Introduction to Vital Signs and Basic Laboratory Tests

Joel N. Kniep, M.D.

Dept. of Pathology

Objectives

• Introduce vital signs and their use in clinical practice

• Introduce basic laboratory tests and their use in clinical practice

• Discuss normal values and test interpretation

Clinical Vital Signs (Vitals)

• Temperature

• Pulse rate

• Respiration rate (RR)

• Blood pressure (bp)

Temp

• Measure of body’s core temp (temp of internal organs) – in ° F (or ° C)– Locations: oral, rectum, axilla, ear– Rectal = 0.5 – 0.7° F higher than oral temp– Axilla = 0.3 – 0.4° F lower than oral temp

• Normal: 97.8 – 99° F (36.5 – 37.2° C)• Critical: > 98.6° F orally or 99.8° F rectally

(pyrexia [fever]); < 95° F (hypothermia)

Pulse rate

• Heart rate (HR) or number of heart beats/min

• Normal: 60 – 100/min

• ↑ (tachycardia): ↑ Na+ intake, ↓ Na+ loss, Excessive free body H2O loss

• ↓ (bradycardia): ↓ Na+ intake, ↑ Na+ loss, ↑ free body H2O

RR

• Number of breaths/min– At rest– Also note breathing effort or difficulty

• Normal: 15 – 20/min• Critical: < 12 or > 25• ↑ (hyperventilation): ↑ Na+ intake, ↓ Na+

loss, Excessive free body H2O loss• ↓ (hypoventilation): ↓ Na+ intake, ↑ Na+

loss, ↑ free body H2O

Bp

• Measures the force of blood against the arterial vessel walls– Measured while seated, after resting for 5 mins, arm resting @

heart level (if possible)– Reported as a fraction (systolic/diastolic) & consists of 2

separate measurements:• Systolic – pressure within artery during cardiac contraction• Diastolic – pressure within artery during cardiac relaxation and filling

• Normal: < 120 mm Hg systolic and < 80 mm Hg diastolic• Critical: > 220 mm Hg systolic or > 125 mm Hg diastolic• ↑ (hypertension [htn]): ↑ Na+ intake, ↓ Na+ loss,

Excessive free body H2O loss• ↓ (hypotention): ↓ Na+ intake, ↑ Na+ loss, ↑ free body

H2O

Complete Blood Count (CBC)

• Provides information on cellular components of blood

• Includes RBC count, Hemoglobin (Hgb), Hematocrit (Hct), RBC indices, White blood cell (WBC) count and differential, Platelet count

Total WBCs (leukocytes)

• Measurement of total WBC count– Consists of total # of WBCs/mm3 of peripheral venous blood– Part of “routine” testing– Useful for evaluation of infection, neoplasm, allergy &

immunosuppression• Normal: 4,000 – 10,000/mm3

• Critical: < 2,500 or > 30,000/mm3

• ↑ (leukocytosis): infection, malignancy, trauma, stress, hemorrhage, tissue necrosis, inflammation, dehydration, thyroid storm

• ↓ (leukopenia): drug toxicity, bone marrow failure, overwhelming infections, dietary deficiency, congenital marrow aplasia, bone marrow infiltration, autoimmune disease, hypersplenism

Erythrocyte count (RBC)

• Measures # of circulating RBCs/mm3 of peripheral venous blood– Direct measure of RBC count– Part of “routine” testing and anemia evaluation

• Normal: 3.5 – 5.5 x 106/μL • ↑: erythrocytosis, congenital heart disease, severe

COPD, polycythemia vera, severe dehydration, hemoglobinopathies

• ↓: anemia, hemoglobinopathy, hemorrhage, bone marrow failure, renal disease, leukemia, prosthetic valves, normal pregnancy, multiple myeloma, Hodgkin disease, lymphoma, dietary deficiency

Hgb

• Measures total amount of Hgb in blood– Indirect measure of RBC count– Part of “routine” testing and anemia evaluation

