Effects of intravenous aspirin on prostaglandin synthesis and kidney function in intensive care patients.

The effects of intravenous acetylsalicylic acid (1.0 g bolus) on renal function and prostaglandin synthesis were evaluated in a prospective, controlled study in eight patients in an intensive care unit. Four of these patients had congestive heart failure. Administration of acetylsalicylic acid caused significant antidiuresis (-56%), antinatriuresis (-82%), renin suppression (-26%) and decreased GFR (-41%). All of these changes were completely reversible within 1-2 hours and tended to be more pronounced in the patients with congestive heart failure. Urinary excretion of prostaglandin E2 was depressed profoundly (-93%) and did not return to more than 45% of control 6 h after the administration of acetylsalicylic acid. We conclude that intravenous acetylsalicylic acid affects kidney function in a manner similar to other prostaglandin synthesis inhibitors. Its effects are, however, short-lived. The inhibition of urinary PGE2 excretion outlasts GFR depression, antidiuresis, antinatriuresis and renin suppression by several hours.