Term
|
Definition
Includes measurement of the following:
RBC count
Hemoglobin
Hematocrit
Mean Corpuscular Volume
Mean Corpuscular Hemoglobin
White Blood Cell Count w/ Differential
Neutrophils
Lymphocytes
Monocytes
Eosinophils
Basophils
Platelet Count |
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Term
| White Blood Cell Count w/ Differential |
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Definition
Neutrophils
Lymphocytes
Monocytes
Eosinophils
Basophils |
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Term
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Definition
Test Range and Collection
(RBC, or erythrocyte count), whole blood
4.3–6.0 x 106/mcL (male)
3.5–5.5 x 106/mcL (female)
Interpretation
Increased in: hemoconcentration (dehydration), Polycythemia Vera, and excessive exercise.
Decreased in: Anemia. |
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Term
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Definition
| Increased in: hemoconcentration (dehydration), Polycythemia Vera, and excessive exercise. |
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Term
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Definition
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Term
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Definition
Test Range and Collection
whole blood (Hb)
Male: 13.6–17.5
Female: 12.0–15.5 g/dL (age-dependent)
Interpretation
Increased in: Hemoconcentration (as in dehydration) polycythemia vera, extreme physical exercise.
Decreased in: All anemias |
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Term
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Definition
| Increased in: Hemoconcentration (as in dehydration) polycythemia vera, extreme physical exercise. |
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Term
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Definition
| Decreased in: All anemias |
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Term
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Definition
Test Range and Collection
whole blood (Hct)
Male: 39–49%
Female: 35–45%
(age-dependent)
Physiologic Basis
The Hct represents the percentage of whole blood volume composed of erythrocytes.
Laboratory instruments calculate the Hct from the erythrocyte count (RBC) and the mean corpuscular volume (MCV) by the formula:
Hct = RBC x MCV
Interpretation
Increased in: Hemoconcentration (as in dehydration, burns, vomiting), polycythemia, extreme physical exercise.
Decreased in: All anemias
Conversion from hemoglobin (Hb) to hematocrit is roughly Hb x 3 = Hct. |
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Term
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Definition
| Increased in: Hemoconcentration (as in dehydration, burns, vomiting), polycythemia, extreme physical exercise. |
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Term
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Definition
| Decreased in: All anemias |
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Term
| Mean Corpuscular Volume (MCV) |
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Definition
Test Range and Collection
blood (MCV)
80–100 fL
Physiologic Basis
MCV is the average volume of the red cells, and it is measured by automated instrument (electrical impedance or light scatter).
Interpretation
Increased in: hemochromatosis, megaloblastic anemia (folate, vitamin B12 deficiencies), newborns.
Decreased in: Iron deficiency, thalassemia, sideroblastic anemia, hereditary spherocytosis,
MCV can be normal in combined iron and folate deficiency.
In patients with two red cell populations (macrocytic and microcytic), MCV may be normal. |
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Term
| Mean Corpuscular Volume (MCV)-up |
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Definition
| Increased in: hemochromatosis, megaloblastic anemia (folate, vitamin B12 deficiencies), newborns. |
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Term
| Mean Corpuscular Volume (MCV)-down |
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Definition
| Decreased in: Iron deficiency, thalassemia, sideroblastic anemia, hereditary spherocytosis, |
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Term
| White Blood Cell Count w/ Differential |
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Definition
Test Range and Collection
blood
Reference ranges are age- and laboratory-specific
Adult ranges: WBC 4.5–11.0 x 103/mcL;
differential:
segmented neutrophils 50–70%; Bacterial
band neutrophils 0–5%; Leukemia
lymphocytes 20–40%; Viral or Fungal
monocytes 2–6%; Parasitic
eosinophils 1–4%; Allergic
basophils 0–1%. Allergic and Parasitic |
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Term
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Definition
Test Range and Collection
whole blood (Plt)
150–450 x 103/mcL
Physiologic Basis
Platelets are released from megakaryocytes in bone marrow and are important for normal hemostasis.
