The ASH-ASPHO Choosing Wisely Campaign: 5 hematologic tests and treatments to question.

Choosing Wisely is a medical stewardship and quality-improvement initiative led by the American Board of Internal Medicine Foundation in collaboration with leading medical societies in the United States. The American Society of Hematology (ASH) has been an active participant in the Choosing Wisely project. In 2019, ASH and the American Society of Pediatric Hematology/Oncology (ASPHO) formed a joint task force to solicit, evaluate, and select items for a pediatric-focused Choosing Wisely list. By using an iterative process and an evidence-based method, the ASH-ASPHO Task Force identified 5 hematologic tests and treatments that health care providers and patients should question because they are not supported by evidence, and/or they involve risks of medical and financial costs with low likelihood of benefit. The ASH-ASPHO Choosing Wisely recommendations are as follows: (1) avoid routine preoperative hemostatic testing in an otherwise healthy child with no previous personal or family history of bleeding, (2) avoid platelet transfusion in asymptomatic children with a platelet count >10 × 103/µL unless an invasive procedure is planned, (3) avoid thrombophilia testing in children with venous access-associated thrombosis and no positive family history, (4) avoid packed red blood cells transfusion for asymptomatic children with iron deficiency anemia and no active bleeding, and (5) avoid routine administration of granulocyte colony-stimulating factor for prophylaxis of children with asymptomatic autoimmune neutropenia and no history of recurrent or severe infections. We recommend that health care providers carefully consider the anticipated risks and benefits of these identified tests and treatments before performing them.

The ASH-ASPHO Choosing Wisely Campaign: 5 hematologic tests and treatments to question.

Choosing Wisely is a medical stewardship and quality-improvement initiative led by the American Board of Internal Medicine Foundation in collaboration with leading medical societies in the United States. The American Society of Hematology (ASH) has been an active participant in the Choosing Wisely project. In 2019, ASH and the American Society of Pediatric Hematology/Oncology (ASPHO) formed a joint task force to solicit, evaluate, and select items for a pediatric-focused Choosing Wisely list. By using an iterative process and an evidence-based method, the ASH-ASPHO Task Force identified 5 hematologic tests and treatments that health care providers and patients should question because they are not supported by evidence, and/or they involve risks of medical and financial costs with low likelihood of benefit. The ASH-ASPHO Choosing Wisely recommendations are as follows: (1) avoid routine preoperative hemostatic testing in an otherwise healthy child with no previous personal or family history of bleeding, (2) avoid platelet transfusion in asymptomatic children with a platelet count 10 × 103 /µL unless an invasive procedure is planned, (3) avoid thrombophilia testing in children with venous access-associated thrombosis and no positive family history, (4) avoid packed red blood cells transfusion for asymptomatic children with iron deficiency anemia and no active bleeding, and (5) avoid routine administration of granulocyte colony-stimulating factor for prophylaxis of children with asymptomatic autoimmune neutropenia and no history of recurrent or severe infections. We recommend that health care providers carefully consider the anticipated risks and benefits of these identified tests and treatments before performing them.

Clinical Practice Guideline: Nosebleed (Epistaxis).

