Topic: Renal Replacement Therapies(RRT) Faculty: General Medicine Course: BSc RDT - 2nd year - Renal replacement therapy - Hemodialysis - Peritoneal Dialysis - Dialysis disequilibrium syndrome - Renal transplantation

1. Renal replacement
therapies
Dr. Salman Ansari
Kanachur Institute of Medical Sciences

2. Contents
● Renal replacement therapy
● Hemodialysis
● Peritoneal dialysis
● Dialysis disequilibrium syndrome
● Renal transplantation

3. Renal replacement therapies(RRT)
RRT is required in:
- As a temporary measure in patients with AKI
- As a permanent measure in patients with CKD

4. Aim of RRT
To replace all the excretory functions of the normal kidney namely
excretion of nitrogenous wastes
Maintenance of:
– Plasma biochemistry
– Normal electrolyte concentrations
– Normal extracellular volume (fluid balance)
But it cannot replace endocrine and metabolic functions of kidney

7. Principle of dialysis
● Solutes shift from high concentration compartment to low
concentration compartment if separated by a semipermeable
membrane
● Patient blood is one compartment(contains high
concentration of urea, creatine) and the other compartment
is formed by dialysis fluid, separated by a semipermeable
membrane

8. Dialysis is divided broadly into three types:
1. Hemodialysis (HD),
2. peritoneal dialysis (PD), and
3. continuous renal replacement therapy (CRRT).

9. Hemodialysis employs an artificial membrane across which the
exchange of solutes takes place.
Peritoneal dialysis is done by using the peritoneal membrane as the
semipermeable membrane.
Continuous renal replacement therapy (CRRT) is a slower type of
dialysis which is over a period of 24 hours continuously to remove
waste products and fluid from the patient.

10. Indications for Dialysis
• Hyperkalemia >6 mmol/l
• Metabolic acidosis not responding to medical management
• Fluid overload and pulmonary edema
• Uremic pericarditis
• Uremic encephalopathy

11. Hemodialysis
● In hemodialysis there is diffusion of solutes between plasma
and dialysate fluid across a semipermeable membrane
following a concentration gradient.
● Semipermeable membrane is made of cellulose, cellulose
acetate or synthetic material (polymethyl methacrylate,
polycarbonate).
● Hemodialysis is more efficient than peritoneal dialysis in
removing urea and creatinine.

13. Technique:
● Blood from the patient is made to flow through the dialysis
machine which contains a semipermeable membrane. This
semipermeable membrane separates the blood and dialysis fluid.
● Solutes such as urea, creatinine and potassium shift from high
concentration compartment (blood) to low concentration
compartment (dialysis fluid) through the semipermeable
membrane.
● Fluid is removed by applying negative pressure to the dialysate
side (ultrafiltration). After passing through the dialysis machine
blood goes back to the patient.
● Heparin is given to prevent clotting of the blood as it passes
through the dialysis machine.

14. ● Catheter is placed into femoral or internal jugular vein. AV
fistula can be created in the forearm for permanent access.
● Initially, hemodialysis is done for 1 hour to avoid sudden
change in fluid and electrolyte balance in the patient.
Subsequently hemodialysis is done for 3–4 hours 3–4 times a
week.

15. Complications of Hemodialysis
● Nausea, vomiting, and headache.
● Hypotension due to fluid removal and hypovolemia.
● Cardiac arrhythmias due to sudden potassium and acid-base shifts.
● Hemorrhage due to anticoagulation.
● Air embolism due to disconnected or faulty lines and equipment
malfunction.
● Allergic reaction to dialysis membrane
● Dialysis disequilibrium syndrome: due to cerebral edema due to
rapid decrease in plasma osmolality
● Dementia

16. Peritoneal dialysis
● In peritoneal dialysis (PD), peritoneum acts as a semipermeable
membrane across which diffusion of solutes and water takes
place.
● It is less efficient than hemodialysis, and is rarely used in AKI
● Access to the peritoneal cavity is obtained through a peritoneal
catheter made of silicon rubber with many side holes at the distal
end.
● 1.5–3 L of a dextrose-containing solution is infused into the
peritoneal cavity and allowed to dwell for 2 to 4 hours. Uremic
toxins diffuse from the peritoneum into the dialysis fluid during this

17. Forms of PD:
● Can be manually done or by an automated device
● Continuous ambulatory peritoneal dialysis (CAPD):
● Continuous cyclic peritoneal dialysis (CCPD):

18. Complications of Peritoneal Dialysis
● Peritonitis.
● Increased risk of hernias.
● Hyperglycemia due to use of dextrose containing fluid as the
dialysis fluid.
● Weight gain due to glucose absorption from the dialysis fluid.
● Protein malnutrition.

19. Dialysis disequilibrium syndrome.

20. Dialysis disequilibrium syndrome.
Array of neurological manifestations that are seen during or shortly
after hemodialysis.
Pathophysiology
Removal of urea from the blood by hemodialysis reduces osmolality of
blood producing an osmotic disequilibrium between blood and brain.
Since it takes some time for the urea concentration in the
brain to reduce, water moves into brain cells causing brain edema.

21. Clinical Features:
Signs and symptoms of cerebral edema, such as:
headache,
blurred vision due to papilledema,
decreased level of consciousness,
Convulsions,
delirium occurring immediately after dialysis should raise the
suspicion of DDS

22. Investigations
● CT or MRI brain is required to rule out other neurological problems
such as stroke, intracranial bleed, etc.
● Serum electrolytes.

23. Treatment
● Usually self-limited. However, for severe symptoms
● hemodialysis should be stopped.
● If seizures occur, antiepileptics should be given such as
diazepam, and phenytoin.
● Brain edema can be reduced by IV mannitol and glycerol
Prevention
Initial sessions of dialysis should be short so as to gradually bring
down the blood urea

24. Renal transplantation

25. Renal transplantation
● Kidney transplantation is the commonest organ
transplantation done.
● It offers the best chance of long-term survival in patients with
end-stage renal disease.
● It can restore normal kidney function and correct all the
metabolic abnormalities of CKD.

26. Procedure
● Kidney grafts are taken from a cadaver or a living donor.
● ABO (blood group) and HLA antigens should be matched
between the donor and recipient
● Patient should be dialyzed before transplantation to achieve a
near normal metabolic state.

27. Management after Transplantation
● Immunosuppressive therapy is given to prevent graft rejection
usually life long.
● Rejection is treated by short courses of high-dose steroids
● All transplant patients require regular life-long follow-up to
monitor renal function and immunosuppression.

28. Complications
- Perioperative Problems:
- Fluid imbalance
- Primary graft non-function.
- Complications due to Immunosuppression:
- Increased risk of infections
- Increased risk of malignancy
- sepsis

29. References:
● Manipal Prep Manual of Medicine
Questions:
salman.s.ansari92@gmail.com
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