Lasix Larry — Loop Diuretics: Hypokalemia & Ototoxicity
Furosemide drains the fluid from his failing heart — and flushes his potassium out with it
Larry's lungs are wet and his ankles are swollen, so furosemide is working overtime. This morning his potassium is 3.1 and he mentions a faint ringing in his ears after his IV dose.
Larry takes furosemide for heart failure. Loop diuretics block sodium and water reabsorption in the loop of Henle, producing powerful diuresis that relieves pulmonary edema — but potassium, magnesium and calcium leave with the water. Hypokalemia is the signature complication, and it becomes deadly in clients also taking digoxin because low potassium potentiates digoxin toxicity. Pushed IV too fast or combined with aminoglycosides, loop diuretics also damage hearing — tinnitus is the early alarm. Daily weights, I&O and potassium levels are the nurse's surveillance tools.
Read Lasix Larry's full story →The story arc
The setup
Larry is admitted with decompensated heart failure — crackles, pitting edema, and a five-pound weight gain in three days — and IV furosemide is started.
The turn
After two days of diuresis Larry's potassium falls to 3.1 mEq/L, he feels weak, and his EKG shows flattened T waves.
The crisis
Larry reports ringing in his ears shortly after a rapid IV push dose of furosemide.
The save
The nurse slows IV push administration, replaces potassium as ordered, tracks daily weight and strict I&O, and checks potassium before each dose — especially because Larry also takes digoxin.
NCLEX study section — Loop Diuretics: Hypokalemia & Ototoxicity
What this chapter is testing: the recognition cues, the numbers and the priority action.
Study section: Pharmacology
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