• Normal: 12 – 15 g/dL • Critical: < 5 or > 20 g/dL• ↑: erythrocytosis, congenital heart disease, severe

COPD, polycythemia vera, severe dehydration↓: anemia, hemoglobinopathy, hemorrhage, bone marrow

failure, renal disease, leukemia, prosthetic valves, normal pregnancy, multiple myeloma, Hodgkin disease, lymphoma, dietary deficiency

Hct

• Measure of RBC percent of total blood vol– Indirect measure of RBC # & volume– Part of “routine” testing and anemia evaluation

• Normal: 36 – 48% • Critical: < 15% or > 60%• ↑: erythrocytosis, congenital heart disease, severe

COPD, polycythemia vera, severe dehydration• ↓: anemia, hemoglobinopathy, hemorrhage, bone

marrow failure, renal disease, leukemia, prosthetic valves, normal pregnancy, multiple myeloma, Hodgkin disease, lymphoma, dietary deficiency

RBC indices

• Measures size and hgb content of RBCs

• Used to classify anemias

• Includes Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell distribution width (RDW)

MCV

• Measure of average volume/size of single RBC– MCV = Hct (%) x 10/RBC (million/mm3)– Useful in anemia classification

• Normal: 80 – 100 mm3

• ↑ (macrocytic): pernicious anemia (vit B12 deficiency), folic acid deficiency, antimetabolic therapy, alcoholism, chronic liver disease, hypothyroidism

• Normocytic: bone marrow failure/replacement, acute blood loss, chronic diseases, hemolytic anemias

• ↓ (microcytic): Fe deficiency anemia, thalassemia, anemia of chronic illness

MCH

• Measure of average amount of hgb within a single RBC– MCH = Hgb (g/dL) x 10/RBC (million/mm3)– Provides little additional info to other indices

• Normal: 24 – 32 pg

• ↑: macrocytic anemias

• ↓: microcytic anemia, hypochromic anemia

MCHC

• Measure of average [hgb] within a single RBC– MCHC = Hgb (g/dL) x 100/Hct (%)– 37 g/dL = maximum Hgb able to fit into an RBC

(cannot be hyperchromic)

• Normal (normochromic): 32 – 36 g/dL• ↑: spherocytosis, intravascular hemolysis, cold

agglutinins• ↓ (hypochromic): Fe deficiency anemia,

thalassemia

RDW

• Measure of variation of RBC size (indicator of degree of anisocytosis)– Useful in anemia classification

• Normal: variation of 11.5 – 16.9%

• ↑: Fe deficiency anemia, vit B12 or folate deficiency anemia, hemoglobinopathies, hemolytic anemias, posthemorrhagic anemias

Platelet count• Measurement of platelets (thrombocytes)

– Consists of actual # of platelets/mm3 of peripheral venous blood– Part of “routine” testing– Useful for evaluation of petechiae, spontaneous bleeding, increasingly

heavy menses or thrombocytopenia– Useful for monitoring discourse/therapy of thrombocytopenia/bone

marrow failure• Normal: 150,000 – 400,000/mm3

• Critical: < 50,000 or > 1,000,000/mm3

• ↑ (thrombocytosis): malignant disorders, polycythemia vera, postsplenectomy syndrome, rheumatoid arthritis, Fe deficiency anemia

• ↓ (thrombocytopenia): Hypersplenism, hemorrhage, immune thrombocytopenia, leukemia & other myelofibrosis disorders, TTP, DIC, SLE, chemotherapy, pernicious anemia

WBC definitions

• Leukocytosis – abnormally large number of leukocytes; generally indicated by WBC count of ≥ 10,000 cells/mm3

• Lymphocytosis – form of actual or relative leukocytosis due to increase in numbers of lymphocytes

• Left shift – increase in the number of immature neutrophils (bands/stabs) found in the blood

