Respuesta :
Answer:
Hemolytic anemia
Explanation:
I'll organize the info provided and explain what my thought process is as I read through it.
HPI: 72M status post MV replacement. New fatigue, SOB.
The first step is to have a DDx based on the presenting symptoms and narrow it based on additional information in the HPI. Fatigue is relatively nonspecific so the DDx is broad but it suggests something is wrong; SOB could be cardiac, pulmonary, or hematological in origin, each of which could be broken down into numerous possible pathologies. In the context of a recent surgery, we are thinking the symptoms are related to it, possibly a complication. This narrows the DDx substantially to cardiac (e.g. CHF) or hematological (e.g. hemolytic anemia). The exam and investigations will help narrow it further.
O/E: pallor, scleral icterus
Pallor is nonspecific but could indicate anemia. Scleral icterus is consistent with hyperbilirubinemia. Likely not hepatic pathology given lack of liver history provided. Other causes of hyperbilirubinemia - hemolysis. The exam doesn't give us any indication of CHF or other cardiac pathology (e.g. crackles, increased JVP, decreased cap refill, displaced PMI, etc.). Hematological rather than cardiac cause of the symptoms, such as hemolytic anemia, is starting to look quite good.
Ix: B/W shows low Hb, high bili, high retic; blood film shows schistocytes (fragmented RBCs).
Low Hb by definition is anemia. Anemia can occur for a wide variety of reasons, and the rest of the investigations help us identify the cause. Bilirubin is a breakdown product of heme, which is in RBCs; if heme escapes RBCs in large quantities (e.g. hemolysis), you get hyperbilirubinemia. Schistocytes provide further evidence of a hemolytic process. The high retic count indicates the bone marrow is responding to the low Hb appropriately, pushing more RBC precursors into circulation to compensate (i.e. we know the anemia isn't a bone marrow issue).
Taken together, the evidence points towards hemolytic anemia. Hemolytic anemia is a well-known complication of mitral valve replacement related to destructive shear forces on RBCs that traverse the replaced valve.
