Yoho

Question 1

define Protein S

Answer 1

• Vitamin D-dependent glycoproteins synthesized in the liver
• Functions as cofactor to protein C in the inactivation of Factors Va and VIIIa
• Exists in free form and bound form

Question 2

etiologies of Protein S deficiency (congenital)

Answer 2

• Congenital
  
  • inheritance is autosomal dominant; homozygotes develop neonatal purpura fulminans shortly after birth; and heterozygotes
  • Types
    
    • Inadquate amounts of protein S in both free and bound forms
    • characterized as defective protein molecules
    • decreased free protein S, but overall normal amount of protein S

Question 3

etiologies of Protein S deficiency (acquired)

Answer 3

(More common than heridetary)

• seen in consumptive processes like DIC or extensive DVT/PE
• patients taking warfarin (other vitamin K-dependent factors)
• pregnancy
• liver disease

Question 4

consequences of protein S deficiency

Answer 4

• Deep venous thrombosis (DVT = VTE)
  
  • 50% frist thrombotic event before age 25
  • 44% with prococations; 56% spontaneous
• Possible assocaition with arterial thrombosis (stroke, heart attack) under investigation (white clot syndrome)

Question 5

preventative measures

Answer 5

• don’t use a tourniquet (or atleast don’t inflate it)
• minimal surgery time
• prophylactic anticoagulatn therapy
  
  • mini dose heparin (below therapeutic dose)
• early range of motion
• monitor
• GOOD HISTORY TAKING SKILLS!!!!!