Despite preventive guidelines, iatrogenic contrast-induced nephropathy (CIN) ranks third as a cause of hospital-acquired AKI, impacts significantly on morbidity and mortality, and is associated with longer stays in hospitals, with higher medical costs. [1][2][3][4] The rates of CIN vary, depending on the study definitions employed and underlying risk factors, and range from 0.6% to 30% or higher among risk groups. [5][6][7][8] CIN is also associated with increased duration of hospitalisation and early and late mortality. In-hospital mortality due to CIN ranges from 7% to 22%. [9] McCullough et al. [9] reported early mortality of 1.1% in controls, 7.1% in CIN patients, and 35% in CIN patients that required dialysis. Owing to increased comorbidities, hospitalised patients have increased risk for developing CIN compared with ambulatory patients .[10]Inflammation and endothelial dysfunction, together with reactive oxygen species (ROS), are implicated in the pathogenesis of CIN. [8] Iodinated contrast media directly injures the renal tubular epithelium by producing ROS radicals that cause intra-renal vasoconstriction leading to ischaemia and death of tubular cells. [8,10,11] Serum albumin is an important antioxidant that reduces the formation of oxygen free radicals and is important in expanding intravascular volume. [12,13] However, the role of serum albumin in reducing the incidence of CIN remains unexplored.Sub-Saharan Africa has a dearth of data on rates of CIN. This study investigated the rates of CIN together with the influence of serum albumin, albuminuria, age, haemoglobin, and glomerular filtration rate (GFR) levels on CIN and patient outcomes.
Methods
Study design, setting and populationThis study was a prospective observational study conducted at Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa, from 1 July 2014 to 30 July 2015. Ethical approval was obtained from the human research ethics committee (HREC) of the University of the Witwatersrand and informed written consent was obtained from all patients. We consecutively recruited hospitalised patients undergoing computed tomography (CT) and angiography from the Divisions of Radiology and Cardiology, respectively. The following exclusion criteria were used: <18 years of age; evidence of pre-existing AKI (clinical or laboratory); end-stage renal disease (ESRD); renal replacement therapy (RRT); prior contrast media administration in the preceding 7 days; pregnancy; or incomplete data.
Study proceduresThe study physician reviewed participants' medical records and examined the participants in order to determine pre-existing risk factors for CIN. The medical records were reviewed to determine patient duration of hospitalisation, dialysis requirements and mortality. Study phlebotomists collected blood samples prior to and post contrast media administration. Pre contrast, urine was collected and analysed for microalbuminuria using the Chemistrip Micral 30 immune assay test (Roche 11544039172). Serum creatinine was analysed using the Jaff...