As part of waste reduction week, I think it is important to highlight some major accomplishments by the dialysis team at Toronto General.  Over the years, the team has developed and implemented a significant waste reduction and reuse program.  Sudarshan Meenakhsi Sundharam presented a poster about the environmental impacts of this program at the 2013 Canadian Association of Nephrology Nurses and Technologists (CANNT) conference and I would like to congratulate him and his dialysis team, led by technical manager Charles Estridge, on taking home the third place prize!

In this blog post, I’ll briefly discuss the program and some of the key impacts we have seen to UHN’s economic and environmental performance.  In a metaphor that is almost too fitting, I think that the nephrology team at TGH is acting very kidney-like in its efforts to eliminate waste.

Introduction to dialysis

The kidney performs many functions critical to maintaining health.  For patients experiencing either acute kidney injury or chronic kidney disease, dialysis may be a treatment that can bridge the gap to returned kidney function, maintain patient condition until a transplant can be performed, or act as a support measure if transplant is not appropriate.  The vital kidney functions replicated by dialysis are removal of waste and excess water from the blood stream.  A key component of the dialysis treatment is the dialyzer, also known as the artificial kidney.  Blood is pumped out of the patient’s body through the dialyzer, where solutes are able to diffuse across a semi-permeable membrane between the blood and a fluid called a dialysate.  Diffusion occurs when a solute moves from a fluid of high concentration to a fluid of low concentration.  The dialysate contains low concentrations of solutes to be removed from the blood (such as potassium, phosphorus, and urea) and high concentrations of solutes to be added to the blood (such as bicarbonate).  Dialysate components are prescribed by a nephrologist according to patient needs.

UHN oversees approximately 56,000 life prolonging and life saving dialysis treatments per year, including 200 inpatients and 100+ home patients.

Dialysis Schematic

TGH Waste Reduction Program

In most hospitals in North America, the dialyzer (a $30 item containing about 1kg of plastic) is used for one treatment and discarded.  The nephrology department at Toronto General has taken a different approach to dialyzer management.  Instead of purchasing a new dialyzer for every treatment, staff have developed a program to reprocess and reuse dialyzers in an effort to reduce waste.  See figure below for an overview of the process.

Dialyzer Process

Strict guidelines are followed to ensure the dialyzer reuse is conducted in a safe manner.  The following measures are adhered to at UHN:

  • Dialyzers must be clearly labeled with patient name, medical registration number and can only be used for the same patient
  • Prior to treatment, dialyzer is verified by the reprocessing technician, nurse, hemodialysis assistant, and patient
  • Dialyzer must be tested after each reprocess to make sure it is working properly
  • Dialyzer must be tested for any traces of disinfectant after rinsing
  • Dialyzers can be used a maximum of 15 times
  • Dialyzers for Hepatitis B and HIV positive patients are not reused
  • Heat labels and oven temperature recorders are used to ensure proper heat exposure

The reprocessing program reduces the number of dialyzers needed from 56,000 (one per treatment) to about 11,250.

These numbers are a major achievement, but the department did not stop there.  Most hospitals also deploy one-time-use disposable bicarbonate cartridges and acid containers (bicarbonate and acid are mixed with purified water by the dialysis machine to produce the dialysate).  After treatment, the remaining acid and bicarbonate in these containers is also discarded.  TGH has centralized acid and bicarbonate distribution systems, which supply these components to all of the dialysis machines in the ward.  These systems eliminate waste of both plastic containers and excess solution, since the central system can supply the exact amounts required by each patient with no leftovers to discard.  The number of acid and bicarbonate containers consumed has been reduced by over 90%.

Dialyzer Processing
Dialyzer Processing Equipment
Bicarbonate Cartridges

Benefits of Waste Reduction

The following are some of the major benefits of the waste management programs in the TGH dialysis ward:

  • Reduced equipment procurement costs
  • Reduced waste to landfill
  • Reduced disposal cost
  • Reduced environmental impact of new equipment manufacture

Approximate annual savings from the program are shown here:


Procurement Savings


Waste Diverted from Landfill

89,000 kg

Reduced Disposal Costs


Reduced Environmental Impact

3 tons CO2


Further environmental impacts not included in this analysis include reduction in packaging and transport of dialysis equipment.  The program costs less than $200,000 per year to run, including additional purified water consumption, additional electricity use, and three full time reprocessing technicians.  I would like to again congratulate Sudarshan, Charles, and their team on their third place prize at CANNT 2013 and on their commitment to waste reduction!

Importance Reuse in Dialysis & Enviro Impact - poster final
Poster Presentation: Importance Reuse in Dialysis & Enviro Impact