NLE Hematologic Nursing — Hematologic Assessment and the AnemiasSummary

Hematopoiesis is the continuous production of blood cells in the bone marrow. The bone marrow produces three cell lines: erythrocytes (RBCs), leukocytes (WBCs), and thrombocytes (platelets). Erythrocytes are stimulated by erythropoietin (EPO), a hormone secreted by the kidneys in response to hypoxia. RBCs have a lifespan of approximately 120 days. Leukocytes combat infection through various mechanisms—neutrophils fight bacteria, lymphocytes provide immune defense, and monocytes engage in phagocytosis. Thrombocytes initiate the clotting cascade. This foundational understanding helps you recognize how disruption at any stage of hematopoiesis affects patient health and oxygen-carrying capacity.

The CBC is the primary diagnostic tool for hematologic assessment. Key normal adult reference values for Filipino population (similar to international standards): Hemoglobin (Hgb)—Male 13–18 g/dL, Female 12–16 g/dL; Hematocrit (Hct)—Male 42–52%, Female 37–47% (approximately 3 times the Hgb value); RBC count 4.2–6.1 million/µL; WBC count 5,000–10,000/µL; Platelets 150,000–400,000/µL; MCV 80–100 fL; Reticulocyte count 0.5–2%. The MCV classifies anemia: microcytic (< 80 fL, typical in iron deficiency), normocytic (80–100 fL, typical in aplastic or acute blood loss anemia), and macrocytic (> 100 fL, typical in B12 or folate deficiency). The reticulocyte count reflects bone marrow response—elevated in blood loss or hemolysis (marrow compensating) and low in marrow failure or nutritional deficiency. The WBC differential and absolute neutrophil count (ANC) guide infection risk assessment; ANC < 500/µL indicates severe neutropenia requiring infection precautions.

The ABO blood group system is determined by the presence or absence of antigens A and B on red cell membranes. Type A blood has A antigen and anti-B antibodies in plasma; Type B has B antigen and anti-A antibodies; Type AB has both A and B antigens and no ABO antibodies (universal recipient); Type O has no A or B antigens but both anti-A and anti-B antibodies (universal donor). The Rh factor (D antigen) determines Rh-positive or Rh-negative status. Type O-negative blood is the universal donor used in emergency situations before crossmatching is complete. Type AB-positive is the universal recipient. Rh-negative individuals do not naturally have anti-D antibodies but will produce them after exposure to Rh-positive blood—critical in pregnancy (risk of hemolytic disease of the newborn if mother is Rh-negative and baby is Rh-positive) and in repeat transfusions. Before transfusion, type and crossmatch testing confirms ABO/Rh compatibility; the direct Coombs test detects antibodies on patient RBCs, and the indirect Coombs detects antibodies in patient serum.

Iron-deficiency anemia is the most common anemia worldwide, including in the Philippines. Iron is essential for hemoglobin synthesis. Causes include chronic blood loss (gastrointestinal bleeding—the most common cause in adults; heavy menstruation—the most common cause in women), inadequate dietary intake, malabsorption, and increased demand (pregnancy, infancy, rapid growth). The result is microcytic, hypochromic anemia with low hemoglobin and low MCV. Laboratory findings include low serum ferritin (the best marker of iron stores), low serum iron, and elevated total iron-binding capacity (TIBC). Clinical manifestations include fatigue, weakness, pallor (visible in conjunctiva, nail beds, and palms—assessment technique critical in darker skin), dyspnea on exertion, tachycardia, and specific signs: koilonychia (spoon-shaped nails), glossitis, angular cheilitis, and pica (craving non-food items like ice or dirt). Management centers on iron replacement: oral ferrous sulfate 325 mg (providing about 65 mg elemental iron) one to three times daily on an empty stomach for optimal absorption; take with vitamin C (orange juice) to enhance absorption; avoid taking with milk, antacids, tea, or coffee. Counsel patients about black, tarry stools (expected and harmless) and possible constipation or GI upset. Administer liquid iron through a straw to prevent tooth staining. For malabsorption or intolerance, give parenteral iron (iron dextran or iron sucrose) by Z-track intramuscular technique to prevent skin staining and tissue damage; observe for anaphylactic reactions (especially with iron dextran, which requires a test dose). Always investigate the source of blood loss, particularly occult GI bleeding.

