Dialysis Nursing Care Plan notes
Description
▪ Dialysis is primarily used to provide an artificial replacement for lost kidney function (renal
replacement therapy) due to renal failure
▪ Dialysis works on the principles of diffusion of solute through a semipermeable membrane
that separates two solutions.
▪ Direction of diffusion depends on concentration of solute in each solution.
▪ Rate and efficiency depend on concentration gradient, temperature of solution, pore size of
membrane, and molecular size.
Two Mechanisms in Dialysis
1. Diffusion – movement of particles from an area of high concentration to one of low
concentration across a semipermeable membrane.
2. Osmosis – movement of water through a semipermeable membrane from an area of lesser
concentration of particles to one of greater concentration.
Indications
The decision to initiate dialysis or hemofiltration in patients with renal failure depends on
several factors. These can be divided into acute or chronic indications.
▪ Indications for dialysis in the patient with acute kidney injury are:
1. Metabolic acidosis in situations where correction with sodium bicarbonate is
impractical or may result in fluid overload.
2. Electrolyte abnormality, such as severe hyperkalaemia, especially when combined
with AKI.
3. Intoxication, that is, acute poisoning with a dialysable drug, such as lithium, or aspirin.
4. Fluid overload not expected to respond to treatment with diuretics.
5. Complications of uraemia, such as pericarditis or encephalopathy.
▪ Chronic indications for dialysis:
1. Symptomatic renal failure
2. Low glomerular filtration rate (GFR) (RRT often recommended to commence at a GFR
of less than 10-15 mls/min/1.73m2). In diabetics dialysis is started earlier.
3. Difficulty in medically controlling fluid overload, serum potassium, and/or serum
phosphorus when the GFR is very low
Goals
▪ Reduce level of nitrogenous waste.
▪ Correct acidosis, reverse electrolyte imbalances, remove excess fluid.
Two main types of dialysis
I. Haemodialysis
▪ Haemodialysis removes wastes and water by circulating blood outside the body through an
external filter, called a dialyzer, that contains a semipermeable membrane
▪ In haemodialysis, the patient’s blood is pumped through the blood compartment of a
dialyzer, exposing it to a partially permeable membrane.
, ▪ The dialyzer is composed of thousands of tiny synthetic hollow fibres.
▪ The fibre wall acts as the semipermeable membrane. Blood flows through the fibres,
dialysis solution flows around the outside the fibres, and water and wastes move between
these two solutions.
▪ The cleansed blood is then returned via the circuit back to the body.
▪ Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer
membrane.
▪ This usually is done by applying a negative pressure to the dialysate compartment of the
dialyzer.
▪ This pressure gradient causes water and dissolved solutes to move from blood to dialysate,
and allows the removal of several litres of excess fluid during a typical 3 to 5 hour
treatment.
▪ Studies have demonstrated the clinical benefits of dialyzing 5 to 7 times a week, for 6 to 8
hours.
▪ These frequent long treatments are often done at home, while sleeping but home dialysis is
a flexible modality and schedules can be changed day to day, week to week.
image credit to : www.niddk.nih.gov
Types of venous access for haemodialysis
1. External shunt
▪ Cannula is placed in a large vein and a large artery that approximate each other.
▪ External shunts, which provide easy and painless access to bloodstream, are prone to
infection and clotting and causes erosion of the skin around the insertion area.
2. Arteriovenous fistulas or graft
▪ Large artery and vein are sewn together (anastomosed) below the surface of the skin
(fistula) or subcutaneous graft using the saphenous vein, synthetic prosthesis, or
bovine xenograft to connect artery and vein.
▪ Purpose is to create one blood vessel for withdrawing and returning blood.
Description
▪ Dialysis is primarily used to provide an artificial replacement for lost kidney function (renal
replacement therapy) due to renal failure
▪ Dialysis works on the principles of diffusion of solute through a semipermeable membrane
that separates two solutions.
▪ Direction of diffusion depends on concentration of solute in each solution.
▪ Rate and efficiency depend on concentration gradient, temperature of solution, pore size of
membrane, and molecular size.
Two Mechanisms in Dialysis
1. Diffusion – movement of particles from an area of high concentration to one of low
concentration across a semipermeable membrane.
2. Osmosis – movement of water through a semipermeable membrane from an area of lesser
concentration of particles to one of greater concentration.
Indications
The decision to initiate dialysis or hemofiltration in patients with renal failure depends on
several factors. These can be divided into acute or chronic indications.
▪ Indications for dialysis in the patient with acute kidney injury are:
1. Metabolic acidosis in situations where correction with sodium bicarbonate is
impractical or may result in fluid overload.
2. Electrolyte abnormality, such as severe hyperkalaemia, especially when combined
with AKI.
3. Intoxication, that is, acute poisoning with a dialysable drug, such as lithium, or aspirin.
4. Fluid overload not expected to respond to treatment with diuretics.
5. Complications of uraemia, such as pericarditis or encephalopathy.
▪ Chronic indications for dialysis:
1. Symptomatic renal failure
2. Low glomerular filtration rate (GFR) (RRT often recommended to commence at a GFR
of less than 10-15 mls/min/1.73m2). In diabetics dialysis is started earlier.
3. Difficulty in medically controlling fluid overload, serum potassium, and/or serum
phosphorus when the GFR is very low
Goals
▪ Reduce level of nitrogenous waste.
▪ Correct acidosis, reverse electrolyte imbalances, remove excess fluid.
Two main types of dialysis
I. Haemodialysis
▪ Haemodialysis removes wastes and water by circulating blood outside the body through an
external filter, called a dialyzer, that contains a semipermeable membrane
▪ In haemodialysis, the patient’s blood is pumped through the blood compartment of a
dialyzer, exposing it to a partially permeable membrane.
, ▪ The dialyzer is composed of thousands of tiny synthetic hollow fibres.
▪ The fibre wall acts as the semipermeable membrane. Blood flows through the fibres,
dialysis solution flows around the outside the fibres, and water and wastes move between
these two solutions.
▪ The cleansed blood is then returned via the circuit back to the body.
▪ Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer
membrane.
▪ This usually is done by applying a negative pressure to the dialysate compartment of the
dialyzer.
▪ This pressure gradient causes water and dissolved solutes to move from blood to dialysate,
and allows the removal of several litres of excess fluid during a typical 3 to 5 hour
treatment.
▪ Studies have demonstrated the clinical benefits of dialyzing 5 to 7 times a week, for 6 to 8
hours.
▪ These frequent long treatments are often done at home, while sleeping but home dialysis is
a flexible modality and schedules can be changed day to day, week to week.
image credit to : www.niddk.nih.gov
Types of venous access for haemodialysis
1. External shunt
▪ Cannula is placed in a large vein and a large artery that approximate each other.
▪ External shunts, which provide easy and painless access to bloodstream, are prone to
infection and clotting and causes erosion of the skin around the insertion area.
2. Arteriovenous fistulas or graft
▪ Large artery and vein are sewn together (anastomosed) below the surface of the skin
(fistula) or subcutaneous graft using the saphenous vein, synthetic prosthesis, or
bovine xenograft to connect artery and vein.
▪ Purpose is to create one blood vessel for withdrawing and returning blood.