OBJECTIVE: Nosebleed, also known as epistaxis, is a common problem that occurs at some point in at least 60% of people in the United States. While the majority of nosebleeds are limited in severity and duration, about 6% of people who experience nosebleeds will seek medical attention. For the purposes of this guideline, we define the target patient with a nosebleed as a patient with bleeding from the nostril, nasal cavity, or nasopharynx that is sufficient to warrant medical advice or care. This includes bleeding that is severe, persistent, and/or recurrent, as well as bleeding that impacts a patient's quality of life. Interventions for nosebleeds range from self-treatment and home remedies to more intensive procedural interventions in medical offices, emergency departments, hospitals, and operating rooms. Epistaxis has been estimated to account for 0.5% of all emergency department visits and up to one-third of all otolaryngology-related emergency department encounters. Inpatient hospitalization for aggressive treatment of severe nosebleeds has been reported in 0.2% of patients with nosebleeds. PURPOSE: The primary purpose of this multidisciplinary guideline is to identify quality improvement opportunities in the management of nosebleeds and to create clear and actionable recommendations to implement these opportunities in clinical practice. Specific goals of this guideline are to promote best practices, reduce unjustified variations in care of patients with nosebleeds, improve health outcomes, and minimize the potential harms of nosebleeds or interventions to treat nosebleeds. The target patient for the guideline is any individual aged ≥3 years with a nosebleed or history of nosebleed who needs medical treatment or seeks medical advice. The target audience of this guideline is clinicians who evaluate and treat patients with nosebleed. This includes primary care providers such as family medicine physicians, internists, pediatricians, physician assistants, and nurse practitioners. It also includes specialists such as emergency medicine providers, otolaryngologists, interventional radiologists/neuroradiologists and neurointerventionalists, hematologists, and cardiologists. The setting for this guideline includes any site of evaluation and treatment for a patient with nosebleed, including ambulatory medical sites, the emergency department, the inpatient hospital, and even remote outpatient encounters with phone calls and telemedicine. Outcomes to be considered for patients with nosebleed include control of acute bleeding, prevention of recurrent episodes of nasal bleeding, complications of treatment modalities, and accuracy of diagnostic measures. This guideline addresses the diagnosis, treatment, and prevention of nosebleed. It focuses on nosebleeds that commonly present to clinicians via phone calls, office visits, and emergency room encounters. This guideline discusses first-line treatments such as nasal compression, application of vasoconstrictors, nasal packing, and nasal cautery. It also addresses more complex epistaxis management, which includes the use of endoscopic arterial ligation and interventional radiology procedures. Management options for 2 special groups of patients-patients with hereditary hemorrhagic telangiectasia syndrome and patients taking medications that inhibit coagulation and/or platelet function-are included in this guideline. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group. It is not intended to be a comprehensive, general guide for managing patients with nosebleed. In this context, the purpose is to define useful actions for clinicians, generalists, and specialists from a variety of disciplines to improve quality of care. Conversely, the statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients. ACTION STATEMENTS: The guideline development group made recommendations for the following key action statements: (1) At the time of initial contact, the clinician should distinguish the nosebleed patient who requires prompt management from the patient who does not. (2) The clinician should treat active bleeding for patients in need of prompt management with firm sustained compression to the lower third of the nose, with or without the assistance of the patient or caregiver, for 5 minutes or longer. (3a) For patients in whom bleeding precludes identification of a bleeding site despite nasal compression, the clinician should treat ongoing active bleeding with nasal packing. (3b) The clinician should use resorbable packing for patients with a suspected bleeding disorder or for patients who are using anticoagulation or antiplatelet medications. (4) The clinician should educate the patient who undergoes nasal packing about the type of packing placed, timing of and plan for removal of packing (if not resorbable), postprocedure care, and any signs or symptoms that would warrant prompt reassessment. (5) The clinician should document factors that increase the frequency or severity of bleeding for any patient with a nosebleed, including personal or family history of bleeding disorders, use of anticoagulant or antiplatelet medications, or intranasal drug use. (6) The clinician should perform anterior rhinoscopy to identify a source of bleeding after removal of any blood clot (if present) for patients with nosebleeds. (7a) The clinician should perform, or should refer to a clinician who can perform, nasal endoscopy to identify the site of bleeding and guide further management in patients with recurrent nasal bleeding, despite prior treatment with packing or cautery, or with recurrent unilateral nasal bleeding. (8) The clinician should treat patients with an identified site of bleeding with an appropriate intervention, which may include one or more of the following: topical vasoconstrictors, nasal cautery, and moisturizing or lubricating agents. (9) When nasal cautery is chosen for treatment, the clinician should anesthetize the bleeding site and restrict application of cautery only to the active or suspected site(s) of bleeding. (10) The clinician should evaluate, or refer to a clinician who can evaluate, candidacy for surgical arterial ligation or endovascular embolization for patients with persistent or recurrent bleeding not controlled by packing or nasal cauterization. (11) In the absence of life-threatening bleeding, the clinician should initiate first-line treatments prior to transfusion, reversal of anticoagulation, or withdrawal of anticoagulation/antiplatelet medications for patients using these medications. (12) The clinician should assess, or refer to a specialist who can assess, the presence of nasal telangiectasias and/or oral mucosal telangiectasias in patients who have a history of recurrent bilateral nosebleeds or a family history of recurrent nosebleeds to diagnose hereditary hemorrhagic telangiectasia syndrome. (13) The clinician should educate patients with nosebleeds and their caregivers about preventive measures for nosebleeds, home treatment for nosebleeds, and indications to seek additional medical care. (14) The clinician or designee should document the outcome of intervention within 30 days or document transition of care in patients who had a nosebleed treated with nonresorbable packing, surgery, or arterial ligation/embolization. The policy level for the following recommendation, about examination of the nasal cavity and nasopharynx using nasal endoscopy, was an option: (7b) The clinician may perform, or may refer to a clinician who can perform, nasal endoscopy to examine the nasal cavity and nasopharynx in patients with epistaxis that is difficult to control or when there is concern for unrecognized pathology contributing to epistaxis.

