Will another trial CONVINCE nephrologists to adopt high-dose haemodiafiltration over conventional haemodialysis?

Abstract

Haemodialysis ( HD ) relies on diffusion for solute clearance us-ing either low-flux or high-flux membranes. High-flux dialysers have increased permeability to middle molecular weight solutes. Haemodiafiltration ( HDF ) employs diffusion and convection in combination thereby allowing even greater clearance of middle and large molecules versus high-flux HD [ 1 ]. Both are accepted treatments for kidney failure, but high-flux HD is much more widely used. The enhanced clearance achieved by HDF may improve haemodynamic stability and survival though high-quality randomised evidence is lacking [ 1 ]. Previous trials have tested whether high-dose HDF confers survival advantage over high-flux HD but with several limitations [ 2 ]. Survival benefits have been linked to higher convection volumes of which there are many determinants [ 2 ]; these are largely modifiable treatment-related factors such as vascular access ( Fig. 1 ) ; however, the observation that higher convection volumes are typically achieved in healthier patients has been cited as a potential confounder in previous trials [ 2 ]. The recently reported CONVINCE trial attempted to overcome this limitation by mandating candidacy for convection volumes ≥ 23 litres in post-dilution mode for enrolment [ 3