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![ No therapy other than education and counseling of the family and
patient for patients with minimal, mild, and moderate symptoms
Treatment with either IVIG or corticosteroids, particularly for children
who present with mucocutaneous bleeding.
◦ A single dose of IVIG [intravenous immune globulin] (0.8-1.0
g/kg) or a short course of corticosteroids should be used as first-
line treatment.”
◦ IVIG at a dose of 0.8-1.0 g/kg/day for 1-2 days induces a rapid
rise in platelet count (usually >20 × 109 /L) in 95% of patients](https://image.slidesharecdn.com/bleedingdisordersedited-251123070431-a9a3304a/85/Bleeding-disorders-in-internal-medicine-pro-40-320.jpg)
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Bleeding disorders in internal medicine pro
- 1.
- 2. Hemophilia Vonwillibrand disease Idiopathic (Autoimmune) Thrombocytopenic Purpura (ITP) Thrombotic thrombocytopenic purpura (TTP) Hemolytic-uremic syndrome (HUS) HSP DIC BLEEDING DISORDERS
- 3. Hemostasis isthe process of blood clotting in areas of blood vessel injury Over time, a clot is lysed by the fibrinolytic system, and normal blood flow is restored. If clotting is impaired, hemorrhage occurs If clotting is excessive, thrombosis occurs. Therefore the hemostatic response needs to be rapid and regulated. HEMOSTASIS
- 4. platelet adheres tosite of vascular injury (plt provides a surface for adhering of clotting factors) Activated enzyme plus substrate plus cofactor on a reaction surface, accelerate reaction rates and provide activated products for reaction with clotting factors further down the coagulation cascade. HEMOSTASIS
- 5. vessel wall, platelets, coagulation proteins, anticoagulant proteins, fibrinolytic system. Components of hemostasis
- 6. Most componentsof hemostasis are multifunctional; fibrinogen - tethers platelet to each other leading to platelet aggregation - substrate for thrombin that forms the fibrin clot. Platelets - provide the reaction surface on which clotting reactions occur, - form the plug at the site of vessel injury, - contract to constrict and limit clot size.
- 7. The intactvascular endothelium is the primary barrier against hemorrhage. The endothelial cells lining vessel walls normally inhibit coagulation and provide a smooth surface----- rapid blood flow. After vascular injury, vasoconstriction occurs and flowing blood comes in contact with the subendothelial matrix. The Hemostatic Process
- 8. composed of 4major events 1- Vascular constriction -limits the flow of blood to the area of injury. 2- Platelet aggregation –Platelets clump when binding to exposed collagen following rupture of the endothelial lining of vessels. -Platelets become activated and aggregate at the site of injury (thrombin and fibrinogen-mediated effects). Upon activation, platelets release ADP and TXA2 (which activate additional platelets). HEMOSTASIS:
- 9. 3-Clot formation -to ensurestability of the initially loose platelet plug, a fibrin mesh (also called the clot) forms and entraps the plug. 4-Fibrinolysis -the clot must be dissolved in order for normal blood flow to resume following tissue repair. Clot dissolution occurs through the action of plasmin. HEMOSTASIS cont.
- 10. Intrinsic pathway:initiated when contact is made between blood and exposed endothelial cell surfaces. Extrinsic pathway: initiated upon vascular injury which leads to exposure of tissue factor (TF) ( a sub endothelial cell-surface glycoprotein that binds phospholipids). Common pathway Coagulation Phase / cascade
- 11. Intrinsic Pathway Allclotting factors are within the blood vessels Clotting slower test: Activated partial thromboplastin time (aPTT) Extrinsic Pathway Initiating factor is outside the blood vessels - tissue factor Clotting - faster - in Seconds Test: Prothrombin time (PT) Coagulation Phase
- 12. There existtwo systems to stop clotting: ◦ Inhibitor system ◦ Fibrinolytic system Inhibitor system consists of: ◦ Anti-thrombin III ◦ Protein C ◦ Protein S Protein C, S are vitamin K-dependent What stops the clotting (anticoagulants)?
