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Disorders of Hemostasis

Disorders of Hemostasis. Sultana Qureshi, PGY-2 Resident Rounds March 1, 2007. Thanks to Adam Oster for some slides!. Goals. Approach and when to be suspicious Pattern of presentation ED Management – when to use blood products. Hemostasis. Endothelial cells Platelets

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Disorders of Hemostasis

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  1. Disorders of Hemostasis Sultana Qureshi, PGY-2 Resident Rounds March 1, 2007 Thanks to Adam Oster for some slides!

  2. Goals • Approach and when to be suspicious • Pattern of presentation • ED Management – when to use blood products

  3. Hemostasis • Endothelial cells • Platelets • Blood flow & vasoconstrictors • Clotting cascade • Fibrinolysis

  4. Primary Hemostasis Exposed endothelial cells cause platelets to aggregate and form plug Platelet Disorders ITP TTP Also partially in liver disease, vWD Secondary Hemostasis Tissue factor iniates coagulation cascade eventually leading to fibrinogen forming fibrin cross links Extrinsic starts pathway, intrinsic sustains Coagulation Disorders vWD Hemophilia A & B Other – consumptive (DIC) Approach to Bleeding Disorders

  5. When to be suspicious • Petechiae, Purpura, Ecchymosis • Nature of bleeding/sites • Significant or multiple episodes • Signs of previous bleeding • Medications (anti-coagulants) • Associated disease: liver disease, sepsis • Massive transfusion • FHx • Other important historical/physical info to know???

  6. Platelet Disorder Immediate onset Superficial bleeding Petechiae/Ecchymoses (mucocutaneous) GI/GU bleeding Menorrhagia, epistaxis, melena Plt or Bleeding Time abn PT/PTT N Coagulation Factor Disorder Delayed onset (hours/days) Deep bleeding Intramuscular Intraarticular Retroperitoneal Hematuria Hemarthrosis/hematomas Less common to have menorrhagia, epistaxis, etc Plt and BT N PT/PTT abn Approach to Bleeding Disorders

  7. Labs • CBC, plts • PTT (intrinsic) – I, II, V, VII, IX, X, XI, XII • INR (extrinsic)– I , II, V, VII, X • Peripheral smear • Fibrinogen • D-dimer • FDP • Factor levels • Thrombin time

  8. What and how do you measure bleeding time? • When is it useful?

  9. Blood Products • Platelets – 1 unit raise value by 5-10 • Cryoprecipitate – FVIII, vWF, fibrinogen, fibronectin • FFP – contains all coagulation factors (about 7% of a 70kg person)

  10. Case • 25F – 32 wks GA presents with decr. LOC • Husband states had intermittent abdo pain X 2 days, suddenly got worse today • Vitals: 120, 90/50, 18, 99% 2L NP, 36.5 • Doppler – fetal bradycardia • Uterus is tender and tense

  11. •Sepsis/severe infection (any microorganism) •Trauma (eg, polytrauma, neurotrauma, fat embolism) • Organ destruction (eg,severe pancreatitis) • Malignancy –solid tumors–myeloproliferative/ lymphoproliferative •Obstetrical calamities –amniotic fluid embolism–abruptio placentae • Vascular abnormalities –Kasabach-Merritt Syndrome–large vascular aneurysms •Severe hepatic failure • Severe toxic or immunologic reactions –snake bites–recreational drugs–transfusion reactions–transplant rejection Hypothermia Acidosis DIC - Causes

  12. Pathophysiology • Unifying cause relates to widespread endothelial damage with extensive cytokine release • DIC is a spectrum, may have thrombosis or bleeding or both • Activation of procoagulant pathway • Hemolysis, tissue injury, malignancy, fat embolism, heat stroke • Endothelial damage • Sepsis, vasculitis, aneurysm, hemangioma • Reticuloendothelial injury • Liver disease, splenectomy • Vascular stasis • Hypotension, hypovolemia, PE • Other • Acute hypoxia/acidosis

  13. Signs of Microvascular Thrombosis (10-40%) Neuro Multifocal, delirium, coma, seizures Skin Focal ischemia, superficial gangrene Renal Oliguria, azotemia, cortical necrosis Pulmonary ARDS GI Acute ulceration RBC Microangiopathic hemolysis Signs of hemorrhagic diasthesis (more common) Neuro IC bleed Skin Petechiae, echymosis, oozing Renal hematuria Mucosal Gingival oozing, epistaxis, massive bleed Clinical Features

