2. Hemodialysis:
⚫Hemodialysis is one of three renal
replacement therapies (the other two being
kidney transplant and peritoneal dialysis).
⚫It is a medical procedure to remove fluid and
waste products from blood and to correct
electrolyte imbalance.
⚫Hemodialysis is done using a hemodialysis
machine and dialyzer aslo called as
‘Artificial kidney’
⚫It can be an outpatient or inpatient therapy.
3. ⚫Hemodialysis is an extracorporeal process
(dialysis membrane is outside of the
body).
Indication For dialysis:
• Acidosis (pH <7.1)
• Electrolyte imbalance (k+ >6.5 mEq/L)
• GFR<10ml/min
• Overload of Fluids (pulmonary Oedema)
• Uremic Symptoms (increased level of
nitrogenous waste products)
4. Principle of Haemodialysis
1. Diffusion: Passive movement of
solute across a semipermeable
membrane.
2. Ultra filtration: solute + Fluid removal
across semipermeable membrane
down a pressure gradient.
8. 1. Dialyzer (Artificial kidney):
⚫Plastic chamber that contains bundles of
capillary tube through which blood
circulates while dialysis solution travels
outside the bundle in opposite counter
current direction.
⚫Diffusion and Ultrafiltration happens
here.
⚫Membranes using in dialyser:
◦ Cellulose
◦ Substituted cellulose: Cellulose acetate
◦ Cellulosynthetic: Cellosyn/Hemophan
◦ Synthetics: Polyacrylonitrile, polysulfone,
polymethyl methacrylate
9.
10. 2. Dialysate:
⚫ Solution used in dialysis which has same solute
concentration as those in plasma.
⚫ Water used in the dialysate is purified by reverse
osmosis.
⚫ Contents of dialysate:
◦ Na+ :136-140mmol/L
◦ K+ :0-4 mmol/L
◦ Mg++ : 0.25-0.75 mmol/L
◦ Ca+ : 2.5-3.5mEq/L
◦ Chloride: 100-124 mEq/L
◦ Bicarbonate: 27-40mmol/L
◦ pH: 7.1-7.3
◦ Dextrose: 0-5.5 mmol/L
11. 3. Blood delivery system:
⚫Blood pump: Moves blood from
access site through the dialyzer and
back to the patient.
⚫Blood flow rate: 250-500ml/min
⚫Heparin syringe pump
⚫2 air traps
⚫Air detector
⚫Venous line clamp
13. Access for Hemodialysis
⚫Arterio venous fistula (AVF)-made by joining
an artery and vein in arm (first preferred
choice for a permanent vascular access).
⚫Arterio venous graft (AVG)-made by using a
soft tube to join an artery and vein in arm (
second preferred choice for a permanent
vascular access).
⚫Cuffed tunneled dialysis catheter- a soft tube
that is placed in a large vein, usually in neck
(temporary access).
⚫Temporary access sites
◦ Internal jugular vein
◦ Femoral vein
◦ Subclavian vein
14. Arterio venous fistula:
⚫Subcutaneous anastomosis (surgical
connection i.e. created between two
stuctures) of an artery to an adjacent
native vein.
⚫Takes 6 weeks for development
(arterialization of vein)
⚫Both the dialysis needles are inserted
into the native vein.
⚫Types:
◦ Radiocephalic (first choice)
◦ Brachiocephalic (second choice)
◦ Brachiobasilic (third choice)
15.
16. Procedure
⚫ Blood flow rate: 300-500 ml/min
⚫ Dialysate : 500-800 ml/min
⚫ Usually done 3 times a week and each dialysis lasts for 4 hours.
17.
18. Complications of
Hemodialysis
⚫Hypotension (22-55%)
⚫Muscle cramps (5-20%)
⚫Nausea and vomiting (5-15%): due to
hypotension
⚫Headache (5%)- common
⚫Chest pain (2-5%)
⚫Back pain (2-5%)
⚫Itching (5%)- precipitated by dialysis may
be due to hypersensitivity to dialyser
membrane
⚫Fever & chills (<1%)
22. ⚫Management of muscle cramps:
🞄Reduced ultrafiltration and infusion of
hypertonic saline or glucose to improve
circulation, exercise/stretching of affectef limb,
or vitamin E 400IU at bedtime with vitamin C
250mg daily for prevention.
23. Less common but serious complication
⚫ Disequilibrium Syndrome:
Set of systemic and neurologic symptoms with
characteristics electroencephalographic findings occur
either during/following dialysis
- Early manifestation: nausea, vomiting, restlessness and
headache
- Serious manifestation: seizure, obtundation, coma
Cause:
Acute increase in brain water content.
Treatment:
-aimed at prevention by initiating dialysis gradually.
- direct treatment involves IV hypertonic saline or
mannitol.
