Caring for Older Adults Holistically, 4th Edition
Chapter Twenty
Laboratory Values and
the Older Adult
Caring for Older Adults Holistically, 4th Edition
Meaning of Laboratory Values
 Many normal ranges are different for older adults
 Greater deviation from normal when under stress
 Return to normal is slower
 Relationship to clinical status
 Lab values should be evaluated in relationship to
individual’s entire clinical situation
 Abnormal lab value may indicate a clinical
stressor or medication side effect rather than illness
Caring for Older Adults Holistically, 4th Edition
Meaning of Laboratory Values
 Routine laboratory evaluations
 Complete blood cell count
 Serum glucose
 Serum creatinine level
 Serum electrolytes
 Thyroid function tests
 Urinalysis
 Stool guaiac test
Caring for Older Adults Holistically, 4th Edition
Common Screening Tests
 Tuberculin skin test
 Negative result <10 mm of induration
 Screening method for tuberculosis
 May need to be repeated 1 week later
 Urinalysis
 Appearance—clear yellow/straw
 Specific gravity—1.005–1.020
 pH—4.5–8.0
 Negative for glucose, ketones, blood, bilirubin
Caring for Older Adults Holistically, 4th Edition
Common Screening Tests
 Urinalysis (cont.)
 Types of specimens
 Mid-stream clean catch
 Fasting
 24-hour
 Send specimen to lab within 10 minutes or keep
refrigerated
Caring for Older Adults Holistically, 4th Edition
Common Screening Tests
 Stool for occult blood
 Negative result—absence of test color
 Test three specimens and two different sections of
each stool
 Avoid red meat, vitamin C intake, iron supplements,
and aspirin 2 to 3 days before and during stool
collection
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count
 Values do not change with age
 Red blood cell count
 Men—5.4 ± 0.9 × 1012/L
 Women—4.8 ± 0.6 × 1012/L
 Diagnose anemia, polycythemia, other bone
marrow abnormalities
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 Hemoglobin
 Men—14–18 g/dL
 Women—12–16 g/dL
 Increase—polycythemia, dehydration
 Decrease—anemia, recent hemorrhage, fluid
retention, kidney disease
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 Hematocrit
 Men—47.0 ≠ 5.0%
 Women—42.0 ≠ 5.0%
 Measures percentage by volume or packed RBC
in whole blood
 Increased—polycythemia
 Decreased—anemia, hemodilution, bone
marrow disease
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 RBC indices
 MCV 90 ± 7 fl
 MCH 29 ± 2 pg
 MCHC 34 ± 2%
 Aid in diagnosis and classification of anemias
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 White blood cell count
 4.5–11.0 ×109/L
 Used to identify infectious or inflammatory
processes, monitor response to chemotherapy
and radiation therapy
 Increased—infection, leukemia, inflammation
 Decreased—bone marrow depression, viral
infection
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 White blood cell differential
 Neutrophils 1.8–7.7 ×109/L or 30%–60%
 Eosinophils 0–0.45 ×109/L or 1%–4%
 Basophils 0–0.20 ×109/L or 0%–0.5%
 Lymphocytes 1.0–4.8 ×109/L or 25%–35%
 Monocytes 0–0.8×109/L or 1%–4.0%
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 White blood cell differential (cont.)
 Used to determine severity of infection, detect
allergic reactions, identify various leukemias
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 Platelet count
 130,000–400,000/mL
 Required for clot formation and hemostasis
 Increased—iron-deficiency anemia, hemorrhage,
malignancies, splenectomy
 Decreased—bone marrow disease, folic acid or
vitamin B12 deficiency, drug side effects
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 Coagulation
 Prothombin time
 Normal: 9.5–11.8 s (control ±1 s)
 Therapeutic: 1.5–2.0 times normal control
 Determined before anticoagulation therapy and
monitored throughout therapy
Caring for Older Adults Holistically, 4th Edition
Hematological Indicators
 Complete blood count (cont.)
 Coagulation
 Activated partial thromboplastin time (APTT)
 Normal: 25–36 s
 Therapeutic: 1.5–2.5 times normal control
 Evaluated clotting factors of the intrinsic pathway
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Blood glucose
 Fasting:
 Normal: 75–115 mg/dL
 Diabetes mellitus: 140 mg/dL on at least two
occasions
 Two hours after eating:
 Normal: 140 mg/dL
 Impaired glucose tolerance: 140–200 mg/dL
 Diabetes mellitus: >200 mg/dl on at least two
occasions
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Blood glucose (cont.)
 Decreased—side effects of various medications,
strenuous exercise
 Increased—medication side effects, recent illness
or infection
 Electrolytes
 Sodium
 136–145 mEq/L
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Electrolytes (cont.)
 Sodium (cont.)
 Hyponatremia
 Caused by vomiting, diarrhea, renal disorders,
diuretics, congestive heart failure
 Hypernatremia
 Caused by inadequate fluid intake, diarrhea,
diuretics
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Electrolytes (cont.)