  14. Labs • Consumptive Coagulopathy • ↓Plts • ↑PT, ↑PTT • ↓Fibrinogen (careful in sepsis) • +D-dimer (DIC)

  15. DIC Scoring System Bakhtiari K et al. Critical Care Med. 2004;32:2416-2421. • Step 1.Risk assessment: does the patient have an underlying disorder known to be associated with overt DIC? If yes, proceed. If no, do not use this algorithm.Step 2. Order global coagulation tests: platelet count, prothrombin time (PT), fibrinogen, soluble fibrin monomers, or fibrin degradation products.Step 3.Score global coagulation test results: • • platelet count (> 100 = 0, < 100 = 1, < 50 = 2)• elevated fibrin-related marker (eg, soluble fibrin monomers/fibrin degradation products) no increase: 0; moderate increase: 2; strong increase: 3*• prolonged prothrombin time (< 3 sec. = 0, > 3 but < 6 sec = 1, > 6 sec = 2)• fibrinogen level (> 1.0 g/L = 0, < 1.0 g/L = 1)Step 4. Calculate score.Step 5. If ≥5: compatible with overt DIC; repeat scoring daily. If <5: suggestive (not affirmative) for non-overt DIC; repeat next 1–2 days. • * In the prospective validation studies, D-dimer assays were used and a value above the upper limit of normal was considered moderately elevated; whereas, a value above five times the upper limit of normal was considered a strong increase.

  16. DIC Scoring System Bakhtiari K et al. Critical Care Med. 2004;32:2416-2421. • Sens 93% • Spec 96%

  17. Management • TREAT UNDERLYING CAUSE!!! • Blood Products • Only if active bleeding or high risk of bleeding (ie. early post op or pre-invasive procedure) • Platelets • Bleeding – tranfuse if count <50 • No bleeding – transfuse if <10-20 • FFP • Cryoprecipitate • If fibrinogen <2 • 1-4U/10 kg

  18. Novel treatments • APC – up to Phase III trials show benefit in septic DIC • TFPI – promising • ATIII- RCT promising • Heparin • Only case series. Controversial • Therapeutically if overt venous TE or purpura fulminans

  19. Case • 22M presents with seizures, decr. LOC, jaundice and fever • Purpuric rash over body • V: 60, 110/70, 16, 96% RA, T=38.3 • Hb 90, WBC 8.0, plt 20 • PT/PTT N • Cr 130, small hematuria • T.bili 60 other LFTs N, LDH 500 • Ddx? • D-dimer/fibrinogen?

  20. TTP • Main ED mgmt point: • NO platelet transfusion unless life threatening hemorrhage

  21. Liver Disease • What mechanisms of coagulopathy? • What blood products to use?

  22. Liver Disease • Why they bleed? • Thrombocytopenia from hypersplenism (portal HTN) • Platelet dysfunction • Reduction in absorption of Vit K dependant factors (2, 7, 9, 10) • Reduction in synthesis of most factors • Dysfibrinogenemia (abn fibrinogen synthesis) • Enhanced fibrinolysis (decr. Plasmin inhibitor) • In bleeding ER – may require transfusion of many different products (RBC, plts, FFP, cryo) • Vs. DIC???

  23. Case • 6F with epistaxis (has had multiple mild episodes in past 2d) • Also history of spitting up blood in morning • Examine mouth and see blood oozing from gums when scraped with tongue depressor • Otherwise well other than flu 3 weeks ago • Notice petechiae around sock elastic • Dx? • Lab results?

  24. Acute ITP • Usually children 2-6 • M=F • Usually have had recent infection • Abrupt onset of bleeding (vs insidious) • Platelets <20 • Usually lasts week • 80% spontaneous remission • Management: IVIG if bleeding significant of plts <10 -splenectomy in very severe cases

  25. Chronic ITP • MCC of isolated thrombocytopenia • Adults (20-40 yo), F>M (3:1) • No precipitating infection • Insidious bleeding (heavy periods, easy bruising) • Plt 30-80 • May last months to years, and uncommon spont. Remission • Mgmt: steroids, IVIG, splenectomy • Need w/u for other causes of thrombocytopenia! Esp if older (ie malignancy)- Smear • Major concern is cerebral hemorrhage is plt<5

  26. Platelet Disorders Quantitative Qualitative Decreased Production Sequestration ASA, plavix rena and hepatic disease, vWD Destruction Immune Non-immune splenomegaly TTP DIC HELLP Sepsis ITP Marrow failure

  27. Case • 12F hx of VWD • Presents with heavy menarche (ongoing bleeding for >7 days) • Pale, asymptomatic • Hb = 60 • Mgmt?

