5-6 Flashcards
Hypernatremia is defined as serum sodium > ___ and it is primarily cause by ___
145
Not enough water
Serum Na = ___
(Na + K)/total body water
Signs and symptoms of hypernatremia
Lethargy Confusion Seizures Dehydration (tach, dry mouth, skin tenting, oligouria) Weakness Weight loss
Hypernatremia classifications
- Hypervolemic
- Euvolemic
- Hypovolemic
- Na retention (water increases, Na increases more)
- Loss of water
- Loss of Na and greater loss of water
___ is the passage of large volumes (>3 L) of dilute urine. There are two types:
Diabetes insipidus
- Central (neurogenic) - not enough ADH
- Nephrogenic - cannot use ADH that is produced (but there is enough)
What are the symptoms of diabetes insipidus?
Polyuria
Polydipsia
Nocturia
What test can you use to differentiate between Central or Nephrogenic DI, and primary polydipsia?
Water deprivation test
- deprive of water
- follow serum osm to steady state
- give ADH
- measure serum osm after 1 hour
Interpretations of water deprivation tests
- Water deprivation - increased uOsm >800 = primary polydipsia
- Water deprivation - no response (uPsm <300) = nephrogenic or central DI
- ADH administered - corrects = central DI (⬆️uOsm >800)
- ADH administered - does not correct = nephrogenic DI (uOsm <300)
Acute vs chronic hypernatremia tx:
Acute (<24 hours): correct rapidly
Chronic: correct slowly due to risk of brain edema
What are the goals of management in hypernatremia?
- Recognize symptoms
- ID cause
- Correct volume disturbances
- Correct hypertonicity
Recommendations for acute hypernatremia:
- correct serum Na at an initial rate of ___.
- Max ___
- Measure serum Na every ___
- 2-3 mEq/L/hr for 2-3 hours
- 12 mEq/L/day
- 1-2 hours
Recommendations for chronic hypernatremia:
- correct serum Na at an initial rate of ___.
- Max ___
- If a volume deficit is present ___
- 0.5 mEq/L/hr
- 8-10 mEq/L/day
- Isotonic NaCl (normal saline)
Hypernatremia classifications TREATMENT
- Hypervolemic
- Euvolemic
- Hypovolemic
- Diuretics
- Water replacement
- Normal saline
Treatment of central DI & its MOA:
Desmopressin (DDAVP)
- increases cAMP in renal tubular cells which increases water permeability resulting in decreased urine volume and increased urine osmolality
Treatment of nephrogenic DI
- Diuretics (increase proximal tubular Na and H2O reabsorption)
- NSAIDs (urinary retention by inhibition of prostaglandin synthesis-mediated detrusor muscle contraction)
- High ADH in SIADH causes ___
2. Low ADH from DI causes ___
- Hyponatremia and low urine output
2. Hypernatremia and polyuria
Lithium commonly causes ___
Nephrogenic DI
-hypernatremia
Renal stones grow where? When do they become symptomatic?
On renal papillae or within collecting system where they do not cause symptoms
-become symptomatic when they pass into the ureter or occlude the ureteropelvic junction
The most common type of renal stone is ___
Calcium oxalate and then calcium phosphate
*most stones are mixed, but the majority is Calcium oxalate
What is the dx test of choice for kidney stones?
Non-contrast helical CT
- previously it was an IV pyelogram
- US is good for pregnant or those who need to avoid radiation
What is the most common metabolic abnormality?
Idiopathic hypercalciuria
Proximal (Type I) renal tubular acidosis can cause ___
Hypocitraturia
Things that factor into kidney stones:
Hypo:
Hyper:
Hypocitraturia
Hypercalciuria
Hyperoxaluria
Hyperuricosuria
Struvite stones come from ___
Urease producing organisms (klebsiella, proteus)
*magnesium ammonium phosphate crystals
