{"id":5148,"date":"2011-07-14T20:23:54","date_gmt":"2011-07-14T20:23:54","guid":{"rendered":"http:\/\/crashtext.org\/misc\/5148.htm\/"},"modified":"2015-08-25T03:49:28","modified_gmt":"2015-08-25T07:49:28","slug":"hemostatic-disorders","status":"publish","type":"post","link":"https:\/\/crashingpatient.com\/medical-surgical\/hematology\/hemostatic-disorders.htm\/","title":{"rendered":"Disorders of Hemostasis"},"content":{"rendered":"
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diagram from Life in the Fast Lane Blog<\/p>\n
Autoimmune thrombocytopenia, other cell lines not effected<\/p>\n
Seen in kids as a acute, usually post-viral disease.\u00a0 In adults, chronic form often seen in women.<\/p>\n
Mucosal or skin bleeding, ptechiae, purpura<\/p>\n
May See spherocytes but no fraged cells<\/p>\n
Steroids (Solumedrol 1 gm over 30 minutes), IgG (1 gm\/kg over 6 hours), plasmapheresis, splenectomy.\u00a0 Can administer platelets if bleeding (6 to 8 units Q8 if CNS\/GI bleeds), but usually patients can tolerate levels as low as 1000 without needing transfusion<\/p>\n
group of three disorders with low platelets and organ failure<\/p>\n
endotheliopathy caused by infection, CP bypass, transplant, radiation, chemotherapy, auto-immune disease, or medications<\/p>\n
Review Article (Crit Care 2006;10:235)<\/p>\n
In differential:\u00a0 DIC (coag path affected,) SLE, Ehrlichiosis, Hemolytic Uremic Syndrome (HUS)<\/p>\n
think TTP whenver there is a combination of renal insufficiency, thrombocytopenia and CNS dysfunction<\/p>\n
\u25cfFever, thrombocytopenia, microangiopathic hemolysis (elevated LDH), renal dysfunction<\/p>\n
Acute form from antibody against vWF cleaving protein; pts have <10% ADAMTS 13 activity<\/p>\n
large vWF multimers can not be cleaved so cause massive amounts of PLT aggregation. SHear stress is greatest in brain and kidney, so largest amounts of thrombi deposition occurs there.<\/p>\n
Thrombotic Microangiopathy<\/p>\n
Always associated c hemolysis, Coag path is spared<\/p>\n
Fever, signs of hemolysis<\/p>\n
PENTAD:\u00a0 fever, Microangiopathic Hemolytic Anemia (MAHA), Thrombocytopenia,\u00a0 Renal Dysfunction, Neuro Sx.\u00a0 (present in less than 50%)<\/p>\n
Reticulocytosis, Shistocytes\/Helmut Cells<\/p>\n
Increased LDH, BUN and Cr, Indirect hyperbillirubinemia,<\/p>\n
Excellent Review Article (Blood 2015;125(25):3860)<\/p>\n
Steroids-b\/c vWF problems can be antibody mediated<\/p>\n
Emergent Plasmapheresis (FFP 2 units Q6) and continued daily<\/p>\n
Vincristine\u00a0as a last resort medication<\/p>\n
No rapid platelet infusion<\/p>\n
Resolution when PLT>150,000<\/p>\n
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Not in the beginning – only when the process has already triggered a certain degree of fibrinolysis. D-dimers are much higher in DIC than in TTP. FDP too. Neoplasia more often causes DIC than TTP…I BET her protein C activity is low…these coagulopathies seen in cancer usually respond well to heparin in small and carefully titrated dosage and antithrombin III reposition. Perhaps some corticosteroids could be a good idea in this case, after you proper address the diagnosis of the lesions…corticosteroids do control some paraneoplastic syndromes and can ameliorate coagulopathies in neoplasic patients for a limited time. If plasma exchange does not improve it, I would try corticosteroids and vincristine…but would try to obtain a biopsy specimen before doing it… Do you think it can be breast cancer??Plasmacytoma?? Uterus\/ovary?? VERY interesting case. I have seen a similar one two years ago that was the first manifestation of an uterine carcinoma. The patient had predominantly thrombosis and low platelet numbers with microangiopathy…we started LMWH and antithrombin and it improved…she was discharged from the ICU. The assistant internist started coumadin to the patient, and it precipitated skin necrosis and finger ischemia – for the protein C levels were too low, and he called me. I asked him to stop coumadin immediately and restart LMWH – we don\u00b4t have thrombin inhibitors easily available here… The patient had to live on enoxaparin since then. One month later, transvaginal US detected endometrial inspissation, and they diagnosed the carcinoma. She received radiotherapy and the coagulation disturbance greatly improved for some time.<\/p>\n
