Lab Panel Components
Lab Panel
What is Included:
CMP
BMP plus liver function panel.
Lipid Panel
Total cholesterol level, triglyceride level, high-density lipoprotein (HDL), low-density lipoprotein (LDL).
Thyroid Panel
Thyroid-stimulating hormone (TSH), free or total thyroxine (T4), free or total triiodothyronine (T3).
ABG
pH, partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2), oxygen saturation of hemoglobin (SaO2), bicarbonate (HCO3), base excess/deficit.
Card 3
Adult Lab Values > Calcium (Ca)
Expected Range
Causes and Symptoms of Lower/Higher Values
Answer
Calcium (Ca)
Electrolyte important for bone/teeth formation, nerve/muscle function, clotting.
Expected Range: 9 – 10.5 mg/dL
California (CA) is due for a big earthquake, 9 – 10.5 on the Richter scale. Call 911 (9 – 11).
Hypocalcemia (Ca < 9.0 mg/dL):
Causes: Hypoparathyroidism, acute pancreatitis, vitamin D deficiency.
Symptoms: Positive Chvostek’s and Trousseau’s signs, muscle spasms, paresthesia (i.e., burning/prickling sensation).
Hypercalcemia (Ca > 10.5 mg/dL):
Causes: Hyperparathyroidism, cancer, prolonged immobility, long-term corticosteroid use.
Symptoms: Kidney stones, GI upset, constipation, bone pain, muscle weakness, confusion.
Card 4
Adult Lab Values > Chloride (Cl)
Expected Range
Causes and Symptoms of Lower/Higher Values
Answer
Chloride (Cl)
Electrolyte important for maintenance of fluid balance. Component of digestive juices.
Expected Range: 98 – 106 mEq/L
I like my hot tub chlorinated, with a temperature between 98 – 106 degrees.
Hypochloremia (Cl < 98 mEq/L):
Causes: Metabolic alkalosis, GI losses (e.g., vomiting, NG suctioning), diuretics, heart failure.
Symptoms: Weakness, fatigue, dyspnea, confusion.
Hyperchloremia (Cl > 106 mEq/L):
Causes: Metabolic acidosis, dehydration, excess salt intake.
Symptoms: Weakness, fatigue, thirst, muscle cramps.
Card 5
Adult Lab Values > Magnesium (Mg)
Expected Range
Causes and Symptoms of Lower/Higher Values
Answer
Magnesium (Mg)
Electrolyte important for nerve/muscle function, biochemical reactions.
Expected Range: 1.3 – 2.1 mEq/L
MGs are VERY small British cars, you can only fit 1 – 2 people in them.
Hypomagnesemia (Mg < 1.3 mEq/L):
Causes: GI losses (e.g., diarrhea), diuretics, malnutrition, alcohol abuse.
Symptoms: Dysrhythmias (Torsades de pointes), tachycardia, hypertension, tremors, seizures, ↑ DTRs.
Hypermagnesemia (Mg > 2.1 mEq/L):
Causes: Kidney disease, laxatives containing Mg.
Symptoms: Hypotension, lethargy, muscle weakness, ↓ DTRs, respiratory depression, dysrhythmias, cardiac arrest.
Card 6
Adult Lab Values > Phosphorous (P)
Expected Range
Causes and Symptoms of Lower/Higher Values
Answer
Phosphorous (P)
Electrolyte important for bone/teeth formation, metabolism, protein synthesis.
Expected Range: 3.0 – 4.5 mg/dL
Phos4us is normally around 4 mg/dL!
Hypophosphatemia (P < 3.0 mg/dL):
Causes: Alcoholism, excess antacids, malnutrition.
Symptoms: Same as hypercalcemia (i.e., bone pain, muscle weakness, confusion).
Hyperphosphatemia (P > 4.5 mg/dL):
Causes: Kidney disease.
Symptoms: Same as hypocalcemia (i.e., positive Chvostek’s and Trousseau’s signs, muscle spasms).
Phosphorus has an inverse relationship with calcium (i.e., when calcium is high, phosphorus is low. When calcium is low, phosphorus is high).
Card 7
Adult Lab Values > Potassium (K)
Expected Range
Causes and Symptoms of Lower/Higher Values
Answer
Potassium (K)
Electrolyte important for maintenance of ICF, regulation of heart/muscle contractions.
Expected Range: 3.5 – 5.0 mEq/L
There are ~3.1 miles in a 5K. Bananas (high in K!) come in bunches of 3 – 5.
Hypokalemia (K < 3.5 mEq/L):
Causes: Diuretics (e.g., furosemide), GI losses, Cushing’s syndrome, metabolic alkalosis.
Symptoms: Dysrhythmias, muscle weakness, constipation/ileus, hypotension, weak pulses.
Hyperkalemia (K > 5 mEq/L):
Causes: Diabetic Ketoacidosis (DKA), metabolic acidosis, salt substitutes, kidney failure.
Symptoms: Dysrhythmias, muscle twitching/weakness, paresthesia (i.e., burning/prickling sensation), diarrhea.
Card 8
Adult Lab Values > Sodium (Na)
Expected Range
Causes and Symptoms of Lower/Higher Values
Answer
Sodium (Na)
Electrolyte important for nerve/muscle function, fluid volume maintenance.
Expected Range: 136 – 145 mEq/L
If you shake a salt shaker, you will get ~ 136 – 145 grains of salt (Na) out of it.
Hyponatremia (Na < 136 mEq/L):
Causes: Diuretics, kidney failure, diaphoresis, SIADH, hyperglycemia, heart failure, fluid volume overload (dilutional hyponatremia).
Symptoms: Confusion (common in elderly!), fatigue, n/v, headache, seizures.
