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

Background: 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.

Methods: 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.

Results: 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 eGFRs < 60 and 45 mL/min/1.73 m2, respectively. Among the CECT patients whose eGFRs were < 60 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 (p < 0.001), and the protocol was the only independently-significant predictor.

Conclusions: Our protocol prevented CIN and provided a renal protective effect without reducing the number of CECT patients.