PD PEARLS

Ezra Hazzan MDNovember 19, 2014

Case study

• 43 year old female, DM and now needs to start dialysis. Works full time, highly motivated and good support system.

• 65 year old male, Spanish speaking, unemployed, recent immigrant with spouse at home.

• 50 year old male, obese, on HD with an IJ permacath (failed fistula) and inquiring about PD.

• 20 year old male who drinks a lot of fluid >1.5liters, and loves eating fruit( tons of potassium).

Peritoneal Dialysis Misconceptions• The prevalence of infections is much higher in PD

than HD• Patient survival is less on PD• PD takes too much of the patient’s time• Patients do not want PD• PD requires high levels of understanding and

education• PD requires a companion at home to help with

therapy

Reality of PD Infections

NOT TRUE

The prevalence of infections is much higher in PD than in HD…

NOT TRUE

Patients survive less time on PD…

“ PD takes too much of the patient’s time”

o On CAPD 4 exchanges x 30 minutes = 2 hours (14 hours a week)

o On CCPD :• Setting up machine, 15-20 min, connection/disconnection 5 min.• Plus day time exchange 45 min = 1 hr 10/15 min.• Total weekly set up time: 8-9 hr + sleep time.

o On HD:• HD time 4 hours plus on/off time, about ½ hour.• Waiting /travel time 1 hr @ treatment• Total weekly time: 16 ½ hr (without resting after HD)

Courtesy of Karen Kelley, Baxter

NOT TRUE

PD takes too much of the patient’s time, when compared with HD…

Patient ratings of dialysis care with PD or HD Rubin et al JAMA 291: 697-703,2004

• Cross- sectional survey at enrollment of patients who recently started dialysis at 37 dialysis centers in 14 states participating in the CHOICE Study.

• A patient administered questionnaire included 20 items rating specific aspects of dialysis care, and 3 overall dialysis care ratings.

• Of 736 enrolled patients, 656 (89%) returned the questionnaire after an average of 7 weeks on dialysis.

Satisfaction with renal replacement therapy and education: the American Association of Kidney

Patients Survey Fadem et al. CJASN 2011

• This was an open invitation on the AAKP website + nearly 9000 patients received the invitation to complete the survey.

• The survey consisted of 46 questions to measure patient satisfaction with their RRT modality.

• Satisfaction was measured on a 1 (extremely dissatisfied) to 7 (extremely satisfied) scale.

Requirements for PD

• Functioning PD catheter• Dialyzer: functioning peritoneum• Ability and interest in learning home

dialysis on part of patient or support person

Patients need to understand that there are two types of PD

• CAPD----continuous ambulatory peritoneal dialysis, done 2-4 times per day.

• APD or CCPD----done at night using a machine

called a cycler.

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From the patient perspective these are not the same.

CAPD: continuous ambulatory peritoneal dialysis

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Each exchange takes about 30 minutes. Number of exchanges depends on residual kidney function

APD: automated peritoneal dialysis

At bedtime the patient places bags on cycler and attaches catheter to cycler tubing,pushes button to start the cycler. Takes about20 minutes.

In the morning, the patientdisconnects and discards usedtubing. (takes <5 min)

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Deciding on modality

Cycler PD In center HD

Nightly, while sleeping 3 times per weekDone by patient Done by staffPrivate In centerPD catheter TDC/Graft/fistulaNo needles Two needles 3 x wkRisk of peritonitis Risk of bacteremia

Why do patients choose PD--

Issues of autonomy and control were important for 95% of patients choosing PD.

Other reasons for choosing PD: (1) flexibility (2) convenience (3) night-time dialysis

Adapted from Wuerth et al PDI 2002; 22:184-19026

• Non adherence is common on in center HD. If PD is the patient choice, patient may be more compliant with PD than HD.

• Most patients can learn PD with a good trainer who tailors the therapy to the individual.

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Other notes on PD selection

Your patient has chosen PD.What now?

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Schedule PD catheter placement

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The PD catheter can be placed as same day surgery.

