Morning report Karen Estrella-Ramadan. Hypernatremia.
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Transcript of Morning report Karen Estrella-Ramadan. Hypernatremia.
Definition serum sodium concentration >145 mEq/L. It is characterized by a deficit of total body
water (TBW) relative to total body sodium levels due to either loss of free water, or infrequently, the administration of hypertonic sodium solutions
Extracellular and plasma volumes tend to be maintained in hypernatremic dehydration until dehydration is severe (ie, when the patient loses >10% of body weight).
Na140meq
Na180meq
Cerebral edema
Na180meq
Na140meq
Symptoms:-Irritability-High-pitched cry-Intermittent lethargy-Seizures-Increased muscle tone-Fever-Rhabdomyolysis]
-Oligoanuria-Excessive diuresis
Sustained hypernatremia can occur only when thirst or access to water is impaired. groups at highest risk are infants and intubated
patients. Mortality rate: 10%
In children with acute hypernatremia, mortality rates are as high as 20%.
Neurologic complications occur in 15% of patients intellectual deficits, seizure disorders, and spastic
plegias
Mechanisms:1. Hypovolemic hypernatremia
Increase water loss > than Na loss
Excessive perspiration Diarrhea Renal dysplasia Obstructive uropathy Osmotic diuresis
Mechanisms: 2. Euvolemic hypernatremia
PURE WATER DEPLETION
Central diabetes insipidus *adipsic diabetes insipidus : When ADH secretion and thirst are both impaired, affected
patients are vulnerable to recurrent episodes of hypernatremia Idiopathic causes Head trauma Suprasellar or infrasellar tumors (eg, craniopharyngioma, pinealoma) Granulomatous disease (sarcoidosis, tuberculosis, Wegener granulomatosis) Histiocytosis Sickle cell disease Cerebral hemorrhage Infection (meningitis, encephalitis) Associated cleft lip and palate Nephrogenic diabetes insipidus Congenital (familial) conditions Renal disease (obstructive uropathy, renal dysplasia, medullary cystic disease, reflux
nephropathy, polycystic disease) Systemic disease with renal involvement (sickle cell disease, sarcoidosis, amyloidosis) Drugs (amphotericin, phenytoin, lithium, aminoglycosides, methoxyflurane)
Mechanisms: 3. Hypervolemic hypernatremia
Sodium excess
Improperly mixed formula NaHCO3 administration NaCl administration Primary hyperaldosteronism
Lab work-MUST HAVE!!! Serum: NA, osmolality, BUN, and creatinine Urine: [Na]
In hypovolemic hypernatremia: extrarenal losses: <20 mEq/L renal losses: [Na]urine >than 20 mEq/L.
In euvolemic hypernatremia, urine sodium data vary. In hypervolemic hypernatremia, the urine sodium level
is more than 20 mEq/L. Urine: Osmolarity
Uosm < Posm then the patient has either central or nephrogenic diabetes insipidus (DI)
Uosm is intermediate (between 300 to 600 mosmol/kg), the hypernatremia may be due to an osmotic diuresis or to DI
Uosm above 600 mosmol/kg, then both the secretion of and response to endogenous ADH are intact.
Imaging-should we do any? Head: should be considered in alert patients
with severe hypernatremia to rule out a hypothalamic lesion affecting the thirst center CT scans may help in diagnosing intracranial
tumors, granulomatous diseases (eg, sarcoid, tuberculosis, histiocytosis), and other intracranial pathologies
Other tests Aldosterone test Cortisol test Antidiuretic hormone (ADH) test Corticotropin (ACTH) test
Gral principles management
SODIUM correction: 0.5 mEq/h or as much as 10-12 mEq/L in 24 hours
Dehydration should be corrected over 48-72 hours.
If the serum sodium concentration is more than 200 mEq/L, peritoneal dialysis should be performed using a high-glucose, low-sodium dialysate.
Main 2 calculations
1. Maintenance fluids2. Water deficit (in L) = [(current Na level in
mEq/L ÷ 145 mEq/L) - 1] X 0.6* X weight (in kg)
*60% BW in children
40% BW in adults
Election of fluids If the patient is hypotensive: use NS, LR or 5%
albumin regardless of a high serum sodium concentration.
In hypernatremic dehydration, 0.45% NS or 0.2% NaCl should be used as a replacement fluid to prevent excessive delivery of free water and a too-rapid decrease in the serum sodium concentration.
In cases of hypernatremia caused by sodium overload, sodium-free intravenous fluid (eg, 5% dextrose in water) may be used, and a loop diuretic may be added.
In cases of associated hyperglycemia, 2.5% dextrose solution may be given. Insulin treatment is not recommended because the acute decrease in glucose, which lowers plasma osmolality, may precipitate cerebral edema.
Follow-up Serum sodium levels should be monitored
every 4-6 hours Once the child is urinating, add 40 mEq/L KCl
to fluids to aid water absorption into cells. Calcium may be added if the patient has an
associated low serum calcium level Record daily body weights. Restrict sodium and protein intake. Treat the underlying disease.
References http://emedicine.medscape.com/article/907653-
followup#a2651 http://
www.uptodate.com.elibrary.einstein.yu.edu/contents/etiology-and-evaluation-of-hypernatremia?source=see_link#H6017722
http://www.uptodate.com.elibrary.einstein.yu.edu/contents/treatment-of-hypernatremia?source=search_result&search=hypernatremia&selectedTitle=1%7E150
http://pediatrics.uchicago.edu/chiefs/resources/documents/HyperHypoNatremia.pdf