Differing haemodynamic stability due to differing sympathetic response: comparison of ultrafiltration, haemodialysis and haemofiltration.

In 12 RDT patients the volume removal related haemodynamic changes were correlated with concomitant changes in sympathetic activity during pure ultrafiltration (UF), post dilution haemofiltration (HF) and haemodialysis using either acetate (HDA) or bicarbonate (HDB) as buffer substitute. Total peripheral resistance (TPR) and plasma noradrenaline concentrations (PNA) increased during UF indicating a qualitatively adequate reaction of ESRD patients to volume removal. This physiological response is maintained during HF, resulting in intratreatment haemodynamic stability. In contrast no increase of PNA and insignificant changes of TPR were seen in HDA and HDB. As small molecule clearances were matched to those in HF, the behaviour of PNA indicates that not PNA removal but an impaired sympathetic response during HDA and HDB is responsible for the inadequate rise of TPR.