What is hypokalemia?
Serum K <3.5
What causes hypokalemia?
-Renal K losses
- Transcellular: alkalemia, insulin, catecolamines
- GI: vomiting, NGT drainage, diarrhea, laxative abuse
- Renal K losses: RTA type IV, Mg depletion, primary mineralcorticoid excess
What are sx of hypokalemia?
Nausea, vomiting, weakness, muscle cramps
What are hypokalemia EKG changes?
U waves, ventricular ectopy (PVCs, VT, VF)
How do you dx hypokalemia?
Clinically, if you can't, can calculate TTKG but it is expensive
How do you tx hypokalemia nl?
- Replate when <3.5
- K is best absorbed PO route, so use gut doing K-Dur tablets or KCl liquid
How do you tx hypokalemia via IV?
- Infuse slowly, no more than 10mEq/hour
- If central line, can infuse up to 20mEq/hour
How do you tx hypokalemia in a renal failure pt?
Err on the lower side, esp. if urine output is dropping off
What do you do if your pt K is low despite repletion?