Hypernatremia (Na > 145 mEq/L):
Causes: Kidney failure, excess sodium intake, Cushing’s syndrome, diabetes insipidus, fever, NPO.
Symptoms: Thirst, lethargy, confusion, GI upset, muscle twitching, seizures, irritability/agitation.
Card 9
Adult Lab Values > Creatinine Kinase MB (CK-MB)
Expected Range
Significance and Timing of Higher Levels
Answer
Creatinine Kinase MB (CK-MB)
Enzyme found in the heart muscle, released with heart muscle injury. Used to distinguish between heart and skeletal muscle damage with chest pain.
Expected Range: 0% of total CK
0% of total CK means your heart is A-OK!
CK-MB > 0%: Indicates damage to the heart due to ischemia. Starting with the onset of symptoms, abnormal levels are:
Detected within: 3 – 6 hours.
Peaked within: 18 hours.
Elevated for: 2 – 3 days.
Card 10
Adult Lab Values > Troponin T
Expected Range
Significance and Timing of Higher Levels
Answer
Troponin T
Protein found in heart muscle protein fibers, released with heart muscle injury. Most specific and reliable cardiac enzyme to diagnose a myocardial infarction.
Expected Range: < 0.1 ng/mL
Troponin T > 0.1 ng/mL: Indicates damage to the heart due to ischemia. Starting with the onset of symptoms, abnormal levels are:
Detected within: 2 – 3 hours.
Peaked within: 12 – 48 hours.
Elevated for: 10 – 14 days.
Troponin T for TWO (elevated levels within TWO hours, elevated for up to TWO weeks).
Card 11
Adult Lab Values > Troponin I
Expected Range
Significance and Timing of Higher Levels
Answer
Troponin I
Protein found in heart muscle protein fibers, released with heart muscle injury. Most specific and reliable cardiac enzyme to diagnose a myocardial infarction.
Expected Range: < 0.03 ng/mL
Troponin I > 0.03 ng/mL: Indicates damage to the heart due to ischemia. Starting with the onset of symptoms, abnormal levels are:
Detected within: 2 – 3 hours.
Peaked within: 12 – 48 hours.
Elevated for: 7 – 10 days.
Troponin I looks like the Roman numeral ONE (levels elevated for ONE week).
Card 12
Adult Lab Values > Myoglobin
Expected Range
Significance and Timing of Higher Levels
Answer
Myoglobin
Oxygen-binding protein found in heart and skeletal muscles, released with muscle injury. Not specific to the heart!
Expected Range: < 90 mcg/L
I have up to 90 days to take a trip around “my globe”.
Myoglobin > 90 mcg/L: Indicates myocardial infarction or muscle damage/inflammation. Starting with the onset of symptoms, abnormal levels are:
Detected within: 2 – 3 hours.
Peaked within: 4 – 12 hours.
Elevated for: 24 hours.
Card 13
Adult Lab Values > Cholesterol (Total)
Expected Range
Significance of Higher Levels
Answer
Cholesterol (Total)
Waxy, fat-like substance used to make hormones, vitamin D, and bile acid. Excess cholesterol in the blood can combine with other substances to form plaque and lead to atherosclerosis. Total cholesterol incorporates LDL, HDL, and triglyceride levels.
Expected Range: < 200 mg/dL
Cholesterol > 200 mg/dL: Indicates increased risk for atherosclerosis, heart disease, myocardial infarction.
Card 14
Adult Lab Values > Low-Density Lipoprotein (LDL)
Expected Range
Significance of Higher Levels
Answer
Low-Density Lipoprotein (LDL)
Serves as a transporter for cholesterol. Can lead to a buildup of cholesterol in the arteries.
Expected Range: < 130 mg/dL
Patients at high risk for cardiovascular disease should have LDL < 100 mg/dL.
“L” for “Lousy” (i.e., bad cholesterol).
LDL > 130 mg/dL: Indicates increased risk for atherosclerosis, heart disease, myocardial infarction.
Card 15
Adult Lab Values > Triglycerides
Expected Range for Females and Males
Significance of Higher Levels
Answer
Triglycerides
Extra calories are turned into triglycerides and stored in fat cells. When energy is needed, they are released from the fat cells.
Females: 35 – 135 mg/dL
Males: 40 – 160 mg/dL
Elevated Levels: Indicates increased risk for atherosclerosis, heart disease, myocardial infarction.
You should try to lower your triglycerides to prevent heart disease.
Card 16
Adult Lab Values > High-Density Lipoprotein (HDL)
Expected Range for Females and Males
Significance of Decreased Levels
Answer
High-Density Lipoprotein (HDL)
Lipoprotein that transports cholesterol from other parts of the body back to the liver (where it can be removed from the body).
Females: > 55 mg/dL
Males: > 45 mg/dL
“H” for “Happy” (i.e., good cholesterol).
Decreased Levels: Associated with increased risk of heart disease.
Card 17
Adult Lab Values > Human B-type Natriuretic Peptides (h > BNP)
Expected Range
Causes Increased Levels
Answer
Human B-type Natriuretic Peptides (hBNP)
Hormone produced in ventricles, released in response to fluid overload.
Expected Range: < 100 pg/mL
hBNP > 100 pg/mL: Causes include heart failure, acute coronary syndrome, renal failure.
Patients with CHF will have a chronically elevated BNP. However, during a period of CHF exacerbation, the higher the BNP, the more severe the situation.
Card 18
Adult Lab Values > Red Blood Cells (RBCs)
Expected Range for Females and Males
Causes of Lower/Higher Levels
Answer
Red Blood Cells (RBCs)
Circulating cells that transport oxygen to the body’s cells.
Females: 4.2 – 5.4 million/uL
Males: 4.7 – 6.1 million/uL
Lower Levels: Causes include anemia, hemorrhage, kidney disease.
