Diagnostic Reference Ranges & Lab Values Flashcards
Sodium (Na+)
135 - 145 mEq/L
- Major electrolyte (cation)
- Regulates extracellular fluid volume – maintains osmotic pressure and acid-base balance
- Assists in the transmission of nerve impulses
Potassium (K+)
3.5 – 5.0 mEq/L
- Major electrolyte (cation)
- Regulates
- Cellular water balance
- Electrical conduction in muscle cells
- Acid-base balance
- Kidneys preserve or excrete potassium based on cellular need
- Potassium levels are used to evaluate cardiac funciton, renal function, GI function, and need for IV replacement therapy
Calcium (Ca2+)
9.0 - 10.5 mg/dL (ATI)
8.6 - 10 mg/dL (Saunders)
- Major electrolyte (cation)
- Functions in:
- Bone formation
- Nerve impulse transmission
- Contraction of myocardial and skeletal muscle
- Aid blood clotting by converting prothrombin to thrombin
- Levels can be affected by
- Decreased protein levels
- Anticonvulsant medications
Magnesium (Mg2+)
1.3 – 2.1 mEq/L (ATI)
1.6 - 2.6 mg/dL (Saunders)
- Major electrolyte (cation)
- Used as an index to determine metabolic activity and renal function
- Functions
- Needed for blood clotting mechanism
- Regulates neuromuscular activity
- Acts as a cofactor that modifies the activity of many enzymes
- Has an effect on the metabolism of calcium
- Acts as a CNS depressant and can reduce respirations and deep tendon reflexes
Chloride (Cl-)
- *97-107 mEq/L** (ATI)
- *98 - 107 mEq/L** (Saunders)
- Major electrolyte (anion)
- Major component of interstitial and lymph fluid
Hyponatremia
Serum Sodium <135 mEq/L
-
S/S: tachycardia, hypotension, muscle cramps and weakness, lethargy, headache, personality changes, dry mucus membranes
- Decreased urine specific gravity
- Causes: GI losses, diuretics, excessive water intake, burns, kidney disease
- Treatment: based on the cause (treat the cause, not just the symptom)
Hypernatremia
Serum Sodium >145 mEq/L
-
S/S: irritability, extreme thirst, fever, dry and flushed skin, dry tongue and mucus membranes, muscle twitching, diminished or absent DTRs (late sign), altered cerebral function
- Increased urine specific gravity
- Causes: Increased water loss, increased ingestion of sodium; corticosteroids; Cushing’s syndrome; kidney disease; hyperaldosteronism
- Treatment: based on cause (treat the cause, not just the symptom)
Hypokalemia
Serum Potassim <3.5 mEq/L
** Potentially life-threatening b/c every body system is affected. **
S/S
- Cardiac arrhythmias
- Weakness and fatigue; hypoactive reflexes
- Decreased muscle tone, paresthesias (tingling)
- Shallow respirations
- Anxiety, lethargy, confusion, coma
- ST depression; shallow, flat, or inverted T wave; prominent U wave
Causes
- Diuretics, corticosteroids
- Increased secretion of aldosterone (Cushing’s)
- GI losses (vomiting, diarrhea, GI bleeding)
- Extreme sweating
- Naso-gastric suctioning
- Inadequat intake
- Alkalosis, hyperinsulinism
Treatment
- Potassium replacement
- NEVER give via IV push, IM, or SubQ
- No more than 1 mEq/10mL
- 5 - 10 mEq/hr, never to exceed 20mEq/hr
- Can cause phlebitis
Foods
- avocado, bananas, cantaloupe, carrots, fihs, mushrooms, oranges, potatoes, raisins, spinach, strawberries, tomatoes, beef, pork, veal
Hyperkalemia
Serum Potassim > 5.0 mEq/L
S/S
- Slow, weak, irregular heart rate
- Cardiac arrhythmias
- Hypotension
- Weakness of skeletal muscle which can progress to the point of respiratory failure
- Muscle twitches progressing to ascending flaccid paralysis
- Increased GI motility, hyperactive bowel sounds, diarrhea
