© 2006 Fresenius Medical Care North America Turning the Light on Peritoneal Dialysis: A Basic Introduction to PD

© 2006 Fresenius Medical Care North America

Turning the Light on Peritoneal Dialysis:Turning the Light on Peritoneal Dialysis: A Basic Introduction to PD A Basic Introduction to PD


Turning the Turning the llight on Peritoneal ight on Peritoneal Dialysis (PD)Dialysis (PD)

I. Understanding the modality

II. Patient selection criteria

III. Components of a successful PD program


Goal statementGoal statement

The goals of this presentation are to understand peritoneal dialysis and to recognize patient selection criteria as one component of a successful PD program.


Learning Learning oobjectivesbjectives

At the end of this presentation the participant will be able to:

• Describe the components of a successful PD program.

• List the organization that provides guidelines for peritoneal dialysis including appropriate patient selection.

• Describe the difference between peritoneal dialysis and hemodialysis

• Describe the function of the peritoneal membrane and dialysate in peritoneal dialysis.


Understanding the Modality:Understanding the Modality:Principles of Peritoneal DialysisPrinciples of Peritoneal Dialysis


Before we can discuss how to grow a PD program we need to understand the modality. The next few slides will be a brief review of principles of PD.

Let’s look at how PD can be used as a renal replacement therapy.


The structure of the peritoneumThe structure of the peritoneum

• Living, serous membrane– Can be damaged

• Semi permeable and selective– Filters various kinds of solute to varying

degrees

• Forms a closed sac in males and in females the sac is open at the fimbria of the fallopian tubes

• Is comprised of two principal types– Visceral peritoneum around the internal organs– Parietal peritoneum lining the abdominal wall


• Size approximates body surface area– Approximates the surface area of the skin 1-

2m2 in most adults– Proportionately larger in infants and small

children

• Effective surface area is about 1m2

– Size equivalent to a hemodialyzer– Size is fixed – Can lose effective surface area

The structure of the peritoneumThe structure of the peritoneum


Peritoneal Peritoneal ddialysis is an internal ialysis is an internal technique for blood purificationtechnique for blood purification

• PD is dialysis but is unlike extracorporeal (out of the body) dialysis systems

• Nature provides– Blood path– Membrane– Dialysate compartment


• The peritoneal membrane forms the peritoneal cavity which functions as the dialysate compartment

• The membrane is semi-permeable and selectively filters solutes to varying degrees

• Capillaries within the membrane provide the blood pathway

Peritoneal dialysis is an internal Peritoneal dialysis is an internal technique for blood purificationtechnique for blood purification


Anatomy of theAnatomy of the p peritoneumeritoneum


• The peritoneum – Forms folds between organs and elsewhere.

The folds which are reflected from the walls over the viscera are called mesenteries. The folds can connect viscera to each other or anchor organs to the abdominal wall.

– The greater omentum is a fold in the serosa of the stomach that hangs down like an apron over the front of the intestines.• Tends to be larger in heavy or previously

heavy individuals. • PD catheter can become entangled in the

omentum.

Anatomy of the peritoneumAnatomy of the peritoneum


Peritoneal cavityPeritoneal cavity

• Potential rather than an actual space– Normally contains approximately 100 ml

• Dialysate volumes which are usually 2 - 4 L can result in:– Discomfort– Respiratory embarrassment (especially if

there is a thoracic leak)– Decreased food intake secondary to a

sensation of fullness– Problems related to fluid weight or pressure

such as back pain, hernia or fluid leak into tissues


Anatomy of theAnatomy of the p peritoneumeritoneum

Peritoneal Cavity


• A catheter (which is a foreign body) placed in the cavity can cause:– Discomfort related to catheter or fluid

pressure (rectal, bladder, penile)– Poor drainage because the catheter floats

freely in the peritoneal cavity and may become:• Displaced or flipped up from pelvic gutter• Wrapped in the omentum• Entangled bowel loops

– Soft tissue penetration by the catheter (rare)

Peritoneal cavityPeritoneal cavity


Function of the peritoneum - solute Function of the peritoneum - solute transport and clearancetransport and clearance

Let’s examine how solutes are transported across the peritoneal membrane.

The peritoneal membrane is the patient's tool for doing the work of dialysis.

Membrane capability varies from person to person but is usually stable in an individual.


DiffusionDiffusion

• Solute movement from an area of higher concentration to an area of lower concentration

• Movement continues until equilibrium occurs

Diffusion


Diffusion and dialysisDiffusion and dialysis

• Diffusion occurs across a membrane that is semi-permeable.

• There are different degrees of permeability to solutes of different sizes.

• Net transfer of molecules occurs until an equal concentration of a given solute on both sides of the membrane.– Movement continues but there is no

net change in concentration from one side to another.

