher odds of PPH [6.8% vs. 4.5%, adjusted OR 1.3 (1.1-1.7)]. Platelet count ≥ 150 × 10³/µL was associated with decreased odds of PPH among patients with hct between 28 and 33% and hct < 28%. In conclusion, anemic women with term singleton pregnancies who delivered with thrombocytopenia had a higher frequency of PPH. Normal platelet count at delivery was protective against PPH in the setting of anemia regardless of severity.

Aspirin use and bleeding events during thrombocytopenia after autologous stem-cell transplantation for multiple myeloma

Background

In patients with cardiovascular (CV) comorbidities that necessitate antiplatelet therapy (APT), its optimal management during chemotherapy-induced thrombocytopenia remains elusive, as the risk of bleeding has to be balanced against the risk of CV events. The purpose of this study was to assess the risk for bleeding with APT during thrombocytopenia in patients with multiple myeloma undergoing high-dose chemotherapy and subsequent autologous stem-cell transplantation (ASCT) with and without acetylsalicylic acid (ASA) as comedication.

Methods

We assessed patients who underwent ASCT at the Heidelberg University Hospital between 2011 and 2020 for bleeding events, management strategies for ASA intake during thrombocytopenia, transfusion requirements, and the occurrence of CV events.

Results

There were 57/1,113 patients who continued ASA until at least 1 day after ASCT; thus, a continuous platelet inhibition during thrombocytopenia was assumed. Most of the patients (41/57) continued ASA until they had a platelet count of 20-50/nl. This range reflects the kinetics of thrombocytopenia and nondaily measurements of platelets during ASCT. A tendency toward a higher risk for bleeding events in the ASA group was demonstrated (1.9% (control group) vs. 5.3% (ASA), p = 0.082). The risk factors for bleeding in multivariate analysis were the duration of thrombocytopenia < 50/nl, a history of gastrointestinal bleeding, and diarrhea. The factors predicting the duration of thrombocytopenia were age >60 years, a hematopoietic stem-cell transplantation comorbidity index ≥3, and an impaired bone marrow reserve at admission. CV events occurred in three patients; none of them took ASA or had an indication for APT.

Conclusions

The intake of ASA until thrombocytopenia with a platelet count of 20-50/nl appears safe, although an elevated risk cannot be excluded. If ASA is indicated for the secondary prevention of CV events, the evaluation of risk factors for bleeding and a prolonged time of thrombocytopenia before conditioning is crucial to adapt the strategy for ASA intake during thrombocytopenia.

How I use platelet transfusions

Platelet transfusions are commonly administered for the prevention or treatment of bleeding in patients with acquired thrombocytopenia across a range of clinical contexts. Recent data, including randomized trials, have highlighted uncertainties in the risk-benefit balance of this therapy, which is the subject of this review. Hemovigilance systems report that platelets are the most frequently implicated component in transfusion reactions. There is considerable variation in platelet count increment after platelet transfusion, and limited evidence of efficacy for clinical outcomes, including prevention of bleeding. Bleeding events commonly occur despite the different policies for platelet transfusion prophylaxis. The underlying mechanisms of harm reported in randomized trials may be related to the role of platelets beyond hemostasis, including mediating inflammation. Research supports the implementation of a restrictive platelet transfusion policy. Research is needed to better understand the impact of platelet donation characteristics on outcomes, and to determine the optimal thresholds for platelet transfusion before invasive procedures or major surgery (eg, laparotomy). Platelet transfusion policies should move toward a risk-adapted approach that does not focus solely on platelet count.

Novel blood derived hemostatic agents for bleeding therapy and prophylaxis

PURPOSE OF REVIEW

Hemorrhage is a major cause of preventable death in trauma and cancer. Trauma induced coagulopathy and cancer-associated endotheliopathy remain major therapeutic challenges. Early, aggressive administration of blood-derived products with hypothesized increased clotting potency has been proposed. A series of early- and late-phase clinical trials testing the safety and/or efficacy of lyophilized plasma and new forms of platelet products in humans have provided light on the future of alternative blood component therapies. This review intends to contextualize and provide a critical review of the information provided by these trials.

RECENT FINDINGS

The beneficial effect of existing freeze-dried plasma products may not be as high as initially anticipated when tested in randomized, multicenter clinical trials. A next-generation freeze dried plasma product has shown safety in an early phase clinical trial and other freeze-dried plasma and spray-dried plasma with promising preclinical profiles are embarking in first-in-human trials. New platelet additive solutions and forms of cryopreservation or lyophilization of platelets with long-term shelf-life have demonstrated feasibility and logistical advantages.

SUMMARY

Recent trials have confirmed logistical advantages of modified plasma and platelet products in the treatment or prophylaxis of bleeding. However, their postulated increased potency profile remains unconfirmed.

Impact of Thrombocytopenia on Preoperative Hematoma Expansion for Acute Traumatic Subdural Hematoma

BACKGROUND

Acute subdural hematoma is a neurosurgical emergency. Thrombocytopenia poses a management challenge for these patients. We aimed to determine the impact of thrombocytopenia on preoperative hemorrhage expansion and postoperative outcomes.

METHODS

This retrospective study evaluated patients presenting at our institution with acute subdural hematoma between 2009 and 2019. Patients who underwent surgery, had thrombocytopenia (platelets <150,000/μL), and had multiple preoperative computed tomography scans were included. Case control 1:1 matching was performed to generate a matched cohort with no thrombocytopenia. Univariate analyses were conducted to determine changes in subdural thickness and midline shift, postoperative Glasgow Coma Scale score, mortality, length of stay, and readmission rates.

