Dr. Amrit parihar IKDRC ITS college of physiotherapy, Ahmedabad amritparihar94@yahoo.com 8233341883

1. Renal Replacement Therapy
Amrit parihar
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2.  Renal replacement therapy (RRT) is therapy that replaces the normal
blood filtering function of the kidneys.
 It is used when the kidneys are not working well, which is
called kidney failure and includes acute kidney injury and chronic
kidney disease.
 Renal replacement therapy includes dialysis (hemodialysis or
peritoneal dialysis), hemofiltration, and hemodiafiltration, which are
various ways of filtration of blood with or without machines.
 Renal replacement therapy also includes kidney transplantation,
which is the ultimate form of replacement.
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3. Renal replacement therapy
Dialysis
• Hemodialysis
• Peritoneal dialysis
• Hemofiltration
• Hemodiafiltration
Kidney transplant
• Place a healthy kidney from
a living or deceased donor
into a person whose kidneys
no longer function properly
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4. Dialysis
Definition : The process of removing waste products and excess fluid
from the body. it is necessary when the kidneys are not able to
adequately filter the blood. Dialysis allows patients with kidney failure
a chance to live productive lives
History :
 Scottish chemist Thomas Graham known as the ‘father of dialysis’,
first described dialysis in 1854. he used osmosis to separate
dissolved substance and remove water through semipermeable
membrane, although hr did not apply the method to medicine.
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5.  In 1913, the first artificial kidney was prepared. Cellulose trinitrate
tubes held in a glass ‘jacket’ were used. Although this device was
revolutionary, it was never used on humans.
 In 1923, Heinrich Necheles in Humburg developed the first
‘sandwich’ artificial kidney using a biological membrane that
consisted of the peritoneal membrane of calves and dialyzed dogs.
 In 1924, Georg Haas performed the first human hemodialysis in
uremic patient.
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6. Types of Dialysis
There are varios types of dialysis we may use: hemodialysis
hemofiltration and peritoneal dialysis, CRRT.
Hemodialysis : There is bidirectional diffusion of solutes between
plasma and dialysate across a semipermeable membrane following
concentration gradients. The dialysate composition is chosen to achieve
a suitable gradient. Fluid is removed by applying negative pressure to
the dialysate side (ultrafiltration)
 Typical small solute clearance 160 mL/min
 Used in both acute and chronic renal failure
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7. Haemofiltration :There is filtration of water from plasma to
ultrafiltrate across a more porous semipermeable membrane down a
pressure gradient with removal of solutes by convection.
‘Replacement’ fluid of chosen electrolytic composition is added to the
blood circuit after the filter. If fluid removal is required, less is replaced
than filtered
 Typical small solute clearance (2 L/hr exchanges) 33 mL/min
 Less circulatory instability than haemodialysis
 Used mostly in acute renal failure
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8. Peritoneal dialysis :
This uses peritoneum as a semipermeable dialysis membrane. Solutes move
down a concentration gradient, and water down an osmotic gradient achieved by
using an osmolar compound (typically glucose) in the dialysis fluid
 Access to the peritoneal cavity via ‘Tenckhoff’ catheter
 Continuous ambulatory peritoneal dialysis (CAPD): typically 4 exchanges
of 2 L of fluid a day 4–6 hrs apart
 Automated peritoneal dialysis (APD): uses a machine to perform exchanges
overnight (8–10 hrs)
 Used mostly in chronic renal failure
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9. Continuous Renal Replacement Therapy (CRRT) :
 it is a slow and continuous extracorporeal blood purification therapy.
 CRRT mimics the functions of the kidneys in regulating water,
electrolytes, and toxic products by the continuous slow removal of
solutes and fluid.
 CRRT is indicated in patients who meet criteria for hemodialysis
therapy but cannot tolerate conventional intermittent hemodialysis
(IHD) due to hemodynamic instability.
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10. SDHD (Short daily hemodialysis)
SDHD consists of 1.5 to 3 hour daytime treatments either in the center
or more conveniently at home, 5 to 6 days per week.
Benefits :
 Better control of extracellular volume, with resulting improved
blood pressure.
 Better nutritional status with increased lean body weight.
 Better control of phosphorus balance.
 Reduced erythropoietin requirments
 Reduced intradialytic hypotension.
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11. Typical SDHD prescription11
Frequency 6-7/wk
Duration 1.5-3 hrs
Dialyzer High flux preferred
Qb 400-500 ml/min.
Qd 500-800 ml/min.
Access Any
Heparin Optional
Remote monitoring None
Dialyzer reuse Optional