Interpretation
Increased in (Thrombocytosis): Myeloproliferative disorders, acute blood loss, pre-eclampsia, reactive thrombocytosis
Decreased in (Thrombocytopenia): Decreased production: bone marrow suppression or replacement/infiltration, chemotherapy, increased destruction or excessive pooling: hypersplenism, DIC |
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Term
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Definition
| Increased in (Thrombocytosis): Myeloproliferative disorders, acute blood loss, pre-eclampsia, reactive thrombocytosis |
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Term
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Definition
| Decreased in (Thrombocytopenia): Decreased production: bone marrow suppression or replacement/infiltration, chemotherapy, increased destruction or excessive pooling: hypersplenism, DIC |
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Term
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Definition
| There is little tendency to bleed until the platelet couint falls below 20,000/mcL. Bleeding due to low platelet counts typically presents as petechiae, epistaxis, and gingival bleeding. |
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Term
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Definition
Test Range and Collection
whole blood (PT)
11–15 seconds
(laboratory specific)
Evaluates the extrinsic clotting cascade
Is sensitive to changes in the Vitamin-K dependent clotting factors
Is used to monitor the effects of warfarin therapy |
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Term
| Partial Thromboplastin Time (PTT) |
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Definition
Test Range and Collection
activated, plasma
(aPTT)
25–35 seconds (range varies)
Is used to monitor the intrinsic coagulation cascade
Is prolonged in heparin therapy |
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Term
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Definition
Test Range and Collection
International Normalized Ratio (INR) is calculated.
INR = [Patient PT/Normal mean PT]
A normalized PT reading
Measures the same components as PT including:
Extrinsic clotting cascade
Vitamin K dependent factors
Warfarin therapy |
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Term
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Definition
Is the least specific of the three cardiac markers
Is not specific to myocytes |
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Term
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Definition
Test Range and Collection
serum enzyme activity (CK-MB)
<16 IU/L
Physiologic Basis
Myocardium has approximately 40% MB isoenzyme.
Interpretation
Increased in: Myocardial infarction
CK-MB is a relatively specific test for MI. It appears in serum approximately 4 hours after infarction, peaks at 12–24 hours, and declines over 48–72 hours. |
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Term
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Definition
Test Range and Collection
serum (cTnI)
<1.5 ng/mL (method- dependent)
Physiologic Basis
Troponin is the contractile regulatory protein of striated muscle.
Troponin I is predominantly a structural protein and is released into the circulation after cellular necrosis. Cardiac troponin I is expressed only in cardiac muscle, throughout development and despite pathology, and thus its presence in serum can distinguish between myocardial injury and skeletal muscle injury. |
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Term
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Definition
Interpretation
Cardiac troponin I is a more specific marker for myocardial infarction than CK-MB
cTnI appears in serum approximately 4 hours after onset of chest pain, peaks at 8–12 hours, and persists for 5–7 days. |
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Term
| Complete Metabolic Panel (CMP) |
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Definition
Includes several parameters:
Sodium
Potassium
Chloride
Bicarbonate
BUN
Creatinine |
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Term
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Definition
Test Range and Collection
serum (Na+)
135–145 meq/L [mmol/L]
Interpretation
Increased in: Dehydration, polyuria, hyperaldosteronism, inadequate water intake
Decreased in: CHF, cirrhosis, excessive sweating (with replacement of water but not salt, eg, marathon running), salt-losing nephropathy, hypoaldosteronism, nephrotic syndrome, SIADH. Drugs:diuretics |
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Term
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Definition
Test Range and Collection
serum (K+)
3.5–5.0 meq/L [mmol/L]
Physiologic Basis
Potassium is predominantly an intracellular cation whose plasma level is regulated by renal excretion.
Plasma potassium concentration determines neuromuscular irritability. Elevated or depressed potassium concentrations interfere with muscle contraction.
Interpretation
Increased in: Massive hemolysis, severe tissue damage, rhabdomyolysis, acute or chronic renal failure, hypoaldosteronism, potassium-sparing diuretics |
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Term
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Definition
Interpretation
Decreased in: Low potassium intake, prolonged vomiting or diarrhea, hyperaldosteronism, diuretics.
Spurious hyperkalemia can occur with hemolysis of sample, delayed separation of serum from erythrocytes, prolonged fist clenching during blood drawing, and prolonged tourniquet placement. |
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Term
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Definition
Test Range and Collection
A blood sample drawn from a vein in the arm
Physiologic Basis
screen for an electrolyte or acid-base imbalance or to monitor a known imbalance
The total CO2 test measures the total amount of carbon dioxide in the blood, mostly in the form of bicarbonate (HCO3-); in many laboratories, bicarbonate is now measured directly. Bicarbonate is a negatively charged electrolyte that is excreted and reabsorbed by the kidneys. It is used by the body to help maintain the body’s acid-base balance (pH) and secondarily to work with sodium, potassium, and chloride to maintain electrical neutrality at the cellular level.
Interpretation
Some of the causes of a low bicarbonate level include:
Addison’s disease
Chronic diarrhea
Diabetic ketoacidosis
Metabolic acidosis
Kidney disease
Ethylene glycol or methanol poisoning
Salicylate (aspirin) overdose
Increased levels may be due to:
Severe vomiting
Lung diseases
Cushing’s syndrome
Conn’s syndrome
Metabolic alkalosis |
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Term
| Blood Urea Nitrogen (BUN) |
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Definition
Test Range and Collection
serum (BUN)
8–20 mg/dL
[2.9–7.1 mmol/L]
Physiologic Basis
Urea, an end product of protein metabolism, is excreted by the kidney.
