title: Automated peritoneal dialysis has significant effects on systemic hemodynamics.
abstract: OBJECTIVE
  Maintenance of residual renal function (RRF) is an important determinant of outcome in peritoneal dialysis patients. It remains contentious as to whether automated peritoneal dialysis (APD) leads to an increased rate of decline of RRF compared with continuous ambulatory peritoneal dialysis (CAPD). We studied whether APD was associated with significant systemic hemodynamic changes that may play a role in the accelerated loss of RRF.
  
  
  METHODS
  As a follow-on from a previous study, 8 well-established CAPD patients underwent a 4-hour APD treatment consisting of 3 drain/fill cycles using 2 x 2.5 L 1.36% glucose and 1 x 3.86% glucose dialysate. Each dwell phase lasted 76 minutes. Blood pressure (BP) and a full range of hemodynamic variables, including pulse (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR), were measured noninvasively using continuous arterial pulse wave analysis.
  
  
  RESULTS
  BP fell during 2 of the 3 drain/fill periods when dialysate was drained from the peritoneal cavity, but then rose upon instillation of dialysate fluid. The fall in BP was associated with a fall in TPR, matched by an inadequate rise in SV and CO. Over the entire study period, TPR progressively rose to +53.4% above baseline (p = 0.032). Both SV and CO fell over the same period, to -21.1% (p = 0.060) and -22.4% from baseline (p = 0.037) respectively. This did not result in any significant difference between start and end BP.
  
  
  CONCLUSIONS
  This study demonstrates that APD is associated with significant systemic hemodynamic effects. The increased number of drain/fill cycles compared to CAPD, or the progressive rise in TPR and reduction in CO (possibly due to a cooling effect), may potentially be factors that adversely affect RRF in APD patients.
authors.affiliation: Department of Renal Medicine, Derby City Hospital, Derby, United Kingdom.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Selby
authors.forename: Sally
authors.initials: S
authors.lastname: Fonseca
authors.forename: Lisa
authors.initials: L
authors.lastname: Hulme
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Fluck
authors.forename: Maarten W
authors.initials: MW
authors.lastname: Taal
authors.forename: Christopher W
authors.initials: CW
authors.lastname: McIntyre
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000379:methods*; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000379:methods*