Higher Levels: Causes include polycythemia, severe dehydration.
Card 19
Adult Lab Values > White Blood Cells (WBCs)
Expected Range
Causes of Lower/Higher Levels
Answer
White Blood Cells (WBCs)
Cells that fight infection and disease as part of the body’s immune system.
Expected Range: 5,000 – 10,000/mm3
Leukopenia (WBC < 4,000/mm³): Causes include autoimmune disease, bone marrow suppression, drug toxicity.
Leukocytosis (WBC > 10,000/mm³): Causes include infection and inflammation.
Card 20
Adult Lab Values > White Blood Cells (WBCs)
Types of White Blood Cells
Percentages in Circulation
Causes of Increased Levels
Answer
White Blood Cells (WBCs)
Type of WBC
Percentage in Circulation
Causes of Increased Levels
Neutrophils
40 – 60%
Acute bacterial infections.
Neutrophils are first to neutro‘lize the threat!
Lymphocytes
20 – 40%
Chronic bacterial or viral infections.
Monocytes
2 – 8%
Protozoal and viral infections, tuberculosis, chronic inflammation.
Eosinophils
1 – 4%
Allergic reactions or parasitic infections.
Basophils
0.5 – 1%
Allergic reactions or leukemia.
With Basophils, you might need Benadryl!
Most to least prevalent WBCs: Never Let Monkeys Eat Bananas.
Card 21
Adult Lab Values > Platelets
Expected Range
Causes of Lower/Higher Levels
Answer
Platelets
Blood cell fragments used to form clots in the body to stop bleeding.
Expected Range: 150,000 – 400,000 mm3
I’m throwing a big party, and I need 150 – 400 plates to feed everyone!
Thrombocytopenia (Platelets < 150,000 mm³): Causes include hemorrhage, leukemia, splenomegaly.
Thrombocytosis (Platelets > 400,000 mm³): Causes include polycythemia, inflammatory diseases (e.g., RA, IBD), infection, cancer, splenectomy.
Low platelets = High risk of bleeding!
Card 22
Adult Lab Values > Hemoglobin (Hgb)
Expected Range in Females and Males
Causes of Lower/Higher Levels
Answer
Hemoglobin (Hgb)
Iron-rich protein in RBCs that carry oxygen.
Females: 12 – 16 g/dL
Males: 14 – 18 g/dL
Lower Levels: Causes include anemia, hemorrhage, kidney disease.
Higher Levels: Causes include COPD, severe dehydration, polycythemia.
Card 23
Adult Lab Values > Hematocrit (Hct)
Expected Range for Females and Males
Causes of Lower/Higher Levels
Answer
Hematocrit (Hct)
Percentage of the blood made up of RBCs.
Females: 37 – 47%
Males: 42 – 52%
Hematocrit is approximately 3 times Hemoglobin.
Lower Levels: Causes include anemia, hemorrhage, kidney disease.
Higher Levels: Causes include COPD, polycythemia, hypovolemic shock, severe dehydration.
Card 24
Adult Lab Values > Activated Partial Thromboplastin Time (a > PTT)
Expected Range
Therapeutic Range
Causes of Increased Time
Answer
Activated Partial Thromboplastin Time (aPTT)
Clotting time of the intrinsic and common pathways in the coagulation cascade.
Expected Range: 30 – 40 seconds
Therapeutic Range on Heparin Therapy:
1.5 – 2.5 times baseline (~ 50 – 100 seconds)
Increased Time: Causes include heparin therapy, DIC, liver disease.
Protamine sulfate is the antidote for heparin.
Card 25
Adult Lab Values > Prothrombin Time (PT)
Expected Range
Therapeutic Range
Causes of Increased Time
Answer
Prothrombin Time (PT)
Clotting time of the extrinsic and common pathways in the coagulation cascade.
Expected Range: 11 – 12.5 seconds
Therapeutic Range on Warfarin Therapy: 1.5 – 2.0 times baseline
Increased Time: Causes include warfarin therapy, DIC, liver disease, vitamin K deficiency, clotting factor deficiency.
Vitamin K is the antidote for warfarin.
Card 26
Adult Lab Values > International Normalized Ratio (INR)
Expected Range
Therapeutic Range
Causes of Elevated Levels
Answer
International Normalized Ratio (INR)
Ratio of the patient’s prothrombin time (PT) to a control PT. Used to determine effectiveness of warfarin therapy.
Expected Range: 0.8 – 1.1
Therapeutic Range on Warfarin Therapy: 2 – 3
Elevated Levels: Causes include warfarin therapy, bleeding disorders, liver disease, sudden decrease in vitamin K intake.
Vitamin K is the antidote for warfarin.
Card 27
Adult Lab Values > D-Dimer
Expected Range
Significance of Positive/Negative Result
Answer
D-Dimer
Protein fragment released into the bloodstream from the breakdown of a blood clot.
Expected Range: < 0.4 mcg/mL
I like to DIM the lights REALLY low, almost to zero.
Positive Result (D-Dimer > 0.4 mcg/mL): Indicates there may be a blood clot in the body (e.g., DVT, PE).
Negative Result (D-Dimer < 0.4 mcg/mL): Used to rule out a blood clot.
Card 28
Adult Lab Values > Aspartate Aminotransferase (AST)
Expected Range
Causes of Elevated Levels
Answer
Aspartate Aminotransferase (AST)
Enzyme found mostly in the liver, but also in the muscles.
Expected Range: 0 – 35 units/L
AST > 35 units/L: Causes include liver dysfunction (e.g., hepatitis, cirrhosis) or other tissue damage in the body (e.g., heart or skeletal muscle).
ALT is more specific to the liver than AST.
