11/14/24, 10\:50 AM Peritoneal Dialysis

Peritoneal Dialysis

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Key points ⚡
Succinct notes to superpower your revision
Dialysis\: removes excess water, wastes, regulates electrolytes. Dialysis types include haemodialysis and peritoneal dialysis
(PD).
Peritoneal dialysis\: uses the peritoneal membrane for
(CAPD) and automated peritoneal dialysis (APD).
CAPD vs APD\: CAPD done manually, while APD is automated at night. Both are e
psychosocial bene
Contraindications\: active abdominal diseases, unrepaired hernias, stomas, non-functional peritoneal membrane. Anuria is
not a contraindication.
Complications\: include peritonitis, catheter issues, membrane
hyperglycaemia and hypokalaemia.
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A comprehensive topic overview

Introduction

Renal replacement therapy (RRT) refers to life-supporting treatments for severe acute kidney injury or end-stage kidney
disease.
1
Peritoneal dialysis (PD) is a form of RRT that utilises the patient’s peritoneal membrane (a double-fold membrane that
lines the abdominal cavity and internal organs) as the interface between the blood and dialysate. It acts as a semi-
permeable membrane to allow bidirectional movement of molecules of certain sizes across it down a concentration
gradient.
There are two main types of PD\:
Continuous ambulatory peritoneal dialysis (CAPD)
Automated peritoneal dialysis (APD)
Both allow the patient to carry out therapy at home after suitable training, depending on whether the patient prefers to
dialyse during the day or the night. PD is usually performed daily, but in patients with good urine output, it may be
performed less frequently.
PD cannot be used inde
continue for more than ten years.
2
It is important to educate patients that they will likely need to change to haemodialysis (HD) at some point unless they
receive a kidney transplant.
2

Indications for RRT

Acute RRT

Important indications can be remembered using the mnemonic AEIOU\:
3,4,5
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Acidosis\: severe metabolic acidosis, pH \<7.2
Electrolyte disturbance\: severe, refractory hyperkalaemia, >7.0
Ingested toxins\: BLAST (barbiturates, lithium, alcohol, salicylate, theophylline)
Refractory pulmonary oedema
Uraemia\: manifesting as pericarditis/encephalopathy

Chronic RRT

NICE recommends the initiation of chronic RRT when there is the presence of\:
1
Symptomatic uraemia (pericarditis/encephalopathy)
Biochemical measures (electrolyte or acid-base disturbances that are refractory to medical therapy) or uncontrollable

Asymptomatic with an eGFR of 5-7 mL/min/1.73m
2
Other indications outlined by KDIGO include\:
5
Anorexia
Reduced energy level
Weight loss with no other potential explanation
Progressive deterioration in nutritional status that is refractory to interventions

Dialysis

Dialysis is a form of RRT which replaces the kidney’s role in
remove excess water and uraemic wastes. 6,7
It also removes excess acid, regulates electrolyte levels, and removes
metabolic waste products.
However, dialysis cannot replace the kidney’s ability to produce EPO (erythropoietin) and activate vitamin D via 1 alpha-
hydroxylase.
6,7
The main dialysis modalities are expressed hierarchically below.
Figure 1. Summary of dialysis modalities

Choice of dialysis modalities

All patients who are likely to require RRT should be o
supportive management and controlling symptoms but without RRT).
1,5
NICE does not provide a straightforward recommendation in the initial choice of dialysis modality, apart from
recommending PD as the
1
The choice of dialysis modality should re
decision after all available options are presented and explained to them.
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Peritoneal dialysis catheter placement

Before PD can be initiated, a catheter must be implanted into the peritoneal cavity to allow the bi-directional
dialysate. The most commonly used catheter is the Tenckho
pores on the intra-abdominal portion.
8,9
Several techniques can be used to implant the catheter, including open surgical, laparoscopic, and percutaneous
procedures. However, there is no strong evidence that favours one over another, as a range of patient and operator factors
can a
9,10
NICE recommends the creation of access around two weeks before the anticipated start of PD to prevent leakage.
1

Principles of peritoneal dialysis

Each bag of dialysate is usually two litres in volume and contains an osmotic agent (traditionally glucose/amino
acids/polypeptides), electrolytes (sodium, calcium and magnesium), and a bu11,12
introduced into the peritoneal cavity (dwell), where it encounters the peritoneal capillaries.
Dialysate is
There are two main physiological concepts involved in the peritoneal transport\:
5,12
Solute transport by di
Ultra
excess water out of the capillary blood into the dialysate via aquaporins.
After a certain period of dwelling, the used dialysate is drained out of the abdomen.