RESULTS

We identified 19 patients with both thrombocytopenia and multiple preoperative computed tomography scans. Median platelet count was 112,000/μL (Q1 69,000, Q3 127,000). Comparing the thrombocytopenia cohort with the control group, there was a statistically significant difference in change in subdural thickness (median 5 mm [Q1 2, Q3 7.4] vs. 0 mm [Q1 0, Q3 1.5]; P = 0.001) and change in midline shift (median 3 mm [Q1 0, Q3 9.5] vs. median 0.5 mm [Q1 0, Q3 1.5]; P = 0.018). The thrombocytopenia cohort had higher in-hospital mortality (10 [52.6%] vs. 2 [10.5%]; P = 0.003). No significant differences were found in postoperative Glasgow Coma Scale score, length of stay, number of readmissions, and number of reoperations.

CONCLUSIONS

Thrombocytopenia is significantly associated with expansion of hematoma preoperatively in patients with acute subdural hematoma. While the benefit of early platelet correction cannot be determined from this study, patients who present with thrombocytopenia will benefit from close monitoring, a low threshold to obtain repeat imaging, and anticipating early surgical evacuation after platelet optimization.

Anticoagulation in thrombocytopenic patients - Time to rethink?

One of the difficult clinical situations in the anticoagulation era is how to give these medications to patients with significantly reduced platelet counts. The concern is the heightened bleeding risk, and the current practice is to apply a certain platelet count threshold below which the use of anticoagulant is deemed unsafe. However, this is not an evidence-based approach especially because the thresholds arose from studies in patients with acute leukemia. In this forum article, we discuss the bleeding risk estimation in thrombocytopenic patients when the decreased counts may not be related to marrow underproduction and aim to identify possible markers which can help in this risk estimation beyond platelet counts. We exhort future studies to include a combination of these markers, which may then guide us to administer safe anticoagulation in patients with severe thrombocytopenia.

Perioperative Blood Transfusion in Head and Neck Cancer Revisited

OBJECTIVE

To reevaluate the frequency of perioperative blood transfusion, transfusion triggers, and survival impact in patients with incident, surgically treated head and neck cancer (HNC) in restrictive transfusion regimens.

METHODS

Retrospective analysis of surgically treated patients with incident HNC with and without perioperative blood transfusion between 2008 and 2019 at the Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Innsbruck, according to the department's clinical Head and Neck Tumor Registry.

RESULTS

Of the 590 patients included, perioperative transfusions were administered in 6.3% (n = 37, transfusion group). Following multivariable logistic regression, likelihood of blood transfusions was increased in patients with poorer general health conditions (ASA score III/IV; OR 3.7; 95% CI 1.9-8.6; p = 0.002), hemoglobin <12.5 g/dL (OR 2.7; 95% CI 1.1-6.4; p = 0.03), longer duration of surgery (OR 1.006 per minute of surgery time; 95% CI 1.003-1.008; p < 0.001), and negative p16 status (OR 5.3; 95% CI = 1.1-25; p = 0.03). Based on 14 matching variables related to survival and perioperative blood transfusion, a control group of 37 matching patients without perioperative transfusion was identified. Using univariate analysis, overall survival in transfusion and control groups did not differ significantly (p = 0.25). After adjusting for four parameters with limited matching accuracy (Chi square p < 0.2) in Cox regression analysis, a transfusion related hazard ratio close to 1 (HR 0.92; 95% CI 0.34-2.51; p = 0.87) was observed.

CONCLUSION

Considering current restrictive transfusion regimens and general transfusion risks, the administration of blood products in HNC patients during the perioperative period is not associated with additional oncologic hazard.

LEVEL OF EVIDENCE

III Laryngoscope, 2022.

EHA Guidelines on Management of Antithrombotic Treatments in Thrombocytopenic Patients With Cancer

In cancer patients, thrombocytopenia can result from bone marrow infiltration or from anticancer medications and represents an important limitation for the use of antithrombotic treatments, including anticoagulant, antiplatelet, and fibrinolytic agents. These drugs are often required for prevention or treatment of cancer-associated thrombosis or for cardioembolic prevention in atrial fibrillation in an increasingly older cancer population. Data indicate that cancer remains an independent risk factor for thrombosis even in case of thrombocytopenia, since mild-to-moderate thrombocytopenia does not protect against arterial or venous thrombosis. In addition, cancer patients are at increased risk of antithrombotic drug-associated bleeding, further complicated by thrombocytopenia and acquired hemostatic defects. Furthermore, some anticancer treatments are associated with increased thrombotic risk and may generate interactions affecting the effectiveness or safety of antithrombotic drugs. In this complex scenario, the European Hematology Association in collaboration with the European Society of Cardiology has produced this scientific document to provide a clinical practice guideline to help clinicians in the management of patients with cancer and thrombocytopenia. The Guidelines focus on adult patients with active cancer and a clear indication for anticoagulation, single or dual antiplatelet therapy, their combination, or reperfusion therapy, who have concurrent thrombocytopenia because of either malignancy or anticancer medications. The level of evidence and the strength of the recommendations were discussed according to a Delphi procedure and graded according to the Oxford Centre for Evidence-Based Medicine.

Red Blood Cell Transfusions and Risk of Postoperative Venous Thromboembolism

INTRODUCTION

Postoperative venous thromboembolism (VTE) is a major risk for orthopaedic surgery and associated with notable morbidity and mortality. Knowing a patient's risk for VTE may help guide the choice of perioperative VTE prophylaxis. Recently, red blood cells (RBCs) have been implicated for their role in pathologic thrombosis. Therefore, we examine the association between perioperative RBC transfusion and postoperative VTE after orthopaedic surgery.