Vitamin B12 (cobalamin) is essential for DNA synthesis and myelin formation. Absorption requires intrinsic factor, a glycoprotein produced by gastric parietal cells. Pernicious anemia results from autoimmune destruction of parietal cells, causing intrinsic factor deficiency. Other causes of B12 deficiency include gastrectomy (surgical removal of parietal cells), ileal disease (impaired absorption site), and strict vegan diets (B12 found only in animal products). The pathophysiology produces macrocytic, megaloblastic anemia with large, immature red cells and elevated MCV > 100 fL. Distinctive clinical manifestations include anemia symptoms (fatigue, weakness, pallor, dyspnea) plus a beefy red, sore tongue (glossitis) and, critically, neurologic signs that differentiate B12 deficiency from folate deficiency: paresthesias of hands and feet, ataxia (lack of coordination), impaired proprioception (position sense), decreased vibration sense, and potential progression to dementia and permanent neurologic damage if untreated. Diagnosis relies on low B12 level, macrocytic indices, and hypersegmented neutrophils on peripheral smear. The Schilling test historically confirmed diagnosis by measuring urinary excretion of radiolabeled oral B12 with and without intrinsic factor; poor absorption corrected by adding intrinsic factor indicated pernicious anemia; this test is now largely replaced by anti-intrinsic factor and anti-parietal cell antibody testing. Management requires lifelong vitamin B12 (cyanocobalamin) replacement because oral B12 cannot be absorbed without intrinsic factor; give intramuscular injections monthly (after initial loading dose of daily or weekly injections). Emphasize that treatment is lifelong; neurologic damage may be irreversible if treatment is delayed, making early recognition critical for patient outcomes.

Folate (vitamin B9) is essential for DNA synthesis and cell division. Causes of folate deficiency include inadequate dietary intake (leafy green vegetables, legumes, citrus are rich sources), malabsorption (celiac disease, small bowel resection), increased demand (pregnancy, infancy, hemolytic anemias), and certain medications (methotrexate, trimethoprim, phenytoin). Folate deficiency produces macrocytic, megaloblastic anemia similar to B12 deficiency with elevated MCV and hypersegmented neutrophils. The critical differentiation: folate deficiency does NOT cause neurologic signs or glossitis. Diagnosis relies on low serum folate level and low RBC folate. Management includes dietary counseling (leafy greens, legumes) and oral folic acid supplementation (typically 1 mg daily). This anemia is preventable through adequate nutrition and is common in developing countries and during pregnancy.

Aplastic anemia represents bone marrow failure with suppression of all three cell lines, producing pancytopenia (simultaneous reduction in RBCs, WBCs, and platelets). The anemia is normocytic and normochromic because it results from inadequate production rather than altered cell morphology. Causes include idiopathic (unknown, most common), drugs and chemicals (chloramphenicol—historically important antimicrobial linked to marrow aplasia; benzene; some chemotherapy agents), radiation exposure, viral infection (parvovirus B19, hepatitis), and autoimmune processes. Manifestations reflect deficits in all three cell lines: anemia symptoms (fatigue, pallor, dyspnea, tachycardia); leukopenia symptoms (recurrent infections, fever); and thrombocytopenia symptoms (bleeding, petechiae, purpura, ecchymoses, bleeding gums). Diagnosis requires pancytopenia on CBC and a hypocellular bone marrow on biopsy. Management includes removing the causative agent (discontinuing offending drugs), supportive transfusions (RBC and platelet transfusions as needed), immunosuppressive therapy (antithymocyte globulin, cyclosporine) for non-transplant candidates, and hematopoietic stem cell (bone marrow) transplant, which is curative for eligible patients—especially important in younger patients. Nursing focus centers on infection prevention (protective isolation protocols, absolute neutrophil count monitoring, fever management as medical emergency), bleeding precautions (soft toothbrush, electric razor, avoiding IM injections and rectal manipulation), and psychological support for patients facing critical diagnosis.