- 13. Antithrombin IIIinactivates: ◦ Thrombin, Factor XIIa, XIa, Xa, IXa During clot formation small amounts of thrombin are swept downstream Binds to thrombomodulin which is on the surface of the intact endothelium Activated protein C (APC) binds protein S,--------- inactivating factors Va, VIIIa Inhibitor System
- 14. Plasminogen isconverted to plasmin Plasminogen activators: ◦ t-PA Synthesized in vascular endothelial cell Stimulated by exercise, stasis ◦ Urokinase Produced in kidneys Fibrinolytic System
- 15.
- 16. due todeficiency of Factor VIII (A) or Factor IX (B) the most common severe inherited bleeding disorders. Occurance– approximately 1 : 5,000 males, - 85% have factor VIII deficiency - 10–15% have factor IX deficiency The genes for factors VIII and IX are carried on the X chromosome Haemophilia (A and B) (inherited bleeding disorder)
- 17. Severe haemophilia ◦activity of specific clotting factor is <1% ◦ bleeding is often spontaneous (no trigger) moderate hemophilia ◦ have factor levels of 1–5% ◦ require mild trauma to induce bleeding. Mild hemophilia ◦ have levels >5%, ◦ require significant trauma to cause bleeding. Classification
- 18. Factors VIIIand IX participate in a complex required for the activation of factor X. Together with phospholipid and calcium, they form the factor X– activating, complex Pathophysiology
- 19. After injury,the initial hemostatic event is formation of the platelet plug, together with generation of the fibrin clot, which prevents further hemorrhage. In hemophilia A and B, clot formation is delayed. Inadequate thrombin generation leads to failure to form a tightly cross-linked fibrin clot to support the platelet plug. Patients with hemophilia slowly form a soft, friable clot.
- 20. Neither factorVIII nor factor IX crosses the placenta; bleeding symptoms may be present from birth or may occur in the fetus intracranial hemorrhages, bleeding with circumcision (males) easy bruising, intramuscular hematomas, hemarthroses,(hallmark of hemophilic bleeding) Bleeding from minor traumatic lacerations of the mouth (torn frenulum) which may persist for hours or days Symptoms
- 21. A reducedlevel of factor VIII or factor IX prolonged PTT. In severe hemophilia, the PTT value is usually 2-3 times the upper limit of normal. platelet count, bleeding time, PT, thrombin time are normal Laboratory findings
- 22. severe thrombocytopenia type 3 (severe) von Willebrand disease vitamin K deficiency Ddx
- 23. Recombinant factor VIII(FVIII) or recombinant factor IX (FIX) Dosage depends on the bleeding site prophylaxis is the standard of care for most children with severe hemophilia, to prevent spontaneous bleeding and early joint deformities Treatment
- 24. chronic arthropathye.g. arthritis development of an inhibitor to either factor VIII or factor IX (Inhibitors are antibodies directed against factor VIII or factor IX that block the clotting activity) risk of transfusion-transmitted infectious diseases complications
- 25. Avoiding trauma anticipatory guidance (use of car seats, seatbelts, and bike helmets) and avoidance of high-risk behaviors like contact sports Avoid aspirin and other NSAIDs that affect platelet function. appropriate vaccinations against hepatitis B Preventions
- 26. most commoninherited bleeding disorder, estimated prevalence 1 : 100 - 1 : 10,000. Patients with VWD typically present with mucosal bleeding. A family history of either VWD or bleeding symptoms Due to defect in or deficiency of von Willebrand factor Von Willebrand Disease
- 27. tether plateletsto injured sub-endothelium via binding sites for platelets and for collagen Protects FVIII from degradation in plasma Functions of VWF
- 28. mucosal bleeding,( epistaxis and menorrhagia) easy bruising potentially surgical bleeding NB: diagnosis based on symptoms may be difficult, since minor bruising and epistaxis are common in childhood Symptoms
- 29. Patients withsignificant bleeding may present with anemia, and some patients may have thrombocytopenia. VWF:Ag, which measures the total amount of VWF protein present VWF activity test, typically using the ristocetin cofactor activity assay (VWF:RCo ) Diagnosis
- 30. Desmopressin (IVor Intranasal) ◦0.3 μg/kg IV ◦1 spray Intranasal (<50 kg) Antifibrinolytics –used in Mucosal bleeding given as PO or IV ◦ Aminocaproic acid: 100 mg/kg PO loading dose followed by 50 mg/kg every 6 hr ◦Tranexamic acid: 1,300 mg PO 3 times daily for 5 days Treatment
