Fluids and Electrolytes Flashcards
Three components of extracellular fluid
interstitial fluid, plasma, lymphatic fluid
Electrolytes of ECF
Na+, Cl-, HCO3-
Electrolytes of ICF
K+, Mg, Phosphates
What is the most important plasma osmolality factor?
Na+
Saline equivalents
normal saline or lactated ringers
Water equivalents
D5W
What is the max amt you can give through perpheral line?
900 mOsm/L . 3% normal saline (1028mOsm/L) must be given centrally
Pareneteral colloids given for intravascular problems
albumin, packed RBCs, FFP
Cause of hyponatremia
excess water load either oral or IV. <120meq/L is very severe
What happens to brain in chronic hyponatremia?
cerebral adaptation–> less cerebral edema
Hyponatremia classification based on ECF status
Hypovolemic: GI losses; renal losses (thiazides)
Normovolemic: SIADH; low Na+ intake
Hypervolemic: CHF; cirrhosis
treatment for non-critical hypovolemic hyponatremia
normal saline given as slow bolus
treatment for hypervolemic hyponatremia
fluid/sodium restriction and loop diuretics
Which of the following should be included in treatment of SIADH for severe hyponatremia: 3% hypertonic saline, furosemide, salt pills, fluid restriction, K+ administration?
everything is included except K+ administration
T/F hypernatremia increases brain volume and can rupture cerebral veins
false hypernatremia decreases brain volume
Treatment of hypernatremia
D5W
treatment for central DI
Desmopressin 10 mcg/day and restrict fluid intake
treatment for nephrogenic DI
Thiazide diuretic and sodium restriction
what do you need to know to get a corrected Ca+?
serum albumin ((4.5 - serum albumin) x 0.8) + Ca = Corrected Ca)
treatment for hypercalcmic crisis
saline and loop diuretics (2-3 mg/dL drop in 24-48 hours). If malignant etiology bisphosphonate. Osteoclast inhibitors
ECG changes associated with hypocalcemia
QT prolongation and decreased myocardial contractility
hallmark symptoms of hypocalcemia
tetany, paresthesias around mouth
treatment of acute hypocalcemia and chronic hypocalemia
acute- IV admin of calcium salts. chronic- oral calcium supplements
what should you avoid when treating hyperphosphatemia?
aluminum-containing antacids
cardiovascular changes associated with hypomagnesemia
widened QRS, a fib, ventricular arrhythmias
what can cause hypomagnesemia?
alcohol
When are you most likely to see hypermagnesemia?
OB patient who is being treated for preeclampsia
treatment of hypermagnesemia
IV Ca+. If renal failure hemodialysis. If normal renal function forced diuresis w/fluid and loops
cardiac symptoms of hypokalemia
U wave
EKG changes associated with hyperkalemia
sharp, peaked T wave
treatment for hyperkalemia
calcium gluconate IV, if acidotic give bicarb. if in renal failure give sodium polystyrene sulfonate (kayexelate), loop diuretics