BUN is directly related to protein intake and nitrogen metabolism and inversely related to the rate of excretion of urea.
Interpretation
Increased in: Renal failure (acute or chronic), urinary tract obstruction, dehydration, shock, burns, CHF, GI bleeding. Nephrotoxic drugs (eg, gentamicin).
Decreased in: Hepatic failure, nephrotic syndrome, cachexia (low-protein and high-carbohydrate diets).
BUN/Cr ratio (normally 12:1–20:1) is decreased in acute tubular necrosis, advanced liver disease, low protein intake, and following hemodialysis.
BUN/Cr ratio is increased in dehydration, GI bleeding, and increased catabolism. |
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Term
| Blood Urea Nitrogen (BUN) up |
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Definition
| Increased in: Renal failure (acute or chronic), urinary tract obstruction, dehydration, shock, burns, CHF, GI bleeding. Nephrotoxic drugs (eg, gentamicin). |
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Term
| Blood Urea Nitrogen (BUN)-down |
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Definition
| Decreased in: Hepatic failure, nephrotic syndrome, cachexia (low-protein and high-carbohydrate diets). |
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Term
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Definition
Test Range and Collection
serum (Cr)
0.6–1.2 mg/dL
[50–100 mcmol/L]
Physiologic Basis
Endogenous creatinine is excreted by filtration through the glomerulus and by tubular secretion. Creatinine clearance is an acceptable clinical measure of glomerular filtration rate (GFR), although it sometimes overestimates GFR (eg, in cirrhosis).
For each 50% reduction in GFR, serum creatinine approximately doubles.
Interpretation
Increased in: Acute or chronic renal failure, urinary tract obstruction, nephrotoxic drugs, hypothyroidism.
Decreased in: Reduced muscle mass |
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Term
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Definition
| Increased in: Acute or chronic renal failure, urinary tract obstruction, nephrotoxic drugs, hypothyroidism. |
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Term
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Definition
| Decreased in: Reduced muscle mass |
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Term
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Definition
Test Range and Collection
whole blood
Arterial: 32–48 mm Hg
(4.26–6.38 kPa)
Heparinized syringe
Physiologic Basis
The partial pressure of carbon dioxide in arterial blood (Pco2) provides important information with regard to adequacy of ventilation, and acid–base balance.
Interpretation
Increased in: Respiratory acidosis: decreased alveolar ventilation (eg, COPD, respiratory depressants), neuromuscular diseases (eg, myasthenia gravis).
Decreased in: Respiratory alkalosis: hyperventilation (eg, anxiety), sepsis, liver disease, fever, early salicylate poisoning, and excessive artificial ventilation. |
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Term
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Definition
| Increased in: Respiratory acidosis: decreased alveolar ventilation (eg, COPD, respiratory depressants), neuromuscular diseases (eg, myasthenia gravis). |
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Term
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Definition
| Decreased in: Respiratory alkalosis: hyperventilation (eg, anxiety), sepsis, liver disease, fever, early salicylate poisoning, and excessive artificial ventilation. |
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Term
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Definition
Test Range and Collection
whole blood
83–108 mm Hg
[11.04–14.36 kPa]
Heparinized syringe
Physiologic Basis
Test measures the partial pressure of oxygen (oxygen tension) in arterial blood.
Partial pressure of oxygen is critical because it determines (along with hemoglobin and blood supply) tissue oxygen supply.
Interpretation
Increased in: Oxygen therapy.
Decreased in: Ventilation/perfusion mismatching (asthma, COPD, atelectasis, pulmonary embolism, pneumonia, interstitial lung disease, airway obstruction by foreign body, shock); alveolar hypoventilation (kyphoscoliosis, neuromuscular disease, head injury, stroke); right-to-left shunt (congenital heart disease). Drugs: barbiturates, opioids. |
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Term
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Definition
Test Range and Collection
whole blood
Arterial: 7.35–7.45
Venous: 7.31–7.41
Heparinized syringe
Physiologic Basis
pH assesses the acid–base status of blood, an extremely useful measure of integrated cardiorespiratory function.
The essential relationship between pH, PCO 2, and bicarbonate (HCO3 –) is expressed by the Henderson–Hasselbalch equation (at 37°C): |
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Term
|
Definition
Interpretation
Increased in: Respiratory alkalosis: hyperventilation (eg, anxiety), sepsis, liver disease, fever, early salicylate poisoning, and excessive artificial ventilation.