- 31. Local treatmentof epistaxis, such as nasal cautery or packing, may be helpful Iron therapy for patients with iron-deficiency anemia Rx con’t
- 32. The mostcommon cause of acute onset of thrombocytopenia in an otherwise well child estimated at 1 in 20,000, 1-4 wk after exposure to a common viral infection, an autoantibody directed against the platelet surface develops with resultant sudden onset of thrombocytopenia recent history of viral illness. peak age : 1-4 yr males and females are equally affected Peak coincides with the end of peak of viral respiratory illnesses (late winter and early spring ) Idiopathic (Autoimmune) Thrombocytopenic Purpura (ITP)
- 33. After bindingof the antibody to the platelet surface, circulating antibody-coated platelets are recognized by the Fc receptor on splenic macrophages, ingested, and destroyed Most common viruses include EBV (acute ITP), HIV ( associated with chronic ITP) Some occurances seen with H. Pylori and following vaccination Pathogenesis
- 34. classic presentationof ITP is a previously healthy 1-4 yr old child who has : ◦ sudden onset of generalized petechiae and purpura There may be bleeding from the gums and mucous membranes, with profound thrombocytopenia (platelet count <10 × 109 /L). h/o a preceding viral infection 1-4 wk before the onset of thrombocytopenia physical examination are normal, other than petechiae and purpura Clinical Manifestations
- 35. 1. No symptoms 2.Mild symptoms: bruising and petechiae, occasional minor epistaxis, very little interference with daily living 3. Moderate symptoms: more severe skin and mucosal lesions, more troublesome epistaxis and menorrhagia 4. Severe symptoms: bleeding episodes—menorrhagia, epistaxis, melena— requiring transfusion or hospitalization, symptoms interfering seriously with the quality of life Severity of ITP
- 36. Severe bleedingis rare (<3% of cases) In 70–80% of children who present with acute ITP, spontaneous resolution occurs within 6 months. intracranial hemorrhage (ICH) Fewer than 1% Approx. 20% of children who present with acute ITP go on to have chronic ITP Prognosis
- 37. Severe thrombocytopenia(platelet count <20 × 109 /L) is common, with normal platelet size or increased, reflective of increased platelet turnover In acute ITP the hemoglobin value, white blood cell (WBC) count, and differential count should be normal. (Hemoglobin may be decreased if there have been profuse nosebleeds (epistaxis) or menorrhagia) Bone marrow examination ◦ normal granulocytic and erythrocytic series, ◦ normal or increased numbers of megakaryocytes. ◦ Immature megakaryocytes A direct antiglobulin test (Coombs) should be done if there is unexplained anemia, to rule out Evans syndrome (autoimmune hemolytic anemia and thrombocytopenia) Diagnosis
- 38. drug-dependent antibodies, splenic sequestration thrombocytopenia–absent radius (TAR) syndrome hemolytic-uremic syndrome (HUS) disseminated intravascular coagulation (DIC) heparin-induced thrombocytopenia Hypersplenism (in association with isolated splenomegaly ) initial manifestation of : SLE, HIV infection, common variable immunodeficiency, lymphoma or autoimmune lymphoproliferative syndrome. Ddx
- 39. no datashowing that treatment affects either short- or long-term clinical outcome of ITP treatment appears to be capable of inducing a more rapid rise in platelet count to the theoretically safe level of >20 × 109 /L, although no data indicate that early therapy prevents ICH Antiplatelet antibodies bind to transfused platelets as well as they do to autologous platelets. Thus, platelet transfusion in ITP is usually contraindicated unless life-threatening bleeding is present. Treatment
- 40. No therapyother than education and counseling of the family and patient for patients with minimal, mild, and moderate symptoms Treatment with either IVIG or corticosteroids, particularly for children who present with mucocutaneous bleeding. ◦ A single dose of IVIG [intravenous immune globulin] (0.8-1.0 g/kg) or a short course of corticosteroids should be used as first- line treatment.” ◦ IVIG at a dose of 0.8-1.0 g/kg/day for 1-2 days induces a rapid rise in platelet count (usually >20 × 109 /L) in 95% of patients
- 41. splenectomy in ◦Chronic ITP ◦ Life threatening hemorrhage (ICH) complicating acute ITP rituximab (alternative to splenectomy)
