Answer Happy

This A 43-year old white bartender presented with a chief
complaint of daily bright red blood with bowel movements for twenty
years. With careful questioning, he admitted to mild fatigue and
some dyspnea on exertion. Physical revealed a pale white man
in no distress. The examination was negative except for "spoon
nails" and large, bleeding hemorrhoids. BP=130/80, Pulse=88/min.
Lab data: Hematocrite 15.9%. Hemoglobin 4.7 g/dL. RBC count 3.26 x
106 / L. WBC count 7,800/UL. Platelet Count 407,000/ul.
Reticulocyte Count 3.0%. Iron studies revealed a serum iron of 10
mg/dL, and iron binding capacity of 495 mg/dL, and a ferritin of 13
mg/dL. A bone marrow aspirate showed a normally cellular marrow
with a M:E ratio of 2:1, and small red cell precursors with ragged
bluish cytoplasm. Iron stain showed no stainable iron in the
macrophages and no siderocytes
1. Why was the patient asymptomatic at such a low hematocrit?
What compensatory mechanisms occur in profound anemia? Should the
patient be transfused?
2. Describe the expected response to oral iron