Can advances in hemodialysis machine technology prevent intradialytic hypotension?

Intradialytic hypotension remains a frequent problem in routine outpatient hemodialysis. Although hypotension can be reduced by more frequent dialysis sessions and longer session duration, these options are not available for many patients. Advances in hemodialysis machine technology have led to the development of relative blood volume monitoring. However, multicenter trials seeking to document a reduction in the frequency of intradialytic hypotension have been disappointing. Further technological advances using "fuzzy" logic systems have been introduced; they track the fall in relative blood volume and then adjust either or both the ultrafiltration rate and dialyzate sodium concentration to maintain a preprogrammed fall in relative blood volume that is likely to be hemodynamically uneventful. Although these systems have been reported to reduce the frequency of serious intradialytic hypotensive episodes, they have not been successful in preventing them probably due to underlying issues with the use of relative blood volume monitoring. More attention needs to be focused on reducing ultrafiltration rates by reducing interdialytic weight gains. Successfully improving patient motivation and education, emphasizing dietary sodium restriction, lowering dialyzate sodium concentrations will all go a long way toward this goal. Technology has much to offer but will not solve this persistent problem.