- 42. Persistent thrombocytopeniafor >12 months Tx---- aimed at controlling symptoms and preventing serious bleeding Treatment options include: ◦ Splenectomy ◦ IVIG, ◦ corticosteroids, ◦ IV anti-D, or rituximab. ◦ romiplostim ◦ eltrombopag Chronic ITP
- 43. associated withimmune thrombocytopenia as the result of either an immune process or megakaryocyte injury Some common drugs used in pediatrics that cause thrombocytopenia include valproic acid ◦ phenytoin ◦ carbamazepine ◦ sulphonamides ◦ vancomycin ◦ trimethoprim-sulfamethoxazole Drug-Induced Thrombocytopenia
- 44. rare thromboticmicroangiopathy characterized by the pentad of : ◦ fever ◦ Microangiopathic hemolytic anemia ◦ thrombocytopenia ◦ abnormal renal function ◦ CNS changes like orientation, aphasia, blindness, and seizures Thrombotic Thrombocytopenic Purpura
- 45. Laboratory findings: microangiopathic hemolytic anemia characterized by: ◦ morphologically abnormal RBCs, with schistocytes, spherocytes, helmet cells, elevated reticulocyte count thrombocytopenia. Coagulation studies are usually nondiagnostic. Blood urea nitrogen and creatinine are sometimes elevated. Diagnosis
- 46. plasma exchange. Indicationof Treatment ◦ thrombocytopenia ◦ microangiopathic hemolytic anemia Rituximab, corticosteroids, and splenectomy (reserved for refractory cases). Treatment
- 47. is acommon cause of community-acquired acute kidney injury in young children. It is the most common form of thrombotic microangiopathy (TMA) in children Hemolytic-uremic syndrome (HUS)
- 48. infection-induced, genetic,drug-induced, associated with systemic diseases (characterized by microvascular injury) The most common form of HUS is caused by : Shiga toxin–producing Escherichia coli (STEC),- O157:H7 which causes prodromal acute enteritis commonly termed STEC-HUS or diarrhea-associated HUS. Aetiology
- 49. The reservoirof STEC is the intestinal tract of domestic animals, usually cows. Disease commonly is transmitted by undercooked meat or unpasteurized (raw) milk and apple cider contaminated municipal water supplies; petting farms; and swimming in contaminated ponds, lakes, or pools. With broad food distribution, Wider epidemics have been traced to lettuce, raw spinach, and bean sprouts contaminated with STEC
- 50. Genetic formsof HUS (atypical, non-diarrheal) compose the second major category of the disease A major feature characteristic of genetic forms of HUS is the absence of a preceding diarrheal prodrome. It develops slowly and unremitting once they become manifest or they can have a relapsing pattern precipitated by an infectious illness HUS can be superimposed on any disease associated with microvascular injury, including malignant hypertension, SLE and antiphospholipid syndrome. It can also occur following bone marrow or solid organ transplantation
- 51. These toxinsare easily absorbed from the colonic mucosa into the systemic circulation, bind to endothelial cells in the glomerulus and elsewhere, and directly cause endothelial cell damage. Shiga toxin can also directly activate platelets to promote their aggregation. Mechanical injury to RBCs passing through the thrombotic microvasculature results in a severe nonimmune anemia with a negative direct Coombs test In each form of HUS, capillary and arteriolar endothelial injury in the kidney leads to localized thrombosis, particularly in glomeruli, causing a direct decrease in glomerular filtration. Progressive platelet aggregation in the areas of microvascular injury results in consumptive thrombocytopenia Pathogenesis
- 52. HUS (diarrheaform) is most common in preschool and school-age children, but it can occur in adolescents and adults. In HUS caused by toxigenic E. coli, the onset of HUS occurs 5-7 days after the onset of gastroenteritis with fever, vomiting, abdominal pain, and diarrhea The diarrhea is often bloody, (but not necessarily so) Following the prodromal illness: the sudden onset of pallor, weakness, and lethargy heralds the onset of HUS (it reflects the development of microangiopathic hemolytic anemia ) Oliguria patients with HUS can present with either significant dehydration or volume overload, depending on whether the enteritis or renal insufficiency from HUS predominates, and the amount of fluid that has been administered. Clinical manifestation