Metabolic alkalosis: Loss of gastric HCl (eg, vomiting), potassium depletion, excessive alkali administration (eg, bicarbonate, antacids), diuretics, volume depletion.
Decreased in: Respiratory acidosis: decreased alveolar ventilation (eg, COPD, respiratory depressants), neuromuscular diseases (eg, myasthenia gravis).
Metabolic acidosis (bicarbonate deficit): increased formation of acids (eg, ketosis [diabetes mellitus, alcohol, starvation], lactic acidosis); decreased H+ excretion (eg, renal failure, renal tubular acidosis, Fanconi syndrome); increased acid intake (eg, ion-exchange resins, salicylates, ammonium chloride, ethylene glycol, methanol); and increased loss of alkaline body fluids (eg, diarrhea, fistulas, aspiration of gastrointestinal contents, biliary drainage). |
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Term
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Definition
| Increased in: Respiratory alkalosis: hyperventilation (eg, anxiety), sepsis, liver disease, fever, early salicylate poisoning, and excessive artificial ventilation. |
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Term
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Definition
| Decreased in: Respiratory acidosis: decreased alveolar ventilation (eg, COPD, respiratory depressants), neuromuscular diseases (eg, myasthenia gravis). |
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Term
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Definition
Test Range and Collection
Total, serum
Desirable: <200 mg/dL
Borderline: 200–239 mg/dL
High risk: >240 mg/dL
Fasting specimen is required for LDL-C determination. HDL-C and total cholesterol can be measured with nonfasting specimen. |
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Term
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Definition
Interpretation
Increased in: familial hypercholesterolemia (deficiency of LDL receptors), hypothyroidism, uncontrolled diabetes mellitus, nephrotic syndrome,
Decreased in: Severe liver disease (acute hepatitis, cirrhosis, malignancy), hyperthyroidism, malnutrition, malabsorption, abetalipoproteinemia.
The recommended LDL-C intervention goals are <100 mg/dL for high-risk patients (eg, patients with CHD), <130 mg/dL for moderate-risk patients ( 2 risk factors), and <160 mg/dL for low-risk patients (no or 1 risk factor). |
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Term
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Definition
| Increased in: familial hypercholesterolemia (deficiency of LDL receptors), hypothyroidism, uncontrolled diabetes mellitus, nephrotic syndrome, |
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Term
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Definition
| Decreased in: Severe liver disease (acute hepatitis, cirrhosis, malignancy), hyperthyroidism, malnutrition, malabsorption, abetalipoproteinemia. |
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Term
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Definition
Test Range and Collection
serum (TG)
<165 mg/dL
Fasting specimen required.
Physiologic Basis
Dietary fat is hydrolyzed in the small intestine, absorbed and resynthesized by mucosal cells, and secreted into lacteals as chylomicrons.
Triglycerides in the chylomicrons are cleared from the blood by tissue lipoprotein lipase.
Endogenous triglyceride production occurs in the liver. |
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Term
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Definition
Interpretation
Increased in: Hypothyroidism, diabetes mellitus, nephrotic syndrome, chronic alcoholism (fatty liver), biliary tract obstruction, stress, familial lipoprotein lipase deficiency, obesity, pancreatitis, glycogen storage diseases Drugs:diazepam, estrogens, oral contraceptives. |
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Term
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Definition
Decreased in: abetalipoproteinemia, malnutrition, malabsorption, parenchymal liver disease, hyperthyroidism,
If serum is clear, the serum triglyceride level is generally <350 mg/dL.
Elevated triglycerides are now considered an independent risk factor for coronary artery disease, and a major risk factor for acute pancreatitis, particularly when serum triglyceride levels are >1000 mg/dL. |
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Term
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Definition
Test Range and Collection
serum (Anti-HAV)
Negative
Physiologic Basis
Hepatitis A is caused by a nonenveloped 27-nm RNA virus of the enterovirus-picornavirus group and is usually acquired by the fecal–oral route. IgM antibody is detectable within 1 week after symptoms develop and persists for 6 months. IgG antibody appears 4 weeks later than IgM and persists for years.
Interpretation
Positive in: Acute hepatitis A (IgM), convalescence from hepatitis A (IgG). |
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Term
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Definition
Test Range and Collection
serum (HBsAg)
Negative
Physiologic Basis
In hepatitis B virus infection, surface antigen is detectable 2–5 weeks before onset of symptoms, rises in titer, and peaks at about the time of onset of clinical illness.
Generally it persists for 1–5 months, declining in titer and disappearing with resolution of clinical symptoms.
Interpretation
Increased in: Acute hepatitis B, chronic hepatitis B (persistence of HBsAg for >6 months, positive HBcAb [total]), HBsAg-positive carriers.
