Contrast-induced nephropathy among Israeli hospitalized patients: Incidence, risk factors, length of stay and mortality

Background: Radiological procedures utilizing intravascular contrast media are being widely applied for both diagnostic and therapeutic purposes. This has resulted in the increasing incidence of procedure-related contrast-induced nephropathy. In Israel, data on the incidence of CIN and its consequences are lacking. Objectives: To describe the epidemiology of CIN among hospitalized patients in the Western Galilee Hospital, Nahariya (northern Israel), and to explore the impact of CIN on mortality and length of stay. Methods: The study group was a historical cohort of 1111 patients hospitalized during the year 2006 who underwent contrast procedure and whose serum creatinine level was measured before and after the procedure. Data were electronically extracted from different computerized medical databases and merged into a uniform platform using visual basic application. Results: The occurrence of CIN among hospitalized patients was 4.6%. Different CIN rates were noticed among various high risk subgroups such as patients with renal insufficiency and diabetes mellitus (14.1%-44%). Average in-hospital length of stay was almost twice as long among patients with CIN compared to subjects without this condition. Furthermore, the in-hospital death rate among CIN patients was 10 times higher. A direct association was observed between severity of CIN based on the RIFLE classification and risk of mortality. Conclusions: Low CIN occurrence was demonstrated in general hospitalized patients (4.6%), and high rates (44%) in selected high risk subgroups of patients (with renal insufficiency or diabetes mellitus). Furthermore, prolonged length of stay and high in-hospital mortality were directly related to CIN severity.