WBC differential

• Measurement of percentage of each WBC type in specimen– Useful for infection, neoplasm, allergy &

immunosuppression evaluations

• Normal: Neutrophils (50 – 70%), Lymphocytes (20 – 40%), Monocytes (2 – 8%), Eosinophils (0 – 5%), Basophils (0 – 2%)

• ↑: refer to individual cell types on chart• ↓: refer to individual cell types on chart

Basic Metabolic Panel (BMP)

• Measures electrolytes, chemicals, metabolic end products & substrates

• Consists of Glucose, Blood Urea Nitrogen (BUN), Creatinine, Na+, K+, Cl-, Bicarbonate (HCO3

-), Ca2+

Glucose

• Direct measure of blood glucose– Commonly used to evaluate diabetic pts– Part of “routine” testing

• Normal: 70 - 100 mg/dL• Critical: < 50 and > 400 mg/dL (♂) or < 40 and > 400

mg/dL (♀)• ↑ (hyperglycemia): DM, acute stress response, Cushing

syndrome, pheochromocytoma, chronic renal failure, acute pancreatitis, acromegaly, corticosteroid therapy

• ↓ (hypoglycemia): insulinoma, hypothyroidism, hypopituitarism, Addison disease, extensive liver disease, insulin overdose, starvation

BUN

• Measures urea nitrogen in blood– End product of protein metabolism (produced in liver)– Indirect measure of renal function & glomerular function

(excretion)– Measure of liver metabolic function– Part of routine labs– Usually interpreted along with Cr (less accurate than Cr for renal

disease)• Normal: 6 -21 mg/dL• Critical: > 100 mg/dL• ↑: prerenal causes, renal causes, postrenal azotemia• ↓: liver failure, overhydration because of SIADH, neg

nitrogen balance, pregnancy, nephrotic syndrome

Creatinine

• Measures serum creatinine– Catabolic product of creatine phosphate (skeletal muscle

contraction)– Excreted entirely by kidneys → direct measure of renal function– Minimally affected by liver function– Elevation occurs slower than BUN – Doubling ≈ 50% reduction in GFR

• Normal: 0.44 – 1.03 mg/dL • Critical: > 4 mg/dL• ↑: diseases affecting renal function (glomerulonephritis,

pyelonephritis, ATN, urinary tract obstruction, reduced renal blood flow, diabetic nephropathy, nephritis), rhabdomyolysis, acromegaly, gigantism

• ↓: debilitation, decreased muscle mass

Na+

• Measures serum sodium level– Major cation in EC space– Balance between dietary intake and renal excretion

• Normal: 136 – 146 mEq/L• Critical: < 120 or > 160 mEq/L• ↑ (hypernatremia): ↑ Na+ intake, ↓ Na+ loss,

Excessive free body H2O loss

• ↓ (hyponatremia): ↓ Na+ intake, ↑ Na+ loss, ↑ free body H2O

K+

• Measures serum potassium level– Major cation within cell

• Normal: 3.4 – 5.2 mEq/L• Critical: < 2.5 or > 6.5 mEq/L• ↑ (hyperkalemia): excessive intake, acidosis,

acute/chronic renal failure, Addison disease, hypoaldosteronism, infection, dehydration

• ↓ (hypokalemia): deficient intake, burns, hyperaldosteronism, Cushing syndrome, RTA, licorice ingestion, alkalosis, renal artery stenosis

Cl-

• Measures serum chloride level– Major anion in EC space– Helps maintain electrical neutrality; follows sodium

• Normal: 98 – 108 mEq/L • Critical: < 80 or > 115 mEq/L• ↑ (hyperchloremia): dehydration, metabolic acidosis,

RTA, Cushing syndrome, renal dysfunction, respiratory alkalosis, hyperparathyroidism

• ↓ (hypochloremia): overhydration, SIADH, CHF, chronic respiratory acidosis, metabolic alkalosis, Addison disease, Aldosteronism, vomiting/prolonged gastric suction, hypokalemia

