Bleeding risks are higher in children versus adults given prophylactic platelet transfusions for treatment-induced hypoproliferative thrombocytopenia

Association between Platelet Count and Bleeding during Central Line Placement in Critically Ill Children

OBJECTIVE

To evaluate the association between platelet count and procedure-related bleeding at the time of central venous line (CVL) placement in critically ill children.

STUDY DESIGN

A retrospective cohort study was performed capturing patient admissions to the pediatric intensive care unit between January 1, 2012 to March 1, 2022. Critically ill children between 0 months and 19 years who underwent bedside CVL placement were included. A total of 363 were included in the final analysis.

RESULTS

Patients' platelet counts prior to line placement ranged from 11 000/uL to 735 000/uL. Bleeding was identified in 26 of 363 (7.2%) of patients, and was categorized as 24 (92%) minimal, 2 (8%) moderate, and none severe. Platelet count and platelet transfusion before line placement were both significantly different between bleeding and non-bleeding patients (P = .04 and P = .032). Patients with lower platelet counts had a higher proportion of bleeding events. There were no significant differences between the bleeding and non-bleeding groups in age, sex, history of bleeding, or number of attempts at CVL. Patients with bleeding were not significantly sicker. Regression analysis determined that female sex and transfusion before CVL placement were both significantly associated with bleeding.

CONCLUSIONS

We found that the platelet count prior to CVL placement was not associated with bleeding events in critically ill pediatric patients. Bleeding was more common in patients receiving platelet transfusions. Additional studies are needed to evaluate further the effect of platelet transfusions on procedure-related bleeding.

Most major bleeds in preterm infants occur in the absence of severe thrombocytopenia: an observational cohort study

OBJECTIVE

To describe the incidence of major bleeds according to different platelet counts in very preterm infants, and to explore whether this association is influenced by other risk factors for bleeding.

DESIGN

Observational cohort study.

SETTING

A Dutch tertiary care neonatal intensive care unit.

PATIENTS

All consecutive infants with a gestational age at birth <32 weeks admitted between January 2004 and July 2022.

EXPOSURE

Infants were stratified into nine groups based on their nadir platelet count (×109/L) during admission (<10, 10-24, 25-49, 50-99, 100-149, 150-199, 200-249, 250-299 and ≥300), measured before the diagnosis of a major bleed and before any platelet transfusion was administered.

MAIN OUTCOME MEASURE

Incidence of major bleeds during admission. Logistic regression analysis was used to quantify the relationship between nadir platelet count and incidence of major bleeds.

RESULTS

Among 2772 included infants, 224 (8%) developed a major bleed. Of the infants with a major bleed, 92% (206/224) had a nadir platelet count ≥50×109/L. The incidence of major bleeds was 8% among infants with and without severe thrombocytopenia (platelet count <50×109/L), 18/231 (95% CI 5 to 12) and 206/2541 (95% CI 7 to 9), respectively. Similarly, after adjustment for measured confounders, there was no notable association between nadir platelet counts below versus above 50×109/L and the occurrence of major bleeds (OR 1.09, 95% CI 0.61 to 1.94).

CONCLUSION

In very preterm infants, the vast majority of major bleeds occur in infants without severe thrombocytopenia.

[The current situation and the future of pediatric blood transfusion]

With advancements in clinical medicine, pediatric blood transfusion has evolved from traditional empirical practices to evidence-based approaches grounded in clinical research data. To better guide pediatric blood transfusion practices and improve clinical outcomes for pediatric patients, the National Health Commission has developed and issued "Guideline for pediatric transfusion". This article summarizes the unique aspects of pediatric blood transfusion, the application of blood component therapy in treating pediatric patients, the significance of interpreting the "Guideline for pediatric transfusion", and anticipates future developments in pediatric blood transfusion medicine.

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.

Bleeding in Critically Ill Children With Malignancy or Hematopoietic Cell Transplant: A Single-Center Prospective Cohort Study

OBJECTIVES

To determine the incidence of bleeding in critically ill children with malignancy and to describe associated patient characteristics, interventions, and clinical outcomes.

DESIGN

Prospective cohort study.

SETTING

PICU in a specialized cancer hospital.

PATIENTS

Children with malignancy or hematopoietic cell transplant 0-18 years of age were admitted to the PICU from November 2020 to November 2021.

INTERVENTIONS

None.

MEASUREMENTS

Patient demographic data, laboratory values, and PICU outcome data were collected. Bleeding was classified according to the Bleeding Assessment Scale in Critically Ill Children.

MAIN RESULTS

Ninety-three bleeding patients were enrolled, and a total of 322 bleeding days were recorded. The median (interquartile range [IQR]) age was 5.8 (2.9-11.8) years and 56% (52/93) of the patients were male. There were 121 new bleeding episodes, in 593 at-risk person-days, translating into a 20% incidence rate per day (95% CI, 17-24%). The incidence of severe, moderate, and minimal bleeding was 2% (95% CI, 1-3), 4% (95% CI, 3-6), and 14% (95% CI, 12-17), respectively. Of the new bleeding episodes, 9% were severe, 25% were moderate and 66% were minimal. Thrombocytopenia was the only laboratory value independently associated with severe bleeding ( p = 0.009), as compared to minimal and moderate bleeding episodes. History of radiation therapy was independently associated with severe bleeding ( p = 0.04). We failed to identify an association between a history of stem cell transplant ( p = 0.49) or tumor type ( p = 0.76), and bleeding severity. Patients were transfused any blood product on 28% (95% CI, 22-34) of the bleeding days. Severe bleeding was associated with increased length of mechanical ventilation ( p = 0.003), longer PICU stays ( p = 0.03), and higher PICU mortality ( p = 0.004).

