Effect of oxygen therapy on the incidence of contrast-induced nephropathy in patients undergoing coronary angiography

Objective This study aimed to evaluate the effect of oxygen therapy on the incidence of contrast-induced nephropathy (CIN) in patients undergoing coronary angiography. Background CIN has been the third leading cause of hospital-acquired renal failure, accounting for 11% of cases. Patients with cardiac diseases are particularly at risk: 49% of CIN occurs after cardiac catheterization and coronary angioplasty in which repeated injections of contrast media are often required. Patient and methods We randomly assigned 200 consecutive patients who underwent elective coronary angiography to two groups: an oxygenation group, in which oxygen was administered through nasal cannula at a rate of 2 l/min from 15 min before the procedure until the end of the procedure (n = 100) and the control group (room air: n = 100). Arterial blood sample was drawn at the beginning of the procedure (coronary angiography) to estimate PaO2level. Baseline and follow-up serum creatinine was compared to diagnose CIN. Results A total of 200 patients were enrolled in the study. There were no significant differences as regards patient characteristics and risk factors for CIN. The PaO2at the baseline was significantly higher in the oxygen preconditioned group than in the control group (115.730 ± 15.774 vs. 84.140 ± 7.916 mmHg, P < 0.001). CIN occurred in 14 (7%) of 200 patients. The incidence of CIN was significantly lower in the oxygen preconditioning group than in the control group [3/100 (3%) vs. 11/100 (11%), P= 0.027], indicating that oxygen preconditioning concomitant with standard isotonic saline hydration suppressed CIN. Conclusion Oxygen preconditioning concomitant with standard isotonic saline hydration decreased the incidence of CIN in patients undergoing coronary angiography.