Continuous ambulatory peritoneal dialysis (CAPD)

One cycle of CAPD is described below\:
Dialysate infused into the peritoneal cavity
After the infusion, the operator disconnects the system and is free to perform their normal activities until the next
exchange
Dialysate dwells in the peritoneal cavity for four to six hours and
The operator re-connects the system and drains the used dialysate out of the peritoneal cavity
This cycle is performed once or up to four times a day. It is usually performed at home by the patient or assisted by a
relative or carer.
13,8
Patients with good urine output and other satisfactory parameters may only dialyse six times a week.

Automated peritoneal dialysis (APD)

APD works in the same way as CAPD, but instead of needing the patient to exchange the dialysate
automated by a dialysis machine while the patient is asleep.
13,14
The machine automatically infuses dialysate into the peritoneal cavity, leaving it to dwell, drain the
it with fresh dialysate. The cycle is usually repeated three to ten times a night, and the patient usually needs to be
attached to the machine for eight to ten hours per night.
13,14

CAPD vs APD

Studies have failed to demonstrate signi
including mortality.
15,16,17
However, patients on APD have reported signi
work, family, and social activities. Therefore, APD may be considered advantageous in younger patient populations,
especially those in education or employment.
There are cost di
that the annual direct cost per patient for APD was 24% more than CAPD (£20,295 vs £16,395).
18

Monitoring

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Urea clearance (Kt/V) or creatine clearance (CrCl) are measures of small solute clearance in peritoneal dialysis.
19,20
However, treatment targets for small solute clearance are no longer recommended.
PD aims to maintain quality of life and minimise symptoms and treatment burden. It should be prescribed using shared
decision-making between the patient and the medical team.
The peritoneal equilibration test (PET), including the sodium dip test, is used to assess the function of the peritoneal
membrane, particularly focusing on the intrinsic properties of the membrane's water channels. This test measures solute
clearance and helps identify variations in membrane transport rates.
19,20
Regular monitoring of peritoneal membrane function is essential, starting six weeks after initiating PD and at least annually
thereafter or more frequently if clinically indicated. Understanding whether a patient is a fast or slow transporter allows for
the customisation of PD therapy.
19,20
Fast transporters may bene
better suited to CAPD or APD with extended day
The most important predictor of survival in PD patients is not dialysis adequacy but the presence of residual renal
function. Therefore, preserving residual renal function is vital\:
21
Blood pressure control should be optimised
Nephrotoxic drugs should be avoided
Avoid dehydration and hypercalcaemia

Contraindications

The most important contraindication is if PD catheter access is not feasible.
Other major clinical contraindications include\:
5,9,22
Active inCrohn’s disease, ulcerative colitis, current c l o s t r i d i u m d i
infection
Main anatomical contraindications include\:
5,9,22
Unrepaired hernia
Presence of stoma or feeding tubes (a PEG should always be inserted before the PD catheter)
Presence of abdominal adhesions (although PD may still be possible)
Other contraindications include\:
5,9,22
Non-functional peritoneal membrane
All other health conditions (e.g. COPD) are relative contraindications
Anuria is not a contraindication. 5
It is well recognised that preserving residual renal function is an important goal for PD, but
it should not be the sole consideration while selecting the initial dialysis modality due to the lack of strong evidence.

Complications

PD catheter-related complications

Early complications (\<30 days)
10
PD catheter obstruction\: causes include constipation, catheter malposition/migration or catheter occlusions (due to
kinking, thrombus,
Cather mispositioning into the upper abdomen or omentum
Bowel perforation (rare)
An obstructed catheter can be irrigated with saline or urokinase if caused by an intra-luminal obstruction. Otherwise,
laparoscopic exploration and subsequent management may be required.
10
Late complications (>30 days)
10
Infection of the exit site or tunnel, which may progress to bacterial peritonitis
Cu
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Out
Peritoneal leak\: dialysate may leak down the catheter tunnel into subcutaneous tissue

