Ch. 38 Postop Bleeding

Question 1

• How does renal failure cause coagulopathy?
• How does liver disease cause coagulopathy?

Answer 1

• How does renal failure cause coagulopathy?
  
  • ESRD results in presence of uremic toxins circulating in the blood, which cause platelet dysfunction.
  • Can be initially managed with desmopressin and/or hemodialysis
• How does liver disease cause coagulopathy?
  
  • As liver disease worsens, so does the synthetic fxn of the liver manifested by prolonged PT and increased INR –> thrombocytopenia and dec. production of coagulation factors

Question 2

What is the most frequently encountered etiology for thrombocytopenia?

Answer 2

Alcohol abuse

Question 3

Common causes of DIC?

Answer 3

Delivery –> Tissue thromboplastin in amniotic fluid activates coagulation cascade

Infection –> Sepsis can result in the induction of endothelial cells to make/release tissue factor; the most common mechanism involves TNF associated with gram negative bacteria

Cancer –> Auer rods in AML = potent activators of coagulation cascade; mucin associated with adenocarcinoma can also activate the cascade

Question 4

HIT

Pathology

Labs

Mgmt

Answer 4

Pathology:

• Heparin forms complex with platelet factor 4 –> produces IgG antibodies which destroy platelets; remnants activate remaining platelets –> thrombus

Labs:

• Sudden decrease in platelet count > 50%

Mgmt:

• Stop heparin, switch to direct thrombin inhibitor

Question 5

ITP

Pathology

Labs

Mgmt

Answer 5

Pathology:

• Autoimmune production of IgG leading to platelet destruction

Labs:

• Platelets commonly < 50,000

Mgmt:

• Children: observe for spontaneous resolution, corticosteroids, and IVIG
• Adults: corticosteroids, IVIG, dapsone, splenectomy

Question 6

TTP

Pathology

Labs

Mgmt

Answer 6

Pathology:

• Platelets are consumed in the formation of microthrombi in small vessels, due to an enzyme deficiency (ADAMSTS13) that normally cleaves VWF multimers

Labs:

• Inc. reticulocytes
• Blood smear shows hemolytic anemia (schistocytes)

Mgmt:

• Emergent plasmapheresis, corticosteroids, FFP, splenectomy

Question 7

What is the best way to urgently reverse warfarin?

Answer 7

FFP