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Micro-angiopathic Hemolytic Anemia (MAHA) thrombocytopenia and neuro findings are often presentLow grade temp maybe kidney rare Inhibitor of protease of vegFFP okPlasma exchange is much better Protease in that is missing is present in FFPExchange gets rid of inhibitor and multimersCryosupperent FTP???????Steroids inhibit inhibitorNo evidence ofr IVIGNo plateletsHUS plt fibrin clotsHUS shiga urine test<\/p>\n
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July 2000 Closure Time Platelet Function Screening Andrea Cortese Hassett, Ph.D. and Franklin A. Bontempo, M.D. BACKGROUND Platelet dysfunction may be acquired, inherited, or induced by platelet inhibiting agents. It is clinically important to assess platelet function as a potential cause of a bleeding diathesis, especially in critically ill patients who may develop life-threatening hemorrhages. The most common causes of platelet dysfunction are related to uremia, liver disease, von Willebrand\u0092s disease (vWD) and exposure to agents such as acetyl salicylic acid (ASA, aspirin). Current methods to assess platelet function include bleeding time (BT), aggregation studies and whole blood in vitro test systems such as the closure time (CT). CLOSURE TIME TESTING Closure times are performed on a PFA-100, an instrument and test cartridge system in which the process of platelet adhesion and aggregation following a vascular injury is simulated in vitro. This system allows for rapid evaluation of platelet function on samples of anticoagulated whole blood. Membranes consisting of Collagen\/Epinephrine (CEPI) and Collagen\/Adenosine-5\u0092-diphosphate CADP and the high shear rates generated under standardized flow conditions, result in platelet attachment, activation and aggregation, building a stable platelet plug at the aperture. The time required to obtain full occlusion of the aperture is reported as the closure time (CT) in seconds. The test is sensitive to platelet adherence and aggregation abnormalities and allows the discrimination of aspirin-like defects and intrinsic platelet disorder. The CEPI membrane is used to detect platelet dysfunction induced by intrinsic platelet defects (vWD, drug effects etc.). Abnormalities result in prolongations of CT >175 seconds. Follow-up testing using the CADP membrane enables the discrimination of aspirin effects. The following table shows expected patterns observed with CT on normal subjects and subjects with various disorders. Normal ASA vWD Glanzmann’s Thrombasthenia CEPI normal abnormal abnormal abnormal CADP normal normal abnormal abnormal CLOSURE TIMES vs. BLEEDING TIMES While thrombocytopenias are accurately assessed by automated platelet counters, qualitative platelet defects are presently difficult to diagnose. The only global screening test for platelet and vascular functions is the BT. BT is a bedside procedure, is labor intensive, expensive and its accuracy is heavily dependent on operator skills. A critical review of BT concluded that the utility of BT is not enhanced by recent standardization attempts; that in individual patients there is no relationship between BT and platelet counts; that the BT is not a specific indicator of platelet function and that the BT is a poor indicator of surgical bleeding risk. As a consequence many clinicians no longer use BT. The noted deficiencies of BT lead to the development of an in vitro device that globally measures platelet-related primary hemostasis. Closure time is sensitive to platelet adherence and aggregation abnormalities and therefore has increased sensitivity for von Willebrand\u0092s