Membrane-related complications

A range of peritoneal membrane-associated complications can occur\:
PD-associated peritonitis\: leading cause of PD discontinuation and needing to switch to HD.
23
Peritoneal
membrane failure where there is insu
24
Encapsulating sclerosing peritonitis (ESP)\: a rare but potentially fatal complication of PD, where the progressively
thickened peritoneal membrane encases the small bowel with adhesions and strictures, resulting in recurrent episodes
of small bowel obstruction.
25
PD-associated peritonitis
Peritonitis is a common and serious complication of PD, it is the direct contributing cause of death in >15% of patients.
26
Most cases are secondary to contamination with pathogenic skin commensal bacteria during exchange or due to an exit-
site or tunnel infection. It is typically caused by coagulase-negative staphylococcus, especially s t a p h y l o c o c c u s
e p i d e r m i d i s .
12,27
As per ISPD (International Society for Peritoneal Dialysis) guidelines, PD-associated peritonitis can be diagnosed when at
least two of the following are present\:
27
Clinical features consistent with peritonitis\: abdominal pain and/or cloudy dialysis e
Dialysis e
Positive dialysis e
Management of PD-associated peritonitis12,27
Clinical examination, including the exit site, exit lumen and catheter tunnel
Collect PD
Start intra-peritoneal (IP) antibiotics (
generation cephalosporin for gram-negative coverage) as soon as possible following collection of PD
allow to dwell for at least six hours.
Treatment lasts 2 - 3 weeks, depending on the culture results. If the
required. If the PD culture remains positive (but the
possible.
Patient technique should be reviewed.

Metabolic complications

Cardiovascular disease is the leading cause of death in patients on PD.
28,29
The development of overhydration after loss of residual renal function is thought to be the most important cardiovascular
risk factor speci
28,29
Furthermore, dialysate used in PD has a high glucose content, ranging from 25-75g of glucose per bag. 21
Systemic
glucose absorption causes hyperglycaemia, insulin resistance, and dyslipidaemia, creating a pro-atherosclerotic state,
thus increasing the risk of cardiovascular diseases.
To minimise metabolic complications, the renal association guidelines recommend using glucose-sparing dialysate
regimens where appropriate.
19
Lastly, PD is also associated with hypokalaemia, which is also found to be associated with an increased risk of
cardiovascular events.
28

Fluid dwelling related-complications

The following complications are associated with the presence of
12
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Hernias\: caused by chronically raised intra-abdominal pressure from the indwelling dialysate; may need to change to a
low volume PD or APD with a dry day,
Pain\: may be associated with either in
in
Abdominal fullness\: due to the presence of intraperitoneal

