Nurse Practitioner Chronicles

  Hemoglobin Electrophoresis & Sickle Cell Testing: Interpreting the Patterns Trait vs. disease, thalassemia clues on the CBC, and why the newborn screen needs follow-up. Hemoglobin electrophoresis separates hemoglobin variants by their electrical charge, identifying the type and proportion of each hemoglobin present. It's the definitive test for diagnosing hemoglobinopathies—but it's also one of the most misunderstood results in primary care. Normal Hemoglobin Composition HbA (adult hemoglobin) : 95–98% (two alpha + two beta globin chains) HbA2 : 2–3.5% (two alpha + two delta chains) HbF (fetal hemoglobin) : <1% in adults (two alpha + two gamma chains; predominates in utero and declines after birth) The Key Patterns Condition HbA HbS HbA2 HbF CBC Clues Normal 95–98% 0 2–3.5% <1% Normal Sickle cell trait (AS) 55–60% 35–45% Normal Normal Usually normal CBC. No anemia. Benign in most contexts. Sickle cell disease (SS) 0 80–95% Normal 2–20% Chronic hemolytic anemia, reti...

  HbA1c Pitfalls: When the Number Lies Hemoglobinopathies, iron deficiency, CKD, and transfusions all break A1c. Here's when to trust it and when to use alternatives. HbA1c is the cornerstone of diabetes diagnosis and monitoring. But it measures glycated hemoglobin, which means  anything that alters hemoglobin or RBC lifespan will alter the A1c —independent of blood glucose. In your patients with sickle cell trait, iron deficiency, chronic kidney disease, or recent transfusions, the A1c may be telling you a completely different story than what their glucometer shows. How A1c Works (and Why It Breaks) A1c measures the percentage of hemoglobin A molecules with glucose attached. It reflects average blood glucose over the preceding 2–3 months (the lifespan of an RBC). This works perfectly when RBC lifespan and hemoglobin structure are normal. When they're not, the test becomes unreliable. Conditions That Falsely LOWER A1c These conditions shorten RBC lifespan or increase RBC turno...