“Need to Know” Laboratory Values

1. I. SERUM ELECTROLYTES
   1. A. Sodium (Na+ ): 136 to 145 mEq/L
   2. B. Potassium (K+ ): 3.5 to 5 mEq/L
   3. C. Calcium total (Ca++ ): 9.0 to 10.5 mg/dL
   4. D. Magnesium (Mg++ ): 1.3 to 2.1 mEq/L
   5. E. Phosphorus (PO4 ): 3.0 to 4.5 mg/dL
   6. F. Chloride (Cl): 98 to 106 mEq/L
2. II. ARTERIAL BLOOD GASES (ABGS)
   1. A. pH: 7.35 to 7.45
   2. B. PaCO2 : 35 to 45 mm Hg
   3. C. PaO2 : 80 to 100 mm Hg
   4. D. HCO3 (bicarbonate): 21 to 28 mEq/L
3. III. CBC
   1. A. RBCs: Males 4.7 to 6.1 million/uL; females 4.2 to 5.4 million/uL
   2. B. Hgb: Males: 14 to 18 g/dL; females: 12 to 16 g/dL
   3. C. Hct: Males: 42% to 52%; females 37% to 47%
   4. D. WBCs: 5,000 to 10,000 mm3
   5. E. Erythrocyte sedimentation rate (ESR): less than 20 mm/hr
4. IV. BLOOD LIPID LEVELS
   1. A. Total serum cholesterol: Desirable less than 200 mg/dL; risk for cardiac or stroke event with levels greater than 150 mg/dL is the target range for therapy and has been shown to be the cut point to decrease cerebrovascular or arterial incidences.
   2. B. LDL (low-density lipids): Desirable less than 130 mg/dL
   3. C. HDL (high-density lipids): Males greater than 45 mg/dL; females greater than 5 mg/dL
   4. D. Triglycerides: Desirable less than 150 mg/dL; males 40 to 160 mg/dL; females 35 to 135 mg/dL
5. V. ANTICOAGULANT THERAPY COAGULATION TIMES
   1. A. PT: 11 to 12.5 seconds. Therapeutic range for anticoagulant therapy is 1.5 to 2 times the normal or control value. Critical value greater than 20 seconds.
   2. B. Activated Partial Thromboplastin Time (aPTT): 30 to 40 seconds. Critical value greater than 70 seconds.
   3. C. Partial Thromboplastin Time (PTT): 60 to 70 seconds, greater than 100 seconds.
   4. D. Therapeutic range for anticoagulant therapy is 1.5 to 2 times the normal or control value.
   5. E. INR
      1. 1. Normal INR is 0.8 to 1.1.
      2. 2. If the client requires anticoagulation, the desired value is increased to approximately 2 to 3. Critical value greater than 5.
      3. 3. The INR is a corrected ratio of a client’s prothrombin time to normal.
      4. 4. Universal test is not affected by variations in laboratory norms.
   6. F. Platelets: 150,000 to 400,000/mm3. Critical value less than 20,000 or greater than 1 million/mm 3.
6. VI. LIVER FUNCTION TESTS
   1. A. Albumin: 3.5 to 5 g/dL
   2. B. Ammonia: 10 to 80 mcg/dL
   3. C. Total bilirubin: 0.1 to 1.0 mg/dL
   4. D. Total protein: 6 to 8 g/dL
7. VII. URINALYSIS
   1. A. Specific gravity: 1.005 to 1.030
   2. B. Protein: 0 to 8 mg/dL
   3. C. Glucose: less than 0.5 g/day
   4. D. Ketones: none
   5. E. pH: 4.6 to 8
   6. F. WBC: males 0 to 3 per high-power field; females 0 to 5 per high-power field
8. VIII. RENAL FUNCTION
   1. A. Serum creatinine: Males 0.6 to 1.2 mg/dL; females 0.5 to 1.1 mg/dL
   2. B. BUN: 10 to 20 mg/dL
   3. C. Creatinine clearance test: Males 90 to 139 mL/min; females 80 to 125 mL/min. This is a calculation of GFR and is the best indicator of overall renal function.
9. IX. THERAPEUTIC MEDICATION MONITORING
   1. A. Digoxin level: 0.8 to 2.0 ng/mL
   2. B. Lithium level: 0.4 to 1.4 mEq/L
   3. C. Phenobarbital: 10 to 40 mcg/mL
   4. D. Theophylline: 10 to 20 mcg/mL
   5. E. Dilantin: 10 to 20 mcg/mL
10. X. BLOOD GLUCOSE LEVELS
    1. A. Glucose (fasting): 70 to 105 mg/dL
    2. B. Glycosylated hemoglobin (HbA1c): 4% to 6% is within the expected reference range. Greater than 8% indicates poor diabetes mellitus control.

NOTE: Normal laboratory value reference ranges can have slight variations depending on the facility or organization. To recognize deviations, candidates should know the laboratory value ranges. It is important to recognize values that are elevated or low.