Hemolytic anemia results from premature destruction of red blood cells faster than the bone marrow can replace them, leading to chronic hemolysis. Causes divide into inherited disorders (sickle cell disease, thalassemia, G6PD deficiency, hereditary spherocytosis) and acquired causes (autoimmune hemolytic anemia, transfusion reactions, drug-induced hemolysis, mechanical destruction from prosthetic heart valves). The pathophysiology produces anemia with characteristic signs of hemolysis: jaundice (from elevated bilirubin), dark urine (hemoglobinuria), splenomegaly (from RBC destruction in spleen), elevated indirect (unconjugated) bilirubin, elevated LDH (from RBC destruction), low haptoglobin (consumed binding hemoglobin from lysed cells), and a high reticulocyte count reflecting bone marrow compensation attempt. The direct Coombs (antiglobulin) test is positive in immune-mediated hemolysis, indicating antibodies coating RBCs. Sickle cell disease (hemoglobinopathy with HbS) is a critical Filipino health issue, particularly in specific regional populations. In sickle cell disease, RBCs sickle (distort into characteristic crescent shapes) under hypoxia, dehydration, infection, acidosis, or cold stress, causing painful vaso-occlusive crises (pain in bones, joints, chest, abdomen, organs), organ infarction (acute chest syndrome, splenic sequestration crisis, renal dysfunction), and chronic hemolysis. Management of acute sickle cell crisis centers on hydration (IV fluids), oxygen therapy for hypoxia, pain control with IV opioids, and treating underlying precipitants (infection with antibiotics). Hydroxyurea reduces crisis frequency by increasing fetal hemoglobin (HbF), which does not sickle. General management of hemolytic anemias includes treating the underlying cause, folic acid supplementation (marrow working at high capacity), transfusions as needed, splenectomy in some cases (removing the site of RBC destruction—must be preceded by vaccination against encapsulated organisms: pneumococcal, meningococcal, Haemophilus influenzae).

Focused hematologic assessment begins with a thorough history exploring fatigue and weakness (duration, impact on activities of daily living), dyspnea (exertional or at rest—reflects severity), dizziness and headache (tissue hypoxia), bleeding or bruising history (mucosal bleeding, easy bruising, nosebleeds, heavy menses), and recurrent infections (suggesting immune compromise). Dietary history assesses iron intake (red meat, fortified cereals, legumes), vitamin B12 sources (animal products), and folate sources (leafy greens, legumes). Medication history identifies potential causative agents (anticoagulants increasing bleeding risk, NSAIDs causing GI blood loss, chemotherapy causing marrow suppression, drugs linked to hemolysis or aplasia). Family history explores inherited anemias (sickle cell, thalassemia, hereditary spherocytosis). Physical assessment systematically examines for pallor (conjunctiva, nail beds, palms—crucial assessment technique for darker skin to visualize internal surfaces), jaundice (hemolysis), cyanosis (inadequate oxygenation), tachycardia and tachypnea (compensatory responses to anemia), and systolic flow murmur (increased cardiac output). Mucosal and skin assessment reveals petechiae and purpura (platelet or coagulation disorders), ecchymoses (bruising from thrombocytopenia or coagulopathy), and bleeding gums (thrombocytopenia). Oral assessment notes glossitis (beefy red, sore tongue in B12 deficiency or iron deficiency) and angular cheilitis (cracks at mouth corners in iron deficiency). Extremity assessment reveals koilonychia (spoon-shaped nails in iron deficiency) and peripheral neuropathy signs (paresthesias, impaired proprioception in B12 deficiency). Abdominal assessment detects lymphadenopathy and splenomegaly (hemolysis, malignancy), important because spleen size correlates with degree of hemolysis. Neurologic examination in suspected B12 deficiency includes tests of vibration and proprioception, gait assessment for ataxia, and mental status evaluation for cognitive changes.