HCO3-

• Measures CO2 content of blood– Major role in acid-base balance– Regulated by kidneys– Used to evaluate pt pH status & electrolytes

• Normal: 22 – 32 mEq/L• Critical: < 6 mEq/L• ↑: severe vomiting, high-volume gastric suction,

aldosteronism, mercurial diuretic use, COPD, metabolic alkalosis

• ↓: chronic diarrhea, chronic loop diuretic use, renal failure, DKA, starvation, metabolic acidosis, shock

Ca2+

• Measures serum calcium level– Direct measurement– Used to evaluate parathyroid function & Ca metabolism– Used to monitor renal failure, renal transplantation,

hyperparathyroidism, various malignancies, & Ca level when giving large-volume blood transfusions

• Normal: Total = 8.3 – 10.3 mg/dL, Ionized = 4.5 – 5.6 mg/dL• Critical: Total < 6 or > 13 mg/dL, Ionized < 2.2 or > 7 mg/dL• ↑ (hypercalcemia): hyperparathyroidism, bone mets, Paget disease

of bone, prolonged immobilization, milk-alkali syndrome, vit D intoxication, hyperthyroidism

• ↓ (hypocalcemia): hypoparathyroidism, renal failure, rickets, vit D deficiency, osteomalacia, pancreatitis, alkalosis, malabsorption, fat embolism

Comprehensive Metabolic Panel (CMP)

• Includes all components of BMP plus Albumin, Total protein, Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), Aspartate aminotransferase (AST) and Bilirubin

Albumin

• Measures amount of albumin in blood– Formed within liver & comprises 60% of total protein in blood– Maintains colloidal osmotic pressure & transports blood

constituents– Measure of both hepatic function and nutritional state

• Normal: 3.5 – 5 g/dL• ↑: dehydration• ↓: malnutrition, pregnancy, liver disease, protein-losing

enteropathies, protein-losing nephropathies, 3rd space losses, overhydration, ↑ capillary permeability, inflammatory disease, familial idiopathic dysproteinemia

Total Protein

• Measures total protein in blood– Combination of prealbumin, albumin &

globulins

• Normal: 6.4 – 8.3 g/dL

ALP

• Measures serum ALP concentration– Detect & monitor liver and bone disease

• Normal: 30 -120 units/L• ↑: 1° cirrhosis, intrahepatic/extrahepatic biliary

obstruction, 1°/metastic liver tumor, hyperparathyroidism, Paget disease, normal growing bones in children, bone mets, RA, MI, sarcoidosis, healing fracture, normal pregnancy, intestinal ischemia or infarction

• ↓: hypophosphatemia, malnutrition, milk-alkali syndrome, pernicious anemia, scurvy

ALT

• Found predominantly in liver – Injury/disease to parenchyma → release into blood– ID & monitor hepatocellular diseases of liver– If jaundiced, implicates liver rather than RBC hemolysis

• Normal: 4 – 36 international units/L @ 37°C• Sig ↑: hepatitis, hepatic necrosis, hepatic ischemia• Mod ↑: cirrhosis, cholestasis, hepatic tumor, hepatotoxic

drugs, obstructive jaundice, severe burns, trauma to striated muscle

• Mild ↑: myositis, pancreatitis, MI, infectious mono, shock

AST

• Found in highly metabolic tissue (cardiac & skeletal muscle, liver cells) – Disease/injury → lysing of cells & release into blood– Elevation proportional to # of cells injured– Used for evaluation of suspected coronary artery

disease or hepatocellular disease• Normal: 0 – 35 units/L• ↑: heart diseases, liver diseases, skeletal

muscle diseases• ↓: acute renal disease, beriberi, DKA,

pregnancy, chronic renal dialysis

Bilirubin

• Measures level of total bilirubin in blood– End product of RBC metabolism (RBCs → Hgb →

Heme (+ globin) → Biliverdin → Bilirubin (unconjugated/indirect) → Bilirubin (conjugated/direct)