Card 29
Adult Lab Values > Alanine Aminotransferase (ALT)
Expected Range
Causes of Elevated Levels
Answer
Alanine Aminotransferase (ALT)
Enzyme produced by the liver. Important in metabolism.
Expected Range: 4 – 36 units/L
I used to be into ALTernative music until I got into my late 30’s.
ALT > 36 units/L: Caused by liver dysfunction (e.g., hepatitis, cirrhosis).
ALT is more specific to the liver than AST.
Card 30
Adult Lab Values > Amylase
Expected Range
Causes of Elevated Levels
Answer
Amylase
Enzyme produced in the pancreas and salivary glands. Helps to digest carbohydrates.
Expected range: 30 – 220 units/L
Amylase > 220 units/L: Causes include pancreatitis, pancreatic cancer, cholecystitis, salivary gland infection.
Lipase offers a higher sensitivity than amylase in diagnosing acute pancreatitis.
Card 31
Adult Lab Values > Lipase
Expected Range
Causes of Elevated Levels
Answer
Lipase
Protein released by the pancreas into the small intestine. Helps the body absorb fat.
Expected Range: 0 – 160 units/L
Lipase > 160 units/L: Caused by pancreatitis, pancreatic cancer.
Lipase offers a higher sensitivity than amylase in diagnosing acute pancreatitis.
Card 32
Adult Lab Values > Bilirubin
Expected Range
Causes of Elevated Levels
Answer
Bilirubin
Yellow substance found in bile; produced during breakdown of RBCs.
Expected Range: 0.3 – 1 mg/dL
Direct (Conjugated) Bilirubin: 0.1 – 0.3 mg/dL
Indirect (Unconjugated) Bilirubin: 0.2 – 0.8 mg/dL
Billy will only pay up to $1 for his reuben sandwich.
Bilirubin > 1 mg/dL: Causes include liver dysfunction, bile duct obstruction, hemolytic or pernicious anemia, transfusion reaction, Gilbert’s syndrome.
Card 33
Adult Lab Values > Albumin
Expected Range
Causes of Decreased Levels
Answer
Albumin
Protein made by the liver; important for transport of substances and synthesis of other proteins. Reflects a patient’s long-term nutritional status. Essential for keeping fluid in the bloodstream.
Expected Range: 3.5 – 5 g/dL
Al is always bummin‘ $3 – 5 dollars from me!
Albumin < 3.5 g/dL: Causes include liver disease, kidney disease, or malnutrition.
Low albumin levels can lead to edema, fatigue, weakness.
Card 34
Adult Lab Values > Prealbumin
Expected Range
Causes of Decreased Levels
Answer
Prealbumin
Protein made by the liver; important for transport of substances and synthesis of other proteins. Reflects a patient’s recent nutritional status.
Expected Range: 15 – 36 mg/dL
Prealbumin < 15 mg/dL: Caused by protein-calorie malnutrition.
Prealbumin levels are used to measure the effectiveness of total parenteral nutrition (TPN).
Card 35
Adult Lab Values > Total Protein
Expected Range
Causes of Decreased Levels
Answer
Total Protein
Total amount of albumin and globulin in the fluid portion of the blood.
Expected Range: 6.4 – 8.3 g/dL
Total Protein < 6.4 g/dL: Causes include liver disorders, malnutrition, kidney dysfunction, celiac disease, inflammatory bowel disease.
Card 36
Adult Lab Values > Ammonia
Expected Range
Causes of Increased Levels
Answer
Ammonia
Waste product made by the body during digestion of protein.
Expected Range: 10 – 80 mcg/dL
Ammonia > 80 mcg/dL: Causes include liver disease (can lead to encephalopathy), kidney failure, Reye’s syndrome.
Lactulose (a laxative) is often used to treat encephalopathy by reducing ammonia levels.
Card 37
Adult Lab Values > Erythrocyte Sedimentation Rate (ESR)
Expected Range
Significance of Increased Levels
Answer
Erythrocyte Sedimentation Rate (ESR)
Measurement of how quickly RBCs settle at the bottom of a test tube (usually very slowly).
Expected Range: < 20 mm/hr
ESR > 20 mm/hr: Indicates the presence of inflammation due to infections, tumors, or autoimmune disease (e.g., rheumatoid arthritis).
Card 38
Adult Lab Values > C-Reactive Protein (CRP)
Expected Range
Significance of Increased Levels
Answer
C-Reactive Protein (CRP)
Protein made by the liver, released into the bloodstream during inflammation.
Expected Range: < 0.3 mg/dL
CRP > 0.3 mg/dL: Indicates the presence of inflammation due to infection or flare-up of chronic inflammatory conditions (e.g., rheumatoid arthritis, lupus, inflammatory bowel disease).
Card 39
Adult Lab Values > Creatinine
Expected Range
Significance of Increased Levels
Answer
Creatinine
Waste product created from the normal breakdown of muscles in the body.
Expected Range: 0.6 – 1.2 mg/dL
CreatiNINE will help you remember that 0.9 is in the middle of the expected range.
Creatinine > 1.2 mg/dL: Indicates the presence of kidney dysfunction.
Creatine is more specific to kidney function than BUN.
Card 40
Adult Lab Values > Blood Urea Nitrogen (BUN)
Expected Range
Significance of Increased Levels
Answer
Blood Urea Nitrogen (BUN)
Nitrogen in the blood from the waste product urea (produced when protein is broken down in the body).
Expected Range: 10 – 20 mg/dL
There are 10 – 20 hamburger BUNs in this package.
BUN > 20 mg/dL: Causes include kidney disease, dehydration, conditions that decrease blood flow to the kidneys (e.g., CHF, AKI, shock).
Creatine is more specific to kidney function than BUN.
