Shoeny Renal 2 Flashcards
What’s in an electrolyte panel? Whats the main regulator of electrolytes?
Na, K, Cl, CO2
Kidney is the main regulator of water and sodium.
What has a normal level of 136-145mEq/L, is the primary ciruclating cation, and is needed for neuromuscular function?
Na+
Serum balances of Na+ are the balance between _________ & ________
Dietary intake and renal excretion
What is sodium an indicator of?
Free body water, it is the major contributer to plasma osmolality.
If free water is increased, Na is diluted and levels decrease
If free water is decreased, Na is concentrated and levels are increased
What is Osmolality?
It is a measure of concentration of dissolved particles in the blood. Useful in the setting of hyponatremia, evaluating ADH related illness
As amount of free water increases amount of particles _____. Osomolality ________
Decrease, decrease
As amount of free water decreases, amount of particles _______, osmolalitly ______
increases, increases
Osmolality decreases with ________ and increases with _______
osmolality decreases with overhydration and increases with dehydration.
What does ADH do? What is it stimulated by?
ADH regulates body water and osmolality
Stimulated by increased osmolality, hypovolemia, thirst.
ADH acts on the collecting tubule to increase permeability = increase water reabsorption - more concentrated urine.
In hypernatremia, hyperglycemia, ketosis, dehydration, diabetes insipidus, osmolality is?
Increased
In overhydration and syndrome of inappropriate ADH osmolality is?
Decreased
What is syndrome of inappropriate ADH?
Abnormally high amount of ADH present.
Leads to increased water reabsorption leading to decreased serum sodium levels and loss of sodium in the urine.
Drugs are common cause
What is diabetes insipidus? What are the symptoms?
Inadequate amount of ADH present. Symptoms are increased thirst and passage of large volumes of dilute urine.
What electrolyte imbalance is present in diabetes insipidus?
Hypernatremia
What does urine osmolality measure? What does it evaluate about the kidney?
Measures dissolved particles in the urine - more accurate than specific gravity.
Evaluates ability of kidney to concentrate urine.
Normal is 50-1200 mOsm/kg H20
Urine osmolality would be _______ in SIADH
Increased
Urine osmolality would be ________ in diabetes insipidus and excess fluid intake.
Decreased.
What are the two types of hyponatremia?
Sodium depletion - free water loss
Dilutional- water intake greater than water output - renal failure.
What are symptoms of hyponatremia?
Asymptomatic until <120
Symptoms include lethargy, nausea, muscle cramps
Cerebral edema.
Hypernatremia is a sodium level above what? When would this be present?
Above 145. Present in impaired thirst mechanism (stroke), or water loss without sodium loss (burns), fever, and dehydration.
What is urine sodium helpful for?
Helpful for distinguishing between renal and nonrenal causes of hyponatremia.
Urine sodium would be _______ in dehydration, diuretic therapy, Adrenocortical insufficiency, SIADH, Chronic renal failure.
Increased.
Urine sodium would be _____ in CHF and diarrhea.
decreased.
How do you initially evaluate hyponatremia?
Look at volume status of the patient. Is the patient hypovolemic? Euvolemic? Or Hypervolemic?
OR
Look at osmolality. Does patient have normal, low or high osmolality levels?
Is someone is hypovolemic and hyponatremic what could be some causes?
Dehydration, diarrhea, vomiting if UNa is less than 10
Renal salt loss is UNa is greater than 20
If a patient is euvolemic and hyponatremic. What could be causes?
SIADH
Postop hyponatremia.
If a patient is hypervolemic but has hyponatremia, would could be a cause?
CHF
Advanced renal failure
Liver disease
If a patient is hyponatremic but has normal osmolality what could be a cause?
Isotonic hyponatremia
Hyperporteinemia
Hyperlipidemia
If a patient is hyponatremic and has low osmolality whats the cause?
Hypotonic hyponatremia