Renal replacement therapy (RRT) replaces the normal blood filtering function of the kidneys. RRT is used in acute kidney injury (AKI) and chronic kidney disease (CKD). The main types of RRT are peritoneal dialysis (PD), hemodialysis (HD), sustained low efficiency dialysis (SLED), and continuous renal replacement therapy (CRRT). PD uses the peritoneal membrane for diffusion and convection, while HD uses a dialyzer and dialysate for diffusion. CRRT provides continuous RRT for hemodynamically unstable patients. Kidney transplantation is the best long-term treatment for end-stage renal disease.

1. RENAL REPLACEMENT THERAPY
Dr Jo Martin Kuncheria
JR , Paediatrics

2. DEFINITION
RRT- replaces normal blood filtering functioning of the kidneys
Used in AKI/CKD
AKI requiring RRT in pediatric ICU ˜ 5%
75% children with ESRD waiting for transplant
Renal transplant is the best RRT

3. History of Dialysis
Thomas Graham –father of dialysis-investigated osmotic forces
in 1980s
Initial PD where done by Georg Ganter (Germany,1923)
William Kolff made first working dialyser in 1945

4. PRINCIPLES OF RRT
Removal of water, optimize electrolytes, remove uremic toxins
Water and solute transport through a semipermeable membrane and
then discarding the waste products
Solute clearance -diffusion and convection
Water is transported across a semipermeable membrane across a
pressure gradient- ultrafiltration

5. DIFFUSION
Higher concentration to lower concentration across
semipermeable membrane
Concentration gradient
Size of the molecules
Number of pores
Electrical charges and shape

6. CONVECTION
Ultrafiltration
Forced movement of water across a membrane-
Transmembrane pressure (HD)
Osmotic force (PD)
Convection- solute is swept along with fluid
Solvent Drag- do not depend upon the concentration gradient

7. Method of clearance- important toxin
Uremic toxin Mode of clearence
Small solute <300D Urea, creatinine Diffusion
Middle molecule 500-5000D - Diffusion
convection
LMW protein 5000-50000 D b 2- microglobulin Convection
Diffusion
Large protein >50,000D Convection

8. Choice of modalities
Acute Chronic
HD (Hemodialysis)
PD (Peritoneal dialysis)
SLED (Sustained low efficacy
dialysis)
CRRT
HD (hemodialysis)
PD (Peritoneal dialysis)
Renal transplant

9. Choice of Renal Replacement Modality
AKI vs CKD
Patient’s age and size
Patient’s haemodynamical status
Coagulation profile
Available facility and expertise
Provision of vascular access
Financial status
Parent's preference

10. Dialysis in AKI

11. TIMING OF DIALYSIS (ADVANTAGE )
Early Late
Avoid onset of major complication Patient may recover spontaneously
May develop therapy related
complications
Studies have not shown added advantage
of early initiation

12. INDICATIONS OF DIALYSIS IN AKI
Stage 2 or 3 AKI (as defined by KDIGO 2012) with any of the following:
(i) Oliguria with fluid overload >10% above baseline, which is refractory to
furosemide (1-2 mg/kg once, intravenously) or where furosemide cannot be
used
(ii) Persistent or worsening metabolic acidosis with arterial pH <7.15 and either
PaCO2<35 mm Hg (pure metabolic acidosis) OR PaCO2 >50 mm Hg (mixed
metabolic acidosis)
(iii) Refractory or significant hyperkalemia: Serum potassium >6 mEq/L, OR
persistently >5.5 mEq/L despite medical management

13. INDICATIONS OF DIALYSIS IN AKI
(iv) Requirement of large amounts of blood products/infusion in a patient at
risk for pulmonary edema, acute respiratory distress syndrome, and/or worsening
fluid overload
Acute tumor lysis syndrome
Hyperammonemia
Organic acidemia with refractory acidosis
MSUD crisis
RRTs are also indicated in the treatment of removal of toxins or drugs

14. RRT modality
PD HD SLED CRRT
Clinical indication
matching
- √ - √
Profound
hemodynamic
compromise shock
√ - √ √√
Expertise and
infrastructure
-- √ √ √
Duration of the
therapy
Continuous Intermittent Intermittent Continuous
Vascular access -- √ √ √
Controlled therapy - √ √ √

15. Peritoneal Dialysis
Access
Cuffed Tenckhoff catheter
Stiff PD
Improvised catheters or other devices
Nasogastric tubes, suprapubic catheters, rubber catheters, intercostal drainage tubes,
iv cannula, pigtail catheters or single lumen femoral catheters
PD delivery system
Manual (closed or open)
Cycler

