The Great Dilemma of IntraDialytic Hypotension Definition: A Comparative Approach

Study: Intra-dialysis hypotension (IDH) is the most diffused hemodialysis complication. Its recognition, based on clinician’s ability to identify patients’ specific symptoms, makes it difficult reaching a univocal definition that should be required to develop automatic IDH prevention systems. Different literature IDH identification criteria, applied to the same dataset, were here compared. Methods: The DialysIS DataBase, populated during DialysIS Project, INTERREG IT-CH2007-13, was used. Data refer to 142 patients (1050 sessions), enrolled in 4 centers. IDH identification criteria have been classified as: 1- ‘only symptoms based’, KDOQI and Tilser criteria considered; 2- ‘hybrid’ (symptoms and pressure variations), Chesterton and IDH_D criteria; 3- ‘only pressure threshold based’, Flythe, Dubin and Palmer criteria. The three groups of criteria were compared in term of patient’s proneness to IDH and frequency of events. Results: Depending on the used group criteria a large number of pressure conditions is identified as being IDH or not (33,2% of the clinical data). All the criteria agreed in identifying as IDH only the 1,6% of the analysed data. Group 1 criteria identified the lowest number of IDH, with respect to groups 2–3 (p<0,05); similar differences were observed in the proneness to IDH. The ‘only symptoms based’ criteria seem to be too specific to identify as IDH a number of pressure conditions, which instead are reported in the literature as correlated with increased long-term mortality risk. Group 2 and 3 criteria display similar IDH identification ability, however, group 3 criteria appear more suitable for implementation in automatic systems not accounting for symptomatology.