Red Blood Cell Count, Indices, Morphology, and Inclusions

General

Synonym/Acronym:
RBC.

Rationale
RBC Count: To evaluate the number of circulating red cells in the blood toward diagnosing disease and monitoring therapeutic treatment. RBC Indices: To evaluate cell size, shape, weight, and hemoglobin (Hgb) concentration. Used to diagnose and monitor therapy for conditions such as iron-deficiency anemia. Variations in the number of cells are most often seen in anemias, cancer, and hemorrhage. Morphology and Inclusions: To make a visual evaluation of the red blood cell (RBC) shape and/or size as a confirmation in assisting to diagnose and monitor disease progression.

Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings
Method: Automated, computerized, multichannel analyzers; microscopic, manual review of stained blood smear.

RBC Count
AgeConventional Units (106 cells/microL)SI Units (1012 cells/L) (Conventional Units × 1)
Cord blood4.41–6.214.41–6.21
0–1 wk4.71–7.314.71–7.31
2–3 wk4.31–6.514.31–6.51
1–2 mo3.41–5.813.41–5.81
3–6 mo3.11–4.513.11–4.51
7 mo–15 yr3.71–5.213.71–5.21
16–18 yr4.01–5.414.01–5.41
Adult
Male4.51–6.014.51–6.01
Female4.01–5.514.01–5.51
Values are decreased in pregnancy related to the dilutional effects of increased fluid volume and potential nutritional deficiency related to decreased intake, nausea, and/or vomiting. Values are slightly lower in older adults associated with potential nutritional deficiency. Care must be taken when reviewing complete blood count (CBC) values after a blood product transfusion—documentation should clearly reflect the time and date of the last transfusion with respect to the collection time and date of the study.
RBC Indices
AgeMCV (fL)MCH (pg/cell)MCHC (g/dL)RDWCVRDWSD
Cord blood107–11935–3931–3514.9–18.751–66
0–1 wk104–11629–4524–3614.9–18.751–66
2–3 wk95–11726–3826–3414.9–18.751–66
1–2 mo81–12525–3726–3414.9–18.744–55
3–11 mo78–11022–3426–3414.9–18.735–46
1–15 yr74–9424–3230–3411.6–14.835–42
16 yr–adult
Male77–9726–3432–3611.6–14.838–48
Female78–9826–3432–3611.6–14.838–48
Older adult
Male79–10327–3532–3611.6–14.838–48
Female78–10227–3532–3611.6–14.838–48
MCH = mean corpuscular hemoglobin; MCHC = mean corpuscular hemoglobin concentration; MCV = mean corpuscular volume; RDWCV = coefficient of variation in red blood cell distribution width; RDWSD = standard deviation in RBC distribution width.
RBC Morphology and Inclusions
RBC MorphologyWithin Normal Limits1+2+3+4+
Size
Anisocytosis0–55–1010–2020–50Greater than 50
Macrocytes0–55–1010–2020–50Greater than 50
Microcytes0–55–1010–2020–50Greater than 50
Shape
Poikilocytes0–23–1010–2020–50Greater than 50
Burr cells0–23–1010–2020–50Greater than 50
AcanthocytesLess than 12–55–1010–20Greater than 20
SchistocytesLess than 12–55–1010–20Greater than 20
Dacryocytes (teardrop cells)0–22–55–1010–20Greater than 20
Codocytes (target cells)0–22–1010–2020–50Greater than 50
Spherocytes0–22–1010–2020–50Greater than 50
Ovalocytes0–22–1010–2020–50Greater than 50
Stomatocytes0–22–1010–2020–50Greater than 50
Drepanocytes (sickle cells)AbsentReported as present or absent
Helmet cellsAbsentReported as present or absent
AgglutinationAbsentReported as present or absent
RouleauxAbsentReported as present or absent
Hgb Content
Hypochromia0–23–1010–5050–75Greater than 75
Polychromasia
AdultLess than 12–55–1010–20Greater than 20
Newborn1–67–1515–2020–50Greater than 50
Inclusions
Cabot ringsAbsentReported as present or absent
Basophilic stippling0–11–55–1010–20Greater than 20
Howell-Jolly bodiesAbsent1–23–55–10Greater than 10
Heinz bodiesAbsentReported as present or absent
Hgb C crystalsAbsentReported as present or absent
Pappenheimer bodiesAbsentReported as present or absent
Intracellular parasites (e.g., Plasmodium, Babesia, Trypanosoma)AbsentReported as present or absent