Card 41
Adult Lab Values > Glomerular Filtration Rate (GFR)
Expected Range
GFR Ranges for CKD Stages
Answer
Glomerular Filtration Rate (GFR)
Measurement of how much blood passes through the glomeruli each minute. Used to assess kidney function.
Expected Range: > 90 mL/min
CKD Stage
GFR
Interpretation
Stage 1
≥ 90 mL/min
Normal kidney function with persistent proteinuria.
Stage 2
60 – 89 mL/min
Mild kidney damage with persistent proteinuria.
Stage 3
30 – 59 mL/min
Moderate kidney damage.
Stage 4
15 – 29 mL/min
Severe kidney damage.
Stage 5
< 15 mL/min
Kidney failure.
Card 42
Adult Lab Values > Urine Specific Gravity
Expected Range
Significance of Decreased/Increased Levels
Answer
Urine Specific Gravity
Comparison of the density of urine to the density of water.
Expected Range: 1.005 – 1.030
Urine Specific Gravity < 1.005: Dilute urine! Causes include kidney dysfunction, diabetes insipidus, excess fluid intake.
Urine Specific Gravity > 1.030: Concentrated urine! Causes include dehydration (e.g., diarrhea, emesis), SIADH, UTI.
Card 43
Adult Lab Values > Urine Osmolality
Expected Range
Significance of Decreased/Increased Levels
Answer
Urine Osmolality
Measures the amount of dissolved substances in the urine.
Expected Range: 300 – 1,300 mOsm/kg
Urine Osmolality < 300 mOsm/kg: Dilute urine! Causes include diabetes insipidus, excess fluid intake.
Urine Osmolality > 1,300 mOsm/kg: Concentrated urine! Causes include dehydration (e.g., diarrhea, emesis), SIADH, kidney dysfunction.
Card 44
Adult Lab Values > Serum Osmolality
Expected Range
Significance of Decreased/Increased Levels
Answer
Serum Osmolality
Measures the amount of dissolved substances in the liquid part (plasma) of the blood.
Expected Range: 275 – 295 mOsm/L
Serum Osmolality < 275 mOsm/L: Dilute blood! Causes include SIADH, overhydration, hyponatremia.
Serum Osmolality > 295 mOsm/L: Concentrated blood! Causes include diabetes insipidus, dehydration, DKA, hypernatremia.
Card 45
Adult Lab Values > Triiodothyronine (T3)
Expected Range
Causes of Decreased/Increased Levels
Answer
Triiodothyronine (T3)
Hormone produced by the thyroid gland; regulates metabolism and growth.
Expected Range: 70 – 205 ng/dL
T3 = “Times 3”. Range is ~ 70 – 210 (i.e., 70 times 3).
T3 < 70 ng/dL: Indicates hypothyroidism.
T3 > 205 ng/dL: Indicates hyperthyroidism.
Thyroid dysfunction can be primary (issue with thyroid gland), secondary (issue with pituitary gland), or tertiary (issue with hypothalamus).
Card 46
Adult Lab Values > Thyroxine (T4)
Expected Range
Causes of Decreased/Increased Levels
Answer
Thyroxine (T4)
Hormone produced by the thyroid gland; regulates metabolism and growth.
Expected Range: 4 – 12 mcg/dL
T4 has a range of 4 – 12.
T4 < 4 mcg/dL: Indicates hypothyroidism.
T4 > 12 mcg/dL: Indicates hyperthyroidism.
Thyroid dysfunction can be primary (issue with thyroid gland), secondary (issue with pituitary gland), or tertiary (issue with hypothalamus).
Card 47
Adult Lab Values > Thyroid Stimulating Hormone (TSH)
Expected Range
Causes of Decreased/Increased Levels
Answer
Thyroid Stimulating Hormone (TSH)
Hormone produced by the pituitary gland that regulates the amount of hormones released by the thyroid gland.
Expected Range: 0.5 – 5.0 mU/L
If you touch my ‘TUSH’ (TSH) again, I will smack you with all 5 fingers.
TSH < 0.5 mU/L:
Primary hyperthyroidism: ↓ TSH, ↑ T3/T4.
Secondary hypothyroidism: ↓ TSH, ↓ T3/T4.
TSH > 5 mU/L:
Primary hypothyroidism: ↑ TSH, ↓ T3/T4.
Secondary hyperthyroidism: ↑ TSH, ↑ T3/T4.
Blood Glucose
Diabetes Diagnostic Criteria: Two abnormal test results from the same sample or from two different samples.
Fasting Blood Glucose: > 126 mg/dL
Casual Blood Glucose: > 200 mg/dL
2 Hour Oral Glucose Tolerance Test: > 200 mg/dL
HgbA1C: > 6.5%
HgbA1C is the BEST indicator of blood glucose levels over the past 2 – 3 months. Goal for diabetic patients is to have an HgbA1C < 7%.
Blood Glucose
Diabetic Ketoacidosis (DKA):
Blood glucose > 300 mg/dL
Hyperglycemic-Hyperosmolar State (HHS):
Blood glucose > 600 mg/dL
With DKA, there will be ketones in the blood and urine, and the presence of metabolic acidosis. With HHS, there are no ketones in the blood or urine, and no metabolic acidosis.
CD4+ T-Lymphocytes
Type of lymphocyte that triggers the body’s immune response to infection.
Stages of HIV Infection:
Stage 1: > 500 cells/mm3
Stage 2: 200 – 499 cells/mm3
Stage 3: < 200 cells/mm3
Decreased CD4+ count results in decreased immune function and increased susceptibility to infections.
Card 52
Adult Lab Values > Prostate-Specific Antigen (PSA)
Expected Range
Significance of Increased Levels
Answer
Prostate-Specific Antigen (PSA)
Protein produced by the prostate gland cells.
