A patient presents with a gastrointestinal hemorrhage. Can you predict anemia from the physical examination? The short answer is yes, but not very well.
A review of the current literature reveals that the results are mixed. Sensitivity is often below 50% and specificity varies enough that we can’t totally trust the bedside finding of pallor. Most of these studies were done on outpatient populations with varying hemoglobin levels defining anemia.
At the bedside, you look at the conjunctival rim, the palms, the nailbeds, and the tongue. The conjunctiva has color but the palms and nailbeds are pallid. The tongue appears slightly pallid. The hemoglobin turns out to be normal. After IV fluids the extremity pallor has resolved. In this case the pallor seems to be the result of vasoconstriction. Perhaps that is also the explanation in those patients whose pallor did predict anemia? If that is true it explains why, after decades of research and dozens (hundreds?) of studies, we still can’t establish the diagnosis of anemia on physical examination alone
TAKE HOME POINTS:
-Physical diagnosis for anemia has mixed results
-If you are going to look for it, look at multiple areas (hands, eyes, tongue)
-Whether you do or don’t find pallor, order confirmatory hemoglobin levels