– Component of bile– Consists of conjugated (direct) & unconjugated

(indirect) bilirubin– Used to evaluate liver function; hemolytic anemia

workup in adults & jaundice in newborns– Jaundice occurs when total bilirubin > 2.5 mg/dL

• Normal: 0.3 – 1 mg/dL• Critical: > 12 mg/dL

Unconjugated bilirubin

• Measures level of indirect bilirubin in blood• Normal: 0.2 – 0.8 mg/dL• ↑: erythroblastosis fetalis, transfusion rxn,

sickle cell anemia, hemolytic jaundice, hemolytic anemia, pernicious anemia, large-volume blood transfusion, large hematoma resolution, hepatitis, cirrhosis, sepsis, neonatal hyperbilirubinemia, Crigler-Najjar syndrome, Gilbert syndrome

Conjugated bilirubin

• Measures level of direct bilirubin in blood– Produced by conjugating glucuronide w/

unconjugated/indirect bilirubin in liver

• Normal: 0.1 – 0.3 mg/dL

• ↑: gallstones, extrahepatic duct obstruction, extensive liver mets, cholestasis from drugs, Dubin-Johnson syndrome, Rotor syndrome

Urinary Analysis (UA)

• Provides information about kidneys & other metabolic processes

• Used for diagnosis, screening & monitoring

• Frequently used to test for urinary tract infections (UTIs)

UA Normal Values

• Appearance: clear• Color: amber yellow• Odor: aromatic• pH: 4.6 – 8• Protein: 0 – 8 mg/dL• Specific gravity: 1.005 – 1.030• Leukocyte esterase: negative• Nitrites: none• Ketones: none

UA Normal Values cont.

• Bilirubin: none• Urobilinogen: 0.01 – 1 Ehrlich unit/mL• Crystals: none• Casts: none• Glucose: negative• White Blood Cells: 0 – 4/low-power field• WBC casts: none• Red Blood Cells (RBCs): ≤ 2• RBC casts: none

Urinary Protein

• Used to monitor kidney function• Normally not present in normal kidney due to

size barrier in glomerulous• Normally tested by dipstick method,

quantification requires 24-hour urine collection• Presence (proteinuria) can indicate nephrotic

syndrome, multiple myeloma or complications of DM, glomerulonephritis, amyloidosis

Urinary Glucose

• Glucosuria – presence of glucose in urine– Reflection of serum glucose levels– Helpful in monitoring DM therapy– Renal glucose reabsorption threshold = 180 mg/dL (in proximal

renal tubules)– Not always abnormal

• Can occur after a high-carbohydrate meal or IV dextrose fluids• Can occur in diseases affecting renal tubules; genetic defects of

metabolism & glucose excretion

• ↑: DM & other causes of hyperglycemia, pregnancy, renal glycosuria, Fanconi syndrome, Hereditary defects in metabolism of other reducing substances, ↑ ICP, nephrotoxic chemicals

Urinary Leukocyte esterase

• Screen to detect leukocytes in urine (dipstick method)

• Presence indicates UTI

• 90% accurate

Urinary Ketones

• End products of fatty acid catabolism

• Examples: β-hydroxybutyric acid, acetoacetic acid, acetone

• Associated with poorly controlled diabetes

• Used to evaluate ketoacidosis associated w/ alcoholism, fasting, starvation, high-protein diets, isopropanol ingestion

Urinary Nitrites

• Screen for UTI (dipstick method)

• Test based on chemical rxn by bacterial reductase (reduces nitrate to nitrite)

• 50% accurate

• Enhances leukocyte esterase sensitivity

Urinary Casts

• Hyaline – conglomerations of protein; indicative of proteinuria; few = normal especially after exercise

• Cellular – conglomerations of degenerated cells– Granular – glomerular disease– Fatty – nephrotic syndrome– Waxy – chronic renal disease– Epithelial cells & casts (renal tubular casts)– WBCs & casts – acute pyelonephritis– RBCs & casts – glomerular diseases