- Tall, peaked T waves; flat P waves; widened QRS complexes; prolonged PR intervals
Causes
- Renal failure, diabetic ketoacidosis, tissue damage
Treatment
- Kayexelate (fluid, oral; binds with potassium and is excreted – can result in diarrhea)
- Instruct clients to avoid salt substitutes which often contain potassium
- Insulin drives potassium into cells and can be used as an intervention
Hypocalcemia
Serum Calcium
< 9.0 mg/dL(ATI)
< 8.6 mg/dL (Saunders)
S/S
- Decreased heart rate, hypotension, diminished peripheral pulses
- Irritable skeletal muscles - twitches, cramps, tetany, seizures
- Paresthesias in lips, nose, ears, and limbs
- Positive Trousseau’s and Chvostek’s signs
- Hyperactive DTR
- Anxiety, irritability
- Prolonged ST interval; prolonged QT interval
Causes
- Vitamin D deficiency
- Pancreatitis
- Crohn’s
- End-stage renal disease
- Hyperphosphatemia
Treatment
- Calcium supplementation with Vit D
- Reduction of phosphorous increases calcium
Hypercalcemia
Serum Calcium
> 10.5 mg/dL(ATI)
> 10 mg/dL (Saunders)
Manifestations
- Early - increased HR
- Late - bradycardia that can lead to cardiac arrest
- Increased BP; bounding peripheral pulses
- Skeletal muscle weakness can lead to respiratory difficulty
- Diminished or absent DTRs
- Disorientation, lethargy, coma
- Kidney stones, flank pain
- Decreased motility; hypoactive bowel sounds
- Shortened ST segment; widened T waves
Causes
- Hyperparathyroidism
- Large doses of Vitamin D
- Thiazide diuretics
- Malignancy - bone destruction from metastatic tumors
Treatment
- identify underlying cause
Hypomagnesemia
Serum Magnesium
< 1.2 mEq/L (ATI)
< 1.6 mEq/L (Saunders)
Manifestations
- Tachycardia, hypertension
- Shallow respirations
- Twitches; paresthesias
- Positive Chvostek’s and Trousseau’s signs
- Hyperreflexia, muscle tremors
- Confusion, irritability
- Tall T waves; depressed ST segments
Causes
- Malnutrition and alcoholism
- Diarrhea, NG suctioning; Celiac, Crohn’s
- Hyperglycemia
- Sepsis
Treatment
- Magnesium administration
- Hypomagnesemia is often coupled with hypocalcemia – treat both
- Foods: avocado, canned white tuna, cauliflower, green leafy vegetables, milk, oatmeal and wheat bran, peanut butter, almonds, peas, potatoes, raisins, yogurt, pork, beef, chicken, soy beans
Hypermagnesemia
Serum Magnesium
> 2.0 mEq/L(ATI)
> 2.6 mEq/L (Saunders)
Manifestations
- Bradycardia, dysrhythmias, hypotension,
- Flushing and skin warmth
- Decreased respirations; respiratory insufficiency
- Diminished or absent DTRs; skeletal muscle weakness
- Drowsiness and lethargy that can progress to coma
- Prolonged PR interval; widened QRS
Causes
- Renal failure
- Increased magnesium intake/administration
Treatment
- Symptomatic
- Antidote: calcium gluconate
Phosphorous
3.0 - 4.5 mg/dL (ATI)
2.7 - 4.5 mg/dL (Saunders)
- Important component of
- Bone formation
- Energy storage and release
- Urinary acid-base buffering
- Carbohydrate metabolism
- Excreted by kidneys
- High concentrations are stored in bone and skeletal muscle
- Foods: pumpkin and squash, fish, nuts, whole-grain breads and cereals, dairy products, pork, beef, chicken
Blood Urea Nitrogen: BUN
10 - 20 mg/dL (ATI)
8 - 25 mg/dL (Saunders)
- Elevated levels indicate a slowing of the glomerular rate
- An increased level may indicate: hepatic or renal disease, dehydration, decreased kidney perfusion, high protein diet, infection, stress, steroid use, GI bleeding.
- A decreased level may indicate: malnutrition, fluid volume excess, severe hepatic damage.