Diffusion


Diffusion and dialysisDiffusion and dialysis

Diffusion

In this diagram the green triangles and red circles represent two different molecules that transport at different rates. We see that the red circles are already in equilibrium on both sides of the membrane while the green triangles are not yet equilibrated.

If this were to represent dialysis, then there would be no further removal of the red circles but green triangles could still be further dialyzed off.


OsmosisOsmosis

• Water movement from an area of lower to higher solute concentration

• Ultrafiltration, or the amount of water removed, is related to the osmotic pressure gradient

Osmosis

Blood Dialysate


Osmosis and dialysisOsmosis and dialysis

In this diagram the “D”s represent dextrose, the solute used as an osmotic agent.

The dialysis solution is very highly concentrated compared to blood so that water moves into the dialysate.

Osmosis

Blood Dialysate


Test yourselfTest yourself

1. The peritoneum removes solutes and fluids much like the dialyzer or artificial kidney in hemodialysis.True False

2. The peritoneal membrane forms the peritoneal cavity which functions as the dialysate compartment. True False

3. Osmosis moves solutes out of the blood and into the dialysate.True False


Answers for test yourselfAnswers for test yourself

1. The peritoneum removes solutes and fluids much like the dialyzer or artificial kidney in hemodialysis.

Answer: True. The peritoneum is a semi-permeable membrane and filters solutes and water during peritoneal dialysis.

2. The peritoneal membrane forms the peritoneal cavity which functions as the dialysate compartment.

Answer: True

3. Osmosis moves solutes out of the blood and into the dialysate.

Answer: False. Osmosis is the movement of water from an area of lower concentration to an area of higher concentration.


PD Therapies:PD Therapies:

Understanding the Understanding the different types of PDdifferent types of PD


Continuous therapiesContinuous therapies

• Continuous Ambulatory Peritoneal Dialysis (CAPD)– 4 - 5 exchanges* /24 hours– 2L - 2.5L exchanges*– 8 - 10L per 24 hours*– The exchanges are done manually by the

patient *May be more

• Dialysate is present in the peritoneal cavity at all times



• Continuous Cycling Peritoneal Dialysis (CCPD)– Machine automated during sleep hours

• 10 - 12 hours at night– 8L or more at night– 2L or more during the day– 10L or more in 24 hours




• PD Plus: Utilizing the cycler for a daytime exchange in addition to cycling at night– Night cycles for 8 – 10 hours– All exchanges delivered by cycler

• Pause exchange• Night exchanges• Daytime fill• 10L or more / 24 hours



PD solutions: Understanding what is in PD solutions: Understanding what is in the dialysatethe dialysate

• Composition of PD solutions:– Sodium 132 mEq/L– Potassium none– Calcium 2.5 - 3.5 mEq/L– Chloride 96 - 102 mEq/L– Sodium lactate 448 gm/100ml– Magnesium 0.5 - 1.5 mEq/L– Dextrose 1.5% - 4.25%


Dialysis exchange processDialysis exchange process

FillDrain Dwell

An exchange should take approximately 20-40 minutes to complete.


The drain phaseThe drain phase

• Drain– About 15 - 25 minutes and depends on:

• Catheter function• Amount of solution• Gravity• Diameter of tubing• Position or intra-abdominal

pressure• Condition of system


The fill phaseThe fill phase

• Fill– About 10 minutes and depends on

• Amount of solution• Solution bag height• Diameter of tubing• Intra-abdominal pressure• Condition of system


The dwellThe dwell

• Dwell (a prescribed time)– Dialysis takes place during the dwell time– Time required for transport of solutes across the

peritoneum– CAPD

• Usually 4 - 5 hours during the day and • 9 hours at night

– Cycling• Usually 1 - 3 hours at night and • 15 hours during the day



Peritoneal dialysis can be done manually or by a machine as the patient prefers.True False

The fill time is the time that it takes toa. Stay in the peritoneal cavityb. Allow the dialysate to flow out of the

cavity into a bagc. Drain fresh dialysate from the bag

into the peritoneal cavity


Answers for test yourselfAnswers for test yourself

Peritoneal dialysis can be done manually or by a machine as the patient prefers.Answer: True

The fill time is the time that it takes toc. Drain fresh dialysate from the bag

into the peritoneal cavity, filling the cavity with the dialysate fluid



An exchange consists of _____ and ______.a. drain and fillb. fill and dwellc. fill, dwell and drain

Continuous means that dialysatea. is always present in the peritoneal cavityb. is present except during the dayc. is present except at night

PD cyclers are most commonly used while the patient sleeps

True False


Answers to test yourselfAnswers to test yourself

An exchange consist of _____ and ______.a. drain and fill

Continuous means that dialysatea. is always present in the peritoneal cavity

PD cyclers are most commonly used while the patient sleeps

True


Patient selection criteria: Who should do Patient selection criteria: Who should do peritoneal dialysis?peritoneal dialysis?