- 53. Patients withHUS who appear mildly affected at presentation can rapidly develop severe, multisystem, life-threatening complications. Renal insufficiency can be mild but also can rapidly evolve into severe oliguric or anuric renal failure.( dialysis requirement in 50% of patients with STEC-HUS The combination of rapidly developing renal failure and severe hemolysis can result in life-threatening hyperkalemia. Volume overload, hypertension, and severe anemia can all develop soon after the onset of HUS, and together can precipitate heart failure
- 54. central nervous system(CNS)involvement. significant irritability, lethargy, or non-specific encephalopathic features. Severe CNS involvement occurs in 20% of cases. ≤ Seizures and significant encephalopathy are the most common manifestations in those with severe CNS involvement, Hypertension may produce an encephalopathy and seizures.
- 55. Intestinal complications include: Patients can develop petechiae severe bleeding is rare despite very low platelet counts
- 56. combination ofmicroangiopathic hemolytic anemia with schistocytes, thrombocytopenia, and some degree of kidney involvement. Partial thromboplastin and prothrombin times are usually normal. The Coombs test is negative Urinalysis typically shows microscopic hematuria and low-grade proteinuria. The renal insufficiency can vary from mild elevations in serum blood urea nitrogen and creatinine to acute, anuric kidney failure. The presence or absence of toxigenic organisms on stool culture has little role in making the diagnosis of diarrhea-associated STEC-HUS Significant leucocytosis Diagnosis
- 57. Supportive care(includes careful management of fluid and electrolytes) prompt correction of a volume deficit control of hypertension early institution of dialysis if the patient becomes significantly oliguric or anuric, particularly with hyperkalemia. Red cell transfusions are usually required because hemolysis can be brisk and recurrent until the active phase of the disease has resolved. Antibiotic therapy to clear enteric toxigenic organisms (STEC) not recommended----- can result in increased toxin release, potentially exacerbating the disease. Treatment
- 58. Most patientswith diarrhea-associated HUS recover completely, with little risk of long-term sequelae. Patients with hypertension, any level of renal insufficiency, or residual urinary abnormalities persisting a year after an episode of diarrhea-positive HUS (particularly significant proteinuria) require careful follow-up. Patients who have recovered completely with no residual urinary abnormalities after 1 yr are unlikely to manifest long-term sequelae
- 59. most commonvasculitis of childhood also referred to as IgA vasculitis , based on the presence of vasculitis with predominance of IgA deposits affecting small vessels incidence : estimated at 14-20 per 100,000 children per year affects males more than females. Approximately 90% of HSP cases occur in children, between 3 - 10 yrs Many cases of HSP follow a documented upper respiratory infection. Henoch-Schönlein Purpura (HSP)
- 60. The exactpathogenesis of HSP remains unknown preceding upper respiratory infectious triggers such as group A β-hemolytic streptococcus, Staphylococcus aureus, mycoplasma, and adenovirus have been suspected The common finding of deposition of IgA, suggests that HSP is a disease mediated by IgA and IgA immune complexes genetic component. has been linked to HSP nephritis
- 61. The hallmarkof HSP is its rash : palpable purpura starting as pink macules or wheals and developing into petechiae, raised purpura, or larger ecchymoses. The skin lesions are usually symmetric and occur in gravity- dependent areas (lower extremities), extensor aspect of the upper extremities or on pressure points (buttocks) . The skin lesions often evolve in groups, typically lasting 3-10 days, and may recur up to 4 mo after initial presentation. Clinical features
- 62. Subcutaneous edemalocalized to the dorsa of hands and feet, periorbital area, lips, scrotum, or scalp Musculoskeletal involvement, including arthritis and arthralgias, is common with predilection for large joints such as the knees and ankles, and does not lead to deformities Periarticular swelling and tenderness without erythema or effusions are common. The arthritis usually resolves within 2 wk but can recur.