Common nursing diagnoses for anemic patients using NANDA-I classification include: Activity Intolerance related to inadequate oxygen-carrying capacity; Fatigue related to decreased hemoglobin and tissue oxygenation; Ineffective Tissue Perfusion (specify organ) related to reduced oxygen delivery; Risk for Infection related to leukopenia (particularly in aplastic anemia); Risk for Bleeding related to thrombocytopenia; Impaired Oral Mucous Membrane related to glossitis (B12 or iron deficiency); Peripheral Neuropathy related to B12 deficiency; Deficient Knowledge related to anemia cause, treatment, and self-management; Anxiety related to serious diagnosis or treatment uncertainty; and Altered Nutrition related to poor intake or pica behaviors. Each diagnosis guides specific interventions. For example, Activity Intolerance drives clustering of care activities and scheduling rest periods; Risk for Infection in aplastic anemia drives protective isolation and fever response protocols; Ineffective Tissue Perfusion guides oxygen administration and position changes; Deficient Knowledge guides patient education about medications, diet, and lifestyle modifications. Using NANDA-I provides standardized language for communication among healthcare team members and ensures comprehensive, patient-centered care planning.

Maslow's Hierarchy of Needs provides framework for prioritizing nursing interventions. At the physiologic safety level (foundation), address oxygenation by assessing for dyspnea and tachycardia, administering oxygen as prescribed for symptomatic hypoxia, positioning to facilitate breathing, and monitoring vital signs. Manage infection risk (especially in aplastic anemia) through infection precautions and fever management as medical emergency. Manage bleeding risk (especially in aplastic anemia) through bleeding precautions: soft toothbrush, electric razor, avoiding IM injections and rectal manipulation, applying prolonged pressure to venipuncture sites, and teaching avoidance of contact sports and trauma. At the second level, address basic needs: administer prescribed hematinics (iron with vitamin C, B12 injections, folic acid) with patient education on proper administration; provide blood transfusions as ordered with pre-transfusion and post-transfusion nursing care (assess vital signs before and 15 minutes after, monitor for transfusion reactions); ensure adequate nutrition with diet counseling targeting the specific deficiency; and promote adequate rest with activity scheduling and energy conservation teaching. At the higher levels, address psychologic safety and self-actualization: provide emotional support acknowledging diagnosis impact; involve family in teaching and decision-making; teach about permanent lifestyle modifications (lifelong B12 injections for pernicious anemia, iron-rich diet); teach crisis prevention for sickle cell disease; and support patient autonomy in treatment decisions. This hierarchy ensures that life-threatening physiologic problems (oxygenation, infection, bleeding) are addressed first before moving to educational and psychologic needs.

The bone marrow's production of RBCs, WBCs, and platelets directly determines their numbers in circulation. When production is normal, cells are available to perform functions: RBCs carry oxygen (preventing tissue hypoxia symptoms), WBCs fight infection (preventing recurrent infections), platelets clot blood (preventing bleeding). When production fails (aplastic anemia) or cells are destroyed (hemolytic anemia), manifestations emerge reflecting each cell type's absence. Understanding this relationship helps nurses connect CBC findings to clinical symptoms and predict which complications to prevent.

Reduced hemoglobin creates tissue hypoxia, triggering compensatory responses: increased heart rate (tachycardia), increased respiratory rate (tachypnea), and increased RBC production (elevated reticulocytes). These compensations temporarily maintain oxygen delivery but consume energy and produce fatigue. Physical findings reflect compensation: tachycardia on palpation, tachypnea on observation, systolic flow murmur from increased cardiac output (on auscultation). In chronic anemia, compensation may be incomplete, and symptoms (dyspnea, fatigue, dizziness) emerge. Understanding this relationship helps nurses recognize which symptoms indicate adequate compensation (patient tolerating anemia) versus inadequate compensation (requiring urgent intervention).

MCV classifies anemias by cell size: microcytic (< 80) typically has low ferritin (iron deficiency) requiring iron replacement; macrocytic (> 100) typically has low B12 or folate requiring supplementation; normocytic typically has low reticulocyte count (aplastic) requiring marrow stimulation or transplant. Laboratory findings guide which vitamin/mineral to replace. Understanding this relationship makes CBC interpretation diagnostic, directly guiding treatment selection.

