title: Biofeedback dialysis for hypotension and hypervolemia: a systematic review and meta-analysis.
abstract: BACKGROUND
  Intradialytic hypotension (IDH) is associated with morbidity and mortality. We conducted a systematic review to determine whether biofeedback hemodialysis (HD) can improve IDH and other outcomes, compared with HD without biofeedback.
  
  
  METHODS
  Data sources included the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and ISI Web of Science. We included randomized trials that enrolled adult patients (>18 years) with IDH or extracellular fluid expansion and that used biofeedback to guide ultrafiltration and/or dialysate conductivity. Two authors assessed trial quality and independently extracted data in duplicate. We assessed heterogeneity using I(2). We applied the GRADE framework for rating the quality of evidence.
  
  
  RESULTS
  We found two parallel-arm randomized controlled clinical trials and six randomized crossover trials meeting inclusion criteria. All trials were open-label and at least four were industry-sponsored. Studies were small (median n = 27). No study evaluated hospitalization and the evidence for effect on mortality was of very low quality. Three studies assessed quality of life (QoL); none demonstrated benefit or harm, and quality of evidence was very low. Biofeedback significantly reduced IDH (risk ratio 0.61, 95% confidence interval 0.44-0.86; I(2)= 0%). Quality of evidence for this outcome was low due to risk of bias and potential publication bias.
  
  
  CONCLUSIONS
  Biofeedback dialysis significantly reduces the frequency of IDH. Large and well-designed randomized trials are needed to assess the effects on survival, hospitalization and QoL.
authors.affiliation: Department of Medicine, The University of Western Ontario, London, Canada. gnesrallah@hrrh.on.ca
authors.forename: Gihad E
authors.initials: GE
authors.lastname: Nesrallah
authors.forename: Rita S
authors.initials: RS
authors.lastname: Suri
authors.forename: Gordon
authors.initials: G
authors.lastname: Guyatt
authors.forename: Reem A
authors.initials: RA
authors.lastname: Mustafa
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Walter
authors.forename: Robert M
authors.initials: RM
authors.lastname: Lindsay
authors.forename: Elie A
authors.initials: EA
authors.lastname: Akl
mesh_terms: D000328:Adult; D001810:Blood Volume / Q000502:physiology*; D018495:Fluid Shifts / Q000502:physiology*; D006760:Hospitalization; D006801:Humans; D007022:Hypotension / Q000628:therapy*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D016896:Treatment Outcome