Patient selection criteriaPatient selection criteria

• There are some patients for whom PD may be a better option than hemodialysis.

• There are pros and cons regarding modality selection for any patient.

• Selection of patients who may do better on PD or for whom PD may be contraindicated as per the KDOQI guidelines will be reviewed.


K/DOQI Guideline 29K/DOQI Guideline 2911: Indications for PD: Indications for PD

• Patients who prefer PD or will not do hemodialysis.– Patients report improved quality of life2 and that they

are more satisfied with their treatments when compared to hemodialysis (HD) patients

• Pediatric patients – No vascular access needed

• Due to the difficulties in maintaining vascular access in infants and small children, PD is usually the modality of choice when weight is < 20 kg.

– More gentle treatment– Regular school attendance

• Can be best achieved by a home modality.

1.National Kidney Foundation. NKF K/DOQI Guidelines http://www.kidney.org/professionals/kdoqi/guidelines2.Merkus, MP. American Journal of Kidney Disease 29:584-592, 1997


• Patients who cannot tolerate HD– Congestive/ischemic heart disease1

• Due to the rapid shifting of volume within fluid compartments during HD, some patients with severe cardiac disease may be better managed on PD.

• Patients on PD have a lower incidence of left ventricular hypertrophy, arrhythmias, and hypertension compared to that of HD patients.

1. Canziani, ME. Artificial Organs 19(3):241-244, 1995

K/DOQI Guideline 29: Indications for PDK/DOQI Guideline 29: Indications for PD


– Extensive vascular disease and – Vascular access problematic patients

• Extensive peripheral or central venous occlusive disease prohibits surgical placement of some types of hemodialysis access. These patients are at risk of severe ischemia or even gangrene following placement of vascular access.

• Marginal vascular beds are at risk for ischemia or reduced perfusion during hypotension, which is frequent in some HD patients. These patients benefit from the increased vascular stability achieved with PD.

Canziani, ME. Artificial Organs 19(3):241-244, 1995

K/DOQI Guideline 29: Indications for PDK/DOQI Guideline 29: Indications for PD


Additional considerations for patients Additional considerations for patients that would do well on PDthat would do well on PD

• Distance from dialysis facility – Patients living in rural communities or where severe

weather could be problematic.

• Nursing home patients– Eliminates the difficulties with transportation three

times per week.

• Working patients– Avoids treatment scheduling conflicts– Patients who work report increased satisfaction with

dialysis

• Diabetic patients– No vascular access needed– IP (intra-peritoneal) insulin option


K/DOQI Guideline 30: Absolute K/DOQI Guideline 30: Absolute Contraindications for PD Contraindications for PD

• Documented loss of peritoneal function or extensive abdominal adhesions that limit dialysate flow.– PD efficiency relies on effective peritoneal

blood flow, dialysate flow, sufficient peritoneal surface area and peritoneal transport rate to allow adequate solute and fluid removal.

– Any compromise in these functions may result in inadequate peritoneal dialysis and thus the failure of PD.

– There is no way of knowing the functionality of the peritoneum until it is tried. Many patients who have been on PD and were transplanted have successfully returned to PD post transplant failure.

National Kidney Foundation. NKF K/DOQI Guidelines http://www.kidney.org/professionals/kdoqi/guidelines


• Absence of suitable assistant in the patient who is physically or mentally incapable of performing PD.– Performing PD requires certain physical and

intellectual capabilities in the patient and/or caregiver.

– It is important that the patient and/or the caregiver be able to identify and troubleshoot any problems that may arise during PD.

– Be open minded, blind patients, patients who cannot read, and patients with severe physical limitations have been successful PD patients.




• Uncorrectable mechanical defects that prevent effective PD or increase the risk of infection (e.g., surgically irreparable hernia, omphalocele, gastroschisis, diaphragmatic hernia and bladder extrophy.)– The dialysate must come into contact with the

vascular bed of the peritoneum, otherwise dialysis will not be accomplished.

– These congenital birth defects involve a weakening of in the abdominal wall wherein abdominal organs herniate.




K/DOQI Guideline 31: Relative K/DOQI Guideline 31: Relative Contraindications for PDContraindications for PD

• Peritoneal leaks • Body size limitations• Intolerance to PD volumes necessary to

achieve adequate PD dose• Inflammatory or ischemic bowel disease• Abdominal wall or skin infection• Morbid obesity (in short people)• Severe malnutrition• Frequent episodes of diverticulitis



• Patients with relative contraindications account for a only small portion of PD candidates and this population is not significant enough to impact the low PD utilization rate that we see in the US today.