• Very important to chose operator to place the PD catheter who will work with you.– Can be surgeon, nephrologist, radiologist.

• Leave exit site covered with clean dressing until training begins; do not allow patient to get this wet.

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Urgent start PD

• PD catheter can be used the same day or the next day.

• This is now called urgent start dialysis. • Appropriate if dialysis needed sooner.• PD should be supine with low volumes. • Generally used when patient hospitalized.

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PD training• We believe one-on-one training is best.• Nurse doing the training must be trained in

not only PD but how to teach PD.• Training best individualized to the patient.• Training covers theory, basics of the

procedure, recognition of peritonitis. • Test is given at the completion of training to

ensure knowledge.

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Dialysis fluid contains

Dextrose 1.5, 2.5, 4.25Na and ClLactateCaMgsterile waterpH low

Efluent is the spent (dwelled) dialysate

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Obtain a clearance early in the course of PD.

• Kt/V is used but described as per week.• Obtained by collecting effluent for one day,

measuring urea nitrogen to calculate Kt and divided by V. This is then multiplied by 7 to get weekly value.

• Renal clearance is added into this, when present.

Minimum: 1.7 per week.

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Peritonitis causespain,hospitalization,peritoneal membrane damageand sometimes death.

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Peritonitis may contribute to death

• AUSNZ registry: examined 1316 PD pts who died on PD or within 30 days of transfer to HD

• 19% of PD pt who died had peritonitis in the preceding 30 days

• Even though only 6% coded as having died from peritonitis.

Boudville et al JASN 2012: 23: 1-8

HD and PD both have associated infections but different types:– HD patients get bacteremia and

pneumonia– PD patients get peritonitis

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Infections are the second leading cause of death in the dialysis patients

Think about what causes peritonitis

• Contamination• Enteric sources• Catheter related: exit site or slime related• Bacteremia (rare)• GU sources (rare)

Preventing peritonitis from contamination: the nurse is all-

important in training the PD patient

Found at ispd.org

Do not assume a nurse who knows PD, knows how to teach PD. ISPD web site has a section on Training the Trainer

• Transmural migration• Bowel ischemia• Diverticulitis• Colitis• Cholecystitis• Perforation of an organ• Appendicitis• GI procedures

GI sources of peritonitis

Ischemic bowel

Cholecystitis

Procedures can lead to peritonitis

• Extensive dental work (streptococcus)• Colonoscopy/proctoscopy (enteric)• Lap cholecystectomy (enteric)• Percutaneous gastrostomy (enteric/fungal)• Endometrial biopsy/hysteroscopy

(streptococcus, funal, anaerobes)

Preventing peritonitis from ESI: Double blinded multi-center RCT of exit site

gentamicin vs mupirocin

0

0.1

0.2

0.3

0.4

0.5

0.6

mupirocin gentamicin

otherfungalP aeruginsosS aureus

Bernardini….Piraino JASN 2005: 16: 539-545

Exit site infections in episodes per year at risk

Peritonitis due to biofilm

Biofilm can lead to refractory, relapsing or repeat peritonitis

Canadian study, POET data base: 181 patients 1996-2005 had 2 episodes peritonitis with same organism

-Coag neg staph caused 2/3-1st episode coag neg staph peritonitis vs other organisms had odds ratio of 2.1 of another episode within one year-½ occurred within 6 months of 1st episodes

Nessim et al PDI 2012

Topics to be Discussed

• The impact of increased intra-abdominal pressure Hernias

Abdominal and Genital Leaks Hydrothorax

• Colored dialysis effluent• Psychosocial issues• Encapsulating Peritoneal Sclerosis• Metabolic changes secondary to PD

Increased Intra-abdominal Pressure

• Hernias: Incisional

Umbilical Ventral

• Diaphragmatic Leaks

• Pericatheter Leaks: Abdominal wall or Genital

Abdominal swelling or bogginess or scrotal or labial edema

• Diagnosis:physical exam , Radiological studies CT scan, Technetium scan

Management

• Hernias: Repair

• Leaks:Use low pressure PD (eg APD with low

volumes with patient lying and a “dry day”).

