Microvascular dilatation after haemodialysis is determined by the volume of fluid removed and fall in mean arterial pressure

Abstract

Background/Aims: The effects of haemodialysis on the microcirculation are poorly understood. This study examined the changes in small vessel calibre. Methods: 24 patients (including 12 males, median age 62.5 years, range 30-87) underwent digital retinal photography immediately before and after routine haemodialysis. Arteriolar and venular calibres were measured from the images by a trained grader using a highly reproducible, computer-assisted method. Results: Patients had an average 2.0 ± 0.3 litres of fluid removed with dialysis, and their mean arterial blood pressure fell by 6.8 mm Hg (CI 13.8-0.2, p = 0.06). Retinal arteriole calibre did not change (mean difference 2.3 μm, CI -1.1 to 5.7,..