Blood Disorders (3) Flashcards
What does vWF play a critical role in?
platelet adherence/adhesion
What is the most common hereditary bleeding disorder?
vWF disorder
Symptoms of vWF:
- easy bruising
- recurrent epistaxis
- menorrhagia
- patients are usually unaware until questionaire/surgery
Classification of Inherited vonWillebrand disease:
Diagnosis for vWF disease:
- PT and aPTT are often normal in patients with vWD
- BT is prolonged
- hematologist to analyze labs
Treatment for vWF disease:
- Correct the deficiency of vWF
- Use desmopressin
- By the transfusion of the specific factor
- Cryoprecipitate
Dose for DDAVP:
IV dose = 0.3 mcg/kg in 50 mL of normal saline over 15 to 20 minutes
What is DDAVP?
A synthetic analogue of vasopressin and stimulates the release of vWF by endothelial cells
The maximal effect of DDAVP:
The maximal effect is in 30 minutes and lasts from 6 to 8 hours
Side effects of DDAVP:
- headache
- rubor
- hypotenstion
- tachycardia
- hyponatremia
- water intoxication
For patients getting DDAVP, how can you decrease water intoxication, hyponatremia, and consequent seizures?
The administration of water, orally or intravenously, should be restricted for 4-6 hours after the use of the drug
CNS and ECG changes for serum Na of 120 meq/L:
CNS: confusion and restlessness
ECG: Widening of QRS
CNS and ECG changes for serum Na of 115 meq/L:
CNS: somnolence and nausea
ECG: Elevated ST segments, widened QRS
CNS and ECG changes for serum Na of 110 meq/L:
CNS: seizures and coma
ECG: Vtach or Vfib
What is a risk of giving cryoprecipitate?
Increase risk of infection/reaction because it’s not submitted to viral attenuation
How much does 1 unit of cryo raise fibrinogen?
50 mg/dL
Anesthesia considerations for patients with vWF disease:
- general anesthesia
- undergoing neuroaxial block = increased risk of developing a hematoma and compression of neurological structures
- avoid traumas (intubating)
- arterial puncture is not recommended
- laryngeal trauma during intubation may cause hematoma - postop obstruction of the airways
- avoid IM
Characteristics of heparin:
- negatively charged, CHO containing glucuronic acid residues
- inhibits thrombin
- heparin derives its anticoagulant effect by activating antithrombin III
How do you monitor heparin intraop?
PTT and ACT
Reversing heparin:
Heparin’s anticoagulant effect is rapidly reversible by protamine (+ polypeptide forming a stable complex neutralizing heparin)
Which heparin is more effective for VTE prophylaxis?
LMWH is more effective compared to UFH
LMWHs have a more predictable ______ ______, fewer effects on ______ ______, and a reduced risk for ___.
Pharmacokinetic response;
platelet function;
HIT (heparin induced thrombocytopenia)
MOA of coumadin:
Interferes with hepatic synthesis of vitamin-k dependent coagulation factors (II, VII, IX, X)
What are the vitamin k dependent coag factors?
Factors II, VII, IX, X