Red blood cell volume distribution width (RDW) in uraemic patients on chronic haemodialysis

Red blood cell volume distribution width (RDW) was obtained with the Coulter counter in 60 haemodialysis patients and 55 normal individuals. RDW tended to be higher in the former and the degree of increase was to some extent correlated with the underlying nephropathy. Although RDW failed to correlate with conventional tests of iron status, it was observed that iron administration could produce a decrease toward normal in RDW and a parallel increase in haemoglobin when the initial RDW was increased. In contrast, the response to iron was negligible in the patients with normal RDW basally. It was concluded that high RDW is an acceptable indicator of iron deficiency in haemodialysis patients.