Loop Diuretics Overview

Overview

This lecture covers loop diuretics, including their mechanism of action, indications, nursing responsibilities, side effects, and patient education.

Loop diuretics act on the thick ascending limb of the loop of Henle in the nephron.
They inhibit the sodium-potassium-chloride (Na⁺/K⁺/2Cl⁻) co-transporter.
Blocking this transporter prevents sodium reabsorption, keeping sodium and water in the filtrate, increasing urinary output.
They decrease the medullary tonicity, reducing water reabsorption and promoting diuresis.
Loop diuretics are the most potent type of diuretics.

Used to treat fluid volume overload, especially in heart failure, pulmonary edema, and liver impairment with ascites.
May be used for hypertension (less commonly than thiazides).
Treat hypercalcemia by preventing calcium reabsorption in the nephron.

Monitor for dehydration by assessing blood pressure, heart rate, intake/output, and daily weights.
Watch for electrolyte imbalances: hypokalemia (low potassium), hypomagnesemia, hyponatremia, and hypocalcemia.
Risk of metabolic alkalosis due to potassium and hydrogen ion loss.
Monitor uric acid levels as they may cause gout.
Loop diuretics can cause ototoxicity (hearing damage); administer IV doses slowly.
Monitor for signs of effectiveness: increased urine output, decreased edema, clear lung sounds, weight loss, patient reports of improvement.
Administer at appropriate times to avoid nocturia and falls.

Monitor for dehydration: excessive thirst, fatigue, low urine output.
Check blood pressure and heart rate at home; report hypotension or tachycardia.
Eat potassium-rich foods (e.g., bananas, potatoes, avocados, spinach) to prevent hypokalemia.
Rise slowly from sitting or lying to avoid orthostatic hypotension and falls.
Weigh daily and report weight gain >3 lbs/day.

Loop Diuretic — medication that increases urine output by inhibiting Na⁺/K⁺/2Cl⁻ co-transporter in the thick ascending limb.
Nephron — functional unit of the kidney responsible for filtering blood and forming urine.
Hypokalemia — low potassium level in the blood.
Ototoxicity — damage to the ear/hearing, a possible side effect of rapid IV loop diuretic administration.
Nocturia — excessive urination at night.

Take the associated quiz to test knowledge on loop diuretics.
Review patient teaching points and practice nursing care scenarios for patients on loop diuretics.