NCLEX Review Guide: Hematological & Oncological Diagnostic Tests

Red Blood Cell Parameters

• Hemoglobin (Hgb): Normal values 12-16 g/dL (females), 14-18 g/dL (males). Decreased levels indicate anemia, blood loss, or nutritional deficiencies.
• Hematocrit (Hct): Normal values 37-47% (females), 42-52% (males). Represents percentage of blood volume occupied by RBCs.
• RBC Count: Normal 4.2-5.4 million/μL (females), 4.7-6.1 million/μL (males). Low counts suggest anemia or bone marrow suppression.

WBC Types and Functions

• Neutrophils: 50-70% of WBCs, first responders to bacterial infections. Left shift indicates immature neutrophils released during severe infection.
• Lymphocytes: 20-40% of WBCs, responsible for viral immunity and antibody production. Elevated in viral infections and some cancers.
• Eosinophils: 1-4% of WBCs, increased in allergic reactions and parasitic infections.
• Basophils: 0.5-1% of WBCs, involved in allergic responses and release histamine.

Essential Clotting Tests

• PT/INR: Prothrombin Time normal 11-13 seconds, INR 0.8-1.2. Monitors warfarin therapy and extrinsic clotting pathway.
• aPTT: Activated Partial Thromboplastin Time normal 25-35 seconds. Monitors heparin therapy and intrinsic clotting pathway.
• Platelet Count: Normal 150,000-450,000/μL. Below 50,000 increases bleeding risk, below 20,000 requires immediate intervention.

Pre-procedure for Coagulation Studies

1. Verify patient is not on anticoagulants (document if they are)
2. Use proper tube (blue top with sodium citrate)
3. Fill tube completely to ensure proper ratio
4. Invert gently 3-4 times, do not shake

Bone Marrow Aspiration and Biopsy

• Bone Marrow Aspiration: Removes liquid portion to examine cell morphology and count. Used to diagnose leukemia, anemia, and thrombocytopenia.
• Bone Marrow Biopsy: Removes solid core of bone marrow to assess architecture and cellularity. Provides more comprehensive evaluation than aspiration alone.

Post-Procedure Care

1. Apply pressure dressing to site for 24 hours
2. Monitor for bleeding, infection, and pain
3. Assess vital signs every 15 minutes x4, then per protocol
4. Instruct patient to avoid heavy lifting for 48 hours

Common Tumor Markers

• PSA (Prostate-Specific Antigen): Normal <4 ng/mL. Elevated in prostate cancer, but also in benign prostatic hyperplasia and prostatitis.
• CA-125: Normal <35 U/mL. Associated with ovarian cancer but can be elevated in other conditions including endometriosis.
• CEA (Carcinoembryonic Antigen): Normal <3 ng/mL (nonsmokers). Used to monitor colorectal cancer treatment response.
• AFP (Alpha-fetoprotein): Normal <10 ng/mL. Elevated in liver cancer and testicular cancer.