CONCLUSIONS

In this prospective cohort of children with malignancy, the incidence rate of bleeding was 20%. Most events were classified as minimal bleeding. Low platelet count and radiation therapy were variables independently associated with severe bleeding episodes.

Prophylactic Platelet Transfusion: Is There Evidence of Benefit, Harm, or No Effect?

The optimal use of prophylactic platelet transfusion remains uncertain in a number of clinical scenarios. Platelet count thresholds have been established in patients with hematologic malignancies, yet thresholds backed by scientific data are limited or do not exist for many patient populations. Clinical scenarios involving transfusion thresholds for thrombocytopenic patients with critical illness, need for surgery or invasive procedures, or those involving specials populations like children and neonates, lack clear evidence for discerning favorable outcomes without undue risk related to platelet transfusion. In addition, while prophylactic platelet transfusions are administered with the goal of enhancing hemostasis, increasing evidence supports critical nonhemostatic roles for platelets related to innate and adaptive immunity, inflammation, and angiogenesis, which may impact patient responses and outcomes. Here we review several recent studies conducted in adult or pediatric patients that highlight the limitations in our current understanding of prophylactic platelet transfusion. Together, these studies underscore the need for additional research, especially in the form of robust randomized clinical trials and integrating additional parameters beyond the platelet count. Future research at the basic, translational, and clinical levels will best define the optimal role for prophylactic transfusion across the lifespan and its broader impact on health and disease.

Patient Blood Management after Hematopoietic Stem Cell Transplantation in a Pediatric Setting: Starting Low and Going Lower

Despite the substantial transfusion requirements, there are few studies on the optimal transfusion strategy in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Our study aimed to retrospectively analyze red blood cell (RBC) and platelet (PLT) transfusion practices during the first 100 days after HSCT at the pediatric hematology/oncology unit of our hospital between 2016 and 2019, due to a more restrictive approach adopted after 2016. We also evaluated the impact on patient outcomes. A total of 146 consecutive HSCT patients were analyzed. In patients without hemorrhagic complications, the Hb threshold for RBC transfusions decreased significantly from 2016 to 2017 (from 7.8 g/dL to 7.3 g/dL; p = 0.010), whereas it remained the same in 2017, 2018, and 2019 (7.3, 7.2, and 7.2 g/dL, respectively). Similarly, the PLT threshold decreased significantly from 2016 to 2017 (from 18,000 to 16,000/μL; p = 0.026) and further decreased in 2019 (15,000/μL). In patients without severe hemorrhagic complications, the number of RBC and PLT transfusions remained very low over time. No increase in 100-day and 180-day non-relapse mortality or adverse events was observed during the study period. No patient died due to hemorrhagic complications. Our preliminary observations support robust studies enrolling HSCT patients in patient blood management programs.

Platelet transfusion in adults: An update

Many patients worldwide receive platelet components (PCs) through the transfusion of diverse types of blood components. PC transfusions are essential for the treatment of central thrombocytopenia of diverse causes, and such treatment is beneficial in patients at risk of severe bleeding. PC transfusions account for almost 10% of all the blood components supplied by blood services, but they are associated with about 3.25 times as many severe reactions (attributable to transfusion) than red blood cell transfusions after stringent in-process leukoreduction to less than 10⁶ residual cells per blood component. PCs are not homogeneous, due to the considerable differences between donors. Furthermore, the modes of PC collection and preparation, the safety precautions taken to limit either the most common (allergic-type reactions and febrile non-hemolytic reactions) or the most severe (bacterial contamination, pulmonary lesions) adverse reactions, and storage and conservation methods can all result in so-called PC "storage lesions". Some storage lesions affect PC quality, with implications for patient outcome. Good transfusion practices should result in higher levels of platelet recovery and efficacy, and lower complication rates. These practices include a matching of tissue ABH antigens whenever possible, and of platelet HLA (and, to a lesser extent, HPA) antigens in immunization situations. This review provides an overview of all the available information relating to platelet transfusion, from donor and donation to bedside transfusion, and considers the impact of the measures applied to increase transfusion efficacy while improving safety and preventing transfusion inefficacy and refractoriness. It also considers alternatives to platelet component (PC) transfusion.

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.

Transfusion Strategies for Hemostatic Blood Products in Critically Ill Children: A Narrative Review and Update on Expert Consensus Guidelines

Critically ill children commonly receive coagulant products (plasma and/or platelet transfusions) to prevent or treat hemorrhage or correct coagulopathy. Unique aspects of pediatric developmental physiology, and the complex pathophysiology of critical illness must be considered and balanced against known transfusion risks. Transfusion practices vary greatly within and across institutions, and high-quality evidence is needed to support transfusion decision-making. We present recent recommendations and expert consensus statements to direct clinicians in the decision to transfuse or not to transfuse hemostatic blood products, including plasma, platelets, cryoprecipitate, and recombinant products to critically ill children.

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.

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.