Clinical Practice Guideline: Nosebleed (Epistaxis) Executive Summary.

OBJECTIVE: Nosebleed, also known as epistaxis, is a common problem that occurs at some point in at least 60% of people in the United States. While the great majority of nosebleeds are limited in severity and duration, about 6% of people who experience nosebleeds will seek medical attention. For the purposes of this guideline, we define the target patient with a nosebleed as a patient with bleeding from the nostril, nasal cavity, or nasopharynx that is sufficient to warrant medical advice or care. This includes bleeding that is severe, persistent, and/or recurrent, as well as bleeding that impacts a patient's quality of life. Interventions for nosebleeds range from self-treatment and home remedies to more intensive procedural interventions in medical offices, emergency departments, hospitals, and operating rooms. Epistaxis has been estimated to account for 0.5% of all emergency department visits and up to one-third of all otolaryngology-related emergency department encounters. Inpatient hospitalization for aggressive treatment of severe nosebleeds has been reported in 0.2% of patients with nosebleeds. PURPOSE: The primary purpose of this multidisciplinary guideline is to identify quality improvement opportunities in the management of nosebleeds and to create clear and actionable recommendations to implement these opportunities in clinical practice. Specific goals of this guideline are to promote best practices, reduce unjustified variations in care of patients with nosebleeds, improve health outcomes, and minimize the potential harms of nosebleeds or interventions to treat nosebleeds. The target patient for the guideline is any individual aged ≥3 years with a nosebleed or history of nosebleed who needs medical treatment or seeks medical advice. The target audience of this guideline is clinicians who evaluate and treat patients with nosebleed. This includes primary care providers such as family medicine physicians, internists, pediatricians, physician assistants, and nurse practitioners. It also includes specialists such as emergency medicine providers, otolaryngologists, interventional radiologists/neuroradiologists and neurointerventionalists, hematologists, and cardiologists. The setting for this guideline includes any site of evaluation and treatment for a patient with nosebleed, including ambulatory medical sites, the emergency department, the inpatient hospital, and even remote outpatient encounters with phone calls and telemedicine. Outcomes to be considered for patients with nosebleed include control of acute bleeding, prevention of recurrent episodes of nasal bleeding, complications of treatment modalities, and accuracy of diagnostic measures. This guideline addresses the diagnosis, treatment, and prevention of nosebleed. It will focus on nosebleeds that commonly present to clinicians with phone calls, office visits, and emergency room encounters. This guideline discusses first-line treatments such as nasal compression, application of vasoconstrictors, nasal packing, and nasal cautery. It also addresses more complex epistaxis management, which includes the use of endoscopic arterial ligation and interventional radiology procedures. Management options for 2 special groups of patients, patients with hemorrhagic telangiectasia syndrome (HHT) and patients taking medications that inhibit coagulation and/or platelet function, are included in this guideline. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the working group. It is not intended to be a comprehensive, general guide for managing patients with nosebleed. In this context, the purpose is to define useful actions for clinicians, generalists, and specialists from a variety of disciplines to improve quality of care. Conversely, the statements in this guideline are not intended to limit or restrict care provided by clinicians based upon their experience and assessment of individual patients. ACTION STATEMENTS: The guideline development group made recommendations for the following key action statements: (1) At the time of initial contact, the clinician should distinguish the nosebleed patient who requires prompt management from the patient who does not. (2) The clinician should treat active bleeding for patients in need of prompt management with firm sustained compression to the lower third of the nose, with or without the assistance of the patient or caregiver, for 5 minutes or longer. (3a) For patients in whom bleeding precludes identification of a bleeding site despite nasal compression, the clinician should treat ongoing active bleeding with nasal packing. (3b) The clinician should use resorbable packing for patients with a suspected bleeding disorder or for patients who are using anticoagulation or antiplatelet medications. (4) The clinician should educate the patient who undergoes nasal packing about the type of packing placed, timing of and plan for removal of packing (if not resorbable), postprocedure care, and any signs or symptoms that would warrant prompt reassessment. (5) The clinician should document factors that increase the frequency or severity of bleeding for any patient with a nosebleed, including personal or family history of bleeding disorders, use of anticoagulant or antiplatelet medications, or intranasal drug use. (6) The clinician should perform anterior rhinoscopy to identify a source of bleeding after removal of any blood clot (if present) for patients with nosebleeds. (7a) The clinician should perform, or should refer to a clinician who can perform, nasal endoscopy to identify the site of bleeding and guide further management in patients with recurrent nasal bleeding, despite prior treatment with packing or cautery, or with recurrent unilateral nasal bleeding. (8) The clinician should treat patients with an identified site of bleeding with an appropriate intervention, which may include 1 or more of the following: topical vasoconstrictors, nasal cautery, and moisturizing or lubricating agents. (9) When nasal cautery is chosen for treatment, the clinician should anesthetize the bleeding site and restrict application of cautery only to the active or suspected site(s) of bleeding. (10) The clinician should evaluate, or refer to a clinician who can evaluate, candidacy for surgical arterial ligation or endovascular embolization for patients with persistent or recurrent bleeding not controlled by packing or nasal cauterization. (11) In the absence of life-threatening bleeding, the clinician should initiate first-line treatments prior to transfusion, reversal of anticoagulation, or withdrawal of anticoagulation/antiplatelet medications for patients using these medications. (12) The clinician should assess, or refer to a specialist who can assess, the presence of nasal telangiectasias and/or oral mucosal telangiectasias in patients who have a history of recurrent bilateral nosebleeds or a family history of recurrent nosebleeds to diagnose hereditary hemorrhagic telangiectasia syndrome (HHT). (13) The clinician should educate patients with nosebleeds and their caregivers about preventive measures for nosebleeds, home treatment for nosebleeds, and indications to seek additional medical care. (14) The clinician or designee should document the outcome of intervention within 30 days or document transition of care in patients who had a nosebleed treated with nonresorbable packing, surgery, or arterial ligation/embolization. The policy level for the following recommendation about examination of the nasal cavity and nasopharynx using nasal endoscopy was an option: (7b) The clinician may perform, or may refer to a clinician who can perform, nasal endoscopy to examine the nasal cavity and nasopharynx in patients with epistaxis that is difficult to control or when there is concern for unrecognized pathology contributing to epistaxis.

Platelet Function Changes during Neonatal Cardiopulmonary Bypass Surgery: Mechanistic Basis and Lack of Correlation with Excessive Bleeding.

