Peritoneal dialysis in Scotland: an analysis of complications and outcomes in a contemporary national cohort

Brown, Michaela Catherine (2012) Peritoneal dialysis in Scotland: an analysis of complications and outcomes in a contemporary national cohort. MD thesis, University of Glasgow.

Abstract

Peritoneal dialysis (PD) utilisation is falling in Western Countries. Concerns regarding
reduced survival on PD, impact of inadequate dialysis on patient outcomes and the serious
complication of encapsulating peritoneal sclerosis (EPS) may be contributing to the decline
of PD. The exact incidence of EPS has been difficult to establish because of differences in
design of published studies. In Scotland there was concern that the incidence of EPS was
increasing, which prompted discussions about the future role and risks of PD. The aim of
the MD was to establish an accurate incidence of EPS in Scotland and to examine
complications and outcomes of PD patients to try to answer the question of who and for
how long PD should be used in our population. Since 1999 all adult renal units in Scotland
have completed a PD Audit form 6 monthly for every PD patient which gives details of PD
population, source of new patients, reasons for stopping PD, causes of technique failure,
details of all peritonitis episodes, adequacy test results and basic laboratory results. This
prospectively collected data was linked to further demographic and laboratory data from
the Scottish Renal Registry database for analysis. The analysis focussed on all incident
patients commencing PD between 1st January 2000 and 31st December 2007 (n=1324),
with follow-up to 30th June 2011. Our data analysis confirmed the ongoing fall in PD
population in Scotland, and greater usage of APD. Peritonitis rates have remained steady at
1 episode every 19.9 months when averaged over the study period; similar to UK and
Australasian results but worse than North American centres. Several risk factors for
peritonitis were identified in our population including unit, CAPD compared to APD,
diabetes mellitus (DM) in females, older age, hypoalbuminaemia, and lower residual renal
function (RRF) at the start of PD. We established that the overall risk of EPS is low, but if
PD is continued beyond 4 years the risk is substantial at 1 in 13 patients, with an
exponentially increasing incidence with longer PD exposure. Survival is poor with 46.8%
mortality at 1 year after diagnosis. No clear risk factors were apparent other than PD
exposure. Analysis of patient survival identified several factors associated with poorer
survival including increasing age, hypoalbuminaemia and RRF at the start of PD, presence
of DM and multisystem primary renal diagnoses as well as having experienced peritonitis.
The main causes of technique failure in our cohort include peritonitis (42.9%) and
inadequate dialysis (22.1%). Predictors of technique failure include DM, lower RRF at the
start of PD and being treated in more recent PD eras. Overall analysis of the PD cohort has
shown that PD is a short-term treatment in Scotland with only a quarter of patients
continuing PD beyond 3 years, with the remainder stopping for a transplant, technique
failure or death. It is not possible to predict how long an individual patient will continue
PD, but certain patients have poorer outcomes including the elderly (>70 years), those with
DM and those hypoalbuminaemic at the start of PD. Therefore the actual number of
patients who will continue PD long enough to be at significant risk of EPS is very small,
and we believe the potential risk of EPS should not prevent patients from being offered PD
in the first instance. Although some patients fare better on PD than others, we cannot state
that any specific patient group should not be offered PD on the basis of our analyses
particularly as we cannot show that they would have improved outcomes on
haemodialysis. For the minority of patients with ongoing technique success at 4 years we
suggest discussing ongoing PD, ensuring patients are informed about the EPS risk and a
risk:benefit assessment of ongoing treatment should be decided on a case by case basis. It
is likely that clinician attitude are driving the decline of PD, in the absence of evidence to
show inferior outcomes on PD compared to HD. There would be an argument for actively
increasing PD utilisation in Scotland, particularly among the elderly by expanding the
assisted PD programs. Similarly, unless efforts are made to ensure adequate PD training
and experience for nephrology trainees it is likely that PD will continue to decline.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Subjects: R Medicine > R Medicine (General)
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
• Supervisor's Name: Jardine, Prof. Alan
• Date of Award: 2012
• Depositing User: Mrs Marie Cairney
• Unique ID: glathesis:2012-4397
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 12 Jun 2013 15:17
• Last Modified: 13 May 2016 15:50
• URI: https://theses.gla.ac.uk/id/eprint/4397