Neonatal platelet transfusions: New evidence and the challenges of translating evidence-based recommendations into clinical practice

Platelet transfusions are a common intervention for thrombocytopenia. Although the main reason for transfusing platelets is to improve hemostasis, platelets have many additional physiological roles, including interactions with immune pathways. Much of the evidence base for safe and effective transfusions has been informed by randomized trials in adult patients with hematological malignancies. Only three randomized trials have been conducted in sick neonates. These trials have indicated evidence of harm, including a significantly higher rate of death or major bleeding within 28 days after randomization for the largest trial, which enrolled 660 infants. The overall research indicates limited effectiveness of platelet transfusions to reduce bleeding risk. It is important that the results of trials are implemented into practice, but uptake of research findings into neonatal medicine remains inconsistent, as for many areas of health care. There is a need to establish which potential implementation strategies (cost-) efficiently enact change, such as audit and feedback, automated reminder systems for ordering transfusions, and use of opinion leaders. Research is exploring potential mechanisms underlying the lack of effectiveness of platelet transfusions and the increased bleeding and mortality observed in neonatal randomized trials. One potential mechanism concerns the roles of platelets to promote excessive angiogenic signals during a vulnerable period of brain development. A further hypothesis explores the effects of transfusing "adult" platelets into "neonatal" thrombocytopenic blood on primary hemostasis and immune responses.

Neonatal platelet physiology and implications for transfusion

The neonatal hemostatic system is different from that of adults. The differences in levels of procoagulant and anticoagulant factors and the evolving equilibrium in secondary hemostasis during the transition from fetal/neonatal life to infancy, childhood, and adult life are known as "developmental hemostasis." In regard to primary hemostasis, while the number (150,000-450,000/µl) and structure of platelets in healthy neonates closely resemble those of adults, there are significant functional differences between neonatal and adult platelets. Specifically, platelets derived from both cord blood and neonatal peripheral blood are less reactive than adult platelets to agonists, such as adenosine diphosphate (ADP), epinephrine, collagen, thrombin, and thromboxane (TXA2) analogs. This platelet hyporeactivity is due to differences in expression levels of key surface receptors and/or in signaling pathways, and is more pronounced in preterm neonates. Despite these differences in platelet function, bleeding times and PFA-100 closure times (an in vitro test of whole-blood primary hemostasis) are shorter in healthy full-term infants than in adults, reflecting enhanced primary hemostasis. This paradoxical finding is explained by the presence of factors in neonatal blood that increase the platelet-vessel wall interaction, such as high von Willebrand factor (vWF) levels, predominance of ultralong vWF multimers, high hematocrit, and high red cell mean corpuscular volume. Thus, the hyporeactivity of neonatal platelets should not be viewed as a developmental deficiency, but rather as an integral part of a developmentally unique, but well balanced, primary hemostatic system. In clinical practice, due to the high incidence of bleeding (especially intraventricular hemorrhage, IVH) among preterm infants, neonatologists frequently transfuse platelets to non-bleeding neonates when platelet counts fall below an arbitrary limit, typically higher than that used in older children and adults. However, recent studies have shown that prophylactic platelet transfusions not only fail to decrease bleeding in preterm neonates, but are associated with increased neonatal morbidity and mortality. In this review, we will describe the developmental differences in platelet function and primary hemostasis between neonates and adults, and will analyze the implications of these differences to platelet transfusion decisions.

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.

Epidemiology of Bleeding in Critically Ill Children With an Underlying Oncologic Diagnosis

Supplemental Digital Content is available in the text.

Critically ill children with malignancy have significant risk of bleeding but the exact epidemiology is unknown. We sought to describe severe bleeding events and associated risk factors in critically ill pediatric patients with an underlying oncologic diagnosis using the newly developed Bleeding Assessment Scale in Critically Ill Children definition.

Platelet Transfusion: An Update on Indications and Guidelines

Platelets are commonly transfused either therapeutically or prophylactically to maintain hemostasis. Most platelet transfusions are used to manage patients with hematologic malignancies. Although platelet transfusion guidelines have been published, platelet transfusion practices are still heterogeneous. Platelet transfusion guidelines partly lack recommendations or differ in the platelet threshold recommendations in some clinical situations. This article reviews platelet transfusions focusing on transfusion guidelines and platelet thresholds in different clinical settings.

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.

Transfusion practices for pediatric oncology and hematopoietic stem cell transplantation patients: Data from the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III (REDS-III)

BACKGROUND

To evaluate transfusion practices in pediatric oncology and hematopoietic stem cell transplant (HSCT) patients.

STUDY DESIGN AND METHODS

This is a multicenter retrospective study of children with oncologic diagnoses treated from 2013 to 2016 at hospitals participating in the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III. Transfusion practices were evaluated by diagnosis codes and pre-transfusion laboratory values.

RESULTS

A total of 4766 inpatient encounters of oncology and HSCT patients were evaluated, with 39.3% (95% confidence interval [CI]: 37.9%-40.7%) involving a transfusion. Red blood cells (RBCs) were the most commonly transfused component (32.4%; 95% CI: 31.1%-33.8%), followed by platelets (22.7%; 95% CI: 21.5%-23.9%). Patients in the 1 to <6 years of range were most likely to be transfused and HSCT, acute myeloid leukemia, and aplastic anemia were the diagnoses most often associated with transfusion. The median hemoglobin (Hb) prior to RBC transfusion was 7.5 g/dl (10-90th percentile: 6.4-8.8 g/dl), with 45.7% of transfusions being given at 7 to <8 g/dl. The median platelet count prior to platelet transfusion was 20 × 10⁹ /L (10-90th percentile: 8-51 × 10⁹ /L), and 37.9% of transfusions were given at platelet count of >20-50 × 10⁹ /L. The median international normalized ratio (INR) prior to plasma transfusion was 1.7 (10-90th percentile: 1.3-2.7), and 36.3% of plasma transfusions were given at an INR between 1.4 and 1.7.

DISCUSSION

Transfusion of blood components is common in hospitalized pediatric oncology/HSCT patients. Relatively high pre-transfusion Hb and platelet values and relatively low INR values prior to transfusion across the studied diagnoses highlight the need for additional studies in this population.

