Misc Flashcards
Hemophilia A and B factor deficiencies
A: Factor 8
B: Factor 9
(Remember: Aight is followed by 9)
Hemophilia considerations
- High risk periop bleeding (especially consider bleeding into closed spaces)
- Possible contraindication neuraxial (may be considered if factor level >50%)
- optimize factors and identify factor antibodies
- blood loss conservation strategies
Hemophilia A optimization
- DDAVP for mild disease
- Recombinant factor VIII (Humate P)
- Factor VIII concentrates (fresh frozen plasma contains minimal factor VIII)
- Recombinant factor VIIa for inhibitors (approved indication)
- Cryoprecipitate if nothing else available (this is the only standard fractionated blood product containing meaningful amounts of factor VIII)
Factors in cryoprecipitate
Factor VIII
fibrinogen
von Willebrand factor
fibronectin
factor XIII
Hemophilia B optimization
- Recombinant factor IX
- Factor IX concentrates
Hemophilia severity by % factor levels
Classification by factor levels:
Mild: 5-25%
Moderate: 1-5%
Severe: <1%
Trough Factor VIII levels for different types of surgery in VWD
Key trough factor VIII levels:
Obstetric > 50%
Minor surgery > 30%
Major surgery > 50%
VWD management
- DDAVP 0.3 mcg/kg (provides 3-5 fold increase in activity); only if known responder; works by stimulating the release of vWF from endothelial cells
- Factor VIII-vWF concentrates (Humate P)
- Platelet concentrates (contains vWF)
- Recombinant factor VIII
- Recombinant factor VIIa
- Emergency: cryoprecipitate (contains vWF, FVIII, FXIII, fibronectin, fibrinogen)
What is VWD?
Quantitative or qualitative deficiency in von Willebrand factor.
VWF functions as a carrier for factor VIII to maintain its levels and help in platelet adhesion and binding to endothelial components after a vascular injury. Made by endothelial cells and secreted into the vascular lumen.
Types of VWD
Inherited:
- Type 1: AD, partial quantitative deficiency
- Type 2: AD, qualitative defects
- Type 3: AR, completely absent
Acquired:
- functional impairment in cancers, inflammatory conditions, etc.
- including high-vascular flow such as AS, VSD, VAD, ECMO, or metallic cardiac valves. (The von Willebrand factor is a large multimeric glycoprotein, susceptible to the shear stress associated with high flow states.)
Post op visual loss - types and associations
CAPO
Central retinal artery occlusion
Anterior ischemic optic neuropathy - pressure on eye
Posterior ischemic optic neuropathy - prone spinal surgery (surgery >6.5 hrs, large EBL)
Occipital stroke
Oxyhemoglobin dissociation curve - leftward shift
Increased affinity (less O2 release)
Decreased temp
Decreased 2,3-DPG
Alkalosis/hypocarbia
CO
Oxyhemoglobin dissociation curve - rightward shift
Reduced affinity (offload O2)
Increased temp
Increased 2,3-DPG
Acidosis/hypercarbia
Peds ETT size
Uncuffed = (age in years/4) + 4
Cuffed = (age in years/4) + 3
Newborn usually 3-0 uncuffed
Standard ASA monitors
Circulation, oxygenation, ventilation, and body temperature
“Non-invasive BP cuff, continuous pulse oximetry, continuous 5-lead EKG, end-tidal capnometry if patient has a secured airway, as well as temperature monitoring if clinically significant changes in temperature are anticipated.”
Circulation: BP and HR q5min minimum, continuous EKG, continuous circulation (eg pulse ox pleth)
Oxygenation: oxygen analyzer, pulse ox
Ventilation: continual EtCO2 monitoring if secure airway, disconnect alarm. If sedation, clinical signs + capnography
Body temp: body temp monitored if clinically significant changes expected
