MCC Block 2 Practice Test

When replacing potassium, the ability of the kidneys to excrete potassium is the deciding factor. IV potassium is concentrated and can rapidly raise serum potassium if renal function is poor, so you must confirm the patient is producing urine before giving IV potassium. If there is little or no urine, administering IV potassium risks dangerous hyperkalemia and arrhythmias, so IV potassium should be delayed until urine output is established and renal function is adequate. In adults, a practical check is ensuring a minimum urine output (about 0.5 mL/kg/hour) before starting IV replacement, and then administering potassium cautiously with continuous monitoring. Oral potassium can be used when renal function is adequate and slower correction is acceptable, but it won’t be appropriate if the patient isn’t producing urine or needs rapid stabilization. Potassium is indeed required in hypokalemia, so choosing not to replace it would be incorrect.