Creatinine (Serum)
- *General**
0. 6 - 1.3 mg/dL - *Females:** 0.5 - 1.1 mg/dL
- *Males**: 0.6 - 1.2 mg/dL
- Indicator of renal function
- An increased level may indicate: kidney impairment – slowing of the glomerular filtration rate
- A decreased level may indicate: decreased muscle mass
Glucose
70 - 105 mg/dL (ATI?)
Fasting
70-110mg/dL (Saunders)
Capillary (finger stick)
60-110mg/dL (Saunders)
2-hr Postprandial
<140mg/dL (Saunders)
- Glucose is the main source of cellular energy for the body and is essential for brain and erythrocyte function
Glycosylated Hemoglobin: HgbA1c
Good Control
7% or lower
Fair Control
7-8%
Poor Control
> 8%
- Blood glucose bound to hemoglobin
- Hemoglobin A1C (HgbA1c) is a reflection of well blood glucose levels have been controlled for the past 3 to 4 months
WBC
5,000 - 10,000 cells/mm3 (ATI)
4,500 - 11,000 cells/mm3 (Saunders)
- Function in the immune defense system
-
“Shift to the left” – an increased number of immature neutrophils is present in the blood
- Low total WBC count with a left shift indicates a recovery from bone marrow depression or an infection so severe that it demanded more than the bone marrow could release
- Increased neutrophil count with left shift usually indicates bacterial infection
-
c – cells have more than the usual number
- Found in liver disease, Down syndrome, and megaloblastic and pernicious anemia
RBC
Women
4.2 - 5.4 million/mm3 (ATI)
4 - 5.5 million/µL (Saunders)
- *Men**
4. 7 - 6.1 million/mm3 (ATI)
4. 5 - 6.2 million/µL (Saunders) - Formed in bone marrow and have a lifespan of 120days
- Removed from the blood via liver, spleen, and bone marrow
Hemoglobin
Women
12-16 g/100mL (ATI)
12-15 g/dL (Saunders)
Men
14-18 g/100mL (ATI)
14-16.5 g/dL (Saunders)
- Hemoglobin is the main component of erythrocytes and serves as the vehicle for transporting O2 and CO2
- Important component in determining anemia
Hematocrit
Women
37-47%
Men
42-52%
- Represents RBC mass
- Important measurement in the identification of anemia or polycythemia
Platelet
150,000 - 400,000 /mm3
- Produced in bone marrow; function in hemostasis
- Institute bleeding precautions for values below normal
- Monitor platelet count closely in chemo pts due to risk of thrombocytopenia
pH
7.35 - 7.45
pCO2
35 - 45 mmHg
pO2
80 - 10 mmHg
HCO3 (Bicarbonate) - Venous
21 - 26 mmol/L (ATI?)
22-29 mEq/L (Saunders)
PT
Prothrombin Time
Normal
11 - 12.5sec (ATI?)
9.5 - 11.3 females (Saunders)
9.6 - 11.8 males (Saunders)
Therapeutic
+/- 2 sec of control value
- Test used when initiating and maintaining anticoagulant therapy with warfarin (coumadin).
- Measures the amount of time it takes in seconds for clot formation
- Measures the activity of prothrombin, fibrinogen, and factors V, VII, and X
- Subtherapeutic values may indicate the warfarin dose is too low (non-therapeutic) or Vit K excess.
- Prolonged values indicate that the patient is at risk for bleeding
- Warfarin may be reduced or held
- Pt may be instructed to eat foods high in vit K.
- Orally administered anticoagulant therapy usually maintains a PT at 1.5-2x lab control value
- If PT value is longer than 30sec, initiate bleeding precautions
INR
International Normalized Ratio
Normal
1 or 0.7 - 1.8 (ATI?)
Therapeutic
2 - 3 (standard therapy)
3 - 4.5 (high-dose therapy)
- Test used when initiating and maintaining anticoagulant therapy with warfarin (coumadin) – generally more accurate than PT.
- Measures the activity of prothrombin, fibrinogen, and factors V, VII, and X
- Individualized for each pt.
aPTT
Activated Partial Thromboplastin Time
Normal
30 - 40 sec(ATI)
20 - 36 sec (Saunders)
- *Therapeutic**
- *1.5-2x normal/control value**
- Assesses the intrinsic clotting cascade and action of factors II, V, VIII, IX, XI, and XII.