METHODS

A retrospective cohort study was done by conducting a secondary analysis of data obtained from the 2016 American College of Surgeons National Surgical Quality Improvement Program database. Our population consisted of 234,608 adults who underwent orthopaedic surgery. The exposure was whether patients received a perioperative RBC transfusion. The primary outcome was postoperative VTE within 30 days of surgery that warranted therapeutic intervention, which was subsequently split into symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE). Odds ratios (ORs) were estimated using a multivariate logistic regression model.

RESULTS

At baseline, 1,952 patients (0.83%) had postoperative VTE (DVT in 1,299 [0.55%], PE in 801 [0.34%], and both DVT and PE in 148 [0.06%]). Seven hundred ninety-five patients (0.3%) received preoperative RBC transfusions only, 11,587 patients (4.9%) received postoperative RBC transfusions only, and 848 patients (0.4%) received both preoperative and postoperative RBC transfusions. Postoperative RBC transfusion was associated with higher odds of VTE (adjusted OR [aOR], 1.47; 95% confidence interval [CI], 1.19-1.81), DVT (aOR, 1.40; 95% CI, 1.09-1.79), PE (aOR, 1.59; 95% CI, 1.14-2.22), and 30-day mortality (aOR, 1.21; 95% CI, 1.01-1.45) independent of various presumed risk factors. When creating subgroups within orthopaedics by Current Procedural Terminology codes, postoperative transfusions in spine (aOR, 2.03; 95% CI, 1.13-3.67) and trauma (aOR, 1.40; 95% CI, 1.06-1.86) were associated with higher odds of postoperative VTE.

CONCLUSION

Our results suggest that postoperative RBC transfusion may be associated with an increased risk of postoperative VTE, both symptomatic DVT and life-threatening PE, independent of confounders. Additional prospective validation in cohort studies is necessary to confirm these findings. In addition, careful perioperative planning for patients deemed to be at high risk of requiring blood transfusion may reduce these postoperative complications in orthopaedic patients.

LEVEL OF EVIDENCE

III.

Thromboprophylaxis with argatroban in critically ill patients with sepsis: a review

During sepsis, an initial prothrombotic shift takes place, in which coagulatory acute-phase proteins are increased, while anticoagulatory factors and platelet count decrease. Further on, the fibrinolytic system becomes impaired, which contributes to disease severity. At a later stage in sepsis, coagulation factors may become depleted, and sepsis patients may shift into a hypo-coagulable state with an increased bleeding risk. During the pro-coagulatory shift, critically ill patients have an increased thrombosis risk that ranges from developing micro-thromboses that impair organ function to life-threatening thromboembolic events. Here, thrombin plays a key role in coagulation as well as in inflammation. For thromboprophylaxis, low molecular weight heparins (LMWH) and unfractionated heparins (UFHs) are recommended. Nevertheless, there are conditions such as heparin resistance or heparin-induced thrombocytopenia (HIT), wherein heparin becomes ineffective or even puts the patient at an increased prothrombotic risk. In these cases, argatroban, a direct thrombin inhibitor (DTI), might be a potential alternative anticoagulatory strategy. Yet, caution is advised with regard to dosing of argatroban especially in sepsis. Therefore, the starting dose of argatroban is recommended to be low and should be titrated to the targeted anticoagulation level and be closely monitored in the further course of treatment. The authors of this review recommend using DTIs such as argatroban as an alternative anticoagulant in critically ill patients suffering from sepsis or COVID-19 with suspected or confirmed HIT, HIT-like conditions, impaired fibrinolysis, in patients on extracorporeal circuits and patients with heparin resistance, when closely monitored.

Prediction of life-threatening and disabling bleeding in patients with AML receiving intensive induction chemotherapy

Bleeding in patients with acute myeloid leukemia (AML) receiving intensive induction chemotherapy is multifactorial and contributes to early death. We sought to define the incidence and risk factors of grade 4 bleeding to support strategies for risk mitigation. Bleeding events were retrospectively assessed between day-14 and day +60 of induction treatment according to the World Health Organization (WHO) bleeding assessment scale, which includes grade 4 bleeding as fatal, life-threatening, retinal with visual impairment, or involving the central nervous system. Predictors were considered pretreatment or prior to grade 4 bleeding. Using multivariable competing-risk regression analysis with grade 4 bleeding as the primary outcome, we identified risk factors in the development cohort (n = 341), which were tested in an independent cohort (n = 143). Grade 4 bleeding occurred in 5.9% and 9.8% of patients in the development and validation cohort, respectively. Risk factors that were independently associated with grade 4 bleeding included baseline platelet count ≤40 × 109/L compared with >40 × 109/L, and baseline international normalized ratio of prothrombin time (PT-INR) >1.5 or 1.3 > 1.5 compared with ≤1.3. These variables were allocated points, which allowed for stratification of patients with low- and high-risk for grade 4 bleeding. Cumulative incidence of grade 4 bleeding at day+60 was significantly higher among patients with high- vs low-risk (development: 31 ± 7% vs 2 ± 1%; P < .001; validation: 25 ± 9% vs 7 ± 2%; P = .008). In both cohorts, high bleeding risk was associated with disseminated intravascular coagulation (DIC) and proliferative disease. We developed and validated a simple risk model for grade 4 bleeding, which enables the development of rational risk mitigation strategies to improve early mortality of intensive induction treatment.

