Presentation about chronic renal failure and dialysis types.

1. CRF and Dialysis
Darya Osman
Eman Salah
Moaz Ahmed
Manal Balla

2. Quick Overview of CRF
 Usually asymptomatic until advanced stages
 Usually detected at earlier stage by blood and urine test
 Common in individuals with:
 HTN
 DM
 Family history of CKD

3. Early Renal Disease – Renal Insufficiency

4. End Stage Renal Disease – Renal Failure

5. Indications for Dialysis
 Should be started when benefit of
relieving uremic signs and symptoms
outweighs risk and decrease in quality of
life
 Indications vary for acute and chronic
kidney injury

6. Dialysis indications for ARF
 Think AEIOU
 Acidemia – from metabolic acidosis
 Electrolyte abnormality
 e.g. severe hyperkalemia
 Intoxication
 acute poisoning with dialyzable SLIME substances (i.e. Salicylic acid, Lithium,
Isopropanol, Mg containing laxatives and Ethylene glycol)
 Overload of fluid
 Uremia complications
 e.g. pericarditis, encephalopathy or GI bleeding

7. Dialysis indications for CRF
 Indicated when patient has symptomatic kidney failure and low glomerular
filtration rate
 Studies found that early start of dialysis may be harmful
 Recently guidelines recommend deferring dialysis until a patient has definite
kidney failure symptoms (i.e. those that occur at GFR of 5-9ml/min/1.732)
 May also be indicated if there is difficulty to medially control fluid overload or
serum potassium level
 If symptoms of Intractable kidney failure may start dialysis at eGFR levels
above 10ml/min/1.732

8. General Principles of Dialysis
 Works on the principles of diffusion and
ultrafiltration of fluid across a semi-
permeable membrane.
 Diffusion: movement of solute across
semi- permeable membrane from region of
high concentration to low concentration
 Ultrafiltration: water is driven by either a
hydrostatic or an osmotic force is pushes
through the membrane.

9. Principle of Dialysis
 Blood flows by one side of a semi-permeable
membrane and a dialysate (special dialysis
fluid) flows by the opposite side
 Semipermeable membrane contains pores of
various sizes
 Smaller solutes and fluid pass through
membrane but large substances do not (e.g.
RBCs, large proteins)
 Replicates filtering process of the glomerulus
of the kidney

10. Goal of Dialysis
 Solute clearance
 Diffusive transport (based on counter current flow of
blood and dialysate)
 Conventional transport (solvent drag with
ultrafiltration)
 Fluid removal

11. Types of Dialysis
 Haemodialysis
 Peritoneal Dialysis
 Hemofiltration

12. Hemodialysis
 Waste products are filtered from blood by a semi-permeable
membrane and removed by the dialysis fluid, or dialysate.
 In-center: 4 hours, 3 days a week
 Home: Daily
 Nocturnal In-centre: 6-8 hours, 3nights/week

13. Types of Hemodialysis
In center dialysis
Home haemodialysis
In centre nocturnal dialysis

14. Dialysate Composition
 Varies according to clinical need
 Major/Common components:
 High purified water
 Sodium
 Potassium
 Calcium
 Magnesium
 Chloride
 Bicarbonate
 dextrose

15. Access for Hemodialysis
 Arteriovenous Fistula
 Arteriovenous Graft
 Central Venous Catheter

16. Arteriovenous Fistula
 Preferred form of dialysis access
 once the fistula properly matures and gets bigger and stronger; it provides
an access with good blood flow that can last for decades.
 Types:
 Radiocephalic (first choice)
 Brachiocephalic (second choice)
 Brachiobasilic (thirs choice, requires superficialization of basilic vein,i.e.
Transposition)

19. Arteriovenous Graft
 Placed between an artery and a vein
 Either straight or looped
 Common sites:
 Radial artery to cephalic vein
 Brachial artery to cephalic vein
 Brachial artery to axillary vein
 Axillary artery to axillary vein

21. Central venous catheters
 Aka cuffed dialysis catheter
 Most commonly placed in the internal jugular Vein, existing at the upper,
anterior chest.
 Can also be placed in the femoral vein.
 Subclavian catheters should be avoided due to risk of subclavian stenosis.
 ADV: no need for fistula.
 DIS ADV: short period use, infection, thrombosis, inadequate blood flow and
overall increased risk of mortality.

