potassium disorders and acid-base Flashcards
pt treated with furosemide has K = 2.4
Hypokalemia -
causes of hypokalemia
shift into cells
decreased intake
excess loss - renal or GI
majority of potassium excreted through
kidney
what can cause potassium to shift into cells
Insulin
and beta 2 agonists like salbutamol
2 causes of potassium loss in the urine
- High aldo
- High flow to ccd
2 stimuli for aldo release
- increase in ECF K+ concentration
- Angiotensin 2
clinical signs for hypokalemia
- weakness
- arrythmias- Vfib, Vtach
acute management of hypokalemia
Give oral KCL, or IV -
chronic management of hypokalemia
diet
K+ sparing diuretics
consider ACEi
pt presents with progressive kidney disease on an ACEi, stops taking insulin, ends up
Hyperkalemic
3 causes of hyperkalemia
shift out of cells -
increased intake
failure of kidney excretion
what can cause K+ to shift out of cells
insulin deficiency
muscle necrosis
Hemolysis
Impaired K+ excretion can be due to
Low flow to ccd
- Low aldo (ace i)
ECG changes for hyperkalemia
small or absent P waves
Broad QRS
tall peaked T-waves
4 principles of management of hyperkalemia
- stabilize myocardium
- shift K into cells
- excrete potassium
- hemodialysis
what must you avoid in post-op and in patients with bowel obstruction or ileus
do not give Cation exchange resins like sodium polystyrene sulfonate
which can cause intestinal necrosis
what acid base problem will you have in hypokalemia
metabolic alkalosis
Patient with CHF, on a diuretic and hypokalemic why does he have a metabolic alkalosis
- acidified kidney cells
- increased excretion of NH4 - if on a diuretic
- reduced ECFV increased aldo
- high flow due to diuretic
non- anion gap MET acidosis is often due to
bicarb loss - GI or renal
osmolar gap =
osm (measured)- osm (calculated)
2 causes of a high osmolar gap
methanol
ethylene glycol
if you only have an AGMA
change in AG = change in bicarb