Critical Findings and Potential Interventions
The presence of abnormal cells, other morphological characteristics, or cellular inclusions may signify a potentially life-threatening or serious health condition and should be investigated. Examples are the presence of sickle cells, moderate numbers of spherocytes, marked schistocytosis, oval macrocytes, basophilic stippling, nucleated RBCs (if the patient is not an infant), or malarial or other parasitic organisms.

Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.

Consideration may be given to verifying the critical findings before action is taken. Policies vary among facilities and may include requesting immediate recollection and retesting by the laboratory or retesting using a rapid point-of-care instrument at the bedside, if available.

Low RBC count leads to anemia.

  • Causes: Anemia can be caused by blood loss, decreased blood cell production, increased blood cell destruction, or hemodilution. Causes of blood loss include menstrual excess or frequency, gastrointestinal bleeding, inflammatory bowel disease, or hematuria. Decreased blood cell production can be caused by folic acid deficiency, vitamin B12 deficiency, iron deficiency, or chronic disease. Increased blood cell destruction can be caused by a hemolytic reaction, chemical reaction, medication reaction, or sickle cell disease. Hemodilution can be caused by heart failure, chronic kidney disease, polydipsia, or overhydration.
  • Symptoms: Symptoms of anemia (due to these causes) include anxiety, dyspnea, edema, fatigue, hypertension, hypotension, hypoxia, jugular venous distention, pallor, rales, restlessness, and weakness.
  • Treatment: Treatment of anemia depends on the cause.


High RBC count leads to polycythemia.

  • Causes: Polycythemia can be caused by dehydration, decreased oxygen levels in the body, and an overproduction of RBCs by the bone marrow. Dehydration by diuretic use, vomiting, diarrhea, excessive sweating, severe burns, or decreased fluid intake decreases the plasma component of whole blood, thereby increasing the ratio of RBCs to plasma, and leads to a higher than normal hematocrit (Hct). Causes of decreased oxygen include smoking, exposure to carbon monoxide, high altitude, and chronic lung disease, which leads to a mild hemoconcentration of blood in the body to carry more oxygen to the body’s tissues. An overproduction of RBCs by the bone marrow leads to polycythemia vera, which is a rare chronic myeloproliferative disorder that leads to a severe hemoconcentration of blood. Severe hemoconcentration can lead to thrombosis (spontaneous blood clotting).
  • Symptoms: Symptoms of hemoconcentration include decreased pulse pressure and volume, dry mucous membranes, headaches, hepatomegaly, loss of skin turgor, low central venous pressure, orthostatic hypotension, pruritus (especially after a hot bath), splenomegaly, tachycardia, thirst, tinnitus, vertigo, and weakness.
  • Treatment: Treatment of polycythemia depends on the cause. Possible interventions for hemoconcentration due to dehydration include IV fluids and discontinuance of diuretics if they are believed to be contributing to critically elevated Hct. Polycythemia due to decreased oxygen states can be treated by removal of the offending substance, such as smoke or carbon monoxide. Treatment includes oxygen therapy in cases of smoke inhalation, carbon monoxide poisoning, and desaturating chronic lung disease. Symptoms of polycythemic overload crisis include signs of thrombosis, pain and redness in extremities, facial flushing, and irritability. Possible interventions for hemoconcentration due to polycythemia include therapeutic phlebotomy and IV fluids.

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