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;
25 Cards in this Set
- Front
- Back
What is the primary IC cation? |
K |
|
What is the primary EC cation? |
Na |
|
What can cause hypokalema? |
1. rarely reduced intake since K is reabsorbed in the kidneys 2. increase in K shift into cells -alkalosis -insulin or carbohydrate load -Breceptor stimulation caused by stress induced epinephrine release or admin of Bagonist (albuterol, dopamine) 3. Increased GI loses, vomiting, diarrhea, fistula, chronic laxative use, etc 4. increased urinary losses, HCTZ, aldosterone (mineralcorticoid excess) 5. hypomagnesemia |
|
When do symptoms present w/ hypokalema? What symptoms? |
K < 3.0 muscle weakness in lower extremities and will progress upward ECG changes: flattened Twaves or elevated Uwaves) Cardiac arrhythmias digoxin toxicity if pt taking dig rhabdomyolysis because hypokalemia can cause reduced blood flow to skeletal muscles |
|
How can the K deficit be estimated? |
200-400 mEq of K for every 1 mEq of K loss 20 mEq = 0.1 reduction |
|
What is the best potassium form for metabolic alkalosis? |
KCl; these pts typically lose Cl through diuretics or GI loss. This is the most common form of hypokalemia |
|
What drugs can cause hyperkalemia? |
ACEI/ARB
Ksparing diuretics |
|
At what level can one expect to see EKG changes? |
K > 6.0 mEq/L Consider medical treatment even if pt isn't showing cardiac abnormalities |
|
What is a good drug for asymptomatic hyperkalemia? |
sodium polystyrene sulfonate (kayexelate) |
|
What should be used to lower K in pts w/ symptomatic hyperkalemia? |
10 ml Ca gluconate 1-% IV peripherally over 2-10 minutes -may repeat after 5 mins if no EKG improvement onset w/in minutes, but duration is short it does not reduce K conc but antagonizes the effect of K in cardiac conduction cells Give prior to other interventions such as insulin and glucose sodium bicarb, albuterol |
|
Patients taking what drug should Ca gluconate be avoided in? |
Digoxin; hypercalcemia canprecipitate digoxin tox There have been reports of sudden death |
|
What drugs can be given after Ca gluconate has corrected EKG changes? |
1. Insulin and glucose -10 units IV plus 25-50 gm of 50% glucose IVpush -if pt hyperglycemic no need for glucose IVPush 2. Sodium bicarbonate -50 mEq infused over 5 minutes -most effective if pt has underlying metabolic acidosis 3. B adrenergic agonists (ex: albuterol) -10-20 mg neb over 10 mins -not recommended as a single agent since up to 40% of pts dont respond |
|
What agents can be used to remove excess K from the body? |
1. loop or thiazide diuretics -ineffective if pt has advanced renal disease 2. Kayexalate (sodium polystyrene sulfonate) -onset is slow, ~2 hours -not for emergencies -considered a cation exchange resin, it exchanges Na for K resulting in GI excretion of K 3. Hemodialysis -for when other measures aren't workin or hyperkalemia is severe |
|
What usually causes hypomagnesemia? |
impaired intestinal absorption (UC, diarrhea, pancreatitis, laxative abuse) Often presents concurrently w/ hypokalemia and hypocalcemia |
|
What are S/S of hypomagnesemia? |
twitching, tetany, seizures, arrhythmias, sudden cardiac death, HTN |
|
How should mag be administered IV? Why? |
Mag sulfate should be adminsted 1/gm per hour to increase absorption About half of administered mag is excreted in the urine Full mag replacement should occur over 3-5 days |
|
How does hypermagnesemia occur? S/S? What level of mag is dangerous? |
rarely; generally associated w/ CKD N/V, bradycardia, hypotension, heart block, asystole, respiratory failure, death symptoms rarely occur unless conc is > 4-5 mg/dL |
|
How can hypermagnesemia be treated? |
d/c all magnesium containing meds asymptomatic pts can be given NS and loop diuretics symptomatic pts should be given 100-200 mg elemental Ca IV for cardiac stability HD will probably be necessary |
|
What can cause hypophosphatemia? |
increased renal elimination refeeding syndrome respiratory alkalosis Diabetic Ketoacidosis treatment; as DKA is corrected phos moves IC |
|
S/S of hypophosphatemia? |
tissue hypoxia can occur due to decreased oxygen release in peripheral tissues confusion, delirium, seizures, coma pulmonary and cardiac symptoms |
|
When does hyperphosphatemia occur? |
usually in pts w/ CKD or hypoparathyroidism |
|
S/S of hyperphosphatemia? |
pts usually asymptomatic could show hypocalcemia, ECG changes, parasthesias, vascular calcifications |
|
How much elemental Ca is in 1 gm CaCl? 1 gm calcium gluconate? |
1 gm CaCl - 273 mg elemental Ca 1 gm Ca gluconate - 90 mg elemental Ca |
|
How much elemental Ca should be used for symptomatic hypocalcemia? |
200-300 mg elemental Ca over 5-10 mins |
|
When is hypercalcemia occur? Treatement? |
hypercalcemia of malignancy zoledronic acid, pamidronate, calcitonin |