Choosing peritoneal dialysis reduces the risk of invasive access interventions

[okarol]

Choosing peritoneal dialysis reduces the risk of invasive access interventions
Matthew J. Oliver1, Mauro Verrelli2, James M. Zacharias2, Peter G. Blake3, Amit X. Garg3, John F. Johnson3, Sanjay Pandeya4, Jeffery Perl6, Alex J. Kiss5 and Robert R. Quinn7
+ Author Affiliations

1Division of Nephrology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Canada
2Division of Nephrology, Manitoba Renal Program and the University of Manitoba, Winnipeg, Canada
3Division of Nephrology, London Health Sciences Centre, University of Western Ontario, London, Canada
4Halton Healthcare, Oakville, Canada
5Department of Research Design and Biostatistics, Sunnybrook Health Sciences Centre, Toronto, Canada
6Division of Nephrology, St. Michael's Hospital and the University of Toronto, Toronto, Canada
7Division of Nephrology, Foothills Medical Centre, and the University of Calgary, Calgary, Canada
Correspondence and offprint requests to: Matthew J. Oliver; E-mail: matthew.oliver@sunnybrook.ca
Received February 23, 2011.
Accepted April 26, 2011.
Abstract

Background. Patients choosing between hemodialysis (HD) and peritoneal dialysis (PD) should be well informed of the risks and benefits of each modality. Invasive access interventions are important outcomes because frequent interventions lower patient’s quality of life and consume limited resources. The objective of this study was to compare the risk of access interventions between the two modalities.

Methods. Three hundred and sixty-nine incident chronic dialysis patients were prospectively enrolled at four Canadian centers that were eligible for both modalities, received at least 4 months of pre-dialysis care and started dialysis electively as an outpatient. Two hundred and twenty-four (61%) chose PD and 145 (39%) chose HD. Patients were followed for an average of 1.3 years (range 0.07–3.6 years).

Results. In the PD group, there were fewer access interventions (2.5 versus 3.1 interventions per patient, adjusted odds ratio of 0.79 for PD versus HD, P = 0.005) and a lower intervention rate (2.3 versus 1.9 per patient-year, adjusted rate ratio of 0.81 for PD versus HD, P = 0.04). PD catheters were less likely to experience primary failure (4.6 versus 32%, P < 0.0001), showed a trend toward lower intervention rates during use (0.8 versus 1.2 per patient-year, P = 0.06), and had equal patency compared to fistulae (1-year patency of 84 versus 88%, P = 0.48). Patients managed exclusively with HD catheters (28% of the HD group) required 1.7 interventions per patient and an intervention rate of 1.9 per patient-year.

Conclusion. Patients who choose PD require fewer access interventions to maintain dialysis access than patients choosing HD.

Key words
arteriovenous access chronic kidney disease end-stage renal disease peritoneal dialysis prospective study

http://ndt.oxfordjournals.org/content/early/2011/06/21/ndt.gfr289.abstract

[Dannyboy]

I'm new, so please bear with me about 2 questions that come up to me after reading this.

The "study" involved (on the HD side) 145 patients who started D "electively", but 28% of those 145 had HD catheters [if I'm understanding correctly].   

I thought an HD catheter was sort of a "not first choice" kind of thing for HD (assuming an HD catheter is an access in a spot like the neck area??), so I'm puzzled.   Do some folks *prefer* an access point like that from the start?   If so, what are the advantages, 'cause it seems that whenever such an access point is mentioned around here, it is always in the context of being a temporary, emergency-type thing until a "better" access point is ready?

Second question is:  Is this study somewhat contrary to a prevailing view that PD has a bit more risk of infection?

---Dan

[MooseMom]

Dannyboy, you may be new, but you are also well informed.

I suppose there are people who prefer a cath from the start simply because it is ready immediately and there is no cannulation involved.  The patient doesn't have to think about fistula surgery and doesn't have to worry about needles.  But those "advantages" are far outweighed by infection risks, so all in all, no, caths are not the gold standard by any means.

I really dislike these papers/discussions about which is the "best" modality.  No modality is perfect, and the risk of infection is present no matter the modality.  It is probably true that there are more interventions with fistulae, but a fistula isn't going to result in peritonitis.  There is more to consider than just the access of a particular modality.  Studying just one aspect alone of dialysis seems generally pointless, but a lot of these doctors are probably under some pressure to have their work published somewhere.  I've read some papers that made me think, "Well, duh.  Why not just ask me?  I'll write a paper on that!"

[jbeany]

The "study" involved (on the HD side) 145 patients who started D "electively", but 28% of those 145 had HD catheters [if I'm understanding correctly].   

I thought an HD catheter was sort of a "not first choice" kind of thing for HD (assuming an HD catheter is an access in a spot like the neck area??), so I'm puzzled.   Do some folks *prefer* an access point like that from the start?   If so, what are the advantages, 'cause it seems that whenever such an access point is mentioned around here, it is always in the context of being a temporary, emergency-type thing until a "better" access point is ready?

---Dan

The only requirement to get in the study was 4 months of pre-D treatment.  Many people aren't diagnosed until they have physical symptoms, so there may not have been time to schedule fistula surgery - or the surgeries may have been scheduled but not done yet, finished but not mature yet, or even failures that need to be redone.  It may not have been a matter of preference, but one of necessity.

Second question is:  Is this study somewhat contrary to a prevailing view that PD has a bit more risk of infection?

The study wasn't looking at infection rates - only surgical interventions needed to the 3 different accesses.  They concluded that PD accesses need slightly fewer interventions.  It's not so much about picking the best modality for patient health, I think, as it is about gathering statistics for cost calculations!

[Jie]

Second question is:  Is this study somewhat contrary to a prevailing view that PD has a bit more risk of infection?
---Dan

I am not sure it is correct that HD is less risky for infection than PD. With the cycler PD, nowdays, there is one peritonitis (infection) for average four years. So the infection for PD is rare. If the infection rate for HD is as low as PD, it should not be a problem at all.

[Dannyboy]

Thanks for the comments/explanations.   I'm guessing that some of this stuff is sort of "accepted wisdom" here, and I'm trying to come up to speed on all of this.

One thing that caught my eye was that the patients in the study started dialysis *electively*, which I took to mean the patients in the study were not up against a hard/fast deadline to get started on D or immediately have a seriously bad outcome, hence my question about a significant percentage *choosing* to have an HD catheter.   

Perhaps i've mixed up the results of other studies, but I had the impression that PD was more infection-prone, percentage wise....1 per 4 years doesn't sound too bad at all.   I see that the study was not dealing with infection per se, but with serious interventions, thanks for pointing that out.   

I continue to appreciate the wealth of combined experience that the posters 'round here share.

---Dan

[MooseMom]

I understand that statistics and percentages may have some purpose, but I'm not sure it is really wise to seem them as information carved in stone.  An elderly incenter hemo patient in a clinic which is understaffed probably has a statistically greater risk of infection than a younger home hemo patient who self-cannulates and is meticulous in their anti-infection protocol.  The same with PD patients; my cousin did PD for a while and suffered several bouts of peritonitis, but he's one of those "devil-may-care" types who probably didn't always take the time to keep his access point at its cleanest.  So personally, I'm not really sure what the point is of this particular study.

[Jie]

PD definitely needs to be careful and to follow the cleaning procedure. A careless patient should go to in-center HD.