  28. Erik Adolf von Willebrand • 1870-1949 • Finnish Pediatrician • “known for integrity and modesty” • Hjordis – 5 yo girl with FHx of bleeding disorders

  29. Von Willebrand’s Disease • AD • Qualitative vs. quantitative abn • Different sized multimers • vWF has 2 jobs • Platelet adhesion, carrier for Factor VIII • New Classification • Type 1: mild quantitative defect (75%) • Type 2: qualitative defect (impaired fxn)20% • Type 3: severe total quantitative defect (rare)

  30. Management • Type 1 • Usually mild symptoms (mucocutaneous bleeding sources) • Mgmt: DDAVP 0.2 mcg/kg IV/IM/IN • Type 2 or 3 • More likely to have mod-severe symptoms incl. soft tissue hematomas, GI bleeds, hemarthroses • Mgmt: Cryoprecipitate +/- DDAVP +/- Humate P

  31. Case • 50M slipped on ice and twisted R knee • On exam: large hemarthrosis • What is most likely hemostatic disorder? • Management?

  32. Hemophilia • A – FVIII deficiency • B – FIX deficiency • X-linked recessive • Mild/mod/severe is based on factor activity • 5-30%, 1-5%, <1% • PTT prolonged (if factor activity <30%) PT N • However, if mild hemophilia, PTT may be N

  33. Bleeding first noticed usually in early years • 5 Hs: • Hemarthroses • Hematomas • Hematochezia • Hematuria • Head hemmorhage

  34. Recurrent hemarthroses lead to joint damage • IC bleed is major cause of death • Also, tend to bleed LATE – days after minor injury • Therefore treat aggressively • Goal to achieve 30-100% factor activity • Options: Specific factor replacement, cryo, FFP • Consider: Severity of bleeding, disease severity and availability of products • Always consider factor activity is zero in ED!!!

  35. Factor Replacement • Is ideal if available in ED, otherwise cryo • 1U/kg will increase factor by 2% • May develop alloantibodies and need 3-4X predicted dose • Goals: • Mild: 5-10% activity desired -initial dose 12.5U/kg • Mod 20-30% - 25U/kg • Severe >50% - 50U/kg

  36. Cryoprecipitate • Contains 80- 100U FVIII (als contains vWF, fibrinogen, FXIII and fibronectin) • Considered a second line agent for Hem A • Dose = 2bags/10kg to raise FVIII to hemostatic levels • T ½ = 8hrs

  37. FFP • Fluid portion of blood separated at 18C then frozen • Contains all coagulation factors • Approx 7% of of all coag factor activity of a 70kg person • Not routinely used as factor replacement in Hem A • Could consider if nothing else available

  38. Case • 25M hemophiliac • Tripped on stairs and fell from 1ft height • Hit head on floor. No LOC, NV. Feels fine • Management?

  39. Mgmt • All hemophiliacs with any trauma need admission for observation • Minor head trauma can be life threatening • Give Factor VIII to 50% activity BEFORE CT

  40. Take Home Points • Approach to bleeding disorders • High index of suspicion • Difference in presentation of platelet dysfunction vs. coagulation factor d/o • When to give blood products?

  41. Take Home Points • DIC – treat underlying cause • vWF – important to know type • Hemophilia – aggressive therapy with factors

  42. Quiz • Which of the following is least likely due to a platelet disorder? • A) Epistaxis • B) Retroperitoneal Bleeding • C) Ecchymoses • D) Petechiae

  43. Quiz • Which is least likely associated with coagulation factor deficiency? • A) Intra-articular bleeding • B) Delayed bleeding • C) Retroperitoneal Bleeding • D) Petechiae

  44. Quiz • Which clinical finding is MOST COMMONLY associated with the onset of ITP? • A) Ecchymoses • B) Purpura • C) Petechiae • D) Gingival bleeding

  45. Quiz • Which of the following are true of chronic ITP? • A) More likely in female children • B) Spontaneous remission typical • C) Underlying disorder is autoimmune • D) Platelet transfusion is initial, definitive therapy

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