May be undetectable in acute hepatitis B infection.
First-line test for the diagnosis of acute or chronic hepatitis B. If positive, no other test is needed. |
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Term
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Definition
Test Range and Collection
serum (HBsAb, anti-HBs)
Negative
Physiologic Basis
Test detects antibodies to hepatitis B virus (HBV), which are thought to confer immunity to hepatitis B. Because several subtypes of hepatitis B exist, there is a possibility of subsequent infection with a second subtype.
Interpretation
Increased in: Hepatitis B immunity due to HBV infection or hepatitis B vaccination.
Absent in: Hepatitis B carrier state, nonexposure.
Test indicates immune status. It is not useful for the evaluation of acute or chronic hepatitis. |
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Term
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Definition
Test Range and Collection
serum (HBcAb, anti-HBc)
Negative
Physiologic Basis
HbcAb (IgG and IgM) will be positive (as IgM) about 2 months after exposure to hepatitis B. Its persistent positivity may reflect chronic hepatitis (IgM) or recovery (IgG).
Interpretation
Positive in: Hepatitis B (acute and chronic), hepatitis B carriers (high levels), prior hepatitis B (immune) when IgG present in low titer with or without HBsAb.
Negative: After hepatitis B vaccination.
HBcAb (total) is useful in evaluation of acute or chronic hepatitis only if HBsAg is negative. An HBcAb (IgM) test is then indicated only if the HBcAb (total) is positive.
HBcAb (IgM) may be the only serologic indication of acute HBV infection. |
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Term
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Definition
Test Range and Collection
serum (HCAb)
Negative
Physiologic Basis
Detects antibody to hepatitis C virus, which is a single-stranded RNA virus of the Flaviviridae family.
Current screening test (ELISA) detects antibodies to proteins expressed by putative structural (HC34) and nonstructural (HC31, C100-3) regions of the HCV genome. The presence of these antibodies indicates that the patient has been infected with HCV, may harbor infectious HCV, and may be capable of transmitting HCV.
A recombinant immunoblot assay (RIBA), equivalent to Western blot, is available as a confirmatory test.
Interpretation
Increased in: Acute hepatitis C (only 20–50%; seroconversion may take 6 months or more), posttransfusion chronic non-A, non-B hepatitis (70–90%), sporadic chronic non-A, non-B hepatitis (30–80%), blood donors (0.5–1%), non–blood-donating general public (2–3%), hemophiliacs (75%), intravenous drug abusers (40–80%), hemodialysis patients (1–30%), male homosexuals (4%).
Seropositivity for hepatitis C documents previous exposure, not necessarily acute infection. |
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Term
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Definition
Test Range and Collection
Negative (detection limit: 50 IU/mL, assay-specific)
Physiologic Basis
Detection of HCV-RNA is used to confirm current infection and to monitor treatment with interferon-a (with or without ribavirin).
Interpretation
Positive in: Hepatitis C.
A negative result does not rule out the presence of PCR inhibitors in the patient specimen or hepatitis C virus RNA concentrations below the level of detection by the assay. |
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Term
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Definition
Test Range and Collection
serum (anti-HDV)
Negative
Physiologic Basis
This antibody is a marker for acute or persisting infection with the delta agent, a defective RNA virus that can only infect HBsAg-positive patients.
HBV plus hepatitis D virus (HDV) infection may be more severe than HBV infection alone. Antibody to HDV ordinarily persists for about 6 months following acute infection. Further persistence indicates carrier status.
Interpretation
Positive in: Hepatitis D.
Test only indicated in HBsAg-positive patients. Chronic HDV hepatitis occurs in 80–90% of HBsAg carriers who are superinfected with delta, but in less than 5% of those who are coinfected with both viruses simultaneously. |
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Term
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Definition
Test Range and Collection
serum
Negative
Physiologic Basis
This test detects antibody against the human immunodeficiency virus-1 (HIV-1), the etiologic agent of the vast majority of all HIV infections in the US.
Antibodies become detectable approximately 22–27 days after acute infection. Early detection is crucial for the institution of highly active antiretroviral therapy (HAART).
HIV antibody test is considered positive only when a repeatedly reactive enzyme immunoassay (ELISA) is confirmed by a Western blot (WB) analysis. |
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Term
|
Definition
Interpretation
Positive in: HIV infection: ELISA sensitivity >99% after first 2–4 months of infection, specificity 99%. When combined with confirmatory test, specificity is 99.995%.
The CDC recommends that all pregnant women be offered HIV testing. |
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Term
| Aspartate aminotransferase (AST) |
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Definition
serum (AST, SGOT, GOT)
0–35 IU/L
Physiologic Basis
Intracellular enzyme involved in amino acid metabolism. Present in large concentrations in liver, skeletal muscle, brain, red cells, and heart. Released into the bloodstream when tissue is damaged, especially in liver injury.