Efficacy of Early Prophylaxis Against Catheter-Associated Thrombosis in Critically Ill Children: A Bayesian Phase 2b Randomized Clinical Trial

OBJECTIVES

We obtained preliminary evidence on the efficacy of early prophylaxis on the risk of central venous catheter-associated deep venous thrombosis and its effect on thrombin generation in critically ill children.

DESIGN

Bayesian phase 2b randomized clinical trial.

SETTING

Seven PICUs.

PATIENTS

Children less than 18 years old with a newly inserted central venous catheter and at low risk of bleeding.

INTERVENTION

Enoxaparin adjusted to anti-Xa level of 0.2-0.5 international units/mL started at less than 24 hours after insertion of central venous catheter (enoxaparin arm) versus usual care without placebo (usual care arm).

MEASUREMENTS AND MAIN RESULTS

At the interim analysis, the proportion of central venous catheter-associated deep venous thrombosis on ultrasonography in the usual care arm, which was 54.2% of 24 children, was significantly higher than that previously reported. This resulted in misspecification of the preapproved Bayesian analysis, reversal of direction of treatment effect, and early termination of the randomized clinical trial. Nevertheless, with 30.4% of 23 children with central venous catheter-associated deep venous thrombosis on ultrasonography in the enoxaparin arm, risk ratio of central venous catheter-associated deep venous thrombosis was 0.55 (95% credible interval, 0.24-1.11). Including children without ultrasonography, clinically relevant central venous catheter-associated deep venous thrombosis developed in one of 27 children (3.7%) in the enoxaparin arm and seven of 24 (29.2%) in the usual care arm (p = 0.02). Clinically relevant bleeding developed in one child randomized to the enoxaparin arm. Response profile of endogenous thrombin potential, a measure of thrombin generation, was not statistically different between trial arms.

CONCLUSIONS

These findings suggest the efficacy and safety of early prophylaxis that should be validated in a pivotal randomized clinical trial.

Transfusion practices in a large cohort of hospitalized children

BACKGROUND

While previous studies have described the use of blood components in subsets of children, such as the critically ill, little is known about transfusion practices in hospitalized children across all departments and diagnostic categories. We sought to describe the utilization of red blood cell, platelet, plasma, and cryoprecipitate transfusions across hospital settings and diagnostic categories in a large cohort of hospitalized children.

STUDY DESIGN AND METHODS

The public datasets from 11 US academic and community hospitals that participated in the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) were accessed. All nonbirth inpatient encounters of children 0-18 years of age from 2013 to 2016 were included.

RESULTS

61,770 inpatient encounters from 41,943 unique patients were analyzed. Nine percent of encounters involved the transfusion of at least one blood component. RBC transfusions were most common (7.5%), followed by platelets (3.9%), plasma (2.5%), and cryoprecipitate (0.9%). Children undergoing cardiopulmonary bypass were most likely to be transfused. For the entire cohort, the median (interquartile range) pretransfusion laboratory values were as follows: hemoglobin, 7.9 g/dl (7.1-10.4 g/dl); platelet count, 27 × 10⁹ cells/L (14-54 × 10⁹ cells/L); and international normalized ratio was 1.6 (1.4-2.0). Recipient age differences were observed in the frequency of RBC irradiation (95% in infants, 67% in children, p < .001) and storage duration of RBC transfusions (median storage duration of 12 [8-17] days in infants and 20 [12-29] days in children, p < .001).

CONCLUSION

Based on a cohort of patients from 2013 to 2016, the transfusion of blood components is relatively common in the care of hospitalized children. The frequency of transfusion across all pediatric hospital settings, especially in children undergoing cardiopulmonary bypass, highlights the opportunities for the development of institutional transfusion guidelines and patient blood management initiatives.

Benefits of lower neonatal platelet transfusion thresholds

Degree of thrombocytopenia is not a predictor of bleeding risk in neonates, yet most platelet transfusions are given prophylactically in non-bleeding premature infants. Recent data support a lower platelet transfusion threshold of 25 × 10⁹ /L in non-bleeding premature neonates and indicate that higher transfusion thresholds may be associated with harm including increased risk of death and bleeding. The mechanism of increased adverse events with higher platelet transfusion threshold is unknown, but considerations include adult platelets disrupting the neonatal hemostatic balance of hypoactive platelets in a hypercoagulable and fragile environment and having a pro-inflammatory effect.

Transfusion in Pediatric Patients: Review of Evidence-Based Guidelines

Children require transfusion of blood components for a vast array of medical conditions, including acute hemorrhage, hematologic and nonhematologic malignancies, hemoglobinopathy, and allogeneic and autologous stem cell transplant. Evidence-based literature on pediatric transfusion practices is limited, particularly for non-red blood cell products, and many recommendations are extrapolated from studies in adult populations. Recognition of these knowledge gaps has led to increasing numbers of clinical trials focusing on children and establishment of pediatric transfusion working groups in recent years. This article reviews existing literature on pediatric transfusion therapy within the larger context of analogous data in adult populations.

Perioperative outcomes for benign hysterectomy among women with thrombocytopenia

OBJECTIVE

To determine whether mild or moderate thrombocytopenia is associated with postoperative complications after benign hysterectomy.

METHODS

A retrospective study of data from women who underwent benign hysterectomy included in the American College of Surgeons National Surgical Quality Improvement Project Database. The data were stratified by normal platelet count, mild thrombocytopenia (100-149 × 10³ platelets/µl), and moderate thrombocytopenia (50-99 × 10³ platelets/µl). Multivariable logistic regression was used to determine the relationship between mild or moderate thrombocytopenia and the main outcome measures.

