[Effectiveness of a practical protocol for the prevention of contrast-induced nephropathy: improved prevention of contrast-induced nephropathy]

In Japan, "Guidelines for iodinated contrast in a patient with chronic kidney disease (CKD) 2012" was published, but preventive protocols for specific contrast-induced nephropathy (CIN) have not been specified. Therefore, we developed a CIN preventive protocol, and validated its operation and renal protective effect.In a retrospective cohort study, we determined eGFR within 3 months before contrast-enhanced computed tomography (CECT). We evaluated CKD stage 3b - 4 adult patients (eGFR 15 - 45 mL/min/1.73m2) who underwent CECT. We observed changes in renal function over 9 months and compared the changes between the pre-protocol group, which received CIN preventive measures from clinicians, and the post-protocol group, which received 500 mL 0.9% saline intravenously over 4 hours or drank 2,000 mL water over 36 hours.The numbers of CT and CECT patients after validation of the protocol were 5,450 and 2,037, respectively. Among the CECT patients, 310 (15.2%) and 77(3.8%)had eGFRs60 and 45 mL/min/1.73 m2, respectively. Among the CECT patients whose eGFRs were60 mL/min/1.73 m2, 74.5% were 70 years or older. Tumor scanning accounted for 77% of all CECT cases. The number of CECT patients after 3 months did not significantly differ between the groups (2,189 vs 2,037). The percentage of patients with CKD stage G3b - 4 showed no significant differences (3.3% vs 3.7%, p = 0.89). The proportion of patients whose eGFR did not deteriorate at 3, 6 and 9 months was significantly higher in the post-protocol group than in the pre-protocol group (p0.001), and the protocol was the only independently-significant predictor.Our protocol prevented CIN and provided a renal protective effect without reducing the number of CECT patients.