screening when compared to bleeding time. Comparative studies at our facility support these findings: CT was abnormal in 64% of patients diagnosed with vWD as compared to 43% by BT. INDICATIONS Closure times are indicated when a disorder of platelet function is suspected by a personal or family history of easy bruising, nose bleeds, menorrhagia, or post-operative bleeding, especially following dental extractions or tonsillectomy. It is not recommended as a screen for potential bleeding risk. Closure times may be prolonged when the platelet count is < 100,000\/mm3 even if platelet function is normal. In addition the CT will be prolonged when hematocrit levels are < 35%, due to the contributory effect of red blood cells on platelet behavior. These restrictions should be considered prior to performing a closure time. Suspected von Willebrand\u0092s disease, inherited platelet disorders and evaluation of acquired disorders of platelet function (hepatic disease, renal disease, drug effects) are appropriate clinical reasons for closure time screening. It may also be useful to monitor the response of therapeutics, such as DDAVP infusions, renal dialysis, platelet and antiplatelet drug therapy. Abnormal closure times, indicating possible defective platelet function, should be further investigated with standard platelet aggregation tests. SUMMARY Closure time is a test system to assess platelet-related primary hemostasis with improved accuracy and reliability in comparison to bleeding time. This assay is an important aid in the assessment of platelet dysfunction and bleeding risk caused by uremia, von Willebrand\u0092s disease, congenital platelet disorders and exposure to agents such as aspirin. REFERENCES 1. Rogers, RPC., Levin J., \u0093A critical reappraisal of the bleeding time.\u0094 Semin. Thromb. Hemost. 1990; 16: 1-20. 2. Cattaneo, M., Federici, AB., et. al. \u0093Evaluation of the PFA-100 system in the diagnosis and therapeutic monitoring of patients with von Willebrand\u0092s disease.\u0094 Thromb. Hemost. 1999; 82: 35-39. 3. Mammen, EF., Comp, PC., et. al. \u0093PFA-100 System: A new method for assessment of platelet dysfunction. Semin. Thromb. Hemost. 1998; 24: 195-202. 4. Fressinaud, E., Veyradier, A., et. al. \u0093Screening for von Willebrand\u0092s disease with a new analyzer using high shear stress: a study of 60 cases.\u0094 Blood 1998; 91: 1325-1331.<\/p>\n
<\/a>TTP<\/p>\n Systemic inflammation results in systemic coagulation. Thrombotic thrombocytopenuc purpura (TTP) is a microangiopathy phenotype characterized by ADAMTS 13 deficiency. Left: Platelets attach to ultra large vWF multimers. Because vWF-CP (ADAMTS 13) is inhibited this leads to massive vWF:platelet thrombosis (right). Ab, antibody; CP, cleaving protease; vWF, von Willebrand factor.<\/p>\n <\/a>TMA<\/p>\n Secondary thrombotic microangiopathy (TMA) has a phenotype characterized by decreased ADAMTS 13, and increased plasminogen activator inhibitor type I (PAI-1) and von Willebrand factor (vWF) levels with normal or high fibrinogen levels. Platelets attach to increased large vWF multimers and form thrombi in the presence of decreased PAI-I activity (left), leading to systemic platelet thrombi with delayed fibrinolysis (right). CP, cleaving protease; TF, tissue factor; TFPI, tissue factor pathway inhibitor; vWF-CP, ADAMTS 13.<\/p>\n <\/a>DIC<\/p>\n Disseminated intravascular coagulation (DIC) is a microangiopathy phenotype characterized by increased tissue factor (TF) and plasminogen activator inhibitor type I (PAI-1), unopposed by the anticoagulant proteins TFPI, protein C, antithrombin III, and prostacyclin. The severest forms also have an ADAMTS 13 deficiency. Tissue factor activates factor VII (left), leading to massive consumptive fibrin thrombosis (right). VII, factor VII; vWF, von Willebrand factor.