Pilot Study Using a Pulse Oximeter Derived Photo-plethysmographic Waveform to Guide Hemodialysis Ultrafiltration

The purpose of this study is to use the photo-plethysmographic \[PPG\] waveform signal to guide the dialysis and ultrafiltration \[UF\] of chronic maintenance hemodialysis patients, and to further the investigators understanding of homeostasis in hemodialysis. The investigators hypothesize that the signals generated from the PPG device along with traditional monitoring and nursing judgment, will allow experienced, oriented staff to anticipate hemodynamic instability, intervene to prevent or mitigate the intradialytic hypotention \[IDH\], forestalling the onset of non-facilitating compensatory reflexes that preclude the patient from achieving an appropriate post-dialysis weight consistent with euvolemia. Furthermore, it is hypothesized that the nephrologist and staff will be able to wean patients from anti-hypertensive medications and craft patient specific dialysis orders and UF profiles that achieve consistent, comfortable treatment to appropriate end points. The study aims include: Aim 1: To confirm the temporal sequence of PPG signals and changes in BP in routine hemodialysis. Aim 2: To refine further the predictive algorithms of PPG, augmented with continuous cardiac event monitoring (pre-intra-post hemodialysis) Aim 3: To develop targeted interventions to reverse the cardiovascular stress indicated by the PPG and to maintain perfusion. Aim 4: To develop care paths approved by the medical staff and primary care nephrologist allowing RNs to respond to signals from the PPG.