Interpretation
Increased in: Acute viral hepatitis (ALT > AST), biliary tract obstruction (cholangitis, choledocholithiasis), alcoholic hepatitis and cirrhosis (AST > ALT)
Decreased in: Pyridoxine (vitamin B6) deficiency.
AST/ALT ratio >1 suggests cirrhosis in patients with hepatitis C. |
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Term
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Definition
serum (ALT, SGPT, GPT)
0–35 U/L
[0–0.58 mckat/L]
Physiologic Basis:
Intracellular enzyme involved in amino acid metabolism. Present in large concentrations in liver, kidney; in smaller amounts, in skeletal muscle and heart. Released with tissue damage, particularly liver injury.
Interpretation
Increased in: Acute viral hepatitis (ALT > AST), biliary tract obstruction (cholangitis, choledocholithiasis), alcoholic hepatitis and cirrhosis (AST > ALT), nonalcoholic steatohepatitis (fatty liver)
Decreased in: Pyridoxine (vitamin B6) deficiency.
ALT is the preferred enzyme for evaluation of liver injury. |
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Term
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Definition
| Increased in: Acute viral hepatitis (ALT > AST), biliary tract obstruction (cholangitis, choledocholithiasis), alcoholic hepatitis and cirrhosis (AST > ALT), nonalcoholic steatohepatitis (fatty liver) |
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Term
|
Definition
Decreased in: Pyridoxine (vitamin B6) deficiency.
ALT is the preferred enzyme for evaluation of liver injury |
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Term
|
Definition
serum
41–133 IU/L
Physiologic Basis:
Alkaline phosphatases are found in liver, bone, intestine, and placenta.
Interpretation
Increased in: Obstructive hepatobiliary disease, bone disease (physiologic bone growth, Paget disease, osteomalacia, osteogenic sarcoma, bone metastases), hyperparathyroidism, rickets,.
Decreased in: Hypophosphatasia
Alkaline phosphatase performs well in measuring the extent of bone metastases in prostate cancer. |
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Term
|
Definition
serum
41–133 IU/L
Physiologic Basis:
Alkaline phosphatases are found in liver, bone, intestine, and placenta.
Interpretation
Increased in: Obstructive hepatobiliary disease, bone disease (physiologic bone growth, Paget disease, osteomalacia, osteogenic sarcoma, bone metastases), hyperparathyroidism, rickets,.
Decreased in: Hypophosphatasia
Alkaline phosphatase performs well in measuring the extent of bone metastases in prostate cancer. |
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Term
|
Definition
| Increased in: Obstructive hepatobiliary disease, bone disease (physiologic bone growth, Paget disease, osteomalacia, osteogenic sarcoma, bone metastases), hyperparathyroidism, rickets,. |
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Term
| Alkaline phosphatase down |
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Definition
| Decreased in: Hypophosphatasia |
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Term
| performs well in measuring the extent of bone metastases in prostate cancer. |
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Definition
|
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Term
|
Definition
0.1–1.2 mg/dL
[2–21 mcmol/L]
Direct (conjugated to glucuronide) bilirubin: 0.1–0.4 mg/dL [<7 mcmol/L];
Indirect (unconjugated) bilirubin: 0.2–0.7 mg/dL [<12 mcmol/L]
Physiologic Basis
Bilirubin, a product of hemoglobin metabolism, is conjugated in the liver to mono- and diglucuronides and excreted in bile.
Some conjugated bilirubin is bound to serum albumin, so-called D (delta) bilirubin.
Elevated serum bilirubin occurs in liver disease, biliary obstruction, or hemolysis.
Interpretation
Increased in: Acute or chronic hepatitis, cirrhosis, biliary tract obstruction, neonatal jaundice, congenital liver enzyme abnormalities, hemolytic disorders. Hepatotoxic drugs.
Only conjugated bilirubin appears in the urine, and it is indicative of liver disease; hemolysis is associated with increased unconjugated |
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Term
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Definition
Increased in: Acute or chronic hepatitis, cirrhosis, biliary tract obstruction, neonatal jaundice, congenital liver enzyme abnormalities, hemolytic disorders. Hepatotoxic drugs.
Only conjugated bilirubin appears in the urine, and it is indicative of liver disease; hemolysis is associated with increased unconjugated bilirubin. |
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Term
|
Definition
serum
20–110 U/L
[0.33–1.83 mckat/L] (laboratory-specific)
Physiologic Basis
Amylase hydrolyzes complex carbohydrates.
Serum amylase is derived primarily from pancreas and salivary glands and is increased with inflammation or obstruction of these glands.