<\/p>\n <\/p>\n <\/a><\/p>\n Specific therapies used to reverse or promote thrombosis and promote or stop fibrinolysis. Therapies used to reverse thrombosis include protein C concentrate (prot C), activated protein C (APC), tissue factor pathway inhibitor (TFPI), antithrombin III, heparin, and thrombin inhibitors such as argatroban and hyarudin. Therapies used to promote thrombosis include activated factor VII. Therapies used to promote fibrinolysis include tissue plasminogen activator (TPA), streptokinase, urokinase, and defibrinopeptide. Therapies used to stop fibrinolysis include aminocaproic acid, tranexamine, and aprotinin. PAI, plasminogen activator inhibitor type I.<\/p>\n <\/p>\n thrombocytopenia with decreased fibrinogen and increased d-dimer. Depletion of factors V and X causes increased pt\/ptt. Increased intravascular coagulation despite increasing pt\/ptt<\/p>\n <\/p>\n hits CNS and kidney hardest.<\/p>\n Dx<\/p>\n 1.\u00a0\u00a0\u00a0\u00a0\u00a0 Risk assessment:\u00a0 Does the pt have an underlying disorder known to be associated with DIC?\u00a0 If yes, proceed<\/p>\n 2.\u00a0\u00a0\u00a0\u00a0 Order global coag tests (CBC, PT, fibrinogen, FDP, D-Dimer)<\/p>\n 3.\u00a0\u00a0\u00a0\u00a0 Score by test results<\/p>\n \u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Platelets (>100=0, <100=1, <50=2)<\/p>\n \u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Elevated FDP (no icrease=0, mod. Increase=1, strong increase=2)<\/p>\n \u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Prolonged PT (<3 sec=0, >3 sec but <6 sec=1, >6 sec=2)<\/p>\n \u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Fibrinogen (>1 gram\/l=0, <1 gram\/l=1)<\/p>\n 4.\u00a0\u00a0\u00a0\u00a0 Greater than or equal to 5 is DIC, <5 may be non-overt DIC or another diagnosis<\/p>\n Validated in Crit Care Med (Volume 32(12) December 2004 pp 2416-2421)<\/p>\n <\/a><\/a><\/p>\n Replace plasma until pt\/ptt is corrected, but only if infusing heparin as well<\/p>\n In places where ATIII or Protein C concentrate are available, these may be used instead or in combination with plasma<\/p>\n May be a role for xigris at some point<\/p>\n May be a role for infusions of prostacyclin (nitroglycerin or nitroprusside as well) all for microcirculatory flow<\/p>\n <\/p>\n <\/p>\n Bleeding<\/p>\n give plts<\/p>\n prbcs<\/p>\n ffp<\/p>\n if fibrinogen is <100, give cryoprecipitate<\/p>\n may need low dose heparin to block consumptive coagulopathy<\/p>\n 20-30 units\/kg then 5-10 units\/kg\/hour<\/p>\n Fibrin deposition-heparin.\u00a0 Treat underlying cause.<\/p>\n <\/p>\n The activity of plasma antithrombin is reduced in sepsis and DIC, indicating defective anticoagulation [12, 21]. In this study the lowest plasma antithrombin activity distinguished well the patients with overt DIC, as did the lowest platelet count and the highest plasma D-dimer. Antithrombin has been suggested to be included as a part of the score for nonovert DIC [6]. Our results suggest that antithrombin could have a role in the diagnosis of overt DIC as well. Furthermore, in an earlier study on septic patients we found higher levels of plasma antithrombin in survivors than in nonsurvivors, although antithrombin did not independently affect mortality [22]. Availability of the plasma antithrombin test may limit its use, however. (Inten Care Med Intensive Care Medicine 2005;31(9))<\/p>\n <\/p>\n secondary TTP or Hemolytic Uremic Syndrome<\/p>\n normal or mildly elevated pt\/ptt<\/p>\n only small amounts of hemolysis<\/p>\n increased d-dimer, but increased <\/strong>\u00a0fibrinogen<\/p>\n Probably benefit from same plasma-exchange therapies as TTP<\/p>\n <\/p>\n Test of vascular integrity and platelet function; independent of the clotting cascade<\/p>\n Increase is seen in thrombocytopenia, qualitative platelet dysfunction, vWD, Vascular disorders<\/p>\n Ask about ASA and NSAIDs as they cause platelet dysfunction<\/p>\n Spontaneous hemorrhage when count falls below 10-20,000<\/p>\n test of the extrinisic pathway (VII) and common pathway (X,V,II, and I)<\/p>\n Normally 10-12 seconds<\/p>\n Deficiencies of Factor VII can be seen with