RBC Physiology
Where is active red bone marrow located in adults?
Sternum, ribs, proximal long bones
Difference between HgbF and HgbA?
HgbF has higher oxygen affinity (lower 2,3-BPG affinity)
Most common cause of microcytic anemia?
Iron deficiency
Immediate response to vascular injury?
Vasoconstriction
Hemophilia A deficiency?
Factor VIII
Top priority in sickle cell intraop?
Oxygenation
What is the lifespan of normal RBCs
100-120 days
Where is iron absorbed?
Duodenum
Macrocytic anemia lab clue?
Elevated MCV
Primary vs secondary hemostasis difference?
Platelet plug vs fibrin stabilization
Lab finding in Hemophilia A?
Prolonged aPTT, normal PT
What must be avoided in sickle cell patients?
Hypoxia, acidosis, hypothermia, dehydration
What stimulates RBC production in chronic anemia?
Erythropoietin from the kidneys
95% of iron for hemoglobin production comes from where?
Recycled RBC breakdown
Anemia of chronic disease is treated how?
Treat the underlying condition
What does TXA2 do?
Vasoconstriction + platelet aggregation
Most common inherited bleeding disorder?
Von Willebrand disease
Cirrhosis affects coagulation because why?
Liver synthesizes most clotting factors
Why does cardiac output increase in anemia?
Decreased blood viscosity + compensation for low O2 delivery
Explain why HgbF is beneficial in fetal circulation.
Extracts O2 from maternal circulation efficiently
G6PD deficiency causes what type of anemia?
Hemolytic anemia
What protein helps platelets adhere to damaged endothelium?
vWF
Virchow triad components?
Endothelial injury, stasis, hypercoagulability
What guides transfusion decisions in DIC?
Coag studies, TEG if available
Why can severe anemia lead to high-output heart failure?
Persistent increased CO to maintain oxygen delivery
Why are vegans at risk for macrocytic anemia?
Vitamin B12 deficiency
Rapid blood loss leads to what physiologic state?
Hypovolemic shock
Name 3 substances released during platelet degranulation
ADP, serotonin, thrombin
Factor V Leiden causes what problem?
Prolonged prothrombinase activity → hypercoagulability
Severe thalassemia patient — airway concern?
Skeletal malformations → difficult intubation
Which factors are Vitamin K dependent?”
II, VII, IX, X (and Protein C & S)