Effect of IV contrast medium on renal function in oncologic patients undergoing CT in ICU.

OBJECTIVE: The purpose of our study was to assess the effect of IV contrast medium administered at CT on serum creatinine in an oncologic ICU population and to determine which of the variables before CT are most associated with renal function after administration of contrast material.

MATERIALS AND METHODS: We retrospectively reviewed 3,848 patient admissions to an oncology ICU. The following matched comparisons were undertaken: contrast-enhanced CT versus unenhanced CT and CT (with or without contrast medium) versus no CT. Matching criteria included age, sex, baseline serum creatinine, and severity of illness (modified sequential organ failure assessment [mSOFA] score). No patients with creatinine > 2.0 mg/dL received contrast material. Groups were compared using a rank sum test. Factors influencing creatinine after administration of contrast material were evaluated by multiple regression analysis. Parallel analyses using estimated glomerular filtration rate (eGFR) also were performed.

RESULTS: No significant difference was found in absolute change in creatinine between matched contrast-enhanced CT and unenhanced CT groups (n = 81), with mean (95% CI) creatinine rises after CT of 0.25 (0.04-0.46) and 0.11 (0.04-0.18) mg/dL, respectively. Similarly, for matched CT versus non-CT groups (n = 152), mean creatinine rises were 0.15 (0.05-0.25) and 0.12 (0.08-0.16) mg/dL, respectively. Parallel analyses using eGFR yielded similar results. Creatinine after administration of contrast material was associated with sex and mSOFA (p = 0.04 and 0.02, respectively) but not baseline creatinine. eGFR after administration of contrast material was associated with baseline eGFR (p < 0.0001).

CONCLUSION: Administration of IV contrast medium in oncologic ICU patients with relatively normal creatinine is associated with an increase in creatinine but not beyond that of simply undergoing CT or of a matched non-CT group in ICU. The eGFR, which includes sex in its derivation, may be a better predictor of contrast-enhanced renal function than creatinine.