Cerebral Spinal Fluid (CSF) Analysis

• Collected via lumbar puncture (LP)

• Useful for the diagnosis of 1° or metastatic brain/spinal cord neoplasm, cerebral hemorrhage, meningitis, encephalitis, degenerative brain disease, autoimmune diseases w/ CNS involvement, neurosyphilis, demyelinating diseases

CSF analysis Normal Values

• Opening pressure: <20 cm H2O• Color: clear & colorless• Blood: none• RBCs: 0• WBCs: 0 – 5 cells/μL• Neutrophils: 0 – 6%• Lymphocytes: 40 – 80%• Monocytes: 15 – 45%

CSF analysis Normal Values cont.

• Protein: 15 – 45 mg/dL

• Glucose: 50 – 75 mg/dL or 60 – 70% of blood glucose level

CSF WBC count

• Pleocytosis – turbidity of CSF due to increased #s of cells

CSF PMNs

• Causes of ↑ PMNs: bacterial meningitis, tubercular meningitis, cerebral abscess, subarachnoid bleeding, tumor

CSF Lymphs

• Causes of ↑ lymphs/plasma cells: viral, tubercular, fungal or syphilitic meningitis; multiple sclerosis (MS), Guillain-Barré syndrome

CSF Monos

• Causes of ↑ monos: tubercular or fungal meningitis, hemorrhage, brain infarction

CSF ProfileRBCs/mm3

WBCs/mm3

Glucose (mg/dL)

Protein (mg/dL)

Opening pressure (cm H2O)

Appearance

γ-globulin (% protein)

Bacterial meningitis

↑ (> 1,000 PNMs)

↓ (< 45 mg/dL)

↑ (> 250 mg/dL)

↑ Cloudy

Viral meningitis

↑ (lymphs/monos)

Aseptic meningitis

↑

SAH ↑ ↑ ↑ ↑

Guillain-Barré syndrome

↑ ↑

MS Normal in 2/3 pts; > 15 in < 5% of pts

↑ ↑

Pseudotumor cerebri

↑ ↑ ↑

References

• Pagana, K.D. & Pagna, T.J. (2006). Mosby’s Manual of Diagnostic and Laboratory Tests. St. Louis: Mosby Elsevier.

• 27th edition (2000). Stedman’s Medical Dictionary. Baltimore: Lippincott Williams & Wilkins.

• UpToDate. Retrieved July 26, 2009, from http://www.uptodateonline.com

• Urinalysis. Retrieved July 17, 2009, from http://library.med.utah.edu/WebPath/TUTORIAL/URINE/URINE.html

• Vital Signs. Retrieved July 17, 2009, from http://www.healthsystem.virginia.edu/uvahealth/adult_nontrauma/vital.cfm

Additional Resources

• Corbett, J.V. (2008). Laboratory Tests and Diagnostic Procedures with Nursing Diagnoses 7th Edition. Upper Saddle River: Prentice Hall.

• Fischbach, F.T. & Dunning, M.B. (2008). A Manual of Laboratory & Diagnostic Tests 8th Edition. Philadelphia: Lippincott Williams & Wilkins.

• Jacobs, D.S., De Mott, W.R. & Oxley, D.K. (2001). Jacobs & DeMott Laboratory Test Handbook with Key Word Index 5th Edition. Hudson: Lexi Comp, Inc.

• Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests 4th Edition. St. Louis: Saunders Elsevier.

• Young, R.H. & Hicks, J. (2002). Directory of Rare Analyses 2000-2002. St. Louis: AACC Press.

• http://www.labtestsonline.org/

Special Thanks

• Dr. Amira F. Gohara, M.D.

• Dr. Carol Bennett-Clarke, Ph.D.

• Dr. Constance Shriner, Ph.D.

• Cynthia R. O’Connell, BSMT (ASCP)