RESULTS

Moderate thrombocytopenia was associated with an increased risk of perioperative transfusion (adjusted odds ratio [aOR], 2.87; 95% confidence interval [CI], 1.96-4.21) and reoperation (aOR, 4.03; 95% CI, 1.94-17.33), but mild thrombocytopenia was not. There was an increased risk of infection among women with both mild (aOR, 1.38; 95% CI, 1.12-1.69) and moderate (aOR, 2.00; 95% CI,1.23-3.22) thrombocytopenia. There was no association between either mild or moderate thrombocytopenia and readmission, prolonged hospital stay, or longer surgical time.

CONCLUSION

Thrombocytopenia was found to be associated with increased infectious morbidity after hysterectomy, and moderate thrombocytopenia was associated with an increased risk of perioperative transfusion and reoperation.

Hemostatic Challenges in Neonates

The neonatal hemostatic system is strikingly different from that of adults. Among other differences, neonates exhibit hyporeactive platelets and decreased levels of coagulation factors, the latter translating into prolonged clotting times (PT and PTT). Since pre-term neonates have a high incidence of bleeding, particularly intraventricular hemorrhages, neonatologists frequently administer blood products (i.e., platelets and FFP) to non-bleeding neonates with low platelet counts or prolonged clotting times in an attempt to overcome these "deficiencies" and reduce bleeding risk. However, it has become increasingly clear that both the platelet hyporeactivity as well as the decreased coagulation factor levels are effectively counteracted by other factors in neonatal blood that promote hemostasis (i.e., high levels of vWF, high hematocrit and MCV, reduced levels of natural anticoagulants), resulting in a well-balanced neonatal hemostatic system, perhaps slightly tilted toward a prothrombotic phenotype. While life-saving in the presence of active major bleeding, the administration of platelets and/or FFP to non-bleeding neonates based on laboratory tests has not only failed to decrease bleeding, but has been associated with increased neonatal morbidity and mortality in the case of platelets. In this review, we will present a clinical overview of bleeding in neonates (incidence, sites, risk factors), followed by a description of the key developmental differences between neonates and adults in primary and secondary hemostasis. Next, we will review the clinical tests available for the evaluation of bleeding neonates and their limitations in the context of the developmentally unique neonatal hemostatic system, and will discuss current and emerging approaches to more accurately predict, evaluate and treat bleeding in neonates.

How well do platelets prevent bleeding?

Prophylactic platelet transfusions are used to reduce the risk of spontaneous bleeding in patients with treatment- or disease-related severe thrombocytopenia. A prophylactic platelet-transfusion threshold of <10 × 103/µL has been shown to be safe in stable hematology/oncology patients. A higher threshold and/or larger or more frequent platelet doses may be appropriate for patients with clinical features associated with an increased risk of bleeding such as high fevers, sepsis, disseminated intravascular coagulation, anticoagulation therapy, or splenomegaly. Unique factors in the outpatient setting may support the use of a higher platelet-transfusion threshold and/or dose of platelets. A prophylactic platelet-transfusion strategy has been shown to be associated with a lower risk of bleeding compared with no prophylaxis in adult patients receiving chemotherapy but not for autologous transplant recipients. Despite the use of prophylactic platelet transfusions, a high incidence (50% to 70%) of spontaneous bleeding remains. Using a higher threshold or larger doses of platelets does not change this risk. New approaches to reduce the risk of spontaneous bleeding, including antifibrinolytic therapy, are currently under study.

Additive value of transarterial embolization to systemic sirolimus treatment in kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor in children, which can be accompanied by life-threatening thrombocytopenia, referred to as Kasabach-Merritt phenomenon (KMP). The mTOR inhibitor sirolimus is emerging as targeted therapy in KHE. As the sirolimus effect on KHE occurs only after several weeks, we aimed to evaluate whether additional transarterial embolization is of benefit for children with KHE and KMP. Seventeen patients with KHE and KMP acquired from 11 hospitals in Germany were retrospectively divided into two cohorts. Children being treated with adjunct transarterial embolization and systemic sirolimus, and those being treated with sirolimus without additional embolization. Bleeding grade as defined by WHO was determined for all patients. Response of the primary tumor at 6 and 12 months assessed by magnetic resonance imaging (MRI), time to response of KMP defined as thrombocyte increase >150 × 10³ /μL, as well as rebound rates of both after cessation of sirolimus were compared. N = 8 patients had undergone additive embolization to systemic sirolimus therapy, sirolimus in this group was started after a mean of 6.5 ± 3 days following embolization. N = 9 patients were identified who had received sirolimus without additional embolization. Adjunct embolization induced a more rapid resolution of KMP within a median of 7 days vs 3 months; however, tumor response as well as rebound rates were similar between both groups. Additive embolization may be of value for a more rapid rescue of consumptive coagulopathy in children with KHE and KMP compared to systemic sirolimus only.

Platelet transfusion practice and platelet refractoriness for a cohort of pediatric oncology patients: A single-center study

BACKGROUND

Platelet transfusions are an essential aspect of supportive care for pediatric oncology patients. Data regarding the frequency of transfusions, pretransfusion thresholds, posttransfusion increments, and rate of platelet transfusion refractoriness (PTR) are lacking.

STUDY OBJECTIVES

(a) describe platelet transfusion practice for children with malignancy; (b) determine the normal platelet increment following platelet transfusion; and (c) assess rate of PTR.

METHODS

Inpatient pediatric oncology patients <18 years old and treated between 2009 and 2013 were identified. Data collected retrospectively included patient demographics, clinical information, laboratory values, and transfusion details.

