DIALYSIS

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DIALYSIS

• Dr. Frank Edwin

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CAUSES OF RENAL FAILURE

• ?? Diabetes
• ?? Untreated high blood pressure
• ?? Inflammation
• ?? Heredity
• ?? Chronic infection
• ?? Obstruction
• ?? Accidents

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1.Renal Failure Diagnosis

• Symptoms Anorexia, Nausea, Vomiting, Oliguria
• ? Precipitating factors
• Signs Anaemia, Hypertension, Fluid Overload etc
• Biochemistry
• Blood
• Urea gt7mmol/l
• Creatinine gt120umol/l
• Electrolytes Rising K
• Creatinine Clearance (GFR ltlt120ml/l)
• Urine Proteinuria
• May be Acute or Chronic
• Acute Reversible or Irreversible

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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

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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

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Types

• Haemodialysis (HD)
• Peritoneal Dialysis (PD)
• They work on similar principles Movement of
  solute or water across a semipermeable membrane
  (dialysis membrane)

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Diffusion

• Movement of solute
• Across semipermeable membrane
• From region of high concentration to one of low
  concentration

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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

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Selection for HD/PD

• Clinical condition
• Lifestyle
• Patient competence/hygiene (PD - high risk of
  infection)
• Affordability / Availability

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The process of diffusion 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.
                                               D
iffusion 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.
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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  fluid which need to be changed.
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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

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Requirements for HD

• Good access to patients circulation
• Good cardiovascular status (dramatic changes in
  BP may occur)

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Performing HD

• HD may be carried out
• In a HD Unit
• At a Minimal Care / Self-Care Centre
• At Home

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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

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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

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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

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HD Access

• 2 types of access for HD
• Must provide good flow
• Reliable access
• A fistula arterio-venous (AV)
• Vascular Access Catheter

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AV Fistula
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AV Fistula
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Vascular Access Catheter
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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

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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

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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

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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

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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

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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

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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

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Types

• Continuous Ambulatory Peritoneal Dialysis (CAPD)
• Automated peritoneal Dialysis (APD)

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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

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CAPD Exchange
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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

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PD Access

• Done under
• LA or GA

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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

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CONTROLLING YOUR DIET

• Foods to control are those containing
• Protein
• Potassium
• Sodium
• Phosphorous
• Fluid

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PROTEINS

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

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MAJOR SOURCES OF POTASSIUM

• Milk
• Potatoes
• Bananas
• Oranges
• Dried Fruit

• Legumes
• Nuts
• Salt substitute
• Chocolate

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SODIUM

• Regulates blood volume and pressure
• Avoid salt
• Use Alternate food seasonings lemon and limes,
  spices, seafood seasoning, Italian seasoning,
  vinegars, peppers

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FLUIDS

• Healthy kidneys remove fluids as urine
• Check for fluid and sodium retention
• Need to restrict fluid intake

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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

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VITAMINS

• Folic acid
• Iron supplements
• Do not take OTCs without consulting the doctor.

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MANAGING YOUR DIET

• INDICATORS OF GOOD CONTROL
• Weight loss or gain
• Blood pressure
• Swelling of hands and feet
• Blood samples

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LAB MONITORING

• Haemoglobin
• Albumin
• Calcium
• Phosphorus
• GFR
• (24 hour urine)

• Sodium
• Potassium
• Urea
• Creatinine

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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

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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 months supplies 40 boxes space to store
• Specially recruited and trained delivery staff

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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

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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

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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

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