Dialysis

1. DIALYSIS
Dr. Frank Edwin

2. CAUSES OF RENAL
FAILURE
 􀂃 Diabetes
 􀂃 Untreated high blood pressure
 􀂃 Inflammation
 􀂃 Heredity
 􀂃 Chronic infection
 􀂃 Obstruction
 􀂃 Accidents

3. 1.Renal Failure Diagnosis
Symptoms: Anorexia, Nausea, Vomiting, Oliguria
• ? Precipitating factors
Signs: Anaemia, Hypertension, Fluid Overload etc
Biochemistry:
– Blood
• Urea >7mmol/l
• Creatinine >120umol/l
• Electrolytes: Rising K+
– Creatinine Clearance (GFR <<120ml/l)
– Urine: Proteinuria
May be Acute or Chronic
Acute – Reversible or Irreversible

4. 2. Treatment Options
No Treatment
Monitoring & Predialysis
– Control symptoms
– Preserve Residual Renal Function
• Control rising BP (Antihypertensives)
• Control Renal Bone Disease (Ca2+
, Vit D)
• Prevent/Treat Anaemias (Erythropoietin, Blood)
Dialysis
Renal Transplantation

5. Dialysis
Definition
Artificial process that partially replaces renal
function
Removes waste products from blood by
diffusion (toxin clearance)
Removes excess water by ultrafiltration
(maintenance of fluid balance)
Wastes and water pass into a special liquid –
dialysis fluid or dialysate

6. Types
Haemodialysis (HD)
Peritoneal Dialysis (PD)
They work on similar principles: Movement
of solute or water across a semipermeable
membrane (dialysis membrane)

7. Diffusion
Movement of solute
Across semipermeable membrane
From region of high concentration to one of
low concentration

8. Ultrafiltration
Made possible by osmosis
Movement of water
Across semipermeable membrane
From low osmolality to high osmolality
Osmolality – number of osmotically active
particles in a unit (litre) of solvent

9. Selection for HD/PD
Clinical condition
Lifestyle
Patient competence/hygiene (PD - high risk
of infection)
Affordability / Availability

10. 1.
2.
Blood cells are too big to pass through the dialysis membrane,
but body wastes begin to diffuse (pass) into the dialysis solution.
3.
Diffusion is complete. Body wastes have diffused through the membrane,
and now there are equal amounts of waste in both the blood and the
dialysis solution.

11. The process of ultrafiltration in PD
11.
2
2.
Blood cells are too big to pass through the semi-permeable membrane,
but water in the blood is drawn into the dialysis fluid by the glucose.
3.
Ultrafiltration is complete. Water has been drawn through the peritoneum
by the glucose in the dialysis fluid by the glucose in the dialysis fluid. There is
now extra water in the dialysis

12. Haemodialysis
Dialysis process occurs outside the body in a
machine
The dialysis membrane is an artificial one:
Dialyser
The dialyser removes the excess fluid and
wastes from the blood and returns the filtered
blood to the body
Haemodialysis needs to be performed three
times a week
Each session lasts 3-6 hrs

14. Requirements for HD
Good access to patients circulation
Good cardiovascular status (dramatic
changes in BP may occur)

15. Performing HD
HD may be carried out:
In a HD Unit
At a Minimal Care / Self-Care Centre
At Home

16. HD Unit
Specially designed Renal Unit within a hospital
Patients must travel to the Unit 3x a week
Patients are unable to move around while on
dialysis; may chat, read, watch TV or eat
Nursing staff prepare equipment, insert the
needles and supervise the sessions

17. Minimal / Self-Care Dialysis
Patients take a more active role
Patients prepare the dialysis machine, insert
the needles, adjust pump speeds and
machine settings and chart their progress
under the supervision of dialysis staff
Patients must travel to the unit 3x / week
Patients need to be on a fixed schedule

18. Home Haemodialysis
Use of machines set up at home
Machines have many safety devices inbuilt
Thorough patient training
Requires the help of a partner at home every time
Suitability is assessed by the haemodialysis team
Ideal for patients who value their independence
and need to fit in their treatment around a busy
schedule

