Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
14 Cards in this Set
- Front
- Back
|
Normal serum K+ levels
|
3.5-4.8 mmol/L
|
|
|
Start seeing signs of hypokalemia
|
3 mEq/L with a K+ imbalance of -450 mEq/70kg wt
|
|
|
Hyperkalemia starts
|
exponential increase when get past 0 balance
|
|
|
Causes of Hypokalemia
|
poor diet,
intracellular shift GI or sweat losses; laxative or enema use Urinary losses |
|
|
Urinary losses: cause of hypokalemia
|
mineralcorticoid excess
increased Na excretion, high Na intake, diuretic Rx, osmotic diuresis, salt wasting nephropathies magnesium deficiency metabolic alkalosis high dose Rx with penicillin class, amphotericin B |
|
|
Diuretics and hypokalemia
|
associated with diuretics early after start or an increase in dose
K+ sparing avoid hypokalemia, but risk hyperkalemia prevent Na+/K+ exchange |
|
|
Hypokalemia signs
|
muscle weakness/paralysis with K< 2.5
gut, smooth muscle skeletal muscle--rhabodmylolysis, myoglobinuria Cardiac effects: u waves, digitalis toxicity, arrhythmias Renal: impaired concentrating ability, metabolic alkalosis |
|
|
Management of Hypokalemia
|
3-3.5, usually asymptomatic, po supplement if on digitalis, otherwise diet okay
2.5-3: treat with po supplements until serum at 3 2-2.5: some clinical manifestations likely: rx promptly with po supplements, IV if po route questionable or already receiving IV fluids <2: severe hypokalemia probable: IV needed immediately |
|
|
Oral supplements
|
KCl preferred in most cases
KPhosphate if phosphate deficit non chloride salts: bicarb, citrate, acetate, lactate, gluconate salts useful if bicarb deficit |
|
|
Oral dosage forms
|
solutions effective
wax tablets: released a bit at a time in the gut, prevents ulcers microencapsulated caps sustained release microcrystalloids |
|
|
diet sources of K+
|
lean meat, chicken, fruits, vegetables, legumes, salt substitute
|
|
|
Cautions for K+
|
levels may rise higher than expected if can't excrete K or shift K into ICF normally
|
|
|
Drug cautions for K+
|
K sparing diuretics (spironolactone, amilioride, triamterene)
Heparin beta 2 blocker Decreased renal function ACE-I or ARB |
|
|
IV potassium therapy
|
higher concentration tolerated via central vein: use pump for safety
often piggy backed |