Thrombocytopenia and platelet dysfunction induced by extracorporeal blood circulation are thought to contribute to postsurgical bleeding complications in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this study, we examined how changes in platelet function relate to changes in platelet count and to excessive bleeding in neonatal CPB surgery. Platelet counts and platelet P-selectin exposure in response to agonist stimulation were measured at four times before, during, and after CPB surgery in neonates with normal versus excessive levels of postsurgical bleeding. Relative to baseline, platelet counts were reduced in patients while on CPB, as was platelet activation by the thromboxane A2 analog U46619, thrombin receptor activating peptide (TRAP), and collagen-related peptide (CRP). Platelet activation by adenosine diphosphate (ADP) was instead reduced after platelet transfusion. We provide evidence that thrombocytopenia is a likely contributor to CPB-associated defects in platelet responsiveness to U46619 and TRAP, CPB-induced collagen receptor downregulation likely contributes to defective platelet responsiveness to CRP, and platelet transfusion may contribute to defective platelet responses to ADP. Platelet transfusion restored to baseline levels platelet counts and responsiveness to all agonists except ADP but did not prevent excessive bleeding in all patients. We conclude that platelet count and function defects are characteristic of neonatal CPB surgery and that platelet transfusion corrects these defects. However, since CPB-associated coagulopathy is multifactorial, platelet transfusion alone is insufficient to treat bleeding events in all patients. Therefore, platelet transfusion must be combined with treatment of other factors that contribute to the coagulopathy to prevent excessive bleeding.

Plasma Proteolytic Cascade Activation during Neonatal Cardiopulmonary Bypass Surgery.

BACKGROUND: Neonates undergoing cardiopulmonary bypass (CPB) surgery to correct congenital heart defects often experience excessive bleeding. Exposure of blood to artificial materials during CPB may activate coagulation, complement and inflammatory pathways. In addition, the surgical stress placed on the haemostatic system may result in cross-activation of other plasma proteolytic cascades, which could further complicate physiological responses to the surgical procedure and post-operative recovery. Plasma protease inhibitors undergo distinct conformational changes upon interaction with proteases, and, thereby, can serve as endogenous biosensors to identify activation of the different proteolytic cascades. We tested the hypothesis that changes in the concentration and conformation of protease inhibitors regulating plasma proteolytic cascades during neonatal CPB are associated with post-operative bleeding. PATIENTS AND METHODS: Plasma samples from 44 neonates were obtained at four time points across the surgical procedure. Anti-thrombin, antitrypsin, anti-chymotrypsin, anti-plasmin, C1-inhibitor and tissue factor pathway inhibitor (TFPI) concentrations and conformations were evaluated by enzyme-linked immunosorbent assay, transverse urea gradient gel electrophoresis and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. RESULTS/CONCLUSION: The most striking changes were observed following heparin administration and were associated with the appearance of inactive forms of anti-thrombin and an increase in the plasma concentration of TFPI. Changes in anti-thrombin and TFPI remained evident throughout surgery and into the post-operative period but were not different between patients with or without post-operative bleeding. The concentration of antitrypsin decreased across surgery, but there was no significant accumulation of inactive conformations of any inhibitor besides anti-thrombin, indicating that widespread cross-activation of other plasma proteolytic cascades by coagulation proteases did not occur.

Rotational Thromboelastometry Rapidly Predicts Thrombocytopenia and Hypofibrinogenemia During Neonatal Cardiopulmonary Bypass.

BACKGROUND: Thrombocytopenia and hypofibrinogenemia during neonatal cardiopulmonary bypass (CPB) contribute to bleeding and morbidity. Rotational thromboelastometry (ROTEM) is a viscoelastic assay with a rapid turnaround time. Data validating ROTEM during neonatal cardiac surgery remain limited. This study examined perioperative hemostatic trends in neonates treated with standardized platelet and cryoprecipitate transfusion during CPB. We hypothesized that ROTEM would predict thrombocytopenia, hypofibrinogenemia, and the correction thereof. METHODS: Forty-four neonates undergoing CPB were included in this prospective observational study. Blood samples were obtained at Baseline, On CPB, Post-CPB, and Postoperative. The ROTEM analysis included extrinsically activated (Extem) and fibrinogen-specific (Fibtem) assays. Platelet-specific thromboelastometry (Pltem) values were calculated. Platelet and cryoprecipitate transfusion was initiated prior to termination of CPB. RESULTS: Platelet count and Extem amplitude decreased significantly On CPB ( P < .0001), increased significantly Post-CPB ( P < .0001), and Postoperative values were not significantly different from Baseline. Extem amplitude at 10 minutes (A10) > 46.5 mm (AUC = 0.941) and Pltem A10 > 37.5 mm [area under curve (AUC) = 0.960] predicted platelet count > 100 × 103/µL, and they highly correlated with platelet count ( R = 0.89 and R = 0.90, respectively). Fibrinogen concentration and Fibtem amplitude decreased significantly On CPB ( P ≤ .0001) and normalized after cryoprecipitate transfusion. Fibtem A10 > 9.5 mm predicted fibrinogen >200 mg/dL (AUC = 0.817), but it correlated less well with fibrinogen concentration ( R = 0.65). CONCLUSIONS: ROTEM analysis during neonatal cardiac surgery is sensitive and specific for thrombocytopenia and hypofibrinogenemia, identifying deficits within 10 minutes. Platelet and cryoprecipitate transfusion during neonatal CPB normalizes platelet count, fibrinogen level, and ROTEM amplitudes.

