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Coagulation Disorders. Corrina Mc Mahon. Laboratory investigations. PT : VII, X, V APTT ; XII, XI, IX, VIII TT ; Fibrinogen D dimers ; fibrin breakdown. Case 1. 4 yr old boy URTI 2 weeks ago Sudden onset bruising/petechiae PH: Nil FH: Nil Physical examination:. Investigations.
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Coagulation Disorders Corrina Mc Mahon
Laboratory investigations • PT: VII, X, V • APTT; XII, XI, IX, VIII • TT; Fibrinogen • D dimers; fibrin breakdown
Case 1 • 4 yr old boy • URTI 2 weeks ago • Sudden onset bruising/petechiae • PH: Nil • FH: Nil • Physical examination:
Investigations • FBC: Hb 11g/dl; WCC 8x10^/l; Platelets <10x10^9/l • PT 14 sec ; APTT 33 sec; Fibrinogen 2.0g/l • Treatment options: Nil; IVIg; Steroids • Outcome: 90% recovery; 10% chronic
Congenital Thrombocytopenia • Dysfunctional platelets • Bernard Soulier • Grey platelet syndrome • Wiskott-Aldrich syndrome • Normal Platelet function • May-Hegglin • TAR
Newborn infant Intracranial Haemorrhage No dysmorphic features 1st child No liver/spleen palpable FBC Hb 18.5g/dl WCC 10 x x 109/l /l Platelets 10 x 109/l /l Coagulation screen PT 15 sec. (13-16) APTT 41 sec (28-36) Case 2
Differential diagnosis • Infection • DIC • Immune Thrombocytopenia • Alloimmune • Isoimmune • Congenital Thrombocytopenia • TAR syndrome • Wiscott Aldrich Syndrome • Von Willebrands disease • Type 2B • A-V malformations
Alloimmune Thrombocytopenia • Incidence 1:1000-5000 births • IgG antibodies • HPA1a 80% • HPA5b 15% • 50% occur in 1st pregnancy • Bleeding can be in utero or after birth Treatment • Platelets • IVIg • ?Steroids
Isoimmune Thrombocytopenia • Maternal anti-platelet IgG • Placental Passage • Thrombocytopenia nadir ~5days post-partum • History & examination of mother • Treatment • IvIg ± steroids
Disseminated Intravascular Coagulopathy • Infection • Symptoms and Signs • Petechiae • Bruising • Bleeding • Laboratory results • Anaemia • Thrombocytopenia • ↑PT/ ↑APTT/↓Fibrinogen/ ↑d dimers
Haemophila • Inherited Bleeding Disorder • Factor VIII/FIX deficiency • X-Linked Inheritance • Carrier XX may have low levels • Spontaneous mutation
Bleeding problems in Haemophilia Factor LevelType of Bleed <1% Spontaneous/severe 2%-5% Mild trauma/ occasionally spontaneous >5% Trauma/Surgery
Intracranial Bleeds • At Birth • Injury • Admission • Factor Concentrate • Scanning • Observation • Neurosurgery
Joint bleedSynovial inflammation and hyperaemiaSynovial overgrowth and Bone resorptionFurther BleedJoint Destruction
The role of prophylaxis in the prevention of joint injury Lofqvist, Nilsson et al ( Journal Int. Medicine May 1997): 34 patients aged 7-22yrs. Age at commencement of prophylaxis - 1-4.5yrs. 79% had no joint problems and the rest had no deterioration in joint abnormalities. Liesner,Khair, Hann, ( BJH Mar 1996) 27 children aged 1.3-15.9yrs. No. of bleeds/yr pre-prophylaxis-14.5 and post - 1.5. 20 children had evidence of arthropathy which improved on prophylaxis.
Prophylaxis The Irish Data (1992-1997) Bleeds/yr, pre-prophylaxis, 9.5-106 (mean 38) Bleeds/yr, post-prophylaxis, 0-9 (mean 3.5) Development of inhibitors, 2 - low level (<1Bu) and transient (< 1 year)
Factor VIII T½ = 8 hours Frequency – three times/week Dose – 20-40iu/kg Factor IX T½ = 18 hours Frequency – twice/week Dose – 50iu/kg Prophylaxis
Dose Adjustment • Growth • Break through bleeds
Management of Acute Bleeds • Rest • Factor Concentrate • FVIII; 35-50iu/kg • FIX; 70-100% (7-10iu/ml) • Wt x desired rise x 1.25 • Continuous infusion • FVIII • 50iu/kg bolus; infusion 4iu/kg/hr • FIX • 100% bolus; infusion 6-8iu/kg/hr
Mild Factor VIII Deficiency • Factor VIII • DDAVP • 0.3mcg/kg/30 min • Antifibrinolytic therapy
Haemophilia The problems • Bleeding • Destructive arthropathy • Addiction • Infection • Inhibitors
Inhibitors • Anti-FVIII Antibodies - IgG • Incidence: 10-20% • High responding or lowlevel/transient • Familial incidence (x6) • Majority <10yrs • Occur within first 25 treatment days • Bleeding
Management of Inhibitors • Acute Bleeding episodes • FVIIa • Immune Tolerance • High Dose 200-300iu/kg/d x 1-3 yrs • Cyclophosphamide/FVIII/IVIg • 50iu/kg/d x 1->12m • 25iu/kg/d x 1->12m
Autosomal Inheritance Abnormal VWF S/S: easy bruising, mucosal bleeds, heavy periods Treatment: antifibrinolytic agents DDAVP Plasma derived factor (Fanhdi) Lab Investigations FVIIIc VWF:Ag VWF:RCF Bleeding time VWF Multimers Von Willebrands Disease