Hypo and Hyperkalemia Flashcards
for every 100 mEq of potassium added, how much will serum K+ go up
- by 1
the key site of renal potassium excretion regulation occurs at the
how
- cortical collecting duct
- aldosterone
- reabsorb Na through ENaC
- creates negative membrane potential
- secrete K+ through ROMK
for every H+ secreted, what gets generated
- HCO3
what happens in the beta intercalated cell
- HCO3 secreted
- Cl- reabsorbed
what happens with K in inorganic metabolic acidosis
and why
and this causes
- H+ goes in cell
- Cl- can’t go in
- K+ shifts out of cell to fill the space
- hyperkalemia
what happens in organic acid metabolic acidosis
- both H+ and organic acid enter the cell
a collecting duct that is more electropositive would do what to K+
- not allow it to enter
- would stay in blood
what would decreased flow and sodium delivery to the CCD do to K+
- would make it stay in the blood
MOA of amiloride
- blocks ENaC
- potassium not excreted into urine
pH of blood with amiloride
- acidic
- H+ will stay in the blood
what is the first thing you do in a patient with hyperkalemia
- exclude a lab error
what would cause a lab error in hyperkalemia
- hemolysis
- excess tourniquet time
- severe leukocytosis/thrombocytosis
in hyperkalemia, after you have excluded lab error, what do you consider
- redistribution
what can cause redistribution problems in hyperkalemia
- tissue injury
- insulin deficiency
- mineral metabolic acidosis
- hyperosmolarity
- digoxin
- hyperkalemia periodic paralysis
TIM HDH
if the patient is hyperkalemic, doesn’t have a redistribution injury, and has decreased renal excretion, what do you consider next
- renal failure GFR <20
- decreased urine flow
- hyperkalemic distal RTA
causes of hyperkalemic distal RTA
- impaired release of renin
- ACE inhibitors
- ARBs
- impaired aldosterone metabolism
- aldosterone receptor blockers
- Na channel blockers
RAAAAN
what impairs release of renin
- NSAIDS
- beta blockers
- cyclosporine
- tacrolimus
- diabetes
- urinary tract obstruction
- HIV infection
- advanced age
NBA CT DUH
what drugs and conditions impairs aldosterone metabolism
- adrenal disease
- heparin
- ketoconazole
what blocks aldosterone receptors
- spironolactone
- eplerenone
what blocks Na channels
- amiloride
- triamterene
- trimethoprim
- pentamide
ATTP
hyperkalemia causes what change to the ECG
- elevated T waves
immediate treatment of hyperkalemia with T wave changes
MOA
- IV calcium
- increases membrane threshold potential
treatment of hyperkalemia that increases K+ entry into cells
- insulin
- beta 2 AGONISTS
- bicarb
treatment of hyperkalemia that removes potassium
- dialysis
- cation exchange resin (sodium polystyrene)
- potassium trapping resin (sodium zirconium cyclosilicate)
