Hb Structures Flashcards
Slight pallor and tachycardia Hb level?
9-11
More pronounced pallor, plus dyspnea on exertion Hb level?
7-8
Pallor, tachycardia, dyspnea, plus many complain of weakness Hb level?
6
Pallor, tachycardia, weakness, plus people complain of dyspnea at rest Hb level?
3
Pallor, tachycardia, dyspnea, weakness plus many complain of CHF Hb level?
2-2.5
Normal RBCs lifespan
120 days
Acute anemia (2)
Blood loss and hemolysis
4 chronic anemia situations
- Hemolytic (G6PDH-deficiency, immune mediated, drug induced)
- Hemoglobinopathies (sickle cell, thalassemia)
- Nutritional/consumptive
- Folate deficiency
Shortening of RBC survival to less than 100 days due to an increased rate of destruction of RBCs
Hemolytic anemia
2 mechanism for hemolytic anemia?
- Abnormalities within RBC &/or it’s membrane
2. Abnormalities in environment (extrinsic due to immune mechanisms due to warm and cold agglutinin)
4 hemolytic anemia’s
- Disorder of RBC structure
- Disorder of RBC metabolism
- Immune hemolytic anemia
- Non immune hemolytic anemia
Most common enzyme defect?
G6PDH
Treatment for G6PDH deficiency (3)
- Remove trigger or stop drug
- O2 and fluids
- Transfusion
Main G6PDH deficiency anesthesia consideration?
Some pts cannot reduce methemoglobin
- lidocaine and nitroprusside are contraindicated
- methylene blued can be life threatening
Detected at birth but some present during times of great physiological stress such as pregnancy, or acute illness
Pyruvate kinase deficiency
Destruction of RBCs by autoantibodies may occur suddenly, or it may develop gradually.
Immune hemolytic anemia
What is more common immune hemolytic anemia: cold antibody or warm antibody?
Warm antibody
Cold antibody hemolytic anemia temp:
28-31
Warm antibody hemolytic anemia temp:
37
Severity of anemia is determined by what?
Length of time that RBCs survive and by rate at which bone marrow continue to create new RBC production
CAHA is associated with? (2)
- Idiopathic cold hemagglutinin syndrome
2. Infectious mononucleosis and mycoplasma pneumonia
WAHA is associate with? (3)
- Systemic lupus erythematosus (SLE)
- Lymphoma
- Chronic lymphocytic leukemia
Occurs if body makes antibodies against RBCs that you get from an incompatible blood transfusion; occurs during pregnancy if woman has Rh- and baby is Rh+; drug induced (chemo, acetaminophen, quinine, PCN,)
Alloimmune hemolysis
Non immune hemolytic anemia direct Coombs test result?
Negative
Common causes of non immune hemolytic anemia (7)
- Drugs (ribavirin)
- toxins (snake venom, plant poisons)
- trauma
- mechanical
- Microangiopathic hemolytic anemia (TTP, HUS, DIC, HELLP)
- Infection malaria (babesiosis, sepsis)
- Membrane disorders (liver disease, paroxysmal nocturnal hemoglobinuria)
Minimize disruption of O2 delivery to tissues by avoiding what? (6)
Oxyhemoglobin dissociation curve to the L
- Alkalosis
- Hypocarbia
- Decreased temp
- Carbon monoxide
- Methemoglobin
- Hypophosphatemia
Consider blood transfusion when Hb is what for:
- acute blood loss from healthy person <60
- healthy person with asymptomatic chronic anemia
<6.4g/100ml
Consider blood transfusion when Hb is what for:
- acute blood loss from healthy >60 yrs
- acute blood loss from multi trauma pt
- preop in pt with periop blood loss >500ml
- fever
- postop after uncomplicated cardiac surgery
- uncomplicated operation in pt with ASA 2and3
<8g/100ml
Consider blood transfusion when Hb is what for:
- ASA 4 pts
- HF or valvular disease unable to raise CO
- severe lung disease (COPD)
- septic and toxic
- symptomatic cerebrovascular disease
<10g/100ml
Underlying genetic defect of sickle cell disease
1 amino acid exchanged in beta-chain of hemoglobin
Suckling and subsequent hemolysis starts at what and becomes pronounced at what?
PaO2 50 and 20
Sickle cell disease occurs when (3)
- High altitude
- Severe dehydration
- Very high intensity physics activity
Complications with sickle cell disease (3)
- Muscle breakdown (rhabdomyolysis)
- Reduced blood supply to spleen
- Increased pressure in eye (glaucoma)
How to prevent sickling? (6)
- Avoid excessive premed with vent depression
- Adequate hydration
- Maintain normothermia
- Tourniquet
- Transfuse to reduce fraction of HbS
- Volatile anesthetics prompt sickling
Abnormal formation of hemoglobin with tendency for hemolysis; defect in either alpha or beta globin chain
Alpha and beta thalassemia
What is the main consideration for thalassemia and anesthetic considerations?
Maintenance of sufficient O2 carrying capacity, often require frequent blood transfusions (every few weeks)
Polycythemia causes: an increase in HCT from reduction in plasma volume with no increase in red cell mass
Relative
Polycythemia causes: increased number of RBCs
Absolute