Expected Range: < 4 ng/mL
PSA > 4 ng/mL: May indicate the presence of prostate cancer or benign prostatic hypertrophy (BPH). Further evaluation is required.
Public Service Announcement (PSA) FOR all the guys out there: A PSA over FOUR may indicate prostate cancer or BPH.
Always take a patient’s PSA before performing a digital rectal exam!
Card 53
Adult Lab Values > Digoxin
Therapeutic Serum Levels
Significance of Increased Levels
Signs/Symptoms of Toxicity
Answer
Digoxin
Cardiac glycoside used to treat heart failure and dysrhythmias.
Therapeutic Serum Levels: 0.5 – 2 ng/mL
Digoxin > 2 ng/mL: Indicates digoxin toxicity.
S/S of Toxicity: GI upset (nausea/vomiting), vision issues (diplopia, halos, blurry vision), fatigue.
If your digoxin level is over 2, you might start seeing 2 of everything (i.e. diplopia!) and be TOO sick and tired to get out of bed.
Treat digoxin toxicity with digoxin immune fab. Hypokalemia increases the risk of digoxin toxicity.
Card 54
Adult Lab Values > Lithium
Therapeutic Serum Levels
Significance of Increased Levels
Signs/Symptoms of Toxicity
Answer
Lithium
Mood stabilizer used to treat bipolar disorder.
Therapeutic Serum Levels: 0.6 – 1.2 mEq/L
Lithium > 1.5 mEq/L: Indicates lithium toxicity.
S/S of Toxicity: Coarse tremors, confusion, hypotension, seizures, tinnitus, coma/death.
Lithium and sodium have an inverse relationship. Hyponatremia increases the risk for lithium toxicity.
Card 55
Adult Lab Values > Phenytoin
Therapeutic Serum Levels
Significance of Increased Levels
Signs/Symptoms of Toxicity
Answer
Phenytoin
Anti-epileptic (anticonvulsant) medication used to treat and prevent seizures.
Therapeutic Serum Levels: 10 – 20 mcg/mL
Phenytoin > 20 mcg/mL: Indicates phenytoin toxicity.
S/S of Toxicity: Nystagmus, ataxia, slurred speech, lethargy, confusion.
Card 56
Adult Lab Values > Theophylline
Therapeutic Serum Levels
Significance of Increased Levels
Signs/Symptoms of Toxicity
Answer
Theophylline
Xanthine-derivative medication used to treat asthma, COPD, and infant apnea.
Therapeutic Serum Levels: 10 – 20 mcg/mL
Theophylline > 20 mcg/mL: Indicates theophylline toxicity.
S/S of Toxicity: Nausea, vomiting, headache, gastroesophageal reflux, irritability, dizziness, seizures, restlessness.
Blood Glucose
Hypoglycemia:
Age
Blood Glucose Level
First 4 hours of life
< 40 mg/dL
4 – 24 hours of life
< 45 mg/dL
Children
< 70 mg/dL
Diabetic Ketoacidosis (DKA):
Children: > 250 mg/dL
Card 59
Pediatric Lab Values > Bilirubin
Normal Levels
Levels that Require Intervention
Pediatric Lab Values > Lead
Normal Levels
Significance of Increased Levels
Signs/Symptoms of Lead Poisoning
Levels Requiring Chelation Therapy
Answer
Lead
Toxic metal. Elevated blood lead levels can lead to multiorgan damage, including neurocognitive disease.
Normal Levels: < 3.5 mcg/dL
Increased Levels: Indicates lead poisoning.
S/S of Lead Poisoning: Cognitive impairment (↓ IQ scores), impaired hearing, growth delays, anemia, vomiting, fatigue.
Levels Requiring Chelation Therapy: ≥ 45 mcg/dL
Card 61
Pediatric Lab Values > Sweat Chloride
Normal Levels
Levels Diagnostic for Cystic Fibrosis
Answer
Sweat Chloride
The sweat chloride test is a diagnostic tool for cystic fibrosis (CF). This test measures the amount of chloride present in a child’s sweat.
Sweat Chloride Result
Interpretation
< 30 mEq/L
Normal Result.
30 – 59 mEq/L
CF possible, additional testing needed.
> 60 mEq/L
Diagnostic of CF.
Card 62
ABG Interpretation > Acid-Base Balance
Chemical Buffers
Answer
Acid-Base Balance: Chemical Buffers
First line of defense. Includes chemical buffers (e.g., bicarbonate, phosphate) and protein buffers (e.g., albumin, globulins, hemoglobin) present in the body fluids.
If the blood pH is too low (i.e., acidosis), chemical buffers quickly bind hydrogen ions to reduce hydrogen ion concentration and increase the pH.
If the blood pH is too high (i.e., alkalosis), chemical buffers quickly release hydrogen ions to increase the hydrogen ion concentration and reduce the pH.
Card 63
ABG Interpretation > Acid-Base Balance
Respiratory System
Answer
Acid-Base Balance: Respiratory System
Second line of defense. Controls the amount of carbon dioxide (CO2) in the arterial blood.
In response to high CO2 levels associated with acidosis, the respiratory system increases the rate and depth of breathing (i.e. hyperventilation) to get rid of excess CO2 (and hydrogen ions).
In response to low CO2 levels associated with alkalosis, the respiratory system decreases the rate and depth of breathing (i.e. hypoventilation) to retain more excess CO2 (and hydrogen ions).
Card 64
ABG Interpretation > Acid-Base Balance
Renal System
Answer
Acid-Base Balance: Renal System
Third line of defense. Slowest response in the regulation acid-base balance, but has the longest duration.