RESULTS

Three hundred sixty-seven children were included and 144 (39%) received at least one platelet transfusion. Platelets were transfused during 25% of all inpatient admissions. The median number of platelet transfusion for any given inpatient admission was two (interquartile range [IQR]: 1-3). The median pretransfusion platelet count was 16 × 10⁹ /L and posttransfusion increment was 25 × 10⁹ /L. Most (79%) of the time, the pretransfusion platelet count was >10 × 10⁹ /L. Older children who received ABO incompatible platelet transfusions with a longer storage duration were more likely to have a poor platelet response (increment ≤ 10 × 10⁹ /L). The rate of PTR (immune and/or nonimmune) was low (8%; 11/144).

CONCLUSIONS

Practical information to parents and clinicians of newly diagnosed children regarding the likelihood and frequency of platelet transfusions was determined. The rate of PTR was low, supporting the hypothesis that children receiving leukoreduced products are at a low risk of PTR.

Insertion of central venous catheters in children undergoing bone marrow transplantation: is there a platelet level for a safe procedure?

Background

Bone marrow transplantation (BMT) is a therapeutic procedure for the management of several hematological diseases and malignancies in pediatric population. Central venous catheters (CVCs) play a pivotal role during the process of BMT. The aim of this study was to compare the complications of CVCs placements in children undergoing BMT with platelet levels above and below 50,000/μL and also to detect if there is a platelet count for a safe insertion. This prospective study included all children who had placements of tunneled CVCs during BMT at our hospital between March 2017 and March 2020. Procedures were divided into two groups accordingly to preoperative platelet counts (above and below 50,000/μL). Data were compared between both groups regarding postoperative complications including bleeding or catheter-related blood stream infections (CRBSIs).

Results

Forty-six CVC insertions were performed in 40 patients. There were 20 procedures below 50,000/μL (median 27,500; range 5000–42,000) inserted with perioperative platelet transfusions, and their postoperative levels were median 59,500/μL, range 18,000–88,000. Allogeneic BMT was adopted in 39 patients (97.5%). Beta thalassemia major was the commonest indication (21/40, 52.5%), followed by acute lymphocytic leukemia in six patients (15%). There were nine postoperative complications (bleeding n = 2 and CRBSIs n = 7) encountered in all placements. Four of them occurred in insertions below 50,000/μL (two bleeding complications that managed conservatively, and two CRBSIs). Post-procedural morbidities regarding bleeding or CRBSIs did not differ significantly between both groups (p value = 0.099 and 0.695, respectively).

Conclusions

Postponement of CVC insertions in thrombocytopenic children due to the fear of potential complications seems unwarranted, as it has no significant impact on the morbidity. Placements of such catheters can be safe under cover of perioperative platelet transfusions irrespective of the preoperative platelet count.

Evaluating the appropriateness of platelet transfusions compared with evidence-based platelet guidelines: An audit of platelet transfusions at 57 hospitals

BACKGROUND

Platelet transfusions are used to prevent or control bleeding in patients with thrombocytopenia or platelet dysfunction. The pretransfusion platelet count threshold has been studied extensively in multiple patient settings yielding high-quality evidence that has been summarized in several comprehensive evidence-based platelet guidelines.

STUDY DESIGN AND METHODS

A prospective 12-week audit of consecutive platelet transfusions using validated and evidence-based adjudication criteria was conducted. Patient demographic, laboratory, and transfusion details were collected with an electronic audit tool. Each order was adjudicated either electronically or independently by two transfusion medicine physicians. The aim was to determine platelet transfusion appropriateness and common scenarios with deviations from guidelines.

RESULTS

Fifty-seven (38%) of 150 hospitals provided data on 1903 platelet orders, representing 90% of platelet usage in the region during the time period. Overall, 702 of 1693 adult (41.5%) and 133 of 210 pediatric orders (63.3%) were deemed inappropriate. The most common inappropriate platelet order was for prophylaxis in the absence of bleeding or planned procedure in patients with hypoproliferative thrombocytopenia and a platelet count over 10 x 10⁹ /L (53% of inappropriate orders in adults and 45% in pediatrics). Platelet transfusions ordered with either a preprinted transfusion order set (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.44-2.73) or technologist prospective screening (OR, 1.40; 95% CI, 1.10-1.78) were more likely to be appropriate.

CONCLUSION

There is a discrepancy between clinical practice and evidence-based platelet guidelines. Broad educational and system changes will be needed to align platelet transfusion practice with guideline recommendations.

Neonatal and pediatric platelet transfusions: current concepts and controversies

PURPOSE OF REVIEW

In this review, we focus on three specific concepts related to platelet transfusion in the neonatal and pediatric population: choice of transfusion threshold; use of ABO-mismatched platelets; transfusion of pathogen-reduced or inactivated platelets.

RECENT FINDINGS

Recent trials support the use of lower platelet transfusion thresholds (25 000/μl) in preterm neonates, although data is limited to guide transfusion among more mature neonates. In children, there is low-level evidence as to what the prophylactic platelet transfusion threshold should be in many situations of thrombocytopenia, revealing major variability in platelet transfusion practices. Most pediatric guidelines are extrapolated from adult studies with the most evidence in treatment-associated hypoproliferative thrombocytopenia varying between a platelet transfusion threshold of 10 000/μl to 20 000/μl. Although pathogen-reduced platelets may lower the risks of transfusion-transmitted infection, the effects on platelet refractoriness and transfusion burden in this population warrant additional study.

SUMMARY

Our review highlights recent advances in neonatal and pediatric platelet transfusion and also emphasizes the urgent need for better evidence to guide practice given recent studies showing the potential harms of platelet transfusion, particularly with liberal use.

