Flashcards in Hemostasis Defects Deck (66)
What factors does protime (PT) measure?
II, VII, X, V and fibrinogen
The extrinsic and lower part of the coagulation cascade.
What is a normal PT?
Because the PT is dependent upon the potency of the material that i used to start the reaction in the laboratory what must it be compare to?
International normalized ration (INR)
What is a normal INR?
What are two of the most common causes of abnormal PT?
Deficiency of vitamin K dependent factors (VII, X, II) or
Inadequate liver funciton
What would warfarin do to the PT?
What does the PTT measure?
The procoagulant activity of the entire pathway, but it is more sensitive to deficiencies of the higher numbered factors especially XI, VIII, and IX
What is PTT not effective in measuring?
What can prolong the PTT?
Heparin or acquired anticoagulants such as fibrin split products
Patients with hemophilia
What is a normal PTT?
What is PT used to monitor?
What is PTT used to monitor?
What does thrombin time measure?
The procoagulant activity of fibrinogen and is also very sensitive to the anticoagulant effect of heparin or fibin split products.
What is the normal range of thrombin time?
What does the bleeding time measure?
Platelet and vessel initeraction as well as the number and the function of platelets.
What is a normal bleeding time?
What will cause an increase in bleeding time?
Severe decrease in platelet count
von Willebrand disease
abnormalit in platelet function
OTHER FACTOR DEFICIENCIES DO NOT PROLONG THE BLEEDING TIME
What is PFA-100?
Platelet function analyzer that can perform an in vitro bleeding time
What is most common cause of a severe bleeding tendency?
Hemophilia A (Factor VIII deficiency)
Hemophilia B is characterized as a deficiency of what coagulation factor?
What is the inheritance pattern of both Hemophilia A and Hemophilia B?
Females are carriers
Men are affected
Which test is prolonged in Hemophilia A and B?
What is the genetic defect is seen in 40% of Hemophilia A patients?
Inversion on the long arm of the X chromosome
Less than 1% factor activity is considered a severe hemophilia. What are the symptoms of someone with less than 1% factor activity?
Spontaneous hemorrhaging into their joints, muscles, soft tissues, retroperitoneal space and CNS.
Continuous bleeding into the joints leads to very severe arthritis
Between 2%-5% factor activity is considered to by a moderate hemophilia. What are the symptoms of someone with moderate hemophilia?
It usually takes some degree of trauma to cause bleeding in these patients
>10% factor activity is considered a mild hemophilia. What are the symptoms of someone with >10% factor activity?
Only bleed after trauma and do not develop the chronic joint disease
They are usually diagnosed after a bad traumatic even ot after a bad result from surgery
Female carriers can express anywhere from 30-100% factor activity, but at what percent are they symptomatic carriers?
Factor XI deficiency usually express >5% factor activity. Are they spontaneous bleeders?
What is the inheritance pattern of Factor XI deficiency?
What patient population is Factor XI deficiency common in?