• This section of the K/DOQI guidelines is opinion based.


K/DOQI Guideline 31: Relative K/DOQI Guideline 31: Relative Contraindications for PDContraindications for PD



There are written guidelines regarding patient selection criteriaTrue False

For some patients PD is a better option because it places less stress on the cardiovascular system.True False

Documented extensive abdominal adhesions that limit dialysate flow will not impede PDTrue False


Answers to test yourselfAnswers to test yourself

There are written guidelines regarding patient selection criteriaTrue

For some patients PD is a better option because it places less stress on the cardiovascular system.True

Documented extensive abdominal adhesions that limit dialysate flow will not impede PDFalse, this is a contraindication for peritoneal dialysis.


Building the components of a successful Building the components of a successful PD programPD program

•Physician support

•Active and effective modality education program

•Program infrastructure


Physician support - why it may be lowPhysician support - why it may be low

• Minimal training of PD during fellowships leads to physician:– Lack of confidence– Concern with managing side effects– Perception that adjustments of Rx are

more involved with PD than HD– Perception that PD is more labor/time

intensive

Campbell, D. Nephrology News and Issues 25-27, 2004


Steps to improve physician supportSteps to improve physician support

• Encourage the physician to attend an education program designed to increase comfort with PD

• Provide articles that promote the modality and the importance of modality options education


Components of a successful modality Components of a successful modality education programeducation program

• Modality education process developed and agreed upon by multidisciplinary team

• Dedicated nurse with hours specified to monthly patient modality education meetings

• Physician commitment to refer patients

• Education of hemodialysis staff

• PD awareness days for hemodialysis patients

• Tracking program to monitor success and identify opportunities for improvement


Modality educationModality education

• Benefits of early referral– Improves management of comorbid conditions– Allows for timely education in treatment options

and referral for permanent access placement

• Identifies target patient population:1

– Creatinine > 3mg/dl– Anticipated treatment start within 1 year– New hemo starts who did not receive

information

1. National Kidney Foundation. NKF K/DOQI Guidelines http://www.kidney.org/professionals/kdoqi/guidelines


• There are defined parameters for the program developed by the multi disciplinary team, especially the referring nephrologist

• The nephrologist must clearly communicate patient referrals to the staff

• The referral process will ensure a positive flow of patients to your modality education monthly class

• In addition to new CKD patients, a successful program will include education of hemodialysis patients



• Educators partner with clinic managers to obtain admission reports

• Education promotes a proactive approach to access placement thus decreasing the percentage of vascular catheters being utilized

• The points at which patients may enter the program vary and but can be anywhere from one year to six months prior to initiation of dialysis



Monthly modality education classes Monthly modality education classes should:should:

• Provide regular monthly treatment education programs discussing– Treatment options– Diet and nutrition– Living with dialysis– Support systems– Financial needs/concerns


Education of hemodialysis staffEducation of hemodialysis staff

• Increases understanding of peritoneal dialysis

• Assists PD nurse to identify potential candidates who did not have the opportunity to participate in their own modality selection

( such as acute starts)• Dissolves myths regarding PD

– “You will get an infection”– “You are on the machine for 15 hours at

night”– “Large patients cannot meet adequacy

targets”


PD awareness days for hemodialysis PD awareness days for hemodialysis patientspatients

• Objective: Heighten awareness of HD patients to the clinical and lifestyle benefits of PD therapy.– Acute starts– Patients who were uremic when they started

and now want to know more about PD.– Patients who have returned to work and desire

a more flexible lifestyle


How to conduct a PD awareness dayHow to conduct a PD awareness day

• Requires support of physician and entire staff• Provide a lunch-n-learn for hemo staff prior to

PD awareness days to ensure it’s success• Place posters marking the PD awareness

dates throughout the facility• Meet with each hemodialysis patient during

treatment• Follow up with physician, PD nurse and/or

educator regarding patients who are interested in possibly switching


Methods to develop a positive PD Methods to develop a positive PD program infrastructureprogram infrastructure

• Dedicate a PD nurse with regularly scheduled hours for PD

• Ensure on-call PD support• Develop new PD programs where appropriate, to

reduce travel time for patients and physicians• Develop float positions to cover smaller and new

programs and backup for large programs• Utilize vendor on site education and continuous

education sessions• Establish protocols for ease of treatment• Educate local hospitals and extended care

facilities for continuity of treatment


In summaryIn summary

To have a successful PD program• Understand the modality• Understand the right type of patient for PD• Know your physician’s beliefs and offer

positive educational offerings to increase his/her support

• Develop and implement an active and effective modality options program

• Promote a positive infrastructure within your home training program

Documents

© 2006 Fresenius Medical Care North America Turning the Light on Peritoneal Dialysis: A Basic Introduction to PD