Bleeding Disorders Flashcards
Which pathway does PT represent?
Extrinsic pathway (warfarin)
Which pathway does PTT represent?
Intrinsic pathway (heparin)
What is an INR?
International normalized ratio
It is a standardized PT so that you can compare values between labs
What is hemophilia A caused by?
Congenital Factor VIII deficiency
What is hemophilia B caused by?
Congenital Factor XI deficiency
What is the presentation of hemophilia?
Recurrent hemarthroses and easy bruising and bleeding
What is the most common x-linked disease?
Hemophilia A
What type of inheritance is hemophilia?
X linked recessive
What is a possible progression of hemophilia?
Development of inhibitors to clotting factors that they are already deficient in
What laboratory findings support a hemophilia diagnois?
Low factor level (III or XI)
aPTT is prolonged
PT is normal
CBC is normal
What is the severity of hemophilia determined by?
The level of factor activity
What can hemophiliacs take for pain?
Celebrex (COX-2 selective), opioids
Avoid NSAIDS
What is the prognosis of hemophilia?
Generally full lives if managed well
Deaths typically due to HIV and hepatitis
At risk of ICH
What patient education is necessary for hemophilia?
Avoid contact sports
What is the most common inherited bleeding disorder?
Von Willebrand Disease
What is the function of vWF?
Bridges platelets and tethers them to a site of vascular injury
What is T1 vWD?
Most common type
Not enough vWF
Autosomal dominant
None to severe disease
What is T2 vWD?
Second most common type
Due to dysfunctional vWF
Autosomal dom or recessive
Mod to severe bleeding
What is T3 vWD?
Least common type
Absence of vWF
Autosomal recessive
Severe manifestations (looks similar to Hemophilia A
What are the most common signs of von Willebrand disease?
Nosebleeds and hematomas
What are common laboratory findings to support a vWD diagnosis?
Bleeding time is prolonged or normal (T1)
aPPT is mildly prolonged or normal (2/2 low FVIII)
PT is normal
What affects vWF levels?
Physiologic stress
ABO blood type
->Can be intermittently normal in vWD
What is the treatment for vWD?
Desmopressin (DDAVP)
rVWF
vWF/FVIII concentrates
What is factor XI deficiency?
Autosomal recessive disease common in ashkenazi jewish decent
known as hemophilia C
What is the presentation of factor IX deficiency?
Mild bleeding
What is the treatment for factor XI deficiency?
Factor XI concentrate for bleeding
Can also use FFP
What is thrombocytopenia?
Too few platelets so cannot form a primary plug or secondary clot
What are the symptoms of thrombocytopenia?
Epistaxis, gum bleeding, GI bleeds
What are the causes of thrombocytopenia?
Decreased production of platelets
Increased sequestration of platelets
Pregnancy -> volume overload
What are the causes of destructive or consumption thrombocytopenia?
Spenomegaly
Antibodies (ITP)
Drugs
Massive bleeds
Thrombus formation
How does splenomegaly cause thrombocytopenia?
Spleen has upregulated clearance of platelets. Caused by liver disease or malignancy. Must remove spleen or treat underlying cause.
What is ITP?
Immune Thrombocytopenic purpura
Form auto-antibodies against PLT antigens
What is ITP caused by?
Unknown
Could be post viral syndrome
Could be associated with immunodeficiency
Diagnosis of exclusion
What are the symptoms of ITP?
Sudden onset petechial rash, bruising, and bleeding in otherwise healthy child
How do you diagnose ITP?
PLT <100k
Normal CBC and blood smear
No other clinically apparent associated conditions
What is the treatment for ITP?
Watchful waiting, frequently spontaneously resolves
First treatment is corticosteroids, then IVIG, then platelet transfusions, then splenectomy
What is drug related destruction caused by?
Immune mediated destruction, increases clearance and destruction of PLTs.
Commonly after ABx
What is the presentation of drug-related destruction?
Severe thrombocytopenia and mucocutaenous bleeding 7-14 days after taking the new drug
How to treat drug-related thrombocytopenia?
Stop the drug
Might need corticosteroids
What is bleeding associated consumption?
Caused by massive bleeding that forces the patient to consume PLTs beyond rates of production
DIC like state
What is the treatment for bleeding associated consumption?
Blood product infusions and intervention to stop the bleeds
What is the cause of hypoproliferative thrombocytopenia?
Most commonly caused by bone marrow failure
Can be due to Leukemia/Lymphoma/myelodysplasia/aplasia
Cancers metastatic to bone marrow
Severe infection (CMV, HIV)
Radiation/chemo
What is the treatment for hypoproliferative thrombocytopenia?
Viral - typically self resolving
Cancer - treat the cancer to restore counts
Might need stem cell transplant (esp aplasia)
What are qualitative PLT disorders?
PLT count is normal but there are defects to the PLT that causes them to not function well.
What is the most common cause of qualitative PLT disorders?
Iatrogenic or acquired. Can be congenital but that is rare
How do qualitative PLT disorders manifest?
Mucus membrane bleeding
What is the treatment for qualitative PLT disorders?
Platelet transfusion
What are the most common causes of acquired/iatrogenic PLT defects?
Aspirin, Plavix, NSAIDs
Aspirin and Plavix are irreversible (5-10 days)
NSAIDS are reversible (24-48h)
What is thrombotic microangiopathy?
Incorporation of platelets into thrombi of the microvasculature
What is thrombotic thrombocytopenic purpura?
A disorder from a severe deficiency in ADAMTS13 that causes small clots form more frequently
What is the cause of TTP?
Unknown
What lab findings do you expect to see in TTP?
Large multimeters of vWF
Lack plasma protease
What is the presentation of TTP?
Acute or subacute symptoms related to neurological dysfunction, anemia, or thrombocytopenia. Might also see fevers and dark urine
How do you diagnose TTP?
Elevated WBC
Hgb of 8-9
Platelet 20-50k
Smear shows schistocytosis
PT/PTT are normal
Elevated D-dimer
Fibrinogen is high
LDH and bilirubin are high
Direct Coombs negative
What is the treatment for TTP?
Plasma exchange with FFP
95% mortality rate without plasma exchange
DO NOT just give platelets
What is HUS?
Hemolytic-uremic syndrome
Progressive renal failure that is associated with microangiopathic hemolytic anemia and thrombocytopenia
What is the most common cause of acute renal failure in children?
HUS, also seen in adults though
What i the presentation of HUS?
Gastroenteritis (bloody diarrhea)
Lethargy
Seisures
Renal failure
Anuria
HTN
Edema
Pallor
What is the cause of HUS?
Shiga-like toxin
E coli 0157:H7
What laboratory findings support HUS?
Elevated BUN/CR
Severe anemia and thrombocytopenia
Bilirubin and LDH are elevated
Get a stool sample
What is the treatment for HUS?
Supportive care only
Do not do a plasma exchange
What is disseminated intravascular coagulopathy?
Uncontrolled local or systemic activation of coagulation leading to thrombocytopenia and depletion of coagulation factors and fibrinogen
What are lab findings that support DIC?
Prolonged PT and PTT
Thrombocytopenia
Decreased fibrinogen
Elevated d-dimer
Schistocytes on blood smear
What disorders are associated with DIC?
Sepsis
Cancer/trauma/burns/pregnancy
AAA, cavernous hemangiomas
Snake bites
What clinical features support DIC?
Multiple sites of bleeding
Purpura and petechiae
What is the treatment for DIC?
Ask hematology LOL
Treat the cause, transfuse patient if bleeding, use heparin if persistent