Characteristics of Blood Transfusion During Induction Remission in Children With Acute Lymphoblastic Leukemia: A Single-Center Retrospective Investigation

OBJECTIVE

To investigate the allogeneic blood transfusion (ABT) characteristics of children with acute lymphoblastic leukemia (ALL) in different risk stratification during vincristine, daunorubicin, L-asparaginase and prednisone (VDLP) induction remission.

SUBJECTS AND METHODS

By referring to electronic medical records, the demographic characteristics, diagnosis, test, and treatment information including ABT were collected. According to the risk stratification of the CCCG-ALL-2015 protocol, ABTs between groups were compared, and the differences were statistically analyzed.

RESULTS

One hundred sixty-three newly treated children with ALL were enrolled in this study, who received 643.5 U of red blood cells and 377.6 U of platelets (PLTs) during the VDLP. The amount of ABT in the intermediate-risk (IR) group (n=102) was significantly higher than that in the low-risk group (n=61), which were reflected in the red blood cells in the first half of VDLP (P=0.033) and the PLTs in the second half of VDLP (P<0.001). Meanwhile, the PLT counts in the IR group were significantly lower in the same period. The time node was bounded by the minimal residual disease test on the 19th day.

CONCLUSIONS

Children in the IR group or with unsatisfactory induction may need more ABTs during the VDLP, and the relatively low PLT counts seem to contribute to this. The results of this study can provide a basis for patient blood management, as well as a reference for studying the long-term effects of ABT on children with ALL.

Transfusion support: Considerations in pediatric populations

Over 400,000 units of blood and blood products are transfused to pediatric patients annually, yet only sparse high-quality data exist to guide the preparation and administration of blood products in this population. The direct application of data from studies in adult patients should be undertaken with caution, as there are dissimilarities in the pathology and physiology between adult and pediatric patients. We provide an overview of available evidence in the field of pediatric transfusion medicine, summarizing indications for blood product transfusion, thresholds for transfusion and indications for blood product modifications.

Picking up the Pace: Decreasing Platelet Administration Safely and Effectively

BACKGROUND

Hematology-oncology patients often require blood and blood product transfusions, including platelets (PLTs), to maintain stability. Administering PLTs in a shorter timeframe may prove beneficial by possibly raising platelet counts to a higher level faster, and allowing patients to be disconnected from IV pumps sooner.

OBJECTIVE

To evaluate the optimal (safe and effective) transfusion time by comparing standard administration of PLTs over 2-4 h to the investigational administration of PLTs over 30-45 min in the pediatric hematology-oncology inpatient population.

METHODOLOGY

A pilot trial was conducted using a convenience sample of hematology-oncology children. Children prescribed a PLT transfusion while admitted to an inpatient unit were eligible. If randomized to the intervention group, the nurse administered the PLTs over 30-45 min. If randomized to the standard group, the nurse administered the PLTs over 2-4 h. Post transfusion PLTcount was drawn 30 min after completion. The child was monitored closely for adverse reactions.

RESULTS

Eleven participants were enrolled in the study and 20 PLT infusions administered. No adverse events were noted. There was not a significant difference in changes in PLT counts by group (post minus pre), p = 0.082. There was not a significant difference in post infusion PLT counts, p = 0.727. There was a significant difference in the rate of change in PLT counts by groups, p = 0.003.

NURSING IMPLICATIONS

This pilot study provides preliminary evidence that PLTs may be safely and effectively administered over 30-45 min in pediatric hematology-oncology patients. With quicker PLT administration, patients can be disconnected from IV pumps sooner.

Overview of Plasma and Platelet Transfusions in Critically Ill Children

Critically ill children are a unique population who frequently receive plasma and platelet transfusions for both active bleeding and mitigation of bleeding risk. While these products are frequently administered, transfusion indications in this population remain unclear, and practice varies across institutions and providers. In this manuscript, we will outline the current evidence regarding plasma and platelet transfusions for hemostasis in the pediatric intensive care setting. For both products, we will describe the product composition, epidemiology, and product indications and discuss the potential risks and benefits involved with the transfusion. We will also discuss knowledge gaps and future areas of research.

Transfusion Management in Pediatric Oncology Patients

Pediatric oncology patients will likely require numerous transfusions of blood products, including red blood cell, platelet, and plasma transfusions, during the course of their treatment. Although strong evidence-based guidelines for these products in this patient population do not exist, given the morbidities associated with the receipt of blood products, practitioners should attempt to use restrictive transfusion strategies.

Therapeutic Utility of Cold-Stored Platelets or Cold-Stored Whole Blood for the Bleeding Hematology-Oncology Patient

Bleeding related to thrombocytopenia is common in hematology-oncology patients. Platelets stored at room temperature (RTPs) are the current standard of care. Platelets stored in the cold (CSPs) have enhanced hemostatic function relative to RTPs. CSPs were reported to reduce bleeding in hematology-oncology patients. Recent studies have confirmed the enhanced hemostatic properties of CSPs. CSPs may be the better therapeutic option for this population. CSPs may also offer a preferable immune profile, reduced thrombotic risk, and reduced transfusion-transmitted infection risk. The logistical advantages of CSPs would improve outcomes for many patients who currently cannot access platelet transfusions.

International Study of the Epidemiology of Platelet Transfusions in Critically Ill Children With an Underlying Oncologic Diagnosis

OBJECTIVES

To describe the epidemiology of platelet transfusions in critically ill children with an underlying oncologic diagnosis and to examine effects of prophylactic versus therapeutic transfusions.

DESIGN

Subgroup analysis of a prospective, observational study.

