Impact of oxygen therapy to ameliorate contrast-induced nephropathy in patients with acute coronary syndrome undergoing emergency angiography; a double-blinded clinical trial

Introduction: Contrast-induced nephropathy (CIN) is one of the major causes of acute kidney injury. Objectives: Regarding an increase in mortality and morbidity in patients with CIN, this study aimed to evaluate the effect of oxygen therapy in prevention of the CIN in individuals with acute coronary syndrome undergoing emergent angiography. Patients and Methods: This study was a double-blinded clinical trial with control group (parallel design), randomized, and with a sample size of 204 individuals conducted on male or female patients over 35 years old and suspected of coronary artery disease undergoing emergent angiography refereed to Rasoul Akram hospital in 2018. Participants were divided into 2 groups (supplementary oxygen and oxygen-free groups). The first group received two to three liters of oxygen per minute from 10 minutes before the start of the procedure until the end of the procedure, and the second group inhaled the oxygen in the room air. Arterial blood gas (ABG) was taken prior to receiving oxygen and at the end of the procedure. Serum creatinine level was tested for all individuals before and 48 hours after the procedure. Results: The mean age in intervention and control groups was 61.66 +/- 14.64 years and 60.49 +/- 11.59 years, respectively (P=0.54). Mean glomerular filtration rate (GFR) and serum creatinine before and after angiography was not significantly different (P> 0.05). There was a significant difference between the two genders regarding the development of CI N (P= 0.002), which was higher in women from that of men. Female gender was a strong risk factor and approximately increased four times the risk of CIN (OR = 4.1; (P= 0.001). History of chronic kidney disease (CKD) and hypertension (HTN) also produced such a situation (OR = 22.37; P= 0.007). Conclusion: According to the results, oxygen therapy has no effect on the occurrence of CIN. It is also found that female gender, history of CKD and hypertension are risk factors for CIN.