Validation of a definition of excessive postoperative bleeding in infants undergoing cardiac surgery with cardiopulmonary bypass.

OBJECTIVE: To derive and validate an objective definition of postoperative bleeding in neonates and infants undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Using a retrospective cohort of 124 infants and neonates, we included published bleeding definitions and cumulative chest tube output over different postoperative periods (eg, 2, 12, or 24 hours after intensive care unit admission) in a classification and regression tree model to determine chest tube output volumes that were associated with red blood cell transfusions and surgical re-exploration for bleeding in the first 24 hours after intensive care unit admission. After the definition of excessive bleeding was determined, it was validated via a prospective cohort of 77 infants and neonates. RESULTS: Excessive bleeding was defined as ≥7 mL/kg/h for ≥2 consecutive hours in the first 12 postoperative hours and/or ≥84 mL/kg total for the first 24 postoperative hours and/or surgical re-exploration for bleeding or cardiac tamponade physiology in the first 24 postoperative hours. Excessive bleeding was associated with longer length of hospital stay, increased 30-day readmission rate, and increased transfusions in the postoperative period. CONCLUSIONS: The proposed standard definition of excessive bleeding is based on readily obtained objective data and relates to important early clinical outcomes. Application and validation by other institutions will help determine the extent to which our specialty should consider this definition for both clinical investigation and quality improvement initiatives.

Neonatal Platelet Transfusions and Future Areas of Research.

Thrombocytopenia affects approximately one fourth of neonates admitted to neonatal intensive care units, and prophylactic platelet transfusions are commonly administered to reduce bleeding risk. However, there are few evidence-based guidelines to inform clinicians' decision-making process. Developmental differences in hemostasis and differences in underlying disease processes make it difficult to apply platelet transfusion practices from other patient populations to neonates. Thrombocytopenia is a risk factor for common preterm complications such as intraventricular hemorrhage; however, a causal link has not been established, and platelet transfusions have not been shown to reduce risk of developing intraventricular hemorrhage. Platelet count frequently drives the decision of whether to transfuse platelets, although there is little evidence to demonstrate what a safe platelet nadir is in preterm neonates. Current clinical assays of platelet function often require large sample volumes and are not valid in the setting of thrombocytopenia; however, evaluation of platelet function and/or global hemostasis may aid in the identification of neonates who are at the highest risk of bleeding. Although platelets' primary role is in establishing hemostasis, platelets also carry pro- and antiangiogenic factors in their granules. Aberrant angiogenesis underpins common complications of prematurity including intraventricular hemorrhage and retinopathy of prematurity. In addition, platelets play an important role in host immune defenses. Infectious and inflammatory conditions such as sepsis and necrotizing enterocolitis are commonly associated with late-onset thrombocytopenia in neonates. Severity of thrombocytopenia is correlated with mortality risk. The nature of this association is unclear, but preclinical data suggest that thrombocytopenia contributes to mortality rather than simply being a proxy for disease severity. Neonates are a distinct patient population in whom thrombocytopenia is common. Their unique physiology and associated complications make the risks and benefits of platelet transfusions difficult to understand. The goal of this review was to highlight research areas that need to be addressed to better understand the risks and benefits of platelet transfusions in neonates. Specifically, it will be important to identify neonates at risk of bleeding who would benefit from a platelet transfusion and to determine whether platelet transfusions either abrogate or exacerbate common neonatal complications such as sepsis, chronic lung disease, necrotizing enterocolitis, and retinopathy of prematurity.