Temporary HD to allow healing.

Hydrothorax• The presence of peritoneal dialysis fluid in the pleural

cavity.• PD fluid moves through congenital or acquired

defects in the diaphragm.• Diagnosis:a. Pleural tap with fluid analysisb. Technitium scan, CT scanc. Stop and restart PD with monitoring of extent of pleural effusion.

• Treatment: temporary respite from PD pleurodesis, pleuroscopic repair (diaphragmatic defects identified and patched or sutured)

Metabolic Problems of the CKD Patient

General for CKD patients• Thyroid dysfunction• Metabolic syndrome• Abnormalities of sex

hormones• Lipid abnormalities• Glucose intolerance• Mineral metabolism• Insulin resistance

PD Specific• Dextrose exposure• Weight gain• Metabolic syndrome• Specific lipid related issues• Insulin resistance• Others: Leptin,

Adinoponectin, Ghrelin• Protein losses

Lipid Changes After the Start of PD Pennell

Clin Nephrol 62:35, 2004

• A significant increase in total cholesterol, LDL, cholesterol, triglyceride, and VLDL levels occur after start of PD.

• No change in HDL levels• These changes can be ameliorated with

appropriate management protocols.

Metabolic Syndrome and the PD Patient

Jhang et al : Blood Purification , 26:423, 2008

• Increased risk in PD patients (c. 50% of prevalent PD patients, 20% HD patients, 30% CKD patients.

• The driving forces for the development of Metabolic Syndrome in Pd patients are clearly related to glucose absorption.

• 195 non-diabetic patients maintained on PD

• 22% of patients met criteria for MS* at initiation of PD

• After mean of 34 months (range 20 – 60 months), 69% met criteria for MS

• Development of MS was correlated with dextrose exposure and duration of PD.

* Defined with National Cholesterol Education Adult Treatment Panel III criteria.

Conclusion• There are a variety of non-infectious problems

that are specific to peritoneal dialysis.• With increasing experience, the impact of

these problems may be manageable• The largest problem relates to chronic

dextrose exposure, which in turn results in changes in transport characteristics, damage to the peritoneal membrane and various metabolic issues.

Recommendations• Limiting dextrose exposure must be a

cornerstone of PD management• Liberal use of icodextrin and high dose

furosemide therapy (in those patients with residual function) to minimize dextrose exposure is critically important.

• Targeting Kt/V algorithms to achieve levels of 1.7 – 2.0 should be the standard; there is no benefit of targeting higher doses.

What is important when prescribing PD?

• Clearance targets.

• Adequate ultrafiltration to control volume.

• Avoiding excess glucose exposure.

• Cost of prescription.

What is important when prescribing PD?

But this is the era of patient centered care and we need patient centered PD so…

Patient symptoms

Patient lifestyle

INTRODUCTION

• Achieving high solute clearance in PD is a whole lot easier since the Ademex Study and the consequent reduction in K/DOQI targets.

• A target Kt/V of 1.7 per week for all patients – CAPD and APD, high and low transporters.

Clearance on PD determinants

1. Residual renal function.

2. Body size.

3. Peritoneal transport status.

4. PD prescription

Present Kt/V Targets

• Easy to reach if patients have residual renal function.

• Typically, 60-70% do and it is often substantial due to earlier start on dialysis.

• Each ml/min urea clearance equals about 0.25 Kt/V per week so 4 mls/min = 1.0 Kt/V

Increasing Clearance in CAPD

• Three options:

• Increase dwell volume

• Increase number of exchanges

• Increase dialysate tonicity

Increasing Dwell Volume

• Most cost effective way to increase clearance.• Diffusion gradient lasts longer• Equilibration for 2.5L is only slightly less than

with standard 2L volumes.• Raised intraperitoneal pressure is limiting

factor – mechanical side effects.

Strategies to Achieve Targets CAPD

• In CAPD, many smaller patients will achieve pKt/V 1.7 on 4 x 2L daily.