Interpretation
Increased in: Acute pancreatitis (70–95%), pancreatic duct obstruction, bowel obstruction and infarction, mumps, parotitis, diabetic ketoacidosis, penetrating peptic ulcer.
Decreased in: Pancreatic insufficiency, cystic fibrosis. Usually normal or low in chronic pancreatitis. |
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Term
|
Definition
| Increased in: Acute pancreatitis (70–95%), pancreatic duct obstruction, bowel obstruction and infarction, mumps, parotitis, diabetic ketoacidosis, penetrating peptic ulcer. |
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Term
|
Definition
| Decreased in: Pancreatic insufficiency, cystic fibrosis. Usually normal or low in chronic pancreatitis. |
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Term
|
Definition
serum
0–160 U/L
[0–2.66 mckat/L] (laboratory-specific)
Physiologic Basis
Lipases are responsible for hydrolysis of glycerol esters of long-chain fatty acids to produce fatty acids and glycerol.
Lipases are produced in the liver, intestine, tongue, stomach, and many other cells.
Interpretation
Increased in: Acute, recurrent, or chronic pancreatitis, pancreatic malignancy, biliary disease, hepatic disease, diabetes mellitus (especially diabetic ketoacidosis), intestinal disease, gastric malignancy or perforation, cystic fibrosis, inflammatory bowel disease (Crohn disease and ulcerative colitis).
Serum lipase may be a more reliable test than serum amylase for the initial diagnosis of acute pancreatitis,
Test sensitivity is not very good for chronic pancreatitis or pancreatic cancer. |
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Term
|
Definition
| Increased in: Acute, recurrent, or chronic pancreatitis, pancreatic malignancy, biliary disease, hepatic disease, diabetes mellitus (especially diabetic ketoacidosis), intestinal disease, gastric malignancy or perforation, cystic fibrosis, inflammatory bowel disease (Crohn disease and ulcerative colitis). |
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Term
|
Definition
serum (Ca2 +)
8.5–10.5 mg/dL
Physiologic Basis
Serum calcium is the sum of ionized calcium plus complexed calcium and calcium bound to proteins (mostly albumin).
Level of ionized calcium is regulated by parathyroid hormone and vitamin D.
Interpretation
Increased in: Hyperparathyroidism, malignancies secreting parathyroid hormone–related protein (PTHrP)), vitamin D excess, Paget disease of bone with immobilization, thyrotoxicosis.
Decreased in: Hypoparathyroidism, vitamin D deficiency, renal insufficiency, magnesium deficiency, hyperphosphatemia, hypoalbuminemia.
Corrected Calcium Calculation:
For every decrease in albumin by 1 mg/dL, calcium should be corrected upward by 0.8 mg/dL. |
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Term
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Definition
| Increased in: Hyperparathyroidism, malignancies secreting parathyroid hormone–related protein (PTHrP)), vitamin D excess, Paget disease of bone with immobilization, thyrotoxicosis. |
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Term
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Definition
| Decreased in: Hypoparathyroidism, vitamin D deficiency, renal insufficiency, magnesium deficiency, hyperphosphatemia, hypoalbuminemia. |
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Term
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Definition
Test Range and Collection
serum (T4)
5.0–11.0 mcg/dL
Physiologic Basis
Total T4 is a measure of thyroid gland secretion of T4, bound and free, and thus is influenced by serum thyroid hormone-binding activity.
Interpretation
Increased in: Hyperthyroidism, increased thyroid-binding globulin (TBG) (eg, pregnancy, drug). Drugs: amiodarone, high-dose B-blockers (especially propranolol).
Decreased in: Hypothyroidism, low TBG due to illness or drugs, congenital absence of TBG. |
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Term
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Definition
| Increased in: Hyperthyroidism, increased thyroid-binding globulin (TBG) (eg, pregnancy, drug). Drugs: amiodarone, high-dose B-blockers (especially propranolol). |
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Term
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Definition
| Decreased in: Hypothyroidism, low TBG due to illness or drugs, congenital absence of TBG. |
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Term
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Definition
Test Range and Collection
serum (FT4)
Interpretation
Increased in: Hyperthyroidism, psychiatric disorders. Drugs: amiodarone, B-blockers (high dose).
Decreased in: Hypothyroidism, Drugs: phenytoin.
The TSH assay detects subclinical dysfunction and monitors thyroxine treatment better; the free thyroxine test detects central hypothyroidism and monitors rapidly changing function better. |
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Term
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Definition
| Increased in: Hyperthyroidism, psychiatric disorders. Drugs: amiodarone, B-blockers (high dose). |
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Term
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Definition
| Decreased in: Hypothyroidism, Drugs: phenytoin. |
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Term
| Decreased in: Hypothyroidism, Drugs: phenytoin. |
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Definition
Test Range and Collection
serum (TSH; thyrotropin)
0.4–6 mcU/mL [mU/L]
Physiologic Basis
TSH is an anterior pituitary hormone that stimulates the thyroid gland to produce thyroid hormones.