References

National Institute for Health and Care Excellence (NICE). Renal replacement therapy and conservative management
(Clinical guideline [NG107]). NICE 2018. Published 2018 Oct. Available from\: [LINK]
Floege J, Johnson RJ, Feehally J. Comprehensive Clinical Nephrology, 4th edition. London\: Elsevier Saunders 2010.
Malhotra A. Acute Kidney Injury (AKI). G e r i a t r i c T r a u m a a n d A c u t e C a r e S u r ge r y 2017 Jul;367-380
Baker JB, Navarro Y, Sisroe TA, Everett C. Indications for Urgent and Emergent Hemodialysis. A n n a l s o f V a s c u l a r S u r g e r y
2024 Jan;98\:39-40.
Chan CT, e t a l . Dialysis initiation, modality choice, access, and prescription\: conclusions from a Kidney Disease\: Improving
Global Outcomes (KDIGO) Controversies Conference. K i d n e y I n t e r n a t i o n a l 2019 Jul;96(1)\:37-47.
Vadakedath S, Kandi Venkataramana. Dialysis\: A Review of the Mechanisms Underlying Complications in the Management
of Chronic Renal Failure. C u r e u s 2017 Aug;9(8)\:e1603.
Murdeshwar HN, Anjum F. Hemodialysis. T r e a s u r e I s l a n d ( F L ) \: S t a t P e a r l s P u b l i s h i n g 2 0 2 4 J a n [Internet]. Updated\: 2023 Apr.
Available from\: [LINK]
Andreoli MCC, Totoli C. Peritoneal Dialysis. R e v i s t a d a A s s o c i a ç ã o M é d i c a B r a s i l e i r a 2020; 66(1)\:37-44.
S a c h d e v a B , Z u l
Updated\: 2023 Aug. Available from\: [LINK]
Peppelenbosch A, e t a l . Peritoneal dialysis catheter placement technique and complications. N D T P l u s 2008 Oct;1(4)\:23-28.
Mehrotra R, e t a l . The Current State of Peritoneal Dialysis. J o u r n a l o f t h e A m e r i c a n S o c i e t y o f N e p h r o l o g y 2016
Nov;27(11)\:3238-3252.
Teitelbaum I, Burkart J. Peritoneal dialysis. A m e r i c a n J o u r n a l o f K i d n e y D i s e a s e s 2003 Nov;42(5)\:1082-1096.
N H S D i a l y s i s . Last reviewed\: 2021 Sep. Available from\: [LINK]
Peritoneal dialysis (PD). Kidney Care UK. Available from\: [LINK]
Rabindranath KS, e t a l . Continuous ambulatory peritoneal dialysis versus automated peritoneal dialysis for end-stage renal
disease. C o c h r a n e D a t a b a s e o f S y s t e m a t i c R e v i e w s 2007 Apr;2007(2)\:CD006515
Mehrotra R, e t a l . The outcomes of continuous ambulatory and automated peritoneal dialysis are similar. K i d n e y
I n t e r n a t i o n a l 2009 Jul;76(1)\:97-107.
Bieber SD, e t a l . Comparative Outcomes Between Continuous Ambulatory and Automated Peritoneal Dialysis\: A Narrative
Review. A m e r i c a n J o u r n a l o f K i d n e y D i s e a s e s 2014 Jun;63(6)\:1027-1037.
Roberts G, e t a l . Current costs of dialysis modalities\: A comprehensive analysis within the United Kingdom. S a g e J o u r n a l s
2022 Nov;42(6)\:578-584.
Woodrow G, e t a l . Renal Association Clinical Practice Guideline on peritoneal dialysis in adults and children. B M C
N e p h r o l o g y 2017 Nov;18\:333.
Brown EA, e t a l . International Society for Peritoneal Dialysis practice recommendations\: Prescribing high-quality goal-
directed peritoneal dialysis. J o u r n a l o f t h e I n t e r n a t i o n a l S o c i e t y f o r P e r i t o n e a l D i a l y s i s 2020 May;40(3)\:244-253.
Steddon, S. et al. Chapter 4 Dialysis. Oxford Handbook of Nephrology and Hypertension. Oxford\: Oxford University Press,
2018.
Al-Natour M, Thompson D. Peritoneal Dialysis. S e m i n a r s i n I n t e r v e n t i o n a l R a d i o l o gy 2016 Mar;33(1)\:3-5.
Boissinot L, e t a l . Is Transition Between Peritoneal Dialysis and Haemodialysis Really a Gradual Process? J o u r n a l o f t h e
I n t e r n a t i o n a l S o c i e t y f o r P e r i t o n e a l D i a l y s i s 2013 Jul-Aug;33(4)\:391-397.
Terri M, e t a l . Mechanisms of Peritoneal Fibrosis\: Focus on Immune Cells-Peritoneal Stoma Interactions. F r o n t i e r s i n
I m m u n o l o g y 2021 Mar;12\:607204.
Machado NO. Sclerosing Encapsulating Peritonitis. S u l t a n Q a b o o s U n i v e r s i t y M e d i c a l J o u r n a l 2016 May;16(2)\:142-151.
Szeto CC, Li PKT. Peritoneal Dialysis-Associated Peritonitis C l i n i c a l J o u r n a l o f t h e A m e r i c a n S o c i e t y o f N e p h r o l o gy 2019
Jul;14(7)\:1100-1105.
https\://app.geekymedics.com/notebook/2857/ 6/711/14/24, 10\:50 AM Peritoneal Dialysis
Li PKT, e t a l . ISPD peritonitis guideline recommendations\: 2022 update on prevention and treatment. S a g e J o u r n a l s 2022
Mar;42(2).
th
Mehrotra R. Chapter 32 Metabolic Complications of Peritoneal Dialysis. Handbook of Dialysis Therapy, 6 E l s e v i e r 2023.
Krediet RT, Balafa O. Cardiovascular risk in the peritoneal dialysis patient. N a t u r e R e v i e w s N e p h r o l o g y 2010 Jun;6\:451-460.

Reviewer

Dr Roberta Callus
Consultant Nephrologist
Jayne Woodhouse
Advanced Nurse Practitioner

Related notes

Acute Kidney Injury (AKI)
Chronic Kidney Disease (CKD)
Glomerular Disease (Glomerulonephropathies)
Haemodialysis
Henoch-Schönlein Purpura (IgA Vasculitis)

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Contents

Introduction
Indications for RRT
Dialysis
Choice of dialysis modalities
Peritoneal dialysis catheter placement
Principles of peritoneal dialysis
C t i di ti
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