19. HD Access
2 types of access for HD:
– Must provide good flow
– Reliable access
A fistula: arterio-venous (AV)
Vascular Access Catheter

20. AV Fistula

21. AV Fistula

22. Vascular Access Catheter

23. AV Fistula Access
Matures in about 6 weeks
Ensure good working order
– Avoid tight clothing or wrist watch on fistula arm
– Assess fistula daily; notify immediately if not working
– Avoid BP cuff on fistula arm
– Avoid blood sampling on fistula arm (except daily
HD Rx)
– Avoid sleeping on fistula arm
– Grafts (synthetic) may be used to create an AV fistula

24. Vascular Access Catheter
Double lumen plastic tube
May be placed in Jugular, Subclavian or Femoral
vein
May be temporary or permanent
Temporary – awaiting fistula or maturation
Permanent – poor vessels for fistula creation e.g.
children and diabetics
Catheters must be kept clean, dry and dressed to
prevent infection

25. Effects of HD on Lifestyle
 Flexibility:
– Difficult to fit in with school, work esp if unit is far from home.
Home HD offers more flexibility
 Travel:
– Necessity to book in advance with HD unit of places of travel
 Responsibility & Independence:
– Home HD allows the greatest degree of independence
 Sexual Activity:
– Anxiety of living with renal failure affects relationship with
partner
 Sport & Exercise:
– Can exercise and participate in most sports
 Body Image:
– Esp with fistula; patient can be very self conscious about it

26. Problems with HD
 Rapid changes in BP
– fainting, vomiting, cramps, chest pain, irritability, fatigue, temporary loss of
vision
 Fluid overload
– esp in between sessions
 Fluid restrictions
– more stringent with HD than PD
 Hyperkalaemia
– esp in between sessions
 Loss of independence
 Problems with access
– poor quality, blockage etc. Infection (vascular access catheters)
 Pain with needles
 Bleeding
– from the fistula during or after dialysis
 Infections
– during sessions; exit site infections; blood-borne viruses e.g. Hepatitis, HIV

27. Peritoneal Dialysis (PD)
Uses natural membrane (peritoneum) for dialysis
Access is by PD catheter, a soft plastic tube
Catheter and dialysis fluid may be hidden under
clothing
Suitability
– Excludes patients with prior peritoneal scarring e.g.
peritonitis, laparotomy
– Excludes patients unable to care for self

28. Addendum to Principles (PD)
Fluid across the membrane faster than solutes;
therefore longer dwell times are needed for solute
transfer
Protein loss in PD fluid is significant ~ 8-9g/day
Protein loss ↑s during peritonitis
PD patients require adequate daily protein
averaging 1.2 – 1.5g/kg/day
Other substances lost in the dialysate
– Amino acids, water soluble vitamins, some
medications and hormones
Calcium and dextrose are absorbed from the
dialysate fluid into the circulation

29. Addendum to Principles (PD)
Standard dialysis solution contains:
• Na+
– 132 mEq/l
• Cl-
– 96 -102 mEq/l
• Ca2+
– 2.5 – 3.5 mEq/l
• Mg2+
– 0.5 -1.5 mEq/l
Dialysis solution buffer:
– Sodium lactate
– Pure HCo3
-
– HCo3
-
/Lactate combinations
Lactate is absorbed and converted to HCo3
-
by the
liver
Dextrose solution strengths: 1.5%, 2.5%, 4.25%

30. Types
Continuous Ambulatory Peritoneal Dialysis
(CAPD)
Automated peritoneal Dialysis (APD)

31. CAPD
Dialysis takes place 24hrs a day, 7 days a week
Patient is not attached to a machine for treatment
Exchanges are usually carried out by patient after
training by a CAPD nurse
Most patients need 3-5 exchanges a day i.e.
– 4-6 hour intervals (Dwell time) 30 mins per exchange
May use 2-3 litres of fluid in abdomen
No needles are used
Less dietary and fluid restriction