Transfusion Considerations in Pediatric Hematology and Oncology Patients.

Pediatric patients with malignancies or benign hematologic diseases are a heterogeneous group with complicated underlying pathophysiologies leading to their requirements for transfusion therapy. Common practice among pediatric hematologists, oncologists, and transplant physicians is to transfuse stable patients red cells to maintain a hemoglobin greater than 7 or 8 g/dL and transfuse platelets to maintain a count greater than 10,000 or 20,000 platelets/µL. This review compiles data from myriad studies performed in pediatric patients to give readers the knowledge needed to make an informed choice when considering different management strategies for the transfusion of red blood cells, platelets, plasma, and granulocytes.

Effect of 22q11.2 deletion on bleeding and transfusion utilization in children with congenital heart disease undergoing cardiac surgery.

BACKGROUND: Postsurgical bleeding causes significant morbidity and mortality in children undergoing surgery for congenital heart defects (CHD). 22q11.2 deletion syndrome (DS) is the second most common genetic risk factor for CHD. The deleted segment of chromosome 22q11.2 encompasses the gene encoding glycoprotein (GP) Ibß, which is required for expression of the GPIb-V-IX complex on the platelet surface, where it functions as the receptor for von Willebrand factor (VWF). Binding of GPIb-V-IX to VWF is important for platelets to initiate hemostasis. It is not known whether hemizygosity for the gene encoding GPIbß increases the risk for bleeding following cardiac surgery for patients with 22q11.2 DS. METHODS: We performed a case-control study of 91 pediatric patients who underwent cardiac surgery with cardiopulmonary bypass from 2004 to 2012 at Children's Hospital of Wisconsin. RESULTS: Patients with 22q11.2 DS had larger platelets and lower platelet counts, bled more excessively, and received more transfusion support with packed red blood cells in the early postoperative period relative to control patients. CONCLUSION: Presurgical genetic testing for 22q11.2 DS may help to identify a subset of pediatric cardiac surgery patients who are at increased risk for excessive bleeding and who may require more transfusion support in the postoperative period.

A survey of transfusion practices in pediatric hematopoietic stem cell transplant patients.

Until recovery of hematopoiesis, pediatric hematopoietic stem cell transplant (HSCT) patients are dependent on red blood cell and platelet transfusions to avoid the complications associated with anemia and thrombocytopenia, respectively. Despite the fact that these patients are high utilizers of blood components, there are no evidence-based guidelines regarding optimal transfusion practices in this patient population. A web-based survey was designed to examine current transfusion thresholds used by institutions that perform pediatric HSCT. This survey was sent to department directors identified through the Children's Oncology Group directory with a response rate of 69%. The majority of institutions use 8 g/dL as the hemoglobin threshold for red blood cell transfusions (60%), but a significant minority use 7 g/dL (25%). With respect to platelet transfusion thresholds, 47% of respondents report using 20×10/L and 44% use 10×10/L. Respondents were also asked about specific clinical scenarios that would prompt an increase in a patient's threshold. This survey revealed that there is variation in transfusion practices among pediatric HSCT institutions with respect to both baseline transfusion threshold and what prompts an increase in threshold. Future clinical trials are needed to determine optimal transfusion thresholds in pediatric HSCT patients, which can lead to improved standardization in practices.

Measuring bleeding as an outcome in clinical trials of prophylactic platelet transfusions.

A 12-year-old girl with acute myeloid leukemia has completed her third cycle of chemotherapy and is in the hospital awaiting count recovery. Her platelet count today is 15 000 and, based on your institution's protocol, she should receive a prophylactic platelet transfusion. She has a history of allergic reactions to platelet transfusions and currently has no bleeding symptoms. The patient's mother questions the necessity of today's transfusion and asks what her daughter's risk of bleeding would be if the count is allowed to decrease lower before transfusing. You perform a literature search regarding the risk of bleeding with differing regimens for prophylactic platelet transfusions.

