Coag & hemostasis

• Bleeding Time
• &
• Platelet Aggregation Studies

Screens: PT & PTT

• Mixing Studies
• Factor Assays

• Vascular system 
• Platelets

For the formation of the platelet plug

• Coagulation system
• Fibrinolysis system

to form a thrombus

Antibody mediated platelet destruction.

• Occurs in children
• Rapid onset
• Hx of infection

Plt < 20k

Duration <6mos

• Maybe no treatment
• Prevent intracranial hemorrhage
• IVIG, RhIg, or Corticosteroids

• Occurs in women 2x more frequently
• May be secondary condition

• Plt <30k
• enlarged Plt's

Duration >6mos

• Corticosteroids
• IVIG, Rhig
• Splenectomy 

• Refractory ITP: 
• - Rituximad
• - Immunosuppressive agents
• - Plasma Exchange ***

Thromboticc microangiopathy

• Acute deficiency of vWf cleaving ADAMTS13 leading to accumulation of ultra large vWF multimers. 
•  

Etiology: 

 - Congenital: Upshaw Shulman, MUtation of ADAMTS13 gene

- Idiopathic: Autoantibody formation to ADAMTS13

• 1. MAHA
• 2. Thrombocytopenia
• 3. Fever
• 4. Neurolgoical abnormalities
• 5. Renal dysfunction

• Plt <60k
• Elevated LDH, ibili, & retic
• Schistocytes

* Normal PT, PTT, & Dimer

• Plasma Exchange
•  - Removes UL vWF & anti-ADAMTS13
•  - Provides ADAMTS13
•  
• *** Platelet transfusion may worsen situation!

Endothelial damage causing plt's associated thrombosis& vessel obstruction, MAHA, & renal failure.

Occus mostly in children secondary to E. coli O157:H7 - Undercooked meat

• Atypical reasons:
• Secondary to S. pneumoniae infection, genetic causes, medications, and pregnancy

• Hemolytic anemia
• Renal failure

• Plt < 60k
• Schistocytes
• Giant Plt's
• Low haptoglobin

Elevated Retic, LDH, & IBili

Normal PT, PTT & Neg DAT

Suppoprtive & antibiotics

Antibody mediated platelet destruction

Most common anti-HPA-1a

Destroys antigen pos and neg plt's.

• 2-14 post transfusion
• Bruising
• Mucosal bleeding
• Purpuric rash
• possible fever

Severe thrombocytopenia 

Could lead to life threatening hemorrhage

Identify platelet specific alloantibody

• IVIG
• Splenectomy
• Plasma Exchange

Future: transfuse antgien neg plt's

• Immune mediated
• caused by IgG antibody against heparin & plt Factor 4 complex

• Thobosis
• Skin lesions at heparin injection site

• Decreased plt (20 - 50 k)
• Increased anti-heparin/PF4 antibody

Platelet Agg to confirm

• Discontinue heparin
• Use alternative anticoagulant
• Direct thrombin inhibitors

Assesses platelet function - Measures time for plt's to form a plug

• Affected by :
• low plt counts & /or activity
• Inadequate plasma on vWF
• Inadequate Hct

• Breakdown of formed blood clots
• Keeps thrombi from getting too large
• Aids in wound healing.

Plasminogen activated to plasmin, degrades fibrinogen, 5, 8, & 13, No fibrin formation occurs. The breakdown of fibrin.

• X-linked recessive
• Decreased or absent F8
• Varies in severity

• Delayed bleeding
• Hemathroses
• easy bruising
• Mucous membrane bleeding
• GI bleeding
• Hematuria
• Spontaneous hemorrhage

• Prolonged PTT
• Decreased F8 assay

• IV F8 concentrates
• DDAVP - mild cases

Porcine F8 for those with antibodies

X-linked recessive

• Increased bleeding: mucosa, GI, hematuria, spontatneous, hemathroses, 
• Easy bruising

• Prolonged PTT
• Decreased F9 assay

• IV F9  concentrates
• Plasma
• PCC

• Afibrinogenemia - most severe
• Dysfibrinogemia - moderate
• Hypofibrinogenemia - less severe

• Umbilical cord bleeding
• Mucosal bleeding
• Hemathroses
• Intracranial hemorrhage
• Miscarriages
• Delayed wound healing

• Afibrinogenemia: 
• Prolonged: PT, PTT, BT, & TT
• Absent fibrinogen

• Dys:
• Prolonged TT
• Prolonged Reptilase time

• Hypo: 
• Prolonged TT
• Low fibrinogen

• Cryo
• Fibrinogen concentrates

• Autosomal Recessive  - typical 
• May also be autosomal dominant
• Both sexes affected equally
• 3 different types (1, 2, & 3)

Defect in platelet adhesion at the vascular site of injury.

• Increased bleeding 
• Mucosal Bleeding

• Quantitative defect of vWF
• Decreased F8, 
• <50% Ristocetin
• <70% vWF antigen
• *slight prolonged PTT
• Increased BT

• TREATMENT: 
• DDAVP - may stimulate the release of vWF from vascular endothelium

Qualitative defect

• <50% Ristocetin
• <70% vWF antigen
• Increased BT
• *Decreased PLT

• Treatment: DDAVP (type 2a)
•                  F8, Amicar (Type 2b)

Complete absence of vWF

• <5% F8
• <10% Rostocetin cofactor & vWF antigen
• Increased BT & PTT*
• *No agg with RIPA

• Treatment:
• DDAVP, F8, Amicar

Platelet transfusion is inappropriate since the defects are in the plasma protein and patients platelets function normally.

Causes the release of vWF from the endothelial cells and into circulation, thus increasing plt. adhesion

***DDAVP should NOT be given in patients with type 2b and platelet type vWD

Vit. K is essential for: 

2, 7, 9, & 10

Most commonly a result of warfarin

Increased bleeding episodes

• Prolonged PT & PTT
• Low Vit. K

• Treatment:
• IM Vitamin K - for no excessive bleeding
• IV - Vit K - CNS or GI bleeding
• Plasma -  severe bleeding
• PCC - severe bleeding and warfarin reversal

• Decreased production of coag factors
• maladsorption of vit K. 
• Platelet dysfunction
• May lead to DIC

• Prolonged PT & PTT (PT is more thant PTT)
• Decreased PLT, Protein C & S along with miscellaneous factors. (F8 is not affected)

Differentiate from DIC with DIMER - Dimer is neg with Liver disease.

• TREATMENT:
• Vitamin K
• Plasma
• DDAVP
• PCC

Is the process of systemic uncontrollable clotting that can cause microthrombi with simultaneous lysis of the clots that causes bleeding.

• Sepsis
• Trauma
• Burns
• Hemolytic transfusion reactions
• Acute promyelocytic leukemia
• OB issues (placenta abruptus, amniotic fluid embolism, ecampsia, retained fetus)
• Liver disease
• Some cardiac prosthetic devices

• Low:
• Platelet
• H&H
• Fibrinogen <150 (<100 - bleeding risk)
• AT (<80% risk of thrombosis)
• Plasminogen
• Factor activity levels

• High:
• FDP's
• Dimers
• PT
• PTT
• TT

• Other:
• Schistocytes

• Identify the underlying cause and treat
• Maintain blood volume & hemostatic function
• Cryo >100 mg/dL
• AT/Protein C
• Heparin  (for thrombosis risk)
• RBC's, Plasma, Platelets