Electrolytes Flashcards
What is the normal range for Na levels?
135-145 mEg/L
Which is a primary extracellular cation needed to maintain cellular integrity by maintaining the osmolar gradient?
A. Na
B. K
C. Phos
D. Ca
A. Na
What value indicates hyponatremia?
< 135 mEq/L
What is the equation for Serum Osmolality?
Osm = (2 x Na) + (BUN/2.8) + (Glucose/18)
AW is a 46 yof admitted to the internal medicine service for “unknown intoxication.” Routine labs reveal:
What is AW’s calculated osmolality?
Osm= (2 x 145) + (10/2.8) + (90/18)= 299 mOsm/L
Elevated serum Osm indicates presence of other substance in blood
What value of mOsm indicates pseudo hyponatremia?
275-290 mOsm
Pseudohyponatremia can be seen with what two conditions?
hypertriglyceridemia or hyperproteinemia
What value of mOsm indicates hypertonic hyponatremia?
> 290 mOsm
KZ is a 63 yom with ESRD secondary to uncontrolled HTN and DM currently receiving HD. Today his labs reveal:
What is KZ’s calculated Osm? What does it indicate?
Osm= (2x128) + (50/2.8) + (600/18) = 307 mOsm/L
Hypertonic Hyponatremia
Serum sodium falls by ____ mEq/L for each _____ mg/dL incremental increase in BG > 100 mg/dL
Serum sodium falls by 1.6 mEq/L for each 100 mg/dL incremental increase in BG > 100 mg/dL
What is the equation for Corrected Na?
Na(serum) + 1.6[(BG-100)/100]
KZ is a 63 yom with ESRD secondary to uncontrolled HTN and DM currently receiving HD. Today his labs reveal:
What is his corrected serum sodium?
What is his treatment?
128 + 1.6[(600-100)/100]= 136 mEq/L
Normal (btwn 135-145), go give insulin
What value of mOsm indicates hypotonic hyponatremia?
<275 mOsm
Which volume status decrease TBW and highly decreases Na?
Hypovolemic Hypotonic Hyponatremia
Which volume status increases TBW and keeps Na neutral?
Isovolemic Hypotonic Hyponatremia
Which volume status increases TBW and increases Na?
Hypervolemic Hypotonic Hyponatremia
T/F: Hypovolemic hypotonic hyponatremia are only from renal causes
False: renal and non-renal
What is the common cause of isovolemic hypotonic hyponatremia?
SIADH- Syndrome of Inappropriate AntiDiuretic Hormone Release
What happens to extracellular fluid with an increase in TBW and around normal Na?
Slight excess of ECF
What type of medications most commonly cause drug-induced SIADH?
A. Diuretics
B. Diabetes Meds
C. Psychotropic Meds
D. Antibacterials
C. Psychotropic Meds
How should water intake and medication be regulated in the treatment of SIADH?
Restrict free water (limit water intake) and remove underlying cause (ex meds) if possible
What medication class may be used in the treatment of SIADH?
Vaptans
Which leads to expanded ECF volume and physical edema?
A. Hypovolemic hypotonic hyponatremia
B. Hypervolemic hypotonic hyponatremia
B. Hypervolemic hypotonic hyponatremia