M.B. is a generally healthy 36-year-old woman with complaints of persistent generalized fatigue. At her annual checkup she is noted to have the following vital signs: heart rate 118 beats/min, blood pressure 128/60, oral temperature 37º C, and respiratory rate 26 breaths/min. Her skin and nail beds are pale. Laboratory results demonstrate hematocrit (Hct) 31%; hemoglobin (Hb) 10 g/dl; mean corpuscular hemoglobin concentration 27; mean corpuscular volume 70; total iron binding capacity 600 mg/dl.
Discussion Questions
1. What type of hematologic disorder would you suspect based on M.B.'s history, physical examination, and laboratory values? Why?
2. What other history data would be helpful in determining the cause of this disorder?
3. Which of M.B.'s clinical signs are reflective of the body's effort to compensate for the decreased oxygen carrying capacity seen with this condition?
4. If M.B. has normal blood oxygen levels (PaO2 = 100), what is the oxygen content of her blood?
Hints: Fully bound O2 is considered to be nearly 100% saturated; Oxygen concentration = (PaO2 × 0.003); 1 g Hb can bind 1.34 ml O2.
5. M.B. is counseled to increase her dietary intake of iron-containing foods. What kinds of food would be recommended?
6. M.B. is given a prescription for ferrous sulfate 300 mg three times per day. How long do you anticipate this therapy will continue?