Pathophysiology of dialysis related hypoxaemia

In order to elucidate the pathogenesis of haemodialysis related hypoxaemia, lung function studies, measurements of intra-thoracic fluid changes, leucocytes and complement activity were made in 12 patients during a routine six hours dialysis using cellulose membranes. Coincidently with the fall in arterial oxygen tension, lung function was significantly impaired, paralleled by a decrease in transthoracic impedance, leucopenia and a decrease in plasma complement activity. It therefore is suggested that blood membrane interaction leads to complement-mediated pulmonary leucostasis evoking mild pulmonary oedema with impaired oxygen diffusion, resulting in hypoxaemia.