Oral Review: Anemia Flashcards
Lab values indicating anemia:
Female: 11 Hgb, 36% Hct
Male: 12 Hgb, 40% Hct
Considerations for pre-op transfusion:
Cause of anemia Degree/duration of anemia Intravascular fluid volume Urgency of surgery ABL during surgery Age Co-existing dieases
Co-existing pathologies that increase likelihood for transfusion:
Cardiovascular
Cerebrovascular
Lung disease
PVD
General points of anesthesia management of anemia:
Increase FiO2 and use PEEP to maximize O2 delivery
Avoid decreasing CO and myocardial depression (etomidate +/- ketamine, high opioid technique)
Inhaled agents with low B/G coefficients
Avoid left shifts (don’t hyperventilate, keep warm)
Compensatory changes in anemia of chronic disease:
Decreased SVR
Increased 2-3 DPG, CO, plasma volume, and blood flow to organs with high extraction ratios
Induction in anemia of chronic disease:
Avoid marked reductions in CO; choose agents based on patient’s co-existing
Maintenance in anemia of chronic disease:
Maintain high PaO2 Avoid hyperventilation Maintain high CO Avoid hypovolemia Keep patient warm Maintain Hbg above critical level
Emergence/post-op management in anemia of chronic disease:
Keep patient warm
Maintain high PaO2
Period of greatest risk for ischemia/infarction; consider prolonged drug effects
Manifestations of folic acid deficiency anemia:
Smooth/thick tongue
Peripheral edema
Liver dysfunction
Mental depression
Manifestations of B12 deficiency anemia:
Peripheral neuropathy Loss of sensation in LEs (proprio/vibration) Unsteady gait Memory impairment Mental depression
Anesthetic management of B12/folic acid deficiency anemia:
Avoid regional/PNBs Avoid N2O (inactivates B12) Maintain PaO2 to peripheral tissues Thorough airway exam
Special considerations for anesthetic management of thalassemia:
Potential difficult airway d/t maxillary overgrowth
Spinal cord compression - caution w/ positioning
Predisposed to SVT
Sensitive to digitalis
Coagulopathic
Complications of iron overload in thalassemia:
Diabetes Adrenal insufficiency Liver dysfunction Hypothyroid/parathyroid Arrythmias Heart failure
Clinical signs of 20% EBV loss:
Orthostatic hypotension, tachycardia, CVP changes
Clinical signs of 40% EBV loss:
Hypotension, tachycardia, tachypnea, diaphoresis
Clinical signs of hemorrhagic shock:
SBP
Pre-op preparation for aplastic anemia:
Steroid stress dosing
Reverse isolation
Prophylactic abx
Preop sedation
Induction considerations for aplastic anemia:
Airway bleeding possible
Avoid nasal intubation
Avoid regional anesthesia
Labile HD response (use ketamine, etomidate, high opioid)
Maintenance considerations for aplastic anemia:
Use PEEP to help keep FiO2 below 50%; hyperoxemia will cause bone marrow suppression
Avoid N2O also d/t bone marrow suppression
Normothermia
Measures to avoid sickle cell crisis:
Maintain normothermia Avoid dehydration Maintain oxygenation Avoid acidosis Avoid stasis with proper positioning
Pre-op preparation for sickle cell patients:
Pre-op transfusion to Hct > 30%, Hgb S
Induction for sickle cell patients:
Avoid hypoxemia and hypovolemia
Use IV lido for smooth induction
Emergence and post-op for sickle cell patients:
Continuous hydration
Keep warm
Adequate analgesia
Pulmonary hygiene to prevent post-op respiratory issues that cause acidosis
Lab tests indicating DIC:
Rapid decrease in plt count to
Treatment of DIC:
Treat underlying cause/trigger! Platelets FFP Low molecular weight heparin Antithrombin III
Peri-op management of coumadin:
Stop coumadin 3-4 days pre-op and either:
IV/SQ heparin or
If INR 2-3, hold 4 doses to allow INR to drop to 1.8
INR should be
Emergent reversal of coumadin:
5-8ml/kg of FFP
Discuss dilutional thrombocytopenia:
Most common cause of intra-op coagulopathy
Dilution of platelets due to blood/fluid replacement
Treat with 1:1 PRBC:FFP replacement
Compensatory physiological mechanisms for dilutional thrombocytopenia:
Release of stored platelets from the spleen (33%)
Release of procoagulant proteins from liver
Discuss vitamin K deficiency:
Necessary for production of factors 2, 7, 9 and 10
Deficiency from malnutrition, malabsorption, abx elimination of gut flora, obstructive jaundice
Will see prolonged PT, normal PTT
Tx: daily vit K (takes 6-24 hrs to effect) or FFP (urgent)
Discuss hemophilia A:
Absence or severe deficiency of factor 8
Normal platelet count, normal PT, prolonged PTT
Tx with factor 8 infusion or DDAVP
Avoid IM injection and regional, careful during DVL
Discuss hemophilia B:
Absence or deficiency of factor 9
Prolonged PTT and normal PT
Tx with factor 9 infusion
Discuss von Willebrand’s disease:
Deficient or defective vWF, needed for platelet aggregation
Tx with cryo or DDAVP
