Computational analysis of blood volume curves and risk of intradialytic morbid events in hemodialysis

Background Blood volume (BV) curves have been used to prevent intradialytic morbid events (IMEs) caused by hypotensive episodes in hemodialysis treatm ent. However, no standardized parameter is available to describe BV dynamic s and to enable online interference with ultrafiltration rates in unselecte d patients. Moreover, only time-dependent BV reduction and absolute hematoc rit threshold, but not BV variability, have been suggested as markers of pe nding hypotension. The present study therefore deals with a computer-aided analysis of indices characterizing both BV reduction per time and BV variab ility in treatments of nonselected maintenance hemodialysis patients. Methods. The methodology uses indices obtained by mathematical analysis of BV curves and was designed to potentially enable automatic interference wit h ultrafiltration. Results. In 46 out of 380 treatments (12.1%), IMEs occur red. In these treatments, the indices for long- and short-term variability and slope of the curves were significantly lower than in treatments without IMEs. Moreover, the last 10 minutes before an IME were characterized by ad ditionally decreased variability and slope. In a risk analysis of long-term variability and IMEs, we established an index below 16 to be associated wi th the highest risk of IMEs. Conclusions. Using these kind of index thresholds and online analysis of BV curves, automatic management of ultrafiltration by BV dynamics could be a promising concept to avoid intradialytic morbidity.