Iron is essential for hemoglobin synthesis. Low iron stores → low hemoglobin → reduced oxygen carrying capacity → tissue hypoxia. This linear relationship explains why iron supplementation (repleting stores) leads to hemoglobin increase and symptom improvement. Understanding this causal chain helps nurses explain to patients why iron therapy is needed and why it takes weeks to work (marrow must first make new RBCs with new iron).

Intrinsic factor (produced by gastric parietal cells) is required for B12 absorption in ileum. Without intrinsic factor (pernicious anemia), B12 cannot be absorbed from oral intake, regardless of dietary B12 adequacy. This makes the route of administration critical: oral B12 fails; parenteral (IM) B12 bypasses absorption requirement. Without B12, myelin synthesis fails, causing neurologic damage that becomes irreversible if untreated. This relationship emphasizes the permanent nature of pernicious anemia (no intrinsic factor production recovery) and the critical importance of early diagnosis before irreversible neurologic damage occurs.

In aplastic anemia, marrow suppression affects all cell lines simultaneously, creating three parallel symptom clusters: anemia symptoms (fatigue, pallor, dyspnea), infection risk (leukopenia—fever, recurrent infections), and bleeding risk (thrombocytopenia—petechiae, bruising, bleeding). Nurses must address all three risks simultaneously. The relationship shows why aplastic anemia is life-threatening (multiple critical deficiencies) and why management is complex (requiring transfusions, antibiotics, immunosuppression, and potentially transplant).

In hemolytic anemia, RBCs are destroyed rapidly. The marrow senses this through decreased hemoglobin and increased bilirubin, increasing EPO secretion and accelerating RBC production. Elevated reticulocytes (immature RBCs released early) demonstrate marrow compensation. If destruction exceeds marrow capacity (severe hemolysis), anemia deepens. This relationship explains why reticulocyte count indicates marrow function: high count = marrow responding appropriately (good prognosis if hemolysis can be treated), low count = marrow cannot keep pace (worse prognosis, may need transfusion).

In sickle cell disease, HbS is triggered to polymerize and cause sickling by multiple stressors. Each trigger can independently initiate sickling, explaining why crisis prevention requires addressing multiple factors (hydration status, oxygen saturation, infection prevention, avoiding high altitude/cold). Understanding this cascade helps nurses and patients recognize modifiable risk factors and implement prevention strategies. The relationship shows that avoiding triggers is more effective than treating crises.

If patient receives blood with incompatible antigens, their antibodies attack donor RBCs, causing hemolysis (transfusion reaction). Type O-negative has no A, B, or D antigens so no recipient antibodies attack it (universal donor). Type AB-positive has A and B antigens and is Rh-positive but no ABO antibodies exist to attack it (universal recipient). This relationship ensures that understanding blood group system directly prevents fatal transfusion reactions. Careful type and crossmatch ensure this relationship remains protective.

Chronic GI blood loss slowly depletes iron stores. Initially, marrow compensates by increasing iron absorption and RBC production, so CBC may appear normal despite low ferritin (iron deficiency without anemia). As iron stores deplete further, hemoglobin drops (iron-deficiency anemia with low Hgb). This relationship explains why occult GI bleeding must be investigated—early detection and treatment can prevent progression to symptomatic anemia requiring transfusion. It also explains why ferritin (marker of iron stores) is measured before anemia develops, supporting early intervention.

Iron therapy only works if patients take it consistently. GI side effects, black stools, and lengthy treatment duration (weeks to months for symptom relief, months to years for complete iron store repletion) make adherence challenging. Nursing education addressing side effects, explaining expected timeline, and assessing adherence directly impacts outcomes. This relationship highlights why patient teaching is not optional—it is central to treatment success.

Physical findings (glossitis, koilonychia, neurologic signs) paired with CBC findings (microcytic vs. macrocytic) create a clinical picture suggesting specific anemia. This picture guides laboratory testing selection (ferritin for iron deficiency, B12 level for pernicious anemia, reticulocyte count for hemolysis). Laboratory results confirm diagnosis and guide treatment choice (iron vs. B12 vs. transfusion). This relationship demonstrates integrated clinical reasoning—assessment + labs + diagnosis + treatment form a logical sequence.