EASL Clinical Practice Guidelines on prevention and management of bleeding and thrombosis in patients with cirrhosis

The prevention and management of bleeding and thrombosis in patients with cirrhosis poses several difficult clinical questions. These Clinical Practice Guidelines have been developed to provide practical guidance on debated topics, including current views on haemostasis in liver disease, controversy regarding the need to correct thrombocytopenia and abnormalities in the coagulation system in patients undergoing invasive procedures, and the need for thromboprophylaxis in hospitalised patients with haemostatic abnormalities. Multiple recommendations in this document are based on interventions that the panel feels are not useful, even though widely applied in clinical practice.

There and Back Again: The Once and Current Developments in Donor-Derived Platelet Products for Products for Hemostatic Therapy

Over 100 years ago, Duke transfused whole blood to a thrombocytopenic patient to raise the platelet count and prevent bleeding. Since then, platelet transfusions have undergone numerous modifications from whole blood-derived platelet-rich plasma to apheresis-derived platelet concentrates. Similarly, the storage time and temperature have changed. The mandate to store platelets for a maximum of 5-7 days at room temperature has been challenged by recent clinical trial data, ongoing difficulties with transfusion-transmitted infections, and recurring periods of shortages, further exacerbated by the COVID-19 pandemic. Alternative platelet storage approaches are as old as the first platelet transfusions. Cold-stored platelets may offer increased storage times (days) and improved hemostatic potential at the expense of reduced circulation time. Frozen (cryopreserved) platelets extend the storage time to years but require storage at -80 °C and thawing before transfusion. Lyophilized platelets can be powder-stored for years at room temperature and reconstituted within minutes in sterile water but are probably the least explored alternative platelet product to date. Finally, whole blood offers the hemostatic spectrum of all blood components but has challenges, such as ABO incompatibility. While we know more than ever before about the in vitro properties of these products, clinical trial data on these products are accumulating. The purpose of this review is to summarize the findings of recent preclinical and clinical studies on alternative, donor-derived platelet products.

Platelet Transfusion in Patients With Sepsis and Thrombocytopenia: A Propensity Score-Matched Analysis Using a Large ICU Database

Purpose

Sepsis with thrombocytopenia is highly prevalent in critically ill intensive care unit (ICU) patients and is associated with adverse outcomes. Platelet transfusion is the primary treatment of choice. However, evidence for the beneficial effects of platelet transfusion in patients with sepsis and thrombocytopenia is scarce and low in quality. This study aimed to evaluate the association between platelet transfusion and mortality among ICU patients with sepsis and thrombocytopenia.

Patients and Methods

Using the Medical Information Mart for Intensive Care III database (v. 1.4), the outcomes of sepsis patients with platelet counts of ≤ 150,000/μL were compared between those who did and did not receive platelet transfusion. The primary outcomes were 28- and 90-day all-cause mortalities. The secondary outcomes were red blood cell (RBC) transfusion, ICU-free days, and hospital-free days. Propensity score matching was employed to assemble a cohort of patients with similar baseline characteristics.

Results

Among 7,765 eligible patients, 677 received platelet transfusion and were matched with 677 patients who did not receive platelet transfusion according to propensity scores. Platelet transfusion, as compared with no platelet transfusion, was associated with an increased risk of 28-day all-cause mortality [36.9 vs. 30.4%, odds ratio (OR), 1.21; 95% confidence interval (CI), 1.01–1.46; p = 0.039], increased risk of 90-day all-cause mortality (50.8 vs. 44.6%, OR, 1.13; 95% CI, 1.00–1.31; p = 0.048), fewer mean (standard deviation) 28-day ICU-free days (15.88 ± 8.97 vs. 18.64 ± 8.33 days, p < 0.001), and fewer hospital-free days (10.29 ± 8.49 vs. 11.43 ± 8.85 days, p = 0.017). The rate of RBC transfusion was not significantly different between the platelet transfusion and non-transfusion groups (p = 0.149). The results were maintained across several subgroup and sensitivity analyses.

Conclusion

In this study, platelet transfusion was associated with higher 28- and 90-day all-cause mortalities. These results suggest the potential hazards of platelet transfusion in ICU patients with sepsis and thrombocytopenia.

What Laboratory Tests and Physiologic Triggers Should Guide the Decision to Administer a Platelet or Plasma Transfusion in Critically Ill Children and What Product Attributes Are Optimal to Guide Specific Product Selection? From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present consensus statements and supporting literature for plasma and platelet product variables and related laboratory testing for transfusions in general critically ill children from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill pediatric patients at risk of bleeding and receiving plasma and/or platelet transfusions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 10 experts developed evidence-based and, when evidence was insufficient, expert-based statements for laboratory testing and blood product attributes for platelet and plasma transfusions. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative - Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed five expert consensus statements and two recommendations in answer to two questions: what laboratory tests and physiologic triggers should guide the decision to administer a platelet or plasma transfusion in critically ill children; and what product attributes are optimal to guide specific product selection?

CONCLUSIONS

The Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding program provides some guidance and expert consensus for the laboratory and blood product attributes used for decision-making for plasma and platelet transfusions in critically ill pediatric patients.

Plasma and Platelet Transfusion Strategies in Critically Ill Children With Malignancy, Acute Liver Failure and/or Liver Transplantation, or Sepsis: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children with malignancy, acute liver disease and/or following liver transplantation, and sepsis and/or disseminated intravascular coagulation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children with malignancy, acute liver disease and/or following liver transplantation, and sepsis and/or disseminated intravascular coagulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 13 experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children with malignancy, acute liver disease and/or following liver transplantation, and sepsis and/or disseminated intravascular coagulation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 12 expert consensus statements.