32. CAPD Exchange

33. APD
Uses a home based machine to perform exchanges
Overnight treatment whilst patient sleeps
The APD machine controls the timing of
exchanges, drains the used solution and fills the
peritoneal cavity with new solution
Simple procedure for the patient to perform
Requires about 8-10 hrs
Machines are portable, with in-built safety features
and requires electricity to operate

34. PD Access
 Done under
 LA or GA

35. DIET
Why is diet important?
– Managing the diet can slow renal disease
– The need for dialysis can be delayed
– The diet affects how patients feel

36. CONTROLLING YOUR
DIET
Foods to control are those containing:
 Protein
 Potassium
 Sodium
 Phosphorous
 Fluid

37. PROTEINS
Animal protein
Dairy (milk, cheese)
Meat (steak, pork)
Poultry (chicken, turkey)
Eggs
Plant protein
Vegetables
Breads
Cereals

38. MAJOR SOURCES
OF POTASSIUM
Milk
Potatoes
Bananas
Oranges
Dried Fruit
Legumes
Nuts
Salt substitute
Chocolate

39. SODIUM
Regulates blood volume and pressure
Avoid salt
Use Alternate food seasonings: lemon and limes,
spices, seafood seasoning, Italian seasoning,
vinegars, peppers

40. FLUIDS
Healthy kidneys remove fluids as urine
Check for fluid and sodium retention
Need to restrict fluid intake

41. PHOSPHOROUS
Phosphorus is a mineral which combines with
calcium to keep bones and teeth strong
Too little calcium and too much phosphorus
Need to control the phosphorus in the diet
Need to take a phosphate binder or a calcium
supplement

42. VITAMINS
Folic acid
Iron supplements
Do not take OTC’s without consulting the
doctor.

43. MANAGING YOUR DIET
INDICATORS OF GOOD CONTROL:
 Weight loss or gain
Blood pressure
Swelling of hands and feet
Blood samples

44. LAB MONITORING
 Haemoglobin
 Albumin
 Calcium
 Phosphorus
 GFR
 (24 hour urine)
 Sodium
 Potassium
 Urea
 Creatinine

45. Lifestyle Changes with PD
Flexibility
– Can be performed almost anywhere
– Least impact on work / school life (esp APD)
Travel
– Dialysis supplies can be delivered to most parts of the
world; travel more flexible. APD machines are portable;
will fit into a car boot, can be carried by train/air
Responsibility
– Requires more responsibility from patient but more
independence

46. Lifestyle Changes with PD
Sports/Exercise
– Most are possible
– Advice on swimming, lifting, contact sports
Sexual Activity
– May affect relations based on patient anxiety
Delivery & Storage of Supplies
– Home delivery and storage
– A month’s supplies – 40 boxes; space to store
– Specially recruited and trained delivery staff

47. Problems with Treatment
Monotomy of treatment
– The treatment never goes away against days off with HD
Body Image Problems
– Esp with a permanent catheter
– Abdominal stretching
Fluid Overload
– Much less a problem than with HD
Dehydration
– Less common than fluid overload
Abdominal Discomfort
– Bloated feeling

48. Problems with Treatment
Poor drainage
– Common problem esp with new patients
– Fibrin plug
– Catheter displacement
Leakage
– Fluid may leak around catheter exit site. (May leak
into scrotum)
– Stop PD temporarily
– Resite catheter (use new one)
Infections
– Exit site infections
– Tunnel infection
– peritonitis

49. Problems with Treatment
Hernia
– Aggravation of pre-existing herniae (repair)
– Evolution of new herniae
Declining effectiveness of the peritoneum
– e.g. repeated infection
– Effect of glucose in the dialysis fluid

50. Comparison of Dialysis Treatment Options
PD Unit HD Home HD
Home Dialysis √ × √
Convenient Sessions √ × √
Socializn with other CRF pats × √ ×
Home Equipment/Supplies √ × √
Special diet/fluid allowance √ √ √
Sports/exercises participation Most Most Most
Full day activity -work/school √ Not alwys √
Direct assist–partner/family × × √
Travel √ Delivery of
supplies to most
destins easy.
Some notice req
√ Prior
arrangements
must be made
well in advance
× Prior
arrangements must
be made well in
advance