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