 Potassium
 3.5–5.0 mEq/L
 Hypokalemia
 Caused by diuretics, malnutrition, vomiting,
diarrhea
 Hyperkalemia
 Caused by renal failure, injuries, acidosis,
diabetes mellitus, several medications
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Electrolytes (cont.)
 Calcium 9–10.5 mg/dL
 Hypocalcemia
 Caused by hypoparathyroid, laxative,
chemotherapy, corticosteroids
 Hypercalcemia
 Caused by hyperparathyroid, thiazide
antidiuretics, immobilization, excessive vitamin
D, calcium-containing antacids
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Electrolytes (cont.)
 Phosphate 3–4.5 mg/dL
 Chloride 98–106 mEq/L
 End products of metabolism
 Blood urea nitrogen (BUN) 10–20 mg/dL
 Increased caused by renal disease, urinary tract
obstruction, drugs
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 End products of metabolism (cont.)
 Blood urea nitrogen (cont.)
 Decrease caused by severe liver failure,
malnutrition, overhydration
 Creatinine <1.5 mg/dL
 Increase caused by renal disease, diabetic
acidosis, starvation, diuretics
 High levels indication of renal failure
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 End products of metabolism (cont.)
 Bilirubin
 Total: 0.3–1.0 mg/dL
 Direct: 0.1–0.3 mg/dL
 Indirect: 0.2–0.7 mg/dL
 Uric acid Men: 2.5–8.0 mg/dL
Women: 1.5–6.0 mg/dL
 Increase caused by loop diuretics, thiazides,
starvation, alcohol abuse, chemotherapy
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Liver function tests
 ALT 0–35 U/L
 Increase caused by liver disease, medications,
cholecystitis, trauma, lead ingestion
 AST or SGOT 0–35 U/L
 Increase caused by myocardial infarction, liver
disease, hemolytic anemia, pulmonary emboli
Caring for Older Adults Holistically, 4th Edition
Blood Chemistry Indicators
 Liver function tests
 LDH 60–100 U/mL
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Protein indicators
 Total serum protein 5.5–8.0 g/dL
 Increase caused by dehydration, infection, diabetic
acidosis, chronic alcoholism
 Decreased caused by malnutrition, hepatic disease,
renal disease, congestive heart failure
 Albumin 3.5–5.5 g/dL
 Increased caused by multiple myeloma
 Decreased caused by malnutrition, liver and renal
disease, collagen diseases, rheumatoid arthritis
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Globulins 2.0–3.0 g/dL
 Increase caused by tuberculosis, chronic syphilis,
subacute bacterial endocarditis, myocardial
infarction, diabetes mellitus
 Iron indicators
 Iron: Men 80–180 mg/dL Women 60–160 mg/dL
 Essential in production and function of hemoglobin
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Iron indicators (cont.)
 Ferritin 15–200 ng/mL
 Increased in hepatic disease, iron overload,
leukemia, chronic renal disease
 Decreased in chronic iron deficiency
 Total iron-binding capacity
 250–460 mg/dL
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Lipoproteins
 Total plasma cholesterol
 Desired <200 mg/dL
 Borderline 200–239 mg/dL
 High 240 mg/dL
 High-density lipoprotein HDL
 Desired >35
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Lipoproteins
 Low-density lipoprotein (LDL)
 Desired 130 mg/dL
 Borderline 130–159 mg/dL
 High 160 mg/dL
 Triglycerides
 160 mg/dL
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Lipoproteins
 Lipid abnormalities are often familial
 Secondary causes
 Diets high in saturated fat or cholesterol
 Excessive alcohol intake
 Estrogen supplements
 Smoking
 Sedentary lifestyle
Caring for Older Adults Holistically, 4th Edition
Nutritional Indicators
 Lipoproteins
 Cholesterol is decreased in malnutrition,
hyperthyroidism and chronic obstructive pulmonary
disease
Caring for Older Adults Holistically, 4th Edition
Drug Monitoring and Toxicology
 Drug monitoring is important when toxic and
therapeutic range is narrow
 Commonly monitored drugs
 Digoxin
 Therapeutic: 0.5–20 ng/mL
 Toxic: 2.5 ng/mL
 Signs of toxicity
 Visual changes, headache, nausea and
vomiting, weakness and fatigue
Caring for Older Adults Holistically, 4th Edition
Drug Monitoring and Toxicology
 Commonly monitored drugs (cont.)
 Theophylline
 Therapeutic: 10–20 µg/mL
 Toxic: 20 µg/mL
 Signs of toxicity
 Anorexia, abdominal discomfort, dizziness,
shakiness, restlessness, palpitation, tachycardia,
hypotension
Caring for Older Adults Holistically, 4th Edition
Drug Monitoring and Toxicology
 Commonly monitored drugs (cont.)
 Phenytoin
 Therapeutic: 10–20 µg/mL
 Toxic: 30 µg/mL
 Signs of toxicity
 Drowsiness, mental confusion, tremors,
photophobia, blurred vision