4.3 Hematologic Disorders & Blood Products

Anemias

Iron-deficiency anemia is microcytic and hypochromic with low ferritin and serum iron and an elevated total iron-binding capacity. Causes include chronic blood loss (GI bleeding, menstruation), poor intake, and malabsorption. Ferrous sulfate 325 mg is first-line: give it on an empty stomach with vitamin C (orange juice) to enhance absorption; avoid antacids, dairy, tea, and coffee within 2 hours; warn patients that black stools are expected and harmless; give liquid iron through a straw; and use the Z-track method for IM iron to prevent skin staining. Symptoms include pallor, fatigue, glossitis, brittle nails, and pica.

Vitamin B12 deficiency and pernicious anemia are macrocytic (megaloblastic). Pernicious anemia results from absent intrinsic factor, so oral B12 is poorly absorbed — give IM cyanocobalamin (typically monthly, lifelong) or high-dose sublingual therapy. Neurologic signs (paresthesias, ataxia, confusion, positive Romberg sign) distinguish it from folate deficiency, which is also macrocytic but has no neurologic findings. Never treat with folate alone — it can correct the anemia while irreversible neurologic damage progresses.

Aplastic anemia is bone marrow failure causing pancytopenia — all cell lines are depressed. Priorities are protecting the patient from infection and bleeding: avoid IM injections and rectal procedures, use a soft toothbrush, and institute bleeding and neutropenic precautions. Definitive treatments include immunosuppression and bone marrow transplant.

Sickle cell anemia: hemoglobin S polymerizes and sickles with hypoxia, dehydration, infection, acidosis, or cold. Vaso-occlusive crisis priorities, in order: oxygen if hypoxemic, aggressive IV hydration, and prompt scheduled pain control with opioids; then treat the trigger (antibiotics for infection). Avoid cold compresses, constrictive clothing, and dehydration. Hydroxyurea increases fetal hemoglobin and reduces crisis frequency. Acute chest syndrome and splenic sequestration are life-threatening emergencies.

Coagulation Disorders

• Disseminated intravascular coagulation (DIC) — simultaneous clotting and bleeding: widespread microthrombi consume platelets and clotting factors, then hemorrhage follows. Labs show decreased platelets and fibrinogen with increased PT, aPTT, and D-dimer. Treat the underlying cause (sepsis, obstetric complications) and replace blood products (FFP, platelets, cryoprecipitate) as indicated
• Immune thrombocytopenic purpura (ITP) — autoimmune platelet destruction with counts below 100,000/mm3, petechiae, purpura, and mucosal bleeding. First-line treatments are corticosteroids, IVIG, or anti-D immunoglobulin. Institute bleeding precautions; avoid IM injections and aspirin
• Hemophilia — hemophilia A lacks factor VIII; hemophilia B lacks factor IX. Labs show a prolonged aPTT with normal PT and platelets. Bleeding is deep: hemarthrosis, muscle hematomas, and prolonged bleeding after procedures. Replace the missing factor; avoid aspirin and IM injections
• DVT prophylaxis — early ambulation, sequential compression devices, and pharmacologic prophylaxis such as enoxaparin. Signs of DVT include unilateral swelling, warmth, and calf pain; do not massage or apply heat to the limb. Homan's sign is unreliable and no longer used to diagnose DVT

Anticoagulant and Antiplatelet Nursing

Heparin-induced thrombocytopenia (HIT) is an immune reaction causing a paradoxical clotting state with falling platelets; stop all heparin (including flushes and heparin-coated catheters) and start a non-heparin anticoagulant. Never start warfarin alone during acute HIT — the transient protein C drop can cause venous limb gangrene.

Neutropenic Precautions

The absolute neutrophil count (ANC) equals the WBC count multiplied by the percentage of segments plus bands. An ANC below 1000 cells/mm3 defines neutropenia; below 500 is severe. Interventions: private room; strict hand hygiene before and after contact; no live plants or fresh flowers; no live vaccines; avoid rectal temperatures, suppositories, and unnecessary invasive devices; and a low-bacteria (neutropenic) diet that avoids raw fruits, raw vegetables, and undercooked meats. A single temperature of 38.0 C (100.4 F) is a medical emergency: obtain blood cultures and start broad-spectrum antibiotics, ideally within 60 minutes. Fever may be the only sign of infection because neutropenic patients cannot mount a normal inflammatory response.

Blood Products

• Packed red blood cells (PRBCs) — one unit raises hemoglobin about 1 g/dL and hematocrit about 3%
• Platelets — for thrombocytopenia or active bleeding; a single-donor (apheresis) unit raises the count roughly 30,000-60,000/mm3
• Fresh frozen plasma (FFP) — contains all clotting factors; used for warfarin reversal, DIC, and liver disease
• Cryoprecipitate — concentrated fibrinogen, factor VIII, and von Willebrand factor; used in DIC and hypofibrinogenemia

Transfusion Administration and Reactions

Use an 18-20 gauge line with Y-tubing and a filter; prime and infuse with 0.9% normal saline only — dextrose causes hemolysis and lactated Ringer's causes clotting. Verify the unit at the bedside with two qualified clinicians (patient identity, blood type, unit number, expiration). Obtain baseline vital signs, stay with the patient for the first 15 minutes (most severe reactions occur early), and complete each unit within 4 hours of spiking.

If a reaction is suspected, STOP the transfusion first. Keep the line open with normal saline using new tubing, recheck patient and unit identification, and notify the provider and blood bank. Then manage by type:

Key distinction: TACO is fluid overload (elevated BNP, hypertension) treated with diuretics; TRALI is lung injury (normal BNP, hypotension) treated with respiratory support.