EM@3AM – Anemia

Author: Erica Simon, DO, MHA (@E_M_Simon, EM Chief Resident, SAUSHEC, USAF) // Edited by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UT Southwestern Medical Center / Parkland Memorial Hospital) and Brit Long, MD (@long_brit, EM Attending Physician, SAUSHEC, USAF)

 Welcome to EM@3AM, an emdocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 72-year-old male with a history of hypertension presents to the emergency department for lightheadedness. The patient notes his symptoms as worsening over 4 months duration, with new onset palpitations prompting his desire for evaluation. Review of systems is negative for slurred speech, visual deficits, and gait abnormalities. The patient denies chest pain, but reports shortness of breath with exertion. He notes intermittent tarry stools.

VS: HR 110, BP 145/91, RR 14, T 99.7 Oral, SpO2 95% on room air

Physical examination is remarkable for conjunctival pallor and tachycardia.

What do you suspect as a diagnosis? What’s the next step in your evaluation and treatment?

Answer: Anemia1-5

  • Precipitating Causes: Acute or chronic blood loss, red blood cell (RBC) hemolysis, decreased RBC production, or dilution (rapid intravenous fluid administration).1
  • Presentation:1,2
    • Varies according to the degree of anemia: patients may be asymptomatic or report fatigue, weakness, dyspnea, palpitations, chest pain, or syncope.
  • Evaluation:
    • Possible Physical Examination Findings:1
      • Neuro: Altered mental status, peripheral neuropathy (B12 deficiency)
      • Cardiovascular system: tachycardia, widened pulse pressure, hyperdynamic precordium, venous hum (detected when auscultating vessels of the neck), precordial systolic ejection murmur.
      • Integumentary: pallor is the most common finding (inspect the oral mucous membranes, nail beds, and palpebral conjunctivas).1 Evaluate for jaundice (hemolysis).
      • Abdomen: hepatosplenomegally
    •  Laboratory Testing:
      • Hemoglobin (World Health Organization Definitions):2
        • Menstruating females: < 12 g/dL
        • Pregnant females: < 11 g/dL
        • Males: < 13 g/dL
      • CBC: Mean Corpuscular Volume (MCV):
        • MCV < 81 fL (Microcytic) => Iron deficiency, anemia of chronic disease (late), sideroblastic anemia, thalassemia
        • MCV 81-100 fL (Normocytic) => acute blood loss, aplastic anemia, anemia of chronic disease, renal failure, hemolysis (e.g. – Coombs positive: autoimmune hemolytic anemia; Coombs negative: microangiopathic hemolytic anemia, infection, G6PD, spherocytosis, sickle cell disease, etc.)
        • MCV > 100 fL (Macrocytic) => B12, folate, ETOH, liver disease, thyroid disease, etc.
      •  Type and Screen vs. Type and Cross
      • As directed by the H&P:
        • Serum iron, serum ferritin, serum transferrin, TIBC
        • Serum B12, serum folate
        • Peripheral smear
        • Coombs testing
        • Reticulocyte count
        • Haptoglobin
        • LDH
        • Renal function (renal failure: decreased erythropoietin; elevated BUN in the setting of GI bleed)
        • Liver function
    •  Ancillary Testing:
      • EKG: ST-T wave changes indicative of ischemia (Type II NSTEMI)
      • Lactate
      • FOBT
  • Treatment:
    • Address the underlying etiology
    • Transfuse:
      • Severe anemia manifested as shock, severe lactic acidosis, myocardial or cerebral ischemia, or congestive heart failure.1,3
      • All others: transfusion threshold controversial. A restrictive transfusion strategy (in patients with a Hb < 6-8 g/dL) is associated with improved outcomes as compared to a liberal transfusion strategy.1,3
  • Pearls:
    • Patients receiving transfusions require frequent reassessment: be mindful of transfusion reactions and their management.
    • Question females of childbearing age regarding menorrhagia.
    • Bleeding lesions of the GI tract are identified in up to 50% of patients with iron deficiency anemia.4
    • A negative FOBT can not rule out the GI tract as the source of an iron deficiency anemia: a loss of 10 ml of blood QD is commonly required for a positive result.5



  1. Bunn F. Approach to the Anemias. In: Goldman-Cecil Medicine. 25th ed. Philadelphia, Saunders Elsevier. 2016; 1059-1068.e.2.
  2. Killip S, Bennett J, Chambers M. Iron deficiency anemia. Am Fam Physician. 2007; 75(5): 671-678.
  3. Janz T, Johnson R, Rubenstein S. Anemia in the emergency department: evaluation and treatment. Emerg Med Pract. 2013; 15(11):1-15.
  4. Powell N, McNair A. Gastrointestinal evaluation of anaemic patients without evidence of iron deficiency. Eur J Gastroenterol Hepatol. 2008; 20:1094-1100.
  5. Rockey D. Occult gastrointestinal bleeding. Gastroenterol Clin North Am. 2005; 34: 699-718.

For Additional Reading:

Hemolytic Anemias:

Hemolytic Anemias: Rare but Important Diagnosis in the Emergency Department

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