IV Fluids and Electrolytes >:( Flashcards
Normal plasma osmolality
280 - 295 mOsm/kg
Saline Equivalents
Crystalloids
NS, Lactated ringers
Water equivilants
D5W
Dehydration
Depletion of INTRACELLULAR fluid.
Best replaced with IV NS
Hypovolemia
Depletion of INTRAVASCULAR volume.
Replaced with blood products etc.
Hyponatremia
Sodium < 135 meq/L
Results form a water load
<120 is direct life threat
Hyponatramia etiologies
Inability to suppress ADH True volume depletion SIADH Low dietary intake Renal failure
Hypovolemic Hyponatremia
GI or renal losses
Just replace volume orally or IV
Hypervolemic Hyponatremia
CHF, cirrhosis, renal failure
Fluid, sodium restriction
Utilize loop diuretics
SIADH
Too much ADH
Hypervolemic hypotonic hyponatermia
Drug or dz induced
SIADH Hyponatremia Tx
3% hypertonic saline
Furosemide
Fluid restriction
Hypernatremia Etiologies
Unreplaced water loss
Water loss into cells (seizures)
Sodium overload
Hypernatremia Manifestations
Rapid decrease in brain volume can result in cerebral hemorrhage.
Demyelinating lesions
Can also be chronic, brain adapts.
Acute hypotonic hyponatremia =
Cerebral edema
Neuronal cell expansion
Hypernatremia lab values
> 145 meq/L
Hypernatremia Tx
D5W (hypotonic) and .45% NS
Diabetes Insupidous (DI)
Not enough ADH production (central), or ADH resistant (nephrogenic)
Tx for central DI
Desmporessin (ADH like activity)
Restrict fluid intake
Nephrogenic DI Tx
Thiazide diuretic Sodium restriction (2 mg/day)
Unreplaced water loss hypernatremia tx
Fluid replacement.
simply stunning.
Rapid correction of fluids can lead to?
Cerebral edema
What % of calcium is bound to albumin?
46%
Must obtain corrected Ca with albumin
Hypercalcemia
Serum levels >10.5
Cancer and hyperPTH primary causes
Thiazide diuretics
Hypercalcemia S/S
EKG changes, N/V anorexia, constipation, PolyUD, Neuropsych sx
Hypercalcemic crisis
Acute renal failure, coma, arrhythmias, death. Tx: Saline and loop diuretics Biphosphonates Osteoclast inhibtors (calcitonin) Dialysis
Hypocalcemia
< 8.5 mg/dL
HypoPTH, vitamin D deficiency, loop diuretics
Associated with refractory severe hypocalcemia
Hypocalcemia S/S
tetany, paresthesias around mouth.
QT prolongation, decreased contractility
Tx of Acute symptomatic Hypo-Ca
IV calcium salts
100 - 300 mg elemental over 5-10 minutes
Chronic hypocalcemia Tx
Oral calcium supplementation
1-3 grams elemental Ca/day
Normal serum phosphorus level
2.0 - 4.5
Hyperphosphotemia
Decreased excretion due to low GFR
Chemo and rhabdo
Tx: GI binders, IV calcium salts, dialysis
Hypophosphatemia
Proximal muscle weakness and osteomalacia
IV or oral phosphorous
Hypomagnesemia
Occurs is 12% of hospitalized pt’s
Cramps, tetany, seizure
Hypocalcemia
Widened QRS, Afib, V-arrhythmias
Drugs that cause hypomagnesemia
diuretics, aminoglycosides, alcohol, cisplatin, cyclosporine
When to treat hypomagnesemia
if Less than 1.0
IV MgSO4 if severe
Oral if mild-moderate
Hypermagnesemia
Occurs when >2 mEq/L
IV calcium to treat
Dialysis
Forced diuretics
Hypokalemia
Low potassium
<3.5 mEq/L
Hypokalemia etiologies
Beta 2 agonists Loop diuretics ACE inhibitors Thiazides, Insulin Metabolic acidosis, vomiting, diarrhea
S/S of Hypokalemia
U wave changes (peaked)
Arrhythmias
Hypokalemia Tx
IV or oral potassium
Hyperkalemia
Increased K
>5,5 mEq/L
Hyperkalemia Etiologies
Increased K intake (duh)
Decreased excretion
Aldosterone resistance
Hypokalemia S/S
Ascending muscle weakness
Wont affect resp. muscles.
Peaked T waves, shortened QRS
Hyperkalemia Tx
Abnorma EKG: IV calcium gluconate
Consider bicarb if acidotic
Loop diuretics?
