PERITONEAL DIALYSIS

• SO WHAT IS ALL THIS????

PERITONEAL DIALYSIS

• A FAIRLY SIMPLE TECHNIQUE!

• http://www.kidneypatientguide.org.uk/site/pdanim.html

EQUIPMENT

• Dialysis membrane

• Catheter (Tenckhoff)

• Dialysis fluid

• Tubing

• A stick with a hook

• Scales

• Cycler

Technique

• CAPD- USUALLY 5 CYCLES if smaller, 4 –school child morn., after school, teatime and bedtime

• APD: NIPD, CCPD

• TIDAL PD

• ? Continuous PD

PHYSIOLOGY

• Peritoneal membrane: different pores, large surface area, good blood flow (30-50ml/min in adult)

• Gradient against the plasma

• Semi-permeable ie depends on MW/size and pores.

PHYSIOLOGY

• Diffusion

• Ultrafiltration

• Lymphatic absorption

Ultrafiltration

• Water moves freely through aquaporins…either way!

• Dialysate osmolality largely depends on glucose concentration

• 1.5%- 346, 2.5%-396, 4.25%-485 mosmol/L

• Prob: Glucose can also move into plasma

• High or low transporters/ infection/ sclerosis

Solute transport

• Diffusion

• Dianeal contains– Na- 132

– Cl- 96

– Ca- 1.8

– Lactate- 40

– Mg- 0.25

TREATMENT PARAMETERS

• Fluid status

• BP

• Wt, UF

• Catheter, dialysate

• Biochemistry: Na, K, Phos, Ca, Alb, Urea

• Growth!

• Practical regimen (cycler)

Complications

• Mechanical- fluid related, hernias

• Mechanical- line related, obstruction

• Mechanical- extrusion, migration out of pelvis, constipation

• Sepsis- exit site, tunnel, peritonitis

• Body image

• Protein loss

Complications

• Hyperlipidaemia

• Thrombotic tendency

• Peritoneal sclerosis (esp 4.25%)

• Developmental/ psychosocial

• Pain- Tidal PD, special solutions

• Loss of function of peritoneum

• PARENT BURN-OUT!!!

PARENT BURN-OUT!!!

• Ask how long exchanges take

• How cooperative is the child

• How often are there contamination episodes

• How often do they dress site

• How is it affecting normal activities eg swimming

• Where do they store all the gear

ESRF Signs and Symptoms

• Hypertension, PVD - medication

• Anaemia – tiredness and lethargy. EPO

• electrolyte/fluid imbalance - diet

• Ca and Ph imbalance - osteomalacia and osteodystrophy

• growth retardation - lack of hormone synthesis,hGH

• nausea and nutrition – uraemic environment

PD and Nutrition

• Beginning PD actually benefit by increasing feeling of wellbeing and the lifting of restrictions a little of K and fluid

• Barriers include feeling full and vomiting• Need to run on higher protein intake eg 2-4

g/kg/d• Dialyse off water- soluble vitamins• Special amino acid solutions

So how well does it work?

• NATIVE KIDNEYS- GFR= approx 100ml/min/1.3m2

• PD aims to achieve Cr clearance of >70 l/wk---> >7ml/min

• Residual renal function makes a huge difference to fluid control and clearance

So how do we maximise it?

• Increase osmolality- more UF

• Increase volume- gradient disappears slower + recruit more perit SA

• Increase frequency of exchanges

OTHER ISSUES

• Contamination episodes

• When to consider HD

• Liasison with PD nursing staff

• Bacterial prophylaxis