Prevention of Contrast-induced Nephropathy With Oxygen Supplementation: a Randomized Controlled Trial.

Introduction. The aim of the study was to investigate the efficacy of nasal oxygen as a supplementation to hydration therapy in reducing the risk of developing contrast-induced nephropathy (CIN). Materials and Methods. In a randomized controlled trial, 348 patients scheduled to undergo elective coronary angiography were randomly allocated to standard hydration plus 2 L/min to 3 L/min nasal oxygen (from 10 minutes before the procedure until the end of the procedure) (n = 176) or standard hydration alone (n = 176). The primary outcome measure was development of CIN defined as either an increase of 25% or more in serum creatinine concentrations or an increment of at least 0.5 mg/dL in serum creatinine concentrations 48 hours after catheterization. Results. Of the 348 patients who completed the study, 105 developed CIN (30.2%; 95% confidence interval, 25.4% to 35.0%). A diagnosis of CIN was made in 32 (18.6%) and 73 (41.5%) patients in the nasal oxygen and control arms, respectively ( P < .001). In the intervention arm, creatinine concentrations postcontrast remained relatively constant (average change, 2.7%), whereas a significant increase of 17.3% was recorded in the control arm ( P < .001; effect size, 11.8%). Conclusions. Supplementation with nasal oxygen in addition to standard hydration appears to be an effective strategy in reducing CIN. The effect size for this intervention seems to be moderate.