CONCLUSIONS

In the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding program, the current absence of evidence for use of plasma and/or platelet transfusion in critically ill children with malignancy, acute liver disease and/or following liver transplantation, and sepsis means that only expert consensus statements are possible for these areas of practice.

Preoperative platelet transfusions: A retrospective review of pediatric patients with thrombocytopenia, 2011-2016

BACKGROUND

Thrombocytopenia is a common perioperative clinical problem and preoperative platelet transfusion prior to surgery is standard practice. Recent platelet trials and literature reviews have found no association between platelet count and bleeding incidence except when platelet count is extremely low. Our aim was to evaluate the bleeding risk and the overall platelet transfusion management among pediatric patients with severe thrombocytopenia based on whether they were preoperatively transfused versus transfused at time of incision.

METHODS

This is a retrospective analysis of pediatric patients with a platelet count ≤50 × 10⁹/L in the 12 h prior to surgery at a single tertiary pediatric hospital from 2011 to 2016. Eligible patients were ≤21 years old. Patients with necrotizing enterocolitis and neonates were excluded. The primary outcome was postoperative bleeding complications. Additional outcomes were preoperative platelet change and weight adjusted transfusion volumes.

RESULTS

A total of 37 patients were included in this analysis of which 29 (78%) received preoperative platelet transfusions within 12 h prior to surgery. No postoperative bleeding complications occurred 30 days after operation, regardless of preoperative transfusion status. There was no significant difference in platelet change by preoperative transfusion status and preoperative transfusion volume was a poor predictor of change in preoperative platelet count (crude: r²=0.19, age/gender adjusted: r²=0.48).

CONCLUSION

Patients transfused at time of surgical procedure did not have an increased risk of bleeding over those preoperatively transfused. This finding is in agreement with previous studies in adult populations, supporting the safety of deferring platelet transfusions until the time of incision for thrombocytopenic pediatric surgical patients.

LEVEL OF EVIDENCE

III.

Current challenges in platelet transfusion

The supply of platelets for transfusion is a logistical challenge due to the physiology of platelets and current measures of transfusion performance dictating storage at 22°C and a short product shelf-life (<7 days). Demand for platelets has increased in recent years and changes in the demographics of the population may enhance this further. Many studies have been conducted to understand what the optimal dose and trigger for transfusion should be, mainly in hematology patients who are the largest cohort that receive platelets, mostly to prevent bleeding. Emerging data suggests that for bleeding patients, where immediate hemostasis is a key consideration, the current standard product may not be optimal. Alternative platelet preparation methods/storage options that may improve the hemostatic properties of platelets are under active development. In parallel with research into alternative platelet products that might enhance hemostasis, better measures for assessing bleeding risk and platelet efficacy are needed.

Iron and platelets: A subtle, under-recognized relationship

The role of iron in the formation and functioning of erythrocytes, and to a lesser degree of white blood cells, is well established, but the relationship between iron and platelets is less documented. Physiologically, iron plays an important role in hematopoiesis, including thrombopoiesis; iron levels direct, together with genetic factors, the lineage commitment of megakaryocytic/erythroid progenitors toward either megakaryocyte or erythroid progenitors. Megakaryocytic iron contributes to cellular machinery, especially energy production in platelet mitochondria. Thrombocytosis, possibly favoring vascular thrombosis, is a classical feature observed with abnormally low total body iron stores (mainly due to blood losses or decreased duodenal iron intake), but thrombocytopenia can also occur in severe iron deficiency anemia. Iron sequestration, as seen in inflammatory conditions, can be associated with early thrombocytopenia due to platelet consumption and followed by reactive replenishment of the platelet pool with possibility of thrombocytosis. Iron overload of genetic origin (hemochromatosis), despite expected mitochondrial damage related to ferroptosis, has not been reported to cause thrombocytopenia (except in case of high degree of hepatic fibrosis), and iron-related alteration of platelet function is still a matter of debate. In acquired iron overload (of transfusional and/or dyserythropoiesis origin), quantitative or qualitative platelet changes are difficult to attribute to iron alone due to the interference of the underlying hematological conditions; likewise, hematological improvement, including increased blood platelet counts, observed under iron oral chelation is likely to reflect mechanisms other than the sole beneficial impact of iron depletion.

Surgical management of unilateral oophorectomy for ovarian tissue cryopreservation in high-risk children and adolescents with varied backgrounds

PURPOSE

Fertility preservation (FP) for children is still challenging due to an information gap. In particular, there is little information about the surgical aspects of ovarian tissue cryopreservation (OTC) for children. In the present study, the appropriateness of preoperative management and the criteria of our cases were investigated with the aim of establishing a safe OTC procedure.

METHODS

A total of 25 girls who underwent OTC from November 2015 through May 2020 were retrospectively analyzed with IRB approval.

RESULTS

The median age of the patients was 13 (1-17) years. The medical indications were varied (e.g., leukemia, lymphoma, brain tumor), and included rare diseases. Seventeen cases (68%) underwent OTC during chemotherapy or radiotherapy, and 21 (84%) had comorbidities. All cases underwent ovarian tissue retrieval (OTR) with laparoscopy, and the median operating time was 64 (36-97) min, with little bleeding. Although two had complications, all patients started treatment on schedule. The median WBC and CRP increases a day after OTR were 0 (- 4400 to + 5200)/µl and 0.21 (- 0.2 to 0.87) mg/dl, respectively, with no complications.

CONCLUSION

As long as the preoperative criteria are met, OTC could be possible even for children with a severe blood condition. In such cases, the degrees of the WBC and CRP elevations are useful to assess surgical infection.