• Larger patients will require 4 x 2.5L

• Few will need 4 x 3L or 5 x 2L or switch to APD

Thank you.

APD Prescription

Cycler Related:• Number of cycles

• Dwell volume

• Cycler time

• Tonicity

Day Dwell Related:• No cf Day dwells

• Dwell volume

• Dwell duration

• Tonicity

Day Dwells

• Single most effective way to raise clearance in a day. Dry APD patient is to add a day dwell – raises Kt/V 30 – 40%

• If already has a day dwell, the most effective intervention is a second day dwell raises Kt/V c 20%.

• Should be at least 4 hours duration to get full benefit in Kt/V

Day Dwells POINTS TO REMEMBER

• The larger the dwell volume the greater the clearance i.e. 2.5v 2v 1.5L

• Day dwells can be done more simply and less expensively using cycler tubing and large volume bags.

• Adding a second day dwell creates more work for the patient or caregiver.

Day Dwells POINTS TO REMEMBER

• Longer glucose based day dwells may lead to net fluid resorption and so may actually decrease clearance as well as UF.

• There are a number of strategies to deal with this.

Day Dwell Options for Better UF

• Go “day dry” – an option if there is lots of residual function.

• Do 2 day dwells – drain and refill – maximizes clearance.

• Shorten day dwell by draining and remaining dry part of the day.

• Use Icodextrin for day dwell – increasingly popular.

Increasing Cycler Clearance

• Longer time raises clearance but > 9 hrs is not acceptable to most patients.

• What about dwell volume? Is 4 x 2.5 L cycles better than 5 x 2L?• What about cycle frequency? Is 7 x 2L better than 5 x 2L? Is 9 x 2L better than 7 x 2L?

Optimal Cycle Frequency

• There is confusion about whether or not increasing the number of cycles raises clearance significantly.

• Concern is that more time is spent draining and filling (down time) and less actually dialyzing.

• However, frequent cycling keeps blood to dialysate gradient high and so promotes more diffuse clearance.

Optimal Cycle Frequency Study Perez et al (PDI 2000)

• 18 patients at 2 centers• 4 different prescriptions for 7 days each• Measurement of clearances, UF, Na, K+, and

protein losses and glucose absorption on days 5 -7 on each prescription.

• Clearance due to residual renal function and day dwells was ignored.

Optimal Cycle Frequency Study 4 prescriptions

1. 5 x 2L over 9 hours

2. 7 x 2L over 9 hours

3. 9 x 2L over 9 hours

4. 15L TPD (50%) using 1L + 14 x 1L over 9 hours

Optimal Cycle Frequency Study Perez et al (PDI 2000)

• 9 x 2L was the best in 12 of the 18 (in 9 by > 10%)

• 7 x 2L was the best in 3, TPD in 2• Advantage of 9 x 2L was greatest for Kt/V• Advantage was seen in both low and high

transporters for both Kt/V and Cr Cl• UF was better in 7 x 2L and 9 x 2L versus 5 x

2L.

Optimal Cycle Frequency Study Conclusion

• More cycles raise clearance significantly in most patients.

• 4 – 5 cycles per 9 hours under-uses clearance potential of APD.

• But cost was 27% greater for 15L vs. 10L and 54% for 18L vs. 10L so adding day dwells is more cost effective but also more work for patient.

Incremental Dialysis

• Idea that full dialysis dose need not be prescribed initially in patients with substantial residual renal function.

• In HD – twice weekly treatments.• In PD – 3 dwells daily in CAPD or “day dry” in

APD

Incremental Dialysis “London Approach”

• All elective starts do “day dry” APD.• Quarterly measurements of pKt/V and rKt/V

as well as clinical assessment.• Continue without day dwell as long as patient

well and Kt/V > 1.7• Some cycle < 7 nights a week.

Incremental PD Definition

• Total weekly Kt/V reaching target of > 1.7 with peritoneal Kt/V < 1.7.

PLUS• A “day – dry” or < 7 nights/ week schedule for

APD patients. OR

• < 8L/ day schedule for CAPD patients.