If the blood pH is too low (acidosis), the kidneys increase reabsorption of bicarbonate (HCO3) and increase excretion of hydrogen ions in the urine.
If the blood pH is too high (alkalosis), the kidneys increase excretion of bicarbonate (HCO3) in the urine, and increase reabsorption of hydrogen ions.
Card 65
ABG Interpretation > Arterial Blood Gas (ABG)
Obtaining a Sample
Answer
Arterial Blood Gas (ABG)
Use of an arterial blood sample to assess acid-base balance, ventilation, and oxygenation of critically ill patients.
Obtaining a Sample: Collect a 1 mL blood sample from a functioning arterial line or by directly puncturing an artery (typically the radial artery).
An Allen test is performed prior to obtaining an ABG by puncture.
A is for ABGs, Artey, and Allen test.
After the blood sample is obtained, pressure should be maintained on the insertion site for at least 5 minutes to prevent bleeding.
Card 66
ABG Interpretation > ABG Components: p > H
Expected Range
Significance of Lower/Higher Levels
Answer
pH
Measure of hydrogen ion (H+) concentration in the arterial blood.
Expected Range: 7.35 – 7.45
pH < 7.35: Indicates presence of acidosis.
Respiratory Acidosis: pH < 7.35 and PaCO2 > 45
Metabolic Acidosis: pH < 7.35 and HCO3 < 21
pH > 7.45: Indicates presence of alkalosis.
Respiratory Alkalosis: pH > 7.45 and PaCO2 < 35
Metabolic Alkalosis: pH > 7.45 and HCO3 > 28
Card 67
ABG Interpretation > ABG Components: Pa > O2
Expected Range
Significance and Causes of Lower/Higher Levels
Answer
Partial Pressure of Oxygen (PaO2)
Measure of oxygen pressure in the arterial blood.
Expected Range: 80 – 100 mmHg
PaO2 < 80 mmHg: Indicates poor oxygenation in the arterial blood. Causes include COPD, pneumonia, asthma, pneumothorax, acute respiratory distress and failure.
PaO2 > 100 mmHg: Indicates hyperoxemia related to prolonged exposure to high levels of oxygen (e.g., mechanical ventilation)
Card 68
ABG Interpretation > ABG Components: Pa > CO2
Expected Range
Significance of Lower/Higher Levels
Answer
Partial Pressure of Carbon Dioxide (PaCO2)
Measure of carbon dioxide pressure in the arterial blood.
Expected Range: 35 – 45 mmHg
PaCO2 < 35: Indicates the presence of respiratory alkalosis (due to hyperventilation) OR compensation for metabolic acidosis.
PaCO2 > 45: Indicates the presence of respiratory acidosis (due to hypoventilation) OR compensation for metabolic alkalosis.
Card 69
ABG Interpretation > ABG Components: HCO3
Expected Range
Significance of Lower/Higher Levels
Answer
Bicarbonate (HCO3)
Important chemical buffer regulated by kidneys.
Expected Range: 21 – 28 mEq/L
HCO3 < 21 mEq/L: Indicates metabolic acidosis OR compensation for respiratory alkalosis.
HCO3 > 28 mEq/L: Indicates metabolic alkalosis OR compensation for respiratory acidosis.
Card 70
ABG Interpretation > ABG Components: Sa > O2
Expected Range
Significance of Lower Levels
Answer
Oxygen Saturation of Hemoglobin (SaO2)
Amount of oxygen bound to hemoglobin in the arterial blood.
Expected Range: 95 – 100%
SaO2 < 95%: Indicates hypoxemia due to anemia, pneumonia, COPD, asthma, ARDS, pneumothorax, PE, pulmonary edema.
Patients with COPD are expected to have SaO2 levels in the low 90s.
Card 71
ABG Interpretation > Interpretation Steps
Three Steps
Answer
ABG Interpretation Steps
Analyze the pH. Is acidosis or alkalosis present?
If acidosis or alkalosis is present, which system is to blame… The respiratory system (PaCO2) or the metabolic system (HCO3)?
If the pH shows acidosis:
If PaCO2 > 45, then we have respiratory acidosis.
If HCO3 < 21, then we have metabolic acidosis.
If the pH shows alkalosis:
If PaCO2 < 35, then we respiratory alkalosis.
If HCO3 > 28, then we have metabolic alkalosis.
Is compensation occurring (i.e. is the other system trying to fix the situation)? If so, is the acid/base imbalance partially or fully compensated?
Respiratory Acidosis
pH
PaCO2
HCO3
Interpretation
Acid
< 7.35
Acid
> 45
Normal
21 – 28
Uncompensated respiratory acidosis
(Respiratory system is to blame for the acidosis, Metabolic system is NOT trying to fix the situation).
Acid
< 7.35
Acid
> 45
Base
> 28
Partially compensated respiratory acidosis
(Respiratory system is to blame for the acidosis, Metabolic system is TRYING to fix the situation).
Normal
(but closer to acidic)
Acid
> 45
Base
> 28
Fully compensated respiratory acidosis
(Respiratory system is to blame for the acidosis, Metabolic system has FIXED the situation).
ROME: Respiratory Opposite, Metabolic Equal
(Respiratory = pH and PaCO2 go in opposite directions)
Respiratory Alkalosis
pH
PaCO2
HCO3
Interpretation
Base
> 7.45
Base
> 7.45
Normal
21 – 28
Uncompensated respiratory alkalosis
(Respiratory system is to blame for the alkalosis, Metabolic system is NOT trying to fix the situation).
Base
> 7.45
Base
< 35
Acid
< 21
Partially compensated respiratory alkalosis
(Respiratory system is to blame for the alkalosis, Metabolic system is TRYING to fix the situation).