Platelet enhancement by Carica papaya L. leaf fractions in cyclophosphamide induced thrombocytopenic rats is due to elevated expression of CD110 receptor on megakaryocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Carica papaya leaf juice/decoction has been in use in folk medicine in Srilanka, Malaysia and in few parts of India for enhancing the platelet counts in dengue. In Siddha medicine, a traditional form of medicine in India, papaya leaf juice has been used for increasing the platelet counts. Papaya leaf has been reported to enhance blood volume in ancient Ayurveda books in India. Carica papaya leaf is well known for its platelet enhancement activity. Although many preclinical and clinical studies have demonstrated the ability of papaya leaf juice for platelet enhancement, but the underlying mechanisms are still unclear.

AIM OF THE STUDY

The study is aimed at identifying the key ingredients of papaya leaf extract and elucidate the mechanism (s) of action of the identified potent component in mitigating thrombocytopenia (Thp).

MATERIALS AND METHODS

C. papaya leaf juice was subjected for sequential fractionation to identify the anti-thrombocytopenic phytochemicals. In vivo, stable thrombocytopenia was induced by subcutaneous injection of 70 mg/kg cyclophosphamide (Cyp). After induction, rats were treated with 200 and 400 mg/kg body weight papaya leaf juice and with identified fractions for 14 days. Serum thrombopoietin level was estimated using ELISA. CD110/cMpl, a receptor for thrombopoietin on platelets was measured by western blotting.

RESULTS

Administration of cyclophosphamide for 6 days induced thrombocytopenia (210.4 ± 14.2 × 103 cells/μL) in rats. Treating thrombocytopenic rats with papaya leaf juice and butanol fraction for 14 days significantly increased the platelet count to 1073.50 ± 29.6 and 1189.80 ± 36.5 × 103 cells/μL, respectively. C.papaya extracts normalized the elevated bleeding and clotting time and decreased oxidative markers by increasing endogenous antioxidants. A marginal increase in the serum thrombopoietin (TPO) level was observed in Cyp treated group compared to normal and treatment groups. Low expression of CD110/cMpl receptor found in Cyp treated group was enhanced by C. papaya extracts (CPJ) and CPJ-BT. Furthermore, examination of the morphology of bone marrow megakaryocytes, histopathology of liver and kidneys revealed the ability of CPJ and fractions in mitigating Cyp-induced thrombocytopenia in rats.

CONCLUSION

C. papaya leaf juice enhances the platelet count in chemotherapy-induced thrombocytopenia by increasing the expression of CD110 receptor on the megakaryocytes. Hence, activating CD110 receptor might be a viable strategy to increase the platelet production in individuals suffering from thrombocytopenia.

2020 Asian Pacific Society of Cardiology Consensus Recommendations on Antithrombotic Management for High-risk Chronic Coronary Syndrome

The unique characteristics of patients with chronic coronary syndrome (CCS) in the Asia-Pacific region, heterogeneous approaches because of differences in accesses and resources and low number of patients from the Asia-Pacific region in pivotal studies, mean that international guidelines cannot be routinely applied to these populations. The Asian Pacific Society of Cardiology developed these consensus recommendations to summarise current evidence on the management of CCS and provide recommendations to assist clinicians treat patients from the region. The consensus recommendations were developed by an expert consensus panel who reviewed and appraised the available literature, with focus on data from patients in Asia-Pacific. Consensus statements were developed then put to an online vote. The resulting recommendations provide guidance on the assessment and management of bleeding and ischaemic risks in Asian CCS patients. Furthermore, the selection of long-term antithrombotic therapy is discussed, including the role of single antiplatelet therapy, dual antiplatelet therapy and dual pathway inhibition therapy.

Anemia-Induced Bleeding in Patients with Platelet Disorders

Anemia is not only a consequence of bleeding, but also a modifiable risk factor for bleeding in patients with thrombocytopenia or platelet function defects. In this review we outline the mechanism of anemia-induced bleeding in patients with platelet disorders, which involves a disturbance in normal red blood cell (RBC) rheology and reduced platelet margination to the endothelial surface due to a decrease in RBC mass, leading to impaired primary hemostasis and bleeding. Biologically, anemia reduces the mass of RBCs in the central column of flowing blood through a vessel resulting in fewer platelets coming into contact with the endothelial surface at the periphery of the flowing blood column. Thus, anemia results in impaired primary hemostasis. Von Willebrand factor (vWF) is another component of primary hemostasis and vWF deficiency, especially a deficiency of the highest vWF multimers, can also manifest with bleeding when concomitant anemia occurs. Clinically, patients at greatest risk for anemia-induced bleeding include patients with hematological malignancies in whom anemia and thrombocytopenia occur as a result of the underlying disease or the myelotoxic effects of treatment; patients with renal insufficiency with uremic thrombocytopathy and hypoproliferative anemia; and patients with inherited or acquired bleeding disorders affecting primary hemostasis (eg, Bernard-Soulier syndrome, von Willebrand disease) with chronic blood loss and iron deficiency anemia. Underlying abnormalities of any components of primary hemostasis plus concomitant anemia may result in major bleeding disorders; therefore, correction of remediable abnormalities-most notably, correction of the anemia- would be expected to have important clinical benefit. In this review we discuss how the correction of the anemia may lead to improvement of bleeding outcomes in patients with a primary hemostatic defect, supported by evidence from animal models, clinical trials and clinical experience.

Perioperative thrombocytopenia

PURPOSE OF REVIEW

In this review, we discuss recent developments and trends in the perioperative management of thrombocytopenia.

