A 53-year-old woman arrives at the hospital with bleeding into ...

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A 53-year-old woman arrives at the hospital with bleeding into the back of the throat and has a coagulation screen performed.
 
  She has no history of abnormal bleeding before this despite major stress to hemostasis in the past: she was in a major automobile accident at age 37 and has had impacted wisdom teeth extracted. Her coagulation results follow:
 
   Patient's Results Reference Range 1:1 Mix with Normal Plasma
  Prothrombin time (PT) 13.1 seconds 11-15 seconds
  Partial thromboplastin time (PTT) 87 seconds 25-37 seconds 35
  Fibrinogen 380 mg/dL 200-400 mg/dL
 
  Which of the following is the most likely cause for her bleeding?
 
  a. Factor XII deficiency
  b. Factor IX deficiency
  c. Factor VIII deficiency
  d. Factor VIII inhibitor

Question 2

Which of the following specimens would be acceptable for platelet aggregation studies?
 
  a. Blood drawn in ethylenediaminetetr aacetic acid (EDTA) and kept at room temperature for 6 hours
  b. Blood drawn in 3.2 sodium citrate and transported to the laboratory on ice (2 to 4 C)
  c. Blood drawn in a serum separator tube
  d. Blood drawn in 3.2 sodium citrate and kept at room temperature for 2 hours after drawing

[robbielu01]

Answer to Question 1

ANS: D
This patient is bleeding abnormally. However, she has had major trauma in the past with no abnormal bleeding; this suggests the problem is acquired, not congenital. The PTT is prolonged, so the common pathway appears to be intact. The prolonged PTT fully corrects on a 1:1 mix, although at the upper end of the reference range. Putting all of this together, the most likely problem is an acquired factor VIII inhibitor.

Answer to Question 2

ANS: D
Platelet function studies must be performed within 3 hours of drawing, and the specimen must be kept at room temperature because chilling damages platelets. The blood sample must be drawn in 3.2 sodium citrate.

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TYSM

[diana chang]

Gracias!