Thrombocytopenia and bleeding in pediatric oncology patients.

Prophylactic platelet transfusions are the standard of care for patients with hypoproliferative thrombocytopenia after receiving chemotherapy or radiation for the treatment of malignancy, for BM replacement by leukemia or solid tumor, or in preparation for a hematopoietic stem cell transplantation.(1) During this time of thrombocytopenia, these patients may receive both prophylactic platelet transfusions, which are given to prevent potentially life-threatening bleeding when a patient's platelet count drops below a predetermined threshold, and therapeutic platelet transfusions, which are given to treat active or recurrent bleeding. In the 1950s, the invention of the plastic blood bag allowed for the production and storage of platelet concentrates,(2) and in the 1960s, it was recognized that prophylactic platelet transfusions effectively reduced hemorrhagic death in patients with newly diagnosed leukemia.(3,4) In 1962, Gaydos published the paper that is frequently credited with the inception of the 20 000/µL platelet transfusion threshold.(5) Despite a half-century of experience with prophylactic platelet transfusions, there are still insufficient data to provide clinicians with evidence-based guidelines specific to pediatric oncology and hematopoietic stem cell transplantation (HSCT) patients.

Tumor necrosis factor-alpha causes release of cytosolic interleukin-18 from human neutrophils.

Neutrophils (PMNs) are a vital part of host defense and are the principal leukocyte in innate immunity. Interleukin (IL)-18 is a proinflammatory cytokine with roles in both innate and adaptive immunity. We hypothesize that PMNs contain preformed IL-18, which is released in response to specific inflammatory stimuli. Isolated PMNs were stimulated with a battery of chemoattractants (5 min to 24 h), and IL-18 release was measured. PMNs were also separated into subcellular fractions and immunoblotted with antibodies against IL-18 or were fixed and probed with antibodies to IL-18 as well as to the contents of granules, intracellular organelles, and filamentous actin (F-actin), incubated with fluorescent secondary antibodies, and examined by digital microscopy. Quiescent PMNs contained IL-18 in the cytoplasm, associated with F-actin, as determined by positive fluorescence resonance energy transfer (FRET+). In turn, TNF-alpha stimulation disrupted the association of IL-18 with F-actin, induced a FRET+ interaction of IL-18 with lipid rafts, and elicited IL-18 release. Manipulation of F-actin status confirmed the relationship between IL-18 and F-actin in resting PMNs. Consequently, incubation with monomeric IL-18 binding protein inhibited TNF-alpha-mediated priming of the PMN oxidase. We conclude that human PMNs contain IL-18 associated with F-actin in the cytoplasm and TNF-alpha stimulation causes dissociation of IL-18 from F-actin, association with lipid rafts, and extracellular release. Extracellular IL-18 participates in TNF-alpha priming of the PMN oxidase as demonstrated by inhibition with the IL-18 binding protein.

Acute tumor lysis syndrome in a 7-month-old with hepatoblastoma.

Acute tumor lysis syndrome (TLS) is characterized by the triad of hyperuricemia, hyperkalemia, and hyperphosphatemia and is caused by the death of tumor cells and release of intracellular contents into the circulation. This syndrome is most frequently associated with hematopoietic malignancies with a high growth fraction, including acute leukemias and lymphomas, but can be encountered in patients with nonhematopoietic solid tumors. Acute tumor lysis is typically precipitated by chemotherapy leading to rapid cell death, but may also occur spontaneously prior to treatment. In severe cases, the metabolic abnormalities of TLS can cause renal failure, cardiac arrhythmias, and death. Standard therapies include intravenous hydration, alkalinization of the urine to increase the solubility of uric acid, and administration of allopurinol to block production of uric acid. Recombinant urate oxidase (rasburicase) is a newer agent that directly cleaves uric acid. It is important for the clinician to maintain a high level of clinical suspicion for TLS when initiating therapy in children newly diagnosed with cancer, including those with solid tumors, and to know how to prevent and treat this potentially deadly metabolic complication.