RECENT FINDINGS

Large contemporary data base studies show that preoperative thrombocytopenia is present in about 8% of asymptomatic patients, and is associated with increased risks for bleeding and 30-day mortality. Traditionally specific threshold platelet counts were recommended for specific procedures. However, the risk of bleeding may not correlate well with platelet counts and varies with platelet function depending on the underlying etiology. Evidence to support prophylactic platelet transfusion is limited and refractoriness to platelet transfusion is common. A number of options exist to optimize platelet counts prior to procedures, which include steroids, intravenous immunoglobulin, thrombopoietin receptor agonists, and monoclonal antibodies. In addition, intraoperative alternatives and adjuncts to transfusion should be considered. It appears reasonable to use prophylactic desmopressin and antifibrinolytic agents, whereas activated recombinant factor VII could be considered in severe bleeding. Other options include enhancing thrombin generation with prothrombin complex concentrate or increasing fibrinogen levels with fibrinogen concentrate or cryoprecipitate.

SUMMARY

Given the lack of good quality evidence, much research remains to be done. However, with a multidisciplinary multimodal perioperative strategy, the risk of bleeding can be decreased effectively.

Impact of Thrombocytopenia in Patients With Atrial Fibrillation Undergoing Left Atrial Appendage Occlusion: A Propensity-Matched Comparison of 190 Consecutive Watchman Implantations

Objectives: The purpose of this study was to provide data on the long-term efficacy and safety of left atrial appendage occlusion (LAAO) in patients with atrial fibrillation (AF) and chronic thrombocytopenia (cTCP).

Methods: Between January 2016 and December 2018, a total of 32 AF patients with thrombocytopenia (platelet count <100^*10^∧9/L) undergoing LAAO at our center were identified and their outcomes were compared with a propensity-matched cohort (match ratio 1:5) of patients without cTCP who had also been indicated for LAAO.

Results: Between the cTCP patients and the control group, no difference was found on the incidence of stroke (0 vs. 3.13%, p = 0.592), systematic thromboembolisation (0 vs. 0.63%, p > 0.9) and device-related thrombus (DRT) (3.13 vs. 2.50%, p > 0.9). Major (12.50 vs. 3.75%, p = 0.065) and minor bleeding (15.63 vs. 1.25%, p = 0.002) was more frequent in cTCP patients but no statistical difference was reached in major bleeding. Moreover, thrombocytopenia was also identified as an independent predictor of any bleeding events (OR: 8.150, 95% CI: 2.579–25.757, p < 0.001), while an inverse relationship between higher absolute platelet count and stroke events was revealed (OR: 1.015; 95% CI: 1.002~1.029, p = 0.022). However, in both groups we saw a significant reduction in observed annualized rates of non-procedural complications compared with the predicted values. In the cTCP and control groups, clinical thromboembolism was reduced by 100 and 74.32%, and major bleeding by 42.47 and 71.67%, respectively.

Conclusion: Our preliminary results indicate that LAAO using the Watchman device could be a safe and effective means of preventing stroke in AF patients with or without thrombocytopenia, but bleeding complications should be monitored intensively in cTCP patients.

Challenges and Advances in Managing Thrombocytopenic Cancer Patients

Cancer patients have varying incidence, depth and duration of thrombocytopenia. The mainstay of managing severe chemotherapy-induced thrombocytopenia (CIT) in cancer is the use of platelet transfusions. While prophylactic platelet transfusions reduce the bleeding rate, multiple unmet needs remain, such as high residual rates of bleeding, and anticancer treatment dose reductions/delays. Accordingly, the following promising results in other settings, antifibrinolytic drugs have been evaluated for prevention and treatment of bleeding in patients with hematological malignancies and solid tumors. In addition, Thrombopoeitin receptor agonists have been studied for two major implications in cancer: treatment of severe thrombocytopenia associated with myelodysplastic syndrome and acute myeloid leukemia; primary and secondary prevention of CIT in solid tumors in order to maintain dose density and intensity of anti-cancer treatment. Furthermore, thrombocytopenic cancer patients are often prescribed antithrombotic medication for indications arising prior or post cancer diagnosis. Balancing the bleeding and thrombotic risks in such patients represents a unique clinical challenge. This review focuses upon non-transfusion-based approaches to managing thrombocytopenia and the associated bleeding risk in cancer, and also addresses the management of antithrombotic therapy in thrombocytopenic cancer patients.

Thrombocytopenia and Clinical Outcomes in Intracerebral Hemorrhage: A Retrospective Multicenter Cohort Study

BACKGROUND AND PURPOSE

The impact of platelets on hematoma enlargement (HE) of intracerebral hemorrhage (ICH) is not yet sufficiently elucidated. Especially the role of reduced platelet counts on HE and clinical outcomes is still poorly understood. This study investigated the influence of thrombocytopenia on HE, functional outcome, and mortality in patients with ICH with or without prior antiplatelet therapy (APT).

METHODS

Individual participant data of multicenter cohort studies (multicenter RETRACE program [German-Wide Multicenter Analysis of Oral Anticoagulation-Associated Intracerebral Hemorrhage] and single-center UKER-ICH registry [Universitätsklinikum Erlangen Cohort of Patients With Spontaneous ICH]) were grouped into APT and non-APT ICH patients according to the platelet count, that is, with or without thrombocytopenia (cells <150×10⁹/L). Of all patients, 51.5% (1124 of 2183) were on vitamin K antagonist. Imbalances in baseline characteristics including proportions of vitamin K antagonist patients were addressed using propensity score matching. Outcome analyses included HE (>33%), as well as mortality and functional outcome, after 3 months using the modified Rankin Scale, dichotomized into favorable (modified Rankin Scale score, 0-3) and unfavorable (modified Rankin Scale score, 4-6).

