Prediction of hypotension in hemodialysis patients.

Intradialytic hypotension (IDH) is the most common adverse complication during hemodialysis. Its early prediction and prevention will dramatically improve the quality of life for patients with an end stage renal disease. In a recent study, changes in the normalized envelope of the test statistic of the photoplethysmograpic (PPG) signal were found to predict acute symptomatic IDH. In the present study, the PPG-based predictor is generalized to include a patient-dependent threshold which incorporates on-line information on heart rate variability and heart rate turbulence. From datasets with patients prone and resistant to IDH, the results show that symptomatic IDH could be correctly predicted in 9 out of 14 cases, while 5 out of 24 were falsely predicted. In a subset of the data containing only patients prone to IDH, acute symptomatic IDH could be correctly predicted in 5 out of 5 cases, with one false prediction out of 14. When testing the robustness of the predictor, no significant changes were observed in the test statistic when controlled changes occurred in dialysis fluid temperature, ultrafiltration rate and body position.