Lecture 48 - Hyponatremia Flashcards
4 processes which may be abnormal leading to hyponatremia
GFR
Distal Delivery
Thick Ascending Limb reabsrobtion of NaCl
Suppression of ADH
Conditions/states which may lead to a hypovolemic hyponatremia
Diuretics,
Diarrhea/Vomiting
Salt Losing Nephropathy
Conditions/states which may lead to a euvolemic hyponatremia
SIADH,
Reset Osmostat
Hypothyroid disease
Psychogenic H20 Ingestion
Drugs that increase ADH
Conditions/states which may lead to a hypervolemic hyponatremia
CHF, Cirrhosis, Nephrosis
Signs of Hyponatremia
what is the threshold for obtundation
bnormal sensorium , depressed DTRs, Cheyne Stokes respiration, hypothermia, pathological reflexes, pseudobulbar palsy, Seizures; can even lead to herniation and death
obtundation = < 125
…sz…
<115 … coma, respiratory arrest
Symptoms of Hyponatremia
Symptoms – Lethargy, apathy, disorientation, muscle cramps, anorexia and nausea, agitation
Treatment for Chronic hyponatremia
don’t necessarily treat bc the brain can readjust and compensate
Treatment for acute hypovolemic hyponatremia
Saline; restore the blood volume
Treatment for acute euvolemic hyponatremia
water restriction and/or Vasopressin Receptor (V2) Antagonists (block water resorption)
Treatment for acute hypervolemic hyponatremia
Water restriction, Diuretics; V2 receptor antagonists
Symptoms of Hypervolemia
Elevated JVP
no orthostatic symptoms
Edema – anasarca, CHF, rales, Crackes, Ascities, Hepatomegaly
Symptoms of Hypovolemia
Low/Normal JVP
Orthostatic symptoms
No edema of fluid overload
Poor skin turgor
what is the calculation for Posm
Posm = 2 Na + Gl/18 + BUN/2.8
Euvolemic Hypotonic Hyponatremia DDX
SIADH
Psychogenic H20 Ingestion
Hypothyroidism
Drugs
HyperVolemic Hypotonic Hyponatremia DDX
CHF
Cirrhosis
Nephrotic Syndrome
Non Renal DDx of Hypovolemic, Hypotonic Hyponatremia
how did you know if was non renal losses of Na?
Vomiting, Diarrhea, Fistula
Skin Losses
bc UNa < 20
Renal DDx of Hypovolemic, Hypotonic Hyponatremia
Diuretic Use
Salt Wasting Nephropathy
Adrenal Insufficiency (Addison’s)
Osmotic DIuretics
Hyponatremic Patients; what diagnostic clue specific for adrenal Insuffieciency? why?
Hyperkalemia in the setting of hyponatremia = Adrenal Insuffiency –
Decreased Mineralcorticoid stimulation = decreased K secretion;