- 63. Gastrointestinal (GI)manifestations include : - abdominal pain, - vomiting, - diarrhea, - paralytic ileus, - and melena. - Intussusception, mesenteric ischemia, and intestinal perforation are rare but serious complications. Renal involvement: manifesting as microscopic haematuria, proteinuria, hypertension, frank nephritis, nephrotic syndrome, and acute or chronic renal failure.
- 64. Neurologic manifestationsof HSP, caused by hypertension or central nervous system (CNS) vasculitis: - intracerebral hemorrhage, - seizures, - headaches, - depressed level of consciousness, - cranial or peripheral neuropathies, - and behavior changes. Other, less common potential manifestations of HSP are inflammatory eye disease, carditis, pulmonary hemorrhage, orchitis, and testicular torsion.
- 65. European League AgainstRheumatism/Pediatric Rheumatology European Society Criteria Palpable purpura and 1or more of the following criteria must be present: ◦ Abdominal pain (acute, diffuse, colicky pain) ◦ Arthritis or arthralgia ◦ Biopsy of affected tissue demonstrating predominant IgA deposition ◦ Renal involvement (proteinuria >3 g/24 hr), haematuria or red cell casts Diagnosis
- 66. small vesselvasculitis infections Acute poststreptococcal glomerulonephritis hemolytic-uremic syndrome coagulopathies Systemic lupus erythematosus (SLE) other vasculitis (urticarial, hypersensitivity) thrombocytopenia. Ddx
- 67. No laboratory findingis diagnostic of HSP leukocytosis, thrombocytosis, mild anemia, elevations of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The platelet count is normal in HSP . Occult blood is frequently found in stool specimens Ultrasound is often used in the setting of GI complaints to look for bowel wall edema or the rare occurrence of an associated intussusception. Barium enema can also be used to both diagnose and treat intussusception Laboratory Findings
- 68. Treatment formild and self-limited HSP is supportive, - ensuring adequate hydration, - nutrition, - analgesia. Corticosteroids --- significant GI involvement or other life- threatening manifestations. oral prednisone (1-2 mg/kg/day), or in severe cases, intravenous (IV) methylprednisolone for 1-2 wk, It reduces abdominal and joint pain but do not alter overall prognosis. chronic HSP renal disease is managed with a variety of immunosuppressants, (ie azathioprine, cyclophosphamide, cyclosporine, and mycophenolate mofetil) Treatment
- 69. intussusception andintestinal perforation Renal disease is the major long-term complication Complications
- 70. result inconsumption of clotting factors, platelets, and anticoagulant proteins. Consequences : - widespread intravascular deposition of fibrin, leading to tissue ischemia and necrosis, a generalized hemorrhagic state, and microangiopathic hemolytic anemia. Disseminated intravascular coagulopathy (DIC)
- 71. Activation andrelease of cytokines and chemokines alter endothelial function to a more prothrombotic state enhancing the formation of microvascular thromboses, with resultant consumption of pro- and anticoagulant proteins. Excessive activation of clotting consumes both the physiologic anticoagulants (protein C, protein S, and AT III) and the procoagulants resulting in a deficiency of factor V, factor VIII, prothrombin, fibrinogen, and platelets. Typically, the clinical result of this sequence of events is hemorrhage Pathogenesis
- 72. Causes INFECTIONS New born Meningococcemia (purpura fulminans) Bacterial sepsis (staphylococcal, streptococcal, Escherichia coli , Salmonella ) Rickettsia (Rocky Mountain spotted fever) Viruses (cytomegalovirus, herpes simplex, hemorrhagic fevers) Malaria Fungi Maternal toxemia Bacterial or viral sepsis (group B streptococcus, herpes simplex virus) Abruptio placentae Severe respiratory distress syndrome Necrotizing enterocolitis Erythroblastosis fetalis Fetal demise of a twin