16. How to insert a PD catheter
Rigid catheter with stylet
Evacuate the bowel, catheterize the bladder
Prepare the area, chlorhexidine, drape, local anesthesia
Wide bore cannula, fill around 30 ml per kg fluid until flank full
Remove cannula, catheter and stylet inserted thorough corkscrew movement to RIF/LIF
Test cycle
Single lumen femoral
Cannula- fill the abdomen
Insert guidewire
Remove cannula
Insert single lumen catheter

17. Figure 1: (a) Cuffed PD catheter (Tenckhoff) with instruments for insertion. (b) Rigid PD catheter with stylet and instruments
for insertion. (c) Single-lumen haemodialysis catheter (d) with guidewire; this can be repurposed as a rigid PD catheter in
neonates. Pictures courtesy Dr Sumantra Raut, Kolkata.
(a)
(b)
(c) (d)

18. Peritoneal dialysis solutions
Osmotic agent (glucose/icodextrin/aminoacid)
Glucose 1.5%, 2.5%, 4.5% or 1.7% one litter bags
Buffer (lactate, bicarbonate)
Electrolytes (Na/Ca/Mg/K)
Preparation Glucose Na+ K+ Ca
++
Mg++ Cl- HCO3
- Lacta
te
Normal saline 500 ml + 5% Dextrose 440 ml +
7.5 % NaHCO3 60 ml
2.2% 126.
5
- - - 72.
5
54 -
N/2 saline in 5% Dextrose 1000 ml + 7.5%
NaHCO3 40 ml + 3% NaCl 60 ml
2.4% 138 - - - 103 35 -
Ringers lactate 1000 ml + 50% dextrose 30 ml 1.45% 127 3.8 1.
36
- 107 - 27
Plasmalyte B 1000 ml + 50% dextrose 30 ml 1.45% 126 3.8 - 1.45 108 27 -

19. PD PRESCRIPTION
Dwell volume
30-40 ml per kg
Assess for abdominal pain , distension, respiratory embarrassment
Therapy time:
Inflow time- 10mts
Dwell time- 30 mts
Outflow time – 20mts
Short dwell time (20-30 min)- acidosis, fluid overload, hyperkalemia
Long dwell time –creatinine and phosphate

20. MONITORING
Mechanical failure
Fluid balance, weight, ultra filtration
Electrolyte imbalance (hypokalemia , hypophosphatemia)
Renal function, Acid base status
Cytology of PD effluent

21. COMPLICATIONS
Abdominal pain
Difficult drainage
Bleeding after catheter insertion
Perforation of gut
Leakage around catheter
Exit site infections
Peritonitis
Metabolic problems (Hypo / hypernatremia, hypokalemia ,
hyperglycemia, hypophosphatemia and metabolic alkalosis

22. HEMODIALYSIS -COMPONENTS
Machine
Monitors and sensors
Proportioning system (mixes an acid concentrate with a
bicarbonate concentrate and purified water)
Dialyzer- synthetic semipermeable membrane
Dialysis solution- -Reverse osmosis
Tubing for transport of blood and dialysis solution
Vascular access

23. VASCULAR ACCESS
• AV fistula
• An AV graft made by using a soft tube to join an artery and vein
in your arm
• A catheter, a soft tube that is placed in a large vein, usually in
your neck

24. BLOOD CIRCUIT
DIALYZER
DIALYSIS SOLUTION CIRCUIT
Dialysate

25. Dialyser

27. Prescription OF HD
Size of the dialyser (0.75-1 BSA)
Blood flow rate (depending upon weight)
Dialysate flow rate(usually fixed)
Anticoagulation (usually heparin boluses)
Ultrafiltration (depend upon the fluid status)
Duration (initial less time to avoid Dialysis disequilibrium)

28. SUSTAINED LOW EFFICIENCY DIALYSIS
Hybrid of HD and CRRT
BFR – slow
Duration is at least 6 hours
Used in hemodynamically compromised
Can be done where HD facility is available

29. CRRT
Modality of choice in patients who are critically ill and hemodynamically unstable
patients
Extracorporeal therapy
Dedicated machine
Expertise
Convection is the main method in CVVH, slow continuous process with large amount of
fluids
Anticoagulation is needed
Cost
Circuit clot
Bleeding

