Conventional ways to estimate DW (5)Intradialytic hypotension continues to be a leading problem, especially in the elderly and cardiovascularly compromised patient. This predominance can be explained by the fact that structural and functional abnormalities of the heart and blood vessels increase the sensitivity of the patient to changes in fluid status. It does not only cause discomfort, but also increases mortality. In a recent study, a low post-dialytic blood pressure was associated with a significantly increased risk for mortality . Therefore prevention of intradialytic hypotension, remains an important challenge to the dialysis physician.