Normal
(but closer to basic)
Base
< 35
Acid
< 21
Fully compensated respiratory alkalosis
(Respiratory system is to blame for the alkalosis, Metabolic system has FIXED the situation).
ROME: Respiratory Opposite, Metabolic Equal
(Respiratory = pH and PaCO2 go in opposite directions)
Metabolic Acidosis
pH
PaCO2
HCO3
Interpretation
Acid
< 7.35
Normal
35 – 45
Acid
< 21
Uncompensated metabolic acidosis
(Metabolic system is to blame for the acidosis, Respiratory system is NOT trying to fix the situation).
Acid
< 7.35
Base
< 35
Acid
< 21
Partially compensated metabolic acidosis
(Metabolic system is to blame for the acidosis, Respiratory system is TRYING to fix the situation).
Normal
(but closer to acidic)
Base
< 35
Acid
< 21
Fully compensated metabolic acidosis
(Metabolic system is to blame for the acidosis, Respiratory system has FIXED the situation).
ROME: Respiratory Opposite, Metabolic Equal
(Metabolic = pH and HCO3 go in equal directions)
Metabolic Alkalosis
pH
PaCO2
HCO3
Interpretation
Base
> 7.45
Normal
35 – 45
Base
> 28
Uncompensated metabolic alkalosis
(Metabolic system is to blame for the alkalosis, Respiratory system is NOT trying to fix the situation).
Base
> 7.45
Acid
> 45
Base
> 28
Partially compensated metabolic alkalosis
(Metabolic system is to blame for the alkalosis, Respiratory system is TRYING to fix the situation).
Normal
(but closer to basic)
Acid
> 45
Base
Fully compensated metabolic alkalosis
(Metabolic system is to blame for the alaklosis, Respiratory system has FIXED the situation).
ROME: Respiratory Opposite, Metabolic Equal
(Metabolic = pH and HCO3 go in equal directions)
Metabolic Alkalosis
Causes: Antacid overdose, loss of body acids (e.g., prolonged vomiting, NG suctioning, excess diuretic therapy).
Symptoms: Tachycardia, dysrhythmias, muscle cramping and weakness, lethargy.
Treatment: Treat underlying cause, stop acid loss (e.g., antiemetics for vomiting), replace fluid and electrolytes.
Card 80
Other Important Ranges > Central Venous Pressure
Expected Range
Causes of Lower/Higher Levels
Answer
Central Venous Pressure
Measurement of pressure in the vena cava near the right atrium of the heart. Same as right arterial pressure.
Expected Range: 2 – 8 mmHg
CVP < 2 mmHg: Causes include hypovolemia and distributive shock.
CVP > 8 mmHg: Causes include heart failure, hypervolemia, pulmonary embolism, cardiac tamponade.
Card 81
Other Important Ranges > Pulmonary Artery Wedge Pressure (PAWP)
Expected Range
Causes of Lower/Higher Levels
Answer
Pulmonary Artery Wedge Pressure (PAWP)
Indirect estimate of left arterial pressure. Same as pulmonary capillary wedge pressure.
Expected Range: 6 – 12 mmHg
PAWP < 6 mmHg: Causes include hypovolemia and vasodilation.
PAWP > 12 mmHg: Causes include congestive heart failure (CHF), hypervolemia, pulmonary embolism, cardiac tamponade.
Card 82
Other Important Ranges > Cardiac Output
Expected Range
Causes of Lower/Higher Levels
Answer
Cardiac Output
Amount of blood the heart pumps in one minute. Cardiac output = heart rate x stroke volume.
Expected Range: 4 – 8 L/min
Cardiac Output < 4 L/min: Causes include hypovolemia, MI, vasodilation, heart failure, shock.
Cardiac Output > 8 L/min: Causes include sepsis, anemia, hyperthyroidism.
Card 83
Other Important Ranges > Left Ventricular Ejection Fraction (LVEF)
Expected Range
Causes of Lower Levels
Answer
Left Ventricular Ejection Fraction (LVEF)
Percentage of blood leaving the left ventricle each time it contracts.
Expected Range: 55 – 70%
If I get less than a 55% on my test, I might get “ejected” from my class.
LVEF < 55%: Causes include congestive heart failure (CHF), cardiomyopathy, coronary artery disease, MI, valvular heart disease.
Card 84
Other Important Ranges > Intracranial Pressure (ICP)
Expected Range
Causes of Increased Levels
Signs/Symptoms of Increased Levels
Answer
Intracranial Pressure (ICP)
Pressure inside the skull (including brain tissue and CSF).
Expected Range: 5 – 15 mmHg
Increased Levels: Caused by head injury, tumor, meningitis, hydrocephalus, intracranial hemorrhage, hypertension.
S/S of Increased ICP: Irritability (early sign!), restlessness, headache, decreased LOC, pupil abnormalities, abnormal breathing and/or posturing.
Card 85
Other Important Ranges > Intraocular Pressure (IOP)
Expected Range
Causes of Increased Levels
Answer
Intraocular Pressure (IOP)
Fluid pressure inside the eye.
Expected Range: 10 – 21 mmHg
I can eat between 10 – 21 pancakes at IHOP.
Elevated Levels: Glaucoma.
Open-Angle Glaucoma: Most common, results in a gradual increase in IOP.
Closed-Angle Glaucoma: Less common, results in a sudden increase in IOP.
Card 86
Other Important Ranges > Urine Output
Expected Range
Relationship Between Fluid Intake and Output
Significance of Decreased Levels
Answer
Urine Output
Expected Range: 0.5 – 1.5 mL/kg/hr or ~ 1,500 mL/day
Fluid Balance: Fluid Intake ≈ Urine Output
Decreased Levels: May indicate shock, trauma, renal failure, or infection.
Notify provider for urine output < 30 mL/hr!