- 73. TISSUE INJURY GASTROINTESTINALDISORDERS Central nervous system trauma (massive head injury) Multiple fractures with fat emboli Crush injury Profound shock or asphyxia Hypothermia or hyperthermia Massive burns Fulminant hepatitis Ischemic bowel Pancreatitis
- 74. shock . Bleedingfrequently first occurs from sites of venipuncture or surgical incision. The skin may show petechiae and ecchymoses. Tissue necrosis may involve many organs and can be most spectacularly seen as infarction of large areas of skin, subcutaneous tissue, or kidneys. Anemia caused by hemolysis may develop rapidly because of microangiopathic hemolytic anemia. Clinical manifestation
- 75. Certain coagulation factors(factorsII, V, and VIII; fibrinogen) and platelets consumed prolongation of the prothrombin (PT) Prolonged partial thromboplastin (PTT) Prolonged thrombin (TT) times. Platelet counts may be profoundly depressed. The blood smear may contain fragmented, burr and helmet- shaped red blood cells (schistocytes). fibrinogen degradation products (D-dimers)appear in the blood. Laboratory
- 76. treat thetrigger that caused DIC restore normal homeostasis by correcting the shock, acidosis, and hypoxia that usually complicate DIC. Blood components in patients with hemorrhage consist of: ◦ platelet infusions (for thrombocytopenia), ◦ cryoprecipitate (for hypofibrinogenemia), ◦ fresh-frozen plasma (for replacement of other coagulation factors and natural inhibitors) Treatment
- 77.
- 78.
Editor's Notes
- #5 Active clotting is controlled by negative feedback loops that inhibit the clotting process when the procoagulant process comes in contact with intact endothelium.
- #8 TXA2- thromboxane A2
- #14 t-PA tissue plasminogen activator inhibitors of the inhibitor system exists so as body can clot when needed.
- #15 Known as extrinsic pathway because the pathway of blood coagulation activated by tissue factor which is a protein extrinsic to the blood.
- #19 When untreated bleeding occurs in a closed space, such as a joint, cessation of bleeding may be the result of tamponade . With open wounds, in which tamponade cannot occur, profuse bleeding may result in significant blood loss.
- #27 VWF that facilitates its ability to bind platelets through a binding site on platelet glycoprotein Ib (GPIb). This enables VWF to recruit platelets to the site of clot formation
- #34 The parents often state that the child was fine yesterday and now is covered with bruises and purple dots
- #35 When the onset is insidious, especially in an adolescent, chronic ITP or the possibility of a systemic illness, such as systemic lupus erythematosus (SLE), is more likely
- #50 The latter feature likely explains the association of many infectious agents with HUS
- #51 Microangiopathic hemolytic anemia results from mechanical damage to red blood cells as they pass through the damaged and thrombotic microvasculature
- #63 However, progression to end-stage renal disease (ESRD) is uncommon in children (1–2%)
- #68 ESRD develops in <5% of children with HSP nephritis
- #72 Any life-threatening severe systemic disease associated with hypoxia, acidosis, tissue necrosis, shock, or endothelial damage may trigger DIC.
- #75 The D-dimer is formed by fibrinolysis of a cross-linked fibrin clot. The D-dimer assay is as sensitive as the fibrinogen degradation product test and more specific for activation of coagulation and fibrinolysis.