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.

Comparison of two methods of teaching hypertension in under graduate medical students: "planned lecture" versus "cooperative learning".

BACKGROUND: The direct and indirect negative impacts of hypertension on mortality and morbidity and the deficiencies in physicians' knowledge on its management prompted us to search for new methods of training this item. OBJECTIVES: In this study, 2 methods of teaching-planned lecture and cooperation-were compared in instructing hypertension to medical students. MATERIALS AND METHODS: This study was designed to be a prospective analysis of the efficacy of 2 models of cooperation and planned lecture teaching of hypertension. The medical students, in the second term of the 2010 academic year who were introduced to the nephrology ward for their internal medicine course, were randomly assigned to 2 groups to be taught hypertension by 2 models of cooperation and planned lecture to compare their advantages and disadvantages. In their final exam 2 questions concerning the management of hypertension were asked with regard to evaluating the long-term impact of the models on learning. Data were analyzed by paired t-test to compare pre- and post-test in each group, and independent t-test was used to compare the average and standard deviation scores between groups. RESULTS: Fifty-one students participated in the study. The total number of students in the lecture (group 1) and cooperation (group 2) methods was 28 and 23, respectively. By independent t-test, differences in test scores indicated a similar achievement of the 2 methods for the endpoint of basic knowledge (P = 0.253). But, the cooperation method was more successful in transferring abilities, primarily in the areas of workup and treatment (P < 0.05). CONCLUSIONS: The study findings show that both methods can set in the optimal training for hypertension to students but that the cooperative method is more effective for deduction analysis.