Vit K deficiency, Coumadin, Liver Disease<\/p>\n Test of all factors except VII and XIII, used to evaluate the intrinsic pathway<\/p>\n Normally 25-35 seconds<\/p>\n Increase seen with Factor VIII, IX, or XI and Heparin<\/p>\n Heparin and Coumadin can raise both PT and PTT<\/p>\n Tests fibrinogen to fibrin<\/p>\n Increased with Heparin, LMH, DIC, Liver disease<\/p>\n Increase seen with increased clot burden or consumptive coagulopathy<\/p>\n DIC in association with symmetric limb ecchymosis and necrosis of the skin<\/p>\n seen after viral syndromes or secondarily from meningococcal infections or most other severe infections.<\/p>\n there may be a role for activated protein c.<\/p>\n Thrombolytics<\/p>\n To reverse, use 6 units FFP and 10 units cryoprecipitate<\/p>\n Obtain CBC, fibrinogen level, thrombin time, PT\/APTT, Type and Screen Most cases need no further care. Goal FBG is 100 mg\/dL. If life-threatening bleeding, transfuse 10 units of CRYO (FBG source), 2 FFP (procoagulant source), and PLAT if thrombocytopenic. Protamine sulfate 1 mg\/100 units of heparin may be used if heparin given within the previous 4 hours. Anti-fibrinolytic, e.g., EACA can be given if life-threatening bleeding continues after CRYO\/FFP.<\/p>\n Mild forms can remain undiagnosed until adulthood<\/p>\n Hemostasis is reliant on three mechanisms:\u00a0 platelet activation, coagulation activation, and fibrinolysis<\/p>\n The platelets form a plug at the site of a vascular defect which is then stabilized by fibrin, plasmin then breaks down the fibrin.<\/p>\n Defects in plt adhesion cause immediate bleeding of the mucosal<\/strong> surfaces.\u00a0 Caused by vWF deficiency, NSAIDS, ASA, and Ganzman’s thrombasthenia (IIbIIIa deficiency)<\/p>\n Impaired coagulation causes immediate bleeding in the soft tissue and joints<\/strong>.\u00a0 Caused by VIII, IX deficiency or warfarin\/heparin.<\/p>\n Accelerated fibrinolysis causes delayed, mucosal or GU<\/strong> bleeding.\u00a0 Caused by liver dysfunction, Factor VIII deficiency or thrombolytics.<\/p>\n <\/p>\n The intrinsic pathway is so named b\/c everything needed for activation is already in the plasma.\u00a0 The extrinsic needs inflammatory cytokines.\u00a0 PT=extrinsic, PTT=intrinsic.\u00a0 If both are altered then consider X, V, Fibrinogen, or Thrombin defects.<\/p>\n Get history of minor\/major surgeries, dental work, hepatic, kidney, cancer, drugs<\/p>\n Type of bleeding:\u00a0 Purpura=decreased platelets, Mucosal or Soft Tissue=Coag, hemarthroses=hemophilia<\/p>\n Labs:\u00a0 CBC, Coag, DIC Panel (Fibrinogen, FSP\/D-Dimer, Thrombin Reptilase)<\/p>\n Rx:<\/p>\n Liver-FFP, if fibrinogen<100 give cryoprecipitate<\/p>\n Uremia-dDAVP .3 mcg\/kg IVPB over 15-30 minutes QD, Estrogens 3mg\/kg IV, Blood transfusion<\/p>\n <\/p>\n PT\/PTT may be inaccurate with crits<20 or >50 b\/c of imbalance between plasma and sodium citrate.<\/p>\n If patient is clinically normal, look at smear for platelet clumps and giant platelets<\/p>\n Bleeding secondary to anti-thrombotics<\/p>\n Bleeding and thromboses<\/p>\n Acute Leukemia<\/p>\n Sickle Cell Chest Syndrome<\/p>\n <\/p>\n Br J Anesthaes 1992;69:307<\/p>\n <\/p>\n<\/span>DIC<\/span><\/h3>\n
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Treatment<\/h4>\n
Rarely will fibrinogen get to cutoff in crit care patients, consider ATIII instead<\/h4>\n
<\/span>Non-Consumptive secondary thrombotic micro-angiopathy (TMA)<\/span><\/h3>\n
<\/span>\u00a0<\/span><\/h3>\n
<\/span>Coagulation Pathway Disorders<\/span><\/h2>\n
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Bleeding Time<\/h4>\n
Platelet Count<\/h4>\n
Prothrombin Time (PT)<\/h4>\n
Partial Thromboplastin Time (PTT)<\/h4>\n
Thrombin Time<\/h4>\n
D-Dimer<\/h4>\n
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<\/span>Purpura Fulminans<\/span><\/h2>\n
<\/span>Hematologic Emergencies:<\/span><\/h2>\n
Bleeding Diatheses<\/h4>\n
Severe Thrombocytopenia<\/h4>\n
<\/span>Thromboelastography (TEG)<\/span><\/h2>\n