30. CRRT MACHINE

31. PD HD SLED CRRT
CVVH CVVHD CVVHDF
Mechanism of
clearance
Diffusion &
convection
Diffusion Diffusion Convection Diffusion Convection
and diffusion
Duration of
therapy
Continuous Intermittent
(Often 4 hrs)
Intermittent
(More than 6hrs)
Continuous
Access Peritoneal access Vascular access Vascular access Vascular Access
Machines and
equipment
Not necessary,
cycler can be
used if available
HD Machine,
circuits &
dialyser
HD Machine,
circuit &
dialyzer
CRRT Machine, circuit & filters
Blood flow rate - 5-8 ml/ kg/min 3-5 ml/kg/min Infants is 10-12 ml/kg/min, children is 4-
6ml/kg/min, adolescents 2-4 ml/kg/min
Dialysate flow
rate
20-30
ml/kg/cycle
2 times BFR
(500 ml/min)
1.5-2 times BFR 2000L/1,73
m2/hour
Dialysate
+replacemen
t fluid
similar to
CVVH
Replacement
fluid
- - - 2000L/1,73m2/
hour
-
Ultrafiltration
control
Not controlled Controlled Controlled Controlled
Hemodynamic
stability
Present No Present Present
Anticoagulation Not needed Needed but short Needed but short Needed continuously

32. Indications RRT in CKD
CKD stage V or GFR < 15ml/min/1.73m² BSA with
Growth failure
Severe hypertension
Intractable intravascular volume overload
Refractory acidosis or Mineral bone disease
Profound electrolyte abnormalities ( hyperkalemia, hyperphosphatemia )

33. Complication of PD
– Peritonitis ( most important complication of CAPD)
– Catheter malfunction
– Abdominal wall hernia
– Back pain
– Hydrothorax
– Respiratory difficulty

34. Advantages of PD over HD
Ability to perform dialysis at home
Technically easy than hemodialysis especially in infants
Ability to live a greater distance from medical centre
Freedom to attend school
Less restrictive diet
Less expensive than hemodialysis

35. Disadvantages
Catheter malfunction
Catheter related infections
Impaired appetite
Negative body image
Cost

36. HEMODIALYSIS
Provides an excellent extracorporeal mode for renal replacement
Access
Arteriovenous fistula
Tunneled cuffed catheter
AV graft

37. Complications during hemodialysis
Dialysis disequilibrium syndrome manifests as:
 Seizures
Muscle cramps
Hypotension
Nausea and vomiting
Itching

38. Advantages
Maximum solute clearance
Efficiency
Best treatment for severe hyperkalemia
Ready availability
Limited anti coagulation time
Bed side vascular access

39. DISADVANTAGES
Hemodynamic instability
Rapid fluid and solute shifts
Loss of residual renal function
Complex equipment
Specialized personnel
Difficult in small infants

40. RENAL TRANSPLANT
In most cases kidney is placed retroperitoneally and the iliac arteries and veins are used
for perfusion of this organ and the ureter is transplanted directly to the bladder

41. RENAL TRANSPLANTATION
• Best treatment for patients with ESRD
– 1 . Deceased donor transplantation
– 2. Living donor transplantation
Preemptive transplant :getting a transplant before the need to start dialysis .
Timing –When the need for dialysis is anticipated
Transplant after initiation of RRT

42. DONOR EVALUATION
Not Hypertensive
Not Diabetic
Normal Renal function
No infections (HIV,HBV,HCV)
Psychologically sound
Lab tests: CBC, FBS,LFT, Urine Analysis, urine MC & S, assess
GFR,CXR,ECG,HLA screening, Viral screening, Tuberculin skin test,
IVU, Renal Angiogram

43. IMMUNOSUPRESSION
• Induction Therapy: To prevent early acute rejection
T cell Antibodies- Antithymocyte globulin
IL 2 receptor antibodies- Basiliximab
Other agents: Alemtuzumab against CD 52
If patient needs desensitization-Rituximab against CD 20,
Plasmapheresis /high dose Iv Ig.

44. IMMUNOSUPRESSION
• Maintenance immunosuppression:
Calcineurin Inhibitors.
Antiproliferative agents : Mycophenolic acid 600mg/m²
Corticosteroides: high dose steroides as induction treatment tapering
to low dose over several months 5-10mg or 0.1mg/kg daily

45. CONCLUSION
With most modern techniques of dialysis and Kidney
transplantation as treatment modality in ESRD, patients are
offered the opportunity to live longer and more satisfying life
Thank you