Secretion is stimulated by thyrotropin-releasing hormone from the hypothalamus. There is negative feedback on TSH secretion by circulating thyroid hormone.
Interpretation
Increased in: Hypothyroidism. Subclinical hypothyroidism defined as a mild increase in serum TSH and normal free thyroxine and triiodothyronine levels.
Decreased in: Hyperthyroidism, acute medical or surgical illness, pituitary hypothyroidism. Drugs: dopamine, high-dose corticosteroids. Subclinical hyperthyroidism defined as a mild decrease in serum TSH and normal free thyroxine and triiodothyronine levels.
Measurement of serum TSH is the best initial laboratory test of thyroid function. It should be followed by measurement of free thyroxine if the TSH value is low and by measurement of anti-thyroperoxidase antibody if the TSH value is high. |
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Term
| Thyroid Stimulating Hormone up |
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Definition
| Increased in: Hypothyroidism. Subclinical hypothyroidism defined as a mild increase in serum TSH and normal free thyroxine and triiodothyronine levels. |
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Term
| Thyroid Stimulating Hormone down |
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Definition
| Decreased in: Hyperthyroidism, acute medical or surgical illness, pituitary hypothyroidism. Drugs: dopamine, high-dose corticosteroids. Subclinical hyperthyroidism defined as a mild decrease in serum TSH and normal free thyroxine and triiodothyronine levels. |
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Term
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Definition
Indications
Evaluation of pleural and parenchymal pulmonary disease, mediastinal disease, cardiogenic and noncardiogenic pulmonary edema, congenital and acquired cardiac disease.
Screening for traumatic aortic rupture (though CT is playing an increasing role).
Evaluation of possible pneumothorax (expiratory upright film) or pleural effusion
Contraindications
Contraindications and risks: Caution in pregnancy because of the potential harm of ionizing radiation to the fetus.
Preparation
None |
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Term
| Chest Computed Tomography |
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Definition
Indications
Evaluation of thoracic trauma.
Evaluation of mediastinal and hilar tumor.
Evaluation and staging of primary and metastatic lung neoplasm.
Characterization of pulmonary nodules.
Differentiation of parenchymal versus pleural process (ie, lung abscess versus empyema).
Contraindications
Caution in pregnancy because of the potential harm of ionizing radiation to the fetus. Risks of CT and Angiographic Intravenous Contrast Agents.
Preparation
Preferably NPO for 2 hours before study.
Normal hydration.
Sedation of agitated patients.
Recent serum creatinine determination |
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Term
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Definition
Indications
Differentiation of cystic versus solid lesions of the liver and kidneys.
Detection of intra- and extrahepatic biliary ductal dilation, cholelithiasis, gallbladder wall thickness, pericholecystic fluid, peripancreatic fluid and pseudocyst, hydronephrosis, abdominal aortic aneurysm, appendicitis, ascites, primary and metastatic liver carcinoma.
Contraindications
None
Preparation
NPO for 6 hours. |
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Term
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Definition
Indications
Evaluation of essentially all intracranial disease
Contraindications
Contraindicated in patients with cardiac pacemakers, intraocular metallic foreign bodies, intracranial aneurysm clips, cochlear implants, and some artificial heart valves.
Preparation
Sedation of agitated patients.
Screening CT or plain radiograph images of orbits if history suggests possible metallic foreign body in the eye. |
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Term
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Definition
Indications
Evaluation of primary or metastatic neoplasm, osteomyelitis, arthritis, metabolic disorders, trauma, avascular necrosis, joint prosthesis, and reflex sympathetic dystrophy.
Evaluation of clinically suspected but radiographically occult fractures. Identification of stress fractures.
Contraindications
Caution in pregnancy because of the risk of ionizing radiation to the fetus.
Preparation
Patient should be well hydrated and void frequently after the procedure. |
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Term
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Definition
Colonoscopy is performed by passing a flexible colonoscope through the anal canal into the rectum and colon. The cecum is reached in >95% of cases, and the terminal ileum can often be examined. Colonoscopy is the "gold standard" for diagnosis of colonic mucosal disease.
Conscious sedation is usually given before colonoscopy in the United States, although a willing patient and a skilled examiner can complete the procedure without sedation in many cases.
Contraindications:
Diverticulosis
Diverticulitis
Preparation:
Go Lytley Laxative, NPO |
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