Ketorolac is not nephrotoxic in connection with sevoflurane anesthesia in patients undergoing breast surgery

Ketorolac, which may cause renal vasoconstriction by cyclooxygenase inhibition, is often administered to patients anesthetized with sevoflurane that is metabolized to inorganic fluoride (F(-)), another potential nephrotoxin. We assessed this possible interaction using urine N-acetyl-beta-D-glucosaminidase indexed to urinary creatinine (U-NAG/crea) as a marker of proximal tubular, beta2-microglobulin as a tubular, urine oxygen tension (P(u)O(2)) as a medullary, and erythropoietin as a marker of tubulointerstitial damage. Thirty women (ASA physical status I-II) undergoing breast surgery were included in our double-blinded study. They were allocated into two groups receiving either ketorolac 30 mg IM (Group K) or saline (Group C) at the time of premedication, at the end of, and 6 h after anesthesia maintained with sevoflurane. Urine output, U-NAG/crea, P(u)O(2,) serum creatinine, urea, and F(-) were assessed. Blood loss was larger in Group K (465 +/- 286 mL vs 240 +/- 149 mL, mean +/- SD, P < 0.05). The MAC-doses of sevoflurane were similar. U-NAG/crea increased during the first 2 h of anesthesia and serum F(-) peaked 2 h after the anesthesia without differences between the groups. There were no statistically significant changes in P(u)O(2), erythropoietin, beta2-microglobulin, serum creatinine, urea, or urine output during anesthesia or the recovery period in either group. Our results indicate that the kidneys are not affected by ketorolac administered in connection with sevoflurane anesthesia.

IMPLICATIONS

The different kinetics of N-acetyl-beta-D-glucosaminidase indexed to urinary creatinine and serum inorganic fluoride during and after sevoflurane anesthesia suggest that the observed mild renal tubular function deterioration is not caused by inorganic fluoride. Administration of ketorolac IM is therefore considered safe in adequately hydrated healthy adult patients given sevoflurane anesthesia.