SETTING

Eighty-two PICUs in 16 countries.

PATIENTS

All children (3 d to 16 yr old) who received a platelet transfusion during one of the six predefined screening weeks and had received chemotherapy in the previous 6 months or had undergone hematopoietic stem cell transplantation in the last year.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 548 patients enrolled in the parent study, 237 (43%) had an underlying oncologic diagnosis. In this population, 71% (168/237) of transfusions were given prophylactically, and 59% (139/237) of transfusions were given at a total platelet count greater than 20 × 10/L, higher than the current recommendations. Those with an underlying oncologic diagnosis were significantly older, and received less support including less mechanical ventilation, fewer medications that affect platelet function, and less use of extracorporeal life support than those without an underlying oncologic diagnosis. In this subpopulation, there were no statistically significant differences in median (interquartile range) platelet transfusion thresholds when comparing bleeding or nonbleeding patients (50 × 10/L [10-50 × 10/L] and 30 × 10/L [10-50 × 10/L], respectively [p = 0.166]). The median (interquartile range) interval transfusion increment in children with an underlying oncologic diagnosis was 17 × 10/L (6-52 × 10/L). The presence of an underlying oncologic diagnosis was associated with a poor platelet increment response to platelet transfusion in this cohort (adjusted odds ratio, 0.46; 95% CI, 0.22-0.95; p = 0.035).

CONCLUSIONS

Children with an underlying oncologic diagnosis receive nearly half of platelet transfusions prescribed by pediatric intensivists. Over half of these transfusions are prescribed at total platelet count greater than current recommendations. Studies must be done to clarify appropriate indications for platelet transfusions in this vulnerable population.

Blood Utilization and Transfusion Reactions in Pediatric Patients Transfused with Conventional or Pathogen Reduced Platelets

OBJECTIVES

To assess the safety and efficacy of a Food and Drug Administration-approved pathogen-reduced platelet (PLT) product in children, as ongoing questions regarding their use in this population remain.

STUDY DESIGN

We report findings from a quality assurance review of PLT utilization, associated red blood cell transfusion trends, and short-term safety of conventional vs pathogen-reduced PLTs over a 21-month period while transitioning from conventional to pathogen-reduced PLTs at a large, tertiary care hospital. We assessed utilization in neonatal intensive care unit (NICU) patients, infants 0-1 year not in the NICU, and children age 1-18 years (PED).

RESULTS

In the 48 hours after an index conventional or pathogen-reduced platelet transfusion, respectively, NICU patients received 1.0 ± 1.4 (n = 91 transfusions) compared with 1.2 ± 1.3 (n = 145) additional platelet doses (P = .29); infants 0-1 year not in the NICU received 2.8 ± 3.0 (n = 125) vs 2.6 ± 2.6 (n = 254) additional platelet doses (P = .57); and PEDs received 0.9 ± 1.6 (n = 644) vs 1.4 ± 2.2 (n = 673) additional doses (P < .001). Time to subsequent transfusion and red cell utilization were similar in every group (P > .05). The number and type of transfusion reactions did not significantly vary based on PLT type and no rashes were reported in NICU patients receiving phototherapy and pathogen-reduced PLTs.

CONCLUSIONS

Conventional and pathogen-reduced PLTs had similar utilization patterns in our pediatric populations. A small, but statistically significant, increase in transfusions was noted following pathogen-reduced PLT transfusion in PED patients, but not in other groups. Red cell utilization and transfusion reactions were similar for both products in all age groups.

How low can you go: What is the safe threshold for platelet transfusions in patients with hematologic malignancy in sub-Saharan Africa

Background

Despite the importance of platelet transfusions in treatment of hematologic cancer patients, the optimal platelet count threshold for prophylactic transfusion is unknown in sub-Saharan Africa.

Methods

We followed patients admitted to the Uganda Cancer Institute with a hematological malignancy in 3 sequential 4-month time-periods using incrementally lower thresholds for prophylactic platelet transfusion: platelet counts ≤ 30 x 10⁹/L in period 1, ≤ 20 x 10⁹/L in period 2, and ≤ 10 x 10⁹/L in period 3. Clinically significant bleeding was defined as WHO grade ≥ 2 bleeding. We used generalized estimating equations (GEE) to compare the frequency of clinically significant bleeding and platelet transfusions by study period, adjusting for age, sex, cancer type, chemotherapy, baseline platelet count, and baseline hemoglobin.

Results

Overall, 188 patients were enrolled. The median age was 22 years (range 1–80). Platelet transfusions were given to 42% of patients in period 1, 55% in period 2, and 45% in period 3. These transfusions occurred on 8% of days in period 1, 12% in period 2, and 8% in period 3. In adjusted models, period 3 had significantly fewer transfusions than period 1 (RR = 0.6, 95% CI 0.4–0.9; p = 0.01) and period 2 (RR = 0.5, 95% CI 0.4–0.7; p<0.001). Eighteen patients (30%) had clinically significant bleeding on at least one day in period 1, 23 (30%) in period 2, and 15 (23%) in period 3. Clinically significant bleeding occurred on 8% of patient-days in period 1, 9% in period 2, and 5% in period 3 (adjusted p = 0.41). Thirteen (21%) patients died in period 1, 15 (22%) in period 2, and 11 (19%) in period 3 (adjusted p = 0.96).

Conclusion

Lowering the threshold for platelet transfusion led to fewer transfusions and did not change the incidence of clinically significant bleeding or mortality, suggesting that a threshold of 10 x 10⁹/L platelets, used in resource-rich countries, may be implemented as a safe level for transfusions in sub-Saharan Africa.