- PTT is prolonged whenever any of these factors is deficient (ex: hemophilia, DIC).
- Monitors heparin therapy.
- Do not draw sample from an arm into which heparin is infusing!
- If the aPTT value is prolonged (longer than 90sec), initiate bleeding precautions
Digoxin: Therapeutic Blood Level
0.5 - 2.0 ng/mL
Lithium: Therapeutic Blood Level
0.8 - 1.4 mEq/L (ATI?)
0.5 - 1.2 mEq/L (Saunders)
Dilantin: Therapeutic Blood Level
10 - 20 mcg/mL
Theophylline: Therapeutic Blood Level
10 - 20 mcg/mL
Urine Specific Gravity
- *Normal
1. 005 - 1.030** (ATI?) - *1.016 - 1.022** (Saunders)
- An increased level may indicate
- Decreased kidney perfusion
- Congestive heart failure
- Inappropriate antidiuretic hormone secretion
- A decreased level may indicate
- Chronic kidney disease
- Diabetes insipidus
- Use of diuretics
- Lithium toxicity
- Decreased ability to concentrate urine (often seen in the older adult)
D-dimer Test
- Blood test that measures clot formation and lysis that results from the degredation of fibrin
- Helps to diagnose the presence of thrombus in conditions such as DVT, pulmonary embolism, or stroke
- Used to diagnose disseminated intravascular coagulation (DIC)
Erythrocyte Sedimentation Rate
0 to 30 mm/hr
- Rate at which erythrocytes settle out of anticoagulated blood in 1 hr
- Helps to detect illnesses associated with inflammation, acute and chronic infection, advanced neoplasm, and tissue necrosis or infarction
(depending on age of client)
Serum Iron
Female
50 - 170 mcg/dL
Male
65 - 175 mcg/dL
- Iron acts as a carrier of oxygen from the lungs to the tissues and indirectly aids in the return of carbon dioxide to the lungs
- Found predominantly in hemoglobin
- Level of iron will be increased if the client ingested iron before test
Albumin
3.4 - 5 g/dL
- Main plasma protein of blood
- Transports bilirubin, fatty acids, medications, hormones, and other substances that are insoluble in water
- Increased in conditions such as:
- Dehydration
- Diarrhea
- Metastatic carcinoma
- Decreased in conditions such as:
- Acute infections
- Ascites
- Alcoholism
- Presence of detectable albumin (protein) in the urine is indicative of abnormal renal function
ALT
Alanine Aminotransferase
10 - 40 units/L
- Used to identify hepatocellular injury and inflammation of the liver
- Used to monitor improvement or worsening of liver disease
AST
Aspartate Aminotransferase
10 - 30 units/L
- Used to evaluate a client with suspected hepatocellular disease, injury, or inflammation
- May also be used along with cardiac markers to evaluate coronary artery occlusive disease
Amylase
25 - 151 units/L
- Produced by the pancreas and salivary glands; aids in the digestion of complex carbohydrates and is excreted by the kidneys
- Acute pancreatitis – level may exceed 5x the normal value
- Level starts to rise ~6hrs after onset of pain
- Peaks at ~24hrs
- Returns to normal 2-3days after onset
- Chronic pancreatitis – level usually doesn’t exceed 3x normal value
Lipids
Total Cholesterol: 140 - 199 mg/dL
LDL: < 130 mg/dL
HDL: 30 - 70 mg/dL
Triglycerides: <200 mg/dL
- Blood lipids consist of:
- Cholesterol
- Triglycerides
- Phospholipids
- Increased colesterol levels, LDL levels, and triglyceride levels pace the client at risk for coronary artery disease
- HDL helps protect against coronary artery disease
- Oral contraceptives may increase lipid levels
Acetaminophen: Therapeutic Blood Level
10 - 20 mcg/L
Magnesium Sulfate: Therapeutic Blood Level
4 - 7 mg/dL
Salicylate: Therapeutic Blood Level
100 -250 mcg/mL
Valproic Acid (Depakene): Therapeutic Blood Level
50 - 100 mcg/mL
IOP
Intraocular pressure
An expected reference range for IOP is between 10 and 21 mm/Hg.