Anemia on the CCFP exam

Approach

• Look for signs of failing: chest pain, breathlessness, a fast pulse, a drop in blood pressure on standing, heart failure or ongoing bleeding.
• Stable and not bleeding: treat the cause. Iron deficiency without unstable vital signs gets iron, not blood.
• Base a transfusion on symptoms and the cause of the anemia, not on a hemoglobin alone.
• If a stable patient who is not bleeding needs blood, give one unit. Reassess the patient and the hemoglobin before the next.
• Blood has risks: reactions, infection, fluid overload and lung injury.
• Heavy bleeding with signs of shock goes to hospital now for fluids and blood. Iron by mouth works too slowly.

Approach

• Read the MCV (mean cell volume) first. It sorts the anemia into small, normal or large red cells.
• Small cells: iron deficiency first. Thalassemia trait and long-standing inflammation come next.
• Normal-sized cells: think of recent bleeding, kidney disease, chronic illness, and marrow disease such as myeloma.
• A reticulocyte count (young red cells) shows whether the marrow is keeping up.
• Large cells: think of B12 deficiency, alcohol, liver disease, an underactive thyroid, some drugs and, in older adults, myelodysplasia (a marrow disorder). Folate deficiency is now rare in Canada.
• A wide RDW (spread of red cell sizes) can mean two causes at once. Look at the blood smear.
• Save a bone marrow test for anemia still unexplained after the vitamin and iron studies.

Approach

• Order a ferritin with the CBC. A low ferritin means the iron stores are empty.
• Inflammation, infection and liver disease raise ferritin. A normal value then does not rule out low iron; add transferrin saturation (how full the iron carrier is).
• Do not rely on serum iron alone. It changes with meals and the time of day.
• Test for thalassemia trait once iron is replaced. Low iron lowers hemoglobin A2, the marker of beta-thalassemia trait.
• Do not give iron to every small-cell anemia. Trait gives small cells for life and needs no iron.

Approach

• Ask about blood loss: periods, black or bloody stools, blood thinners, anti-inflammatories, blood donation.
• Ask about intake and absorption: diet, celiac symptoms, stomach surgery, acid pills.
• Do not use a guaiac stool blood test to work up anemia. Its result cannot decide who needs a scope. In Canada, the newer stool test (FIT) is only for screening people with no symptoms.
• Anemia is an alarm feature that can call for a scope. Men and women past menopause with iron deficiency usually need the gut examined.
• Look at both ends of the gut. A stomach cause does not clear the colon.
• An acid pill can lower iron uptake. Do not assume it is the cause, and do not stop the search.

Approach

• Check a CBC in patients on blood thinners, and in older adults on anti-inflammatories, even if they feel well.
• A mechanical heart valve can break red cells. Look for this with a reticulocyte count, bilirubin, a smear, and LDH and haptoglobin: a high LDH and low haptoglobin signal red cells breaking down.
• New or worse angina or heart failure: check the hemoglobin. Anemia can be the cause.
• Ask about tiredness, breathlessness on effort and black stools.
• Heart disease raises the hemoglobin level at which blood is considered. In stable adults in hospital with ongoing heart and vessel disease, blood is considered below 80 g/L, not 70.

Approach

• Ask about tingling or numbness in both feet, unsteadiness in the dark, memory change and a sore tongue.
• Test position and vibration sense, the Romberg test (sway with eyes closed), reflexes and gait. Loss in both feet fits B12 damage to the spinal cord or the nerves.
• Ask about causes: acid pills, metformin, a vegan diet, stomach surgery and other autoimmune disease.
• Check B12 first. Test folate only with large cells or hypersegmented neutrophils (white cells with too many nuclear lobes). It also needs a real reason: a restrictive diet, heavy drinking or poor absorption.
• Canada has added folic acid to white flour since 1998. Folate deficiency is now rare.

Approach

• Ask how much cow's milk he drinks, and whether he still takes a bottle, at night too.
• Ask which iron-rich foods he eats: meat, fish, eggs, beans, iron-fortified cereal.
• Risk is higher with poverty or food insecurity, preterm birth, slow weight gain, and long breastfeeding with few iron foods.
• Look for pallor, and plot his weight and length.
• At risk: check a CBC and ferritin.
• Low iron: cut back cow's milk and give a treatment dose of iron. Diet alone refills stores too slowly.
• A stable child with low iron gets iron, not blood, even with a low hemoglobin.

Approach

• Compare with past results. A fall from her own baseline matters, even inside the lab range.
• Look for blood loss: heavy periods, black stools, anti-inflammatories, blood thinners.
• Look for chronic disease not yet found: kidney disease, celiac disease, ongoing inflammation.
• Think of a hemoglobinopathy by ancestry and family history. Test for it once iron is normal.
• Repeat the CBC and follow it until you have a cause.

Approach

• Ask: heavy since the first period? Flooding, clots, very long periods? Nosebleeds, gum bleeding, or bleeding after dental work or surgery? A family history?
• Check a CBC with platelets and a ferritin. Add von Willebrand studies and clotting tests when the history fits.
• A normal platelet count rules out low platelets, not a bleeding disorder.
• Ask about diet and celiac symptoms. Heavy periods may not be the only cause.
• Heavy bleeding with signs of shock goes to hospital now. Iron, hormones or a clinic visit tomorrow are too slow.