23. Peritoneal Dialysis
 Use of peritoneal membrane as a filter to clear wastes and extra fluid from
the body and to return electrolyte levels to normal.
 Peritoneal cavity: reservoir for dialysate (sodium, chloride, lactate and
glucose)
 Peritoneum: semi- permeable membrane across which excess body fluid
and solutes are removed (fluid, urea, creatinine and potassium)

24. Peritoneal Dialysis

25. Types of Peritoneal Dialysis
 Continuous ambulatory PD:
 4-8 hours
 4 times/day
 Automated PD:
 Continuous cycling once a day

26. PD Transport
 Diffusion
 Ultra-filtration
 Absorption

27. Advantages of Haemodialysis vs.
Peritoneal dialysis
Haemodialysis
 Done by trained health professionals
who can watch for any problems.
 Allows contact with other people
having dialysis, which may give you
emotional support.
 Not done by oneself, as with
peritoneal dialysis.
 Done for shorter amount of time and
on fewer days each week than
peritoneal dialysis.
Peritoneal dialysis
 Gives you more freedom than
hemodialysis.
 Can be done at home.
 You can do it when you travel.
 You may be able to do it while
you sleep.
 You can do it by yourself.
 It doesn't require as many food and
fluid restrictions as hemodialysis.
 It doesn't use needles.

28. Disadvantages of Hemodialysis vs.
Peritoneal dialysis
Hemodialysis
 Causes feeling of tiredness on the
day of dialysis.
 Can cause problems such as low
blood pressure and blood clots in
the dialysis access.
 It increases your risk of
bloodstream infections.
Peritoneal diaysis
 Procedure may be hard for some
people to do.
 Increases risk for an infection of the
lining of the belly, called peritonitis.

29. Hemofiltration
 Based on convective transport rather than diffusion to remove solutes
from blood of uremic patients
 Requires no dialysate, however require substitution fluid
 Positive hydrostatic pressure drives water and solutes get dragged along
the flow of water
 Sometimes used in combination with hemodialysis
 Usually used for ARF and sepsis

32. Types of hemofiltration
 On-line intermittent hemofiltration (IHF) or
hemodiafiltration (IHDF)
 Continuous hemofiltration (CHF) or
hemodiafiltration (CHDF)

33. On-line intermittent hemofiltration (IHF) or
hemodiafiltration (IHDF)
 Given in outpatient dialysis units
 3 or 4 times per week
 3 – 5 hours per treatment
 Substitution fluid is prepared on-line from dialysis solution
 Solution is run through two sets of membranes to purify it before infusing directly
into blood line.

34. Continuous hemofiltration (CHF) or
hemodiafiltration (CHDF)
 Used as treatment for fluid overload
 Treatment usually 8 – 12 hours (SLEF – Slow Extended Hemofiltration)
 A.K.A. continuous veno-venous hemofiltration
 No on-line creation of replacement fluid from dialysis solution
 Native hemodialysis access (i.e. fistulas or grafts) are unsuitable because of prolonged
residence of access needles required might damage accesses

35. Advantages of Hemofiltration
 Convection overcomes reduced removal rate of larger solutes (due to slow speed
of diffusion)
 Characterized by increased solute removal capabilities for higher MW solutes
 More similar to glomeruli in the function of filtration.
 More suitable than Hemodialysis to some symptoms
 Resistant Hypertension
 Water Retention, Hypertension
 Heart Failure caused by high blood volume,
 Uremic Pericarditis,
 Acute Renal Failure
 Hepatic Coma.

36. Disadvantages of Hemofiltration
 price is higher than Hemodialysis due to the need of plentiful
placement fluid
 Blood pressure during Hemofiltration is not easy to control
and low pressure and high pressure may occur if the volume
is in imbalance.
 The small products may be not removed as effectively as
Hemodialysis.
 Therefore, which dialysis to choose depends on each patient’s
individual condition

37. Thank you!