RESULTS

Of overall 2252 ICH patients, 11.4% (52 of 458) under APT and 14.0% (242 of 1725) without APT presented with thrombocytopenia on admission. The proportion of patients with HE was not significantly different between patients with or without thrombocytopenia among APT and non-APT ICH patients after propensity score matching (HE: APT patients: 9 of 40 [22.5%] thrombocytopenia versus 27 of 115 [23.5%] nonthrombocytopenia, P=0.89; non-APT patients: 54 of 174 [31.0%] thrombocytopenia versus 106 of 356 [29.8%] nonthrombocytopenia, P=0.77). In both (APT and non-APT) propensity score matching cohorts, there were no significant differences regarding functional outcome. Mortality after 3 months did not differ among non-APT patients, whereas the mortality rate was significantly higher for APT patients with thrombocytopenia versus APT patients with normal platelet count (APT: 29 of 46 [63.0%] thrombocytopenia versus 58 of 140 [41.4%] nonthrombocytopenia, P=0.01; non-APT: 95 of 227 [41.9%] thrombocytopenia versus 178 of 455 [39.1%] nonthrombocytopenia, P=0.49).

CONCLUSIONS

Our study implies that thrombocytopenia does not affect rates of HE and functional outcome among ICH patients, neither in patients with nor without APT. In light of increased mortality, the significance of platelet transfusions for ICH patients with thrombocytopenia and previous APT should be explored in future studies.

Machine learning models predict coagulopathy in spontaneous intracerebral hemorrhage patients in ER

AIMS

Coagulation abnormality is one of the primary concerns for patients with spontaneous intracerebral hemorrhage admitted to ER. Conventional laboratory indicators require hours for coagulopathy diagnosis, which brings difficulties for appropriate intervention within the optimal window. This study evaluates the possibility of building efficient coagulopathy prediction models using data mining and machine learning algorithms.

METHODS

A retrospective cohort enrolled 1668 cases with acute spontaneous intracerebral hemorrhage from three medical centers, excluding those under antithrombotic therapies. Coagulopathy-related clinical parameters were initially screened by univariate analysis. Two machine learning algorithms, the random forest and the support vector machine, were deployed via an approach of four-fold cross-validation to screen out the most important parameters contributing to the occurrence of coagulopathy. Model discrimination was assessed using metrics, including accuracy, precision, recall, and F1 score.

RESULTS

Albumin/globulin ratio, neutrophil count, lymphocyte percentage, aspartate transaminase, alanine transaminase, hemoglobin, platelet count, white blood cell count, neutrophil percentage, systolic and diastolic pressure were identified as major predictors to the occurrence of acute coagulopathy. Compared to support vector machine, the model based on the random forest algorithm showed better accuracy (93.1%, 95% confidence interval [CI]: 0.913-0.950), precision (92.4%, 95% CI: 0.897-0.951), F1 score (91.5%, 95% CI: 0.889-0.964), and recall score (93.6%, 95% CI: 0.909-0.964), and yielded higher area under the receiver operating characteristic curve (AU-ROC) (0.962, 95% CI: 0.942-0.982).

CONCLUSION

The constructed models exhibit good prediction accuracy and efficiency. It might be used in clinical practice to facilitate target intervention for acute coagulopathy in patients with spontaneous intracerebral hemorrhage.

Red Blood Cell Contribution to Hemostasis

Red Blood Cells (RBCs) have been increasingly recognized to play important roles in hemostasis and the mechanisms by which they do so continue to be elucidated. First and foremost, RBC biomechanics are the principal determinant of viscosity and flow dynamics of blood, which strongly influence all features of hemostasis. Of note, morphologic pathology, such as that found in sickle cell disease, leads to increased risk of thrombotic disease. RBC surface interactions govern signaling between platelets and RBCs and also aid in the conversion of prothrombin to thrombin. Additionally, RBCs generate microparticles which have been shown to reduce clotting time. Finally, blood clot structure and maturation are dependent on the inclusion of RBCs in forming thrombi. Here, we review the above mechanisms of RBC contribution to hemostasis.

The role of platelets in bleeding in patients with thrombocytopenia and hematological disease

This review evaluates the role of platelets in bleeding risk among patients with hematological disease and thrombocytopenia. Platelets are pivotal in primary hemostasis, and possess non-hemostatic properties involved in angiogenesis, tissue repair, inflammation and metastatis. Also, platelets safeguard vascular integrity in inflamed vessels. Overall, bleeding risk depends on the underlying disease, and patients with cancer and platelet count <6-10 × 109/L have a markedly increased bleeding risk, while the platelet count does not correlate with bleeding risk at higher platelet counts. Other factors might affect platelet properties and thus bleeding risk, for example, drugs, low hematocrit, coagulation system impairments or transfusion of dysfunctional donor platelets. For patients with leukemia and immune thrombocytopenia, reduced platelet activation, platelet aggregation, or thrombopoiesis, reflected by the reduced presence of reticulated platelets, are associated with bleeding phenotype. However, mechanistic insight into the cause of reduced platelet function in different thrombocytopenic conditions is sparse, except for some inherited platelet disorders. Promising tools for platelet function studies in thrombocytopenia are flow cytometry and biomarker studies on platelet constituents. An important message from this current paper is that bleeding risk assessment must be tailored to specific patient populations and cannot be applied broadly to all patients with thrombocytopenia.