12.  NHD ( nocturnal hemodialysis ) : consists of 5 to 7
overnight treatments per week, 6 to 8 hours per session.
 High flux hemodialysis :
flux of a dialyzer is measure of ultrafiltration capacity.
High flux membranes have larger pores.
 low flux Kuf <10 ml/h/mmof Hg
High flux Kuf >20 ml/h/mm of Hg
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13. Indications of dialysis
 Sign and symptoms of uraemia : Lethargy, nausea, confusion,
itching, cramps, seizures.
 Hyperkalaemia : >5.2 mmol/L, heart arrhythmias, cardiac arrest.
 Fluid overload : shortness of breath, oedema, hypertension.
 Metabolic acidosis : pH < 7.35, deep rapid breath, muscle weakness,
bone pain.
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14. Hemodialysis prescription
 The hemodialysis prescription should take into account the goals of
the therapy, expected solute clearance needs, volume removal needs,
residual kidney function, timing of the therapy and logistical
concerns.
 When initiating dialysis for the first time in a uremic patient, care
should be taken to avoid dialysis disequilibrium syndrome.
 In dialysis disequilibrium syndrome, cerebral edema can develop as
a result of rapid plasma reduction of plasma osmolality leading to a
solute gradient between the intracellular and extracellular space
which promotes osmotic movement of water into the cellular space
leading to cell swelling.
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15. Prescription for a stable chronic outpatient dialysis session :
 Time: 4 hours
 Dialyzer: High flux, high efficiency (high urea clearance, high β-2
microglobulin clearance, high KoA {Mass transfer area coefficient}, High
Kuf {Ultrafiltration coefficient} )
 Blood Flow (Qb): 300-500 ml/min (as fast as access and hemodynamics
allow)
 Dialysate Flow (Qd): 500-800 ml/min (typically 1.5-2 times the Qb is
sufficient)
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16.  Dialysate Concentrate: Sodium 137 mEq/L, Potassium 2 mEq/L,
Calcium 2.5 mEq/L, Bicarbonate 35 mEq/L. Dialysate concentrate
should be adjusted to fit the patient’s needs based on laboratory
values.
 Heparin anticoagulation: (not always needed) Low dose: bolus 1000
Units followed by 500 Units/hour
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17. Dry weight in HD
Lowest tolerated post dialysis weight achieved via a gradual change in
post dialysis weight at which there are minimal signs or symptoms of
hypovolemia or hypervolemia.
Assessment of dry weight :
 Relative plasma volume
 Echocardiographic markers
 Body impedance analysis
 Portable mass spectrometer
 Biochemical markers
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18. Benefits of assessment of dry weight :
 Lower antihypertensive drug use
 Lower intradialytic weight gain
 Lower LV mass
 Better diastolic and systolic LV function
 Fewer episodes of intradialytic hypotension.
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19. Residual renal function
 Residual renal function, defined as the urinary clearance of urea and
creatinine, is minimal in many patients treated with HD
 Residual renal function contributes significantly to the overall health
and well being of dialysis patients.
 It not only provides small solute clearance but also plays an
important role in maintaining fluid balance, phosphorus control and
removal of middle molecular uremic toxins.
Preservation of RRF : one way to maximize survival of renal function
is to place the patient on PD.
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20. Preparation for Hemodialysis
Planned
1.AV fistulas
2.AV graft
3.Tunneled cuffed
catheters
4.Arterio venous
shunt ( now not in
use )
Emergency
• DLC
• Femoral catheter
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21. AV fistula :
 An AV fistula involves creating an
anastomosis between an artery and
a native vein, allowing the blood
to flow directly from the artery to the
vein.
 The artery is a high pressure
compartment, whereas vein is
superficial compartment so by
anastomoses of both artery and vein
we get good blood flow due to the
arterial part into venous part that will
remain superficial so puncture will be
easy.
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22. AV fistula
 Traditionally, the anastomosis is made at the wrist between the
radial artery and the cephalic vein, although there are many
variations possible like brachiocephalic brachiobasilic and brachial
artery and median antecubital vein.
 An AV fistula cannot be used immediately as the fistula maturation
process generally takes about 6–8 weeks.
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23. AV graft :
 AV graft is similar, except that the
distance between the feeding artery
and vein is bridged by a tube made
of prosthetic material. The most
commonly usedbridging material is
polytetrafluoroethylene (PTFE)
polymer.
 AV graft can be used earlier than a
fistula, generally within 1–3
weeks after placement.
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24. Non tunneled and tunneled cuffed catheters :24

25.  A venous catheter is a tube inserted into a vein in the neck, chest or
leg near the groin usually only for short term HD.
 It is not ideal for long term use because patient may develop a blood
clot, an infection, or scarred vein, causing the vein to narrow.
 When patient need venous catheter for more than 3 weeks than
tunnel catheter is usually used because it is comfortable and fewer
problems.
 Site mainly internal jugular vein.
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26. AV shunt :
 An arterio-venous shunt is
surgically created and consists of
2 pieces of silastic tubing, each
with a Teflon tip on one end.
 The Teflon tip of one piece of the
shunt tubing placed in an artery
and other tip in an adjacent vein.
 The AV shunt has limited life
span due to clotting or infection.
 Now it is not in use.
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27. Vascular access evaluation
It is to be done by Look/listen/feel
1. Look :
compare extremities
look for colour changes and anastomosis signs of wound healing
at the surgical incision.
Check for aneurysms and sign of infection, redness, drainage or
abscess formation.
2. Listen :
Bruit low pitch ; continuous; diastolic and systolic is normal
High pitched; discontinuous; systolic only may indicate stenosis.
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28. 3. Feel :
Pulse : soft, easily compressible is normal.
water hammer may indicate stenosis.
Diameter : firmness indicate thickening of a vessel wall
Thrill : purring and vibrating thrill not a strong pulsation
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29. Adequacy of dialysis
 Two methods are generally used to assess dialysis adequacy : URR
or Kt/v
 Both depends upon urea clearance
 Why UREA?
 An ideal clearance marker
 Accumulates in uremia
 Is easily measured and easily removed by the dialyzer.
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30. Urea reduction ratio :
 The URR is one measure of how effectively a dialysis treatment
removed waste products from the body.
 Expressed as a percentage.
 Blood is sampled at the start of dialysis and at the end. The levels of
urea in the two blood samples are then compared.
 Recommended URR>65%
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31. Kt/V :
The Kt/V is mathematically related to the URR and is in fact derived
from it, except that the Kt/V also takes into account extra urea removed
during dialysis along with excess fluid so the Kt/V is more accurate
than the URR , primarily because the Kt/V also considers the amount
of urea removed with excess fluid.
Here
K – dialyzer clearance of urea
t – dialysis time
V – volume of distribution of urea, approximately equal to patient's
total body water
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32. Complications of Hemodialysis and peritoneal dialysis
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