Hemophilia Flashcards
What is hemophilia A?
Hemophilia A is an X-linked recessive clotting disorder that
results in a deficiency of factor VIII.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421-422.
What are the most common presenting symptoms of
hemophilia A?
Patients with hemophilia A are usually diagnosed in childhood
with spontaneous bleeding into joints and vital organs.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421.
How does the severity of hemophilia A vary and how
can the severity be assessed?
Severe hemophilia A exists when the factor VIII concentration is
less than 1% of normal. Patients whose factor VIII levels are
between 6% and 30% of normal may not suffer spontaneous
bleeding or hemarthroses, but are at increased risk of bleeding
during surgery. Even female carriers can have a mild form that
can reduce factor VIII activity to 30% of normal.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421.
How are coagulation profiles affected by hemophilia
A?
The PTT is significantly prolonged in severe hemophilia A and
only moderately prolonged in milder forms of hemophilia A.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421.
What is the treatment for hemohilia B?
Factor IX concentrate.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 422.
What is the treatment for hemophilia A?
Factor VIII concentrate
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421.
What preparations should be made for the patient
with hemophilia A about to undergo surgery?
Factor VIII concentrate should be administered until levels are
at or near 100% of normal prior to surgery, which may require a
dose of 50-60 units/kilogram.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421.
What is the half-life of factor VIII and what is the
significance of this?
The half-life of factor VIII is about 12 hours, which means that
during the perioperative period, infusions of 30 units/kg may
have to be repeated every 8-12 hours to keep factor VIII levels
at half of normal.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421.
What is hemophilia B?
Hemophilia B is an X-linked recessive coagulation disorder
caused by a deficiency of factor IX. Because factor IX is also
known as Christmas factor, hemophilia B is sometimes known
as Christmas disease.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 422.
How does the severity, course of illness, and
laboratory findings in hemophilia B compare to that
of hemophilia A?
Except for the specific clotting factor involved, the course of
illness with hemophilia B is almost identical to that of hemophilia
A. Also like hemophilia A, severe hemophilia B occurs when
less than 1% of the normal amount of factor is present and
becomes considerably milder when patients have between 5%
and 40% of the normal amount of factor. Like hemophilia A,
patients with hemophilia B exhibit a prolonged PTT and a
normal PT.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 422.
What are the two treatment regimens available for
hemophilia B?
The two main treatments available are recombinant factor IX
and factor IX-PCC preparation.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 422.
Why would one choose to give recombinant factor IX
over factor IX-PCC?
Factor IX-PCC contains a high concentration of activated
clotting factors. When enough is given to raise the factor IX
level to 50% of normal, a significant risk of thromboembolism
develops, especially in the setting of orthopedic surgery. If only
factor IX is needed, then the administration of Factor IX-PCC
may be an unnecessary risk.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 422.
How does the dosing regimen for factor IX compare
to that of factor VIII?
Like factor VIII treatment, factor IX must be administered over
several days during the perioperative period, but because
collagen can absorb factor IX, the doses that must be
administered are about double that of factor VIII. It has a longer
half-life than factor VIII, however, doses of 100 units/kilogram
every 12 to 24 hours is suitable to keep factor IX levels above
50%.
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 421-422.
