Anemia resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: ; Chetan Lokhande, M.B.B.S [2]

Overview

Anemia is defined as a decrease in oxygen-carrying capacity of the blood . It is measured in unit volume concentrations of hemoglobin (Hb), red blood cell volume (MCV), red blood cell number (RBC count).

Causes

Life Threatening Causes

Life-threatening causes include conditions that may result in death or permanent disability within 24 hours if left untreated.

• Aplastic anemia
• Sickle cell anemia
• Hemolytic anemia
• Paroxysmal nocturnal hemoglobinuria
• Severe thalassemia
• Fanconi anemia
• Malaria
• Myelodysplastic syndrome
• Severe Hemorrhage
• Acute leukemia
• Disseminated intravascular coagulation (DIC)

Common causes

Common causes of anemia include:

• Hemolytic anemia
  • Hereditary spherocytosis and Hereditary elliptocytosis
  • Glucose 6 phosphate dehydrogenase deficiency
  • Sickle cell disease
  • Thalassemia
  • Drug induced hemolytic anemia
  • Prosthetic heart valves
  • Autoimmune hemolytic anemia
  • Alloimmune hemolytic anemia
  • Toxins (e.g., snake venom)

For a complete list of hemolytic anemia causes, click here

• Sideroblastic anemia
• Aplastic anemia

• Nutritional Anemia
  • Iron deficiency anemia
  • Megaloblastic anemia due to Vitamin B12 deficiency and Folate deficiency

• Infections
  • Helminth infections
  • Malaria
  • Babesiosis
  • Schistosomiasis
  • HIV
  • Tuberculosis
  • Septicemia

• Pregnancy
• Anemia of chronic disease
• Lead poisoning
• Liver disease
• Chronic renal disease
• Splenomegaly
• Bone marrow suppression
• Alcoholism

For a complete list of anemia causes, click here

Diagnosis

Characterise anemia symptoms ❑ Pallor ❑ Fatigue ❑ Weakness ❑ Dizziness ❑ Dyspnea on exertion

Ask about associated symptoms ❑ Jaundice ❑ Koilonychia ❑ Pica ❑ Back pain ❑ Chest pain ❑ Bone pain or Joint pain ❑ Dark urine ❑ Fever ❑ Chills ❑ Palpitations ❑ Numbness ❑ Tingling ❑ Ataxic gait ❑ Depression ❑ Sore tongue or tongue ulcers ❑ Mucosal bleeding ❑ Menorrhagia ❑ Abdominal pain ❑ Diarrhea ❑ Steatorrhea ❑ Weight loss ❑ Growth retardation ❑ Congenital abnormalities

Obtain a detailed history ❑ Age (causes of anemia varies with age) ❑ Gender (iron deficiency anemia is common in women of reproductive age ❑ Race (sickle cell anemia is common in black patients ❑ Past medical history (recurrent episodes, autoimmune diseases, chronic kidney disease, liver disease) ❑ Past surgical history (excessive blood loss, gastrectomy) ❑ Family history for hereditary anemia ❑ Menstrual history (menorrhagia) ❑ Dietary history (megaloblastic anemia, iron deficiency anemia) ❑ Medications/Poisoning ❑ History of blood transfusion ❑ Travel History (parasitic infections]])

Examine the patient Check vitals ❑ Temperature ❑ Pulse ❑ Blood pressure ❑ Respiratory rate Perform a general physical exam ❑ HEENT examination ❑ Pallor ❑ Jaundice ❑ Skin examination ❑ Pallor ❑ Pale nail beds and palmar creases ❑ Bruises ❑ Ulcers ❑ Nail defects ❑ Abnormal pigmentation ❑ Cardiovascular examination ❑ Tachycardia ❑ Systolic flow murmur ❑ Abdominal examination ❑ Signs of previous surgery ❑ Pulsations ❑ Abdominal distension (splenomegaly, hepatomegaly, ascites, malignancy) ❑ Rectal exam with Stool Guaiac for occult blood ❑ Pelvic Examination ❑ CNS examination (Vitamin B12 deficiency) ❑ Lymph nodes (infection, malignancy ❑ Extremities examination ❑ Edema (unilateral in malignancy) ❑ Leg ulcers ❑ Congenital abnormalities

Order routine laboratory tests ❑ Complete Blood Count with WBC and platelets ❑ Red blood cell indices and morphology ❑ Reticulocyte count ❑ Peripheral blood smear

Management

INDICATIONS FOR TESTING Fatigue, weakness, pallor, dizziness, fainting

Check routine Labs, CBC , smear and reticulocyte count and index

Diagnosed as anemia if Hgb in males < 13g / dl and in females if Hgb < 12g / dl Check whether corrected reticulocyte index ≥ 2.5

If No Check RBC indices

If Yes then

Normal MCV / MCHC Normocytic Normochromic

Low MCV / MCHC Microcytic Hypochromic

High MCV Macrocytic

Check peripheral smear

↓ EPO production or improper response to EPO

Maturation defect

Maturation defect

Fragmented cells on peripheral smear

No fragmented cells on peripheral smear

*Bone marrow disorder Inflammation *Autoimmune disease *Chronic renal disease *Critical illness *Chronic endocrine disorders *Aplastic anemia *Pure red cell aplasia

*Iron deficiency *Chronic disease *Thalassemia (Hemoglobinopathies) *Sideroblastic anemia *Lead toxicity

*Folate, B12 deficiency (Megaloblastic Anemia) * Drug effect *Excessive alcohol use *Hypothyroidism

Suggests hemolytic process *Metabolic defect *Hemoglobinopathies (eg, sickle cell) *Autoimmune destruction *Splenic sequestration *RBC membrane defect *Intravascular hemolysis See Hemolytic Anemia

Suspect hemorrhage and acute blood loss

Abnormal peripheral smear

If yes then work up based on smear bone marrow biopsy may be necessary

If no

ORDER Iron and Iron Binding Capacity and Ferritin check B12, Folate levels

Start Vit B12,Folate If low

Low / normal TIBC Normal / high ferritin Low / normal iron

High TIBC Low iron Low ferritin

Inflammation / Chronic Disease Consider Biopsy in this case

Iron Deficiency anemia

Abbreviations and Formula

MCV = mean cell volume MCHC = mean cell hemoglobin concentration TIBC = total iron binding capacity

Reticulocyte correction for anemia:

Retic Count % x Hgb / Htc x Maturation time correction

Do's

• Before evaluating for anemia, ask about the following:
  • Any medical condition that could be associated
  • Duration of anemia
  • Ethnicity and race
  • Any medication use
  • Occupational history
• Determine if there is anything that shows evidence of:
  • Decreased red cell production
  • Increased red cell destruction
  • Bleeding
  • Bone marrow suppression
  • Nutritional deficiency

• Do a detailed physical examination and keep a high level of suspicion