Certified Hemodialysis Technologist/Technician Exam Dialyzer Reprocessing and Reuse 1 — Questions and Answers
Question 1: According to AAMI guidelines, a dialyzer should be rejected for reuse if the total cell volume (TCV) falls below what percentage of the original volume?
- 50%
- 70%
- 80% (Correct answer)
- 90%
Correct answer: 80%
AAMI standards require dialyzers to be discarded if TCV falls below 80% of original volume, as this indicates significant fiber loss affecting clearance.
Question 2: Which chemical is most commonly used as a germicide in manual dialyzer reprocessing?
- Sodium hypochlorite at 5%
- Formaldehyde (4%) (Correct answer)
- Isopropyl alcohol 70%
- Hydrogen peroxide 35%
Correct answer: Formaldehyde (4%)
Formaldehyde at 4% has been widely used as a dialyzer reprocessing germicide due to its broad-spectrum antimicrobial efficacy.
Question 3: Before a reprocessed dialyzer is used on a patient, residual germicide must be tested. Which test confirms formaldehyde removal?
- pH test strip
- Conductivity test
- Colorimetric test using chromotropic acid or equivalent (Correct answer)
- Glucose oxidase strip
Correct answer: Colorimetric test using chromotropic acid or equivalent
A colorimetric test (such as chromotropic acid) is used to confirm that formaldehyde levels have been reduced to safe levels before reuse.
Question 4: Peracetic acid/hydrogen peroxide (Renalin/Minncare) used in dialyzer reprocessing is advantageous because:
- It requires no rinsing before reuse
- It breaks down into non-toxic products (acetic acid, water, oxygen) (Correct answer)
- It is safe to inhale in concentrated form
- It requires no germicide residual testing
Correct answer: It breaks down into non-toxic products (acetic acid, water, oxygen)
Peracetic acid decomposes into acetic acid, water, and oxygen, making it environmentally safer and decomposing to harmless residuals after adequate contact time.
Question 5: The maximum number of times a dialyzer may be reused is determined by:
- Federal law mandating a fixed maximum of 30 uses
- The dialyzer's TCV, blood leak test, and visual inspection at each reprocessing (Correct answer)
- Patient preference only
- A fixed 10-use maximum in all facilities
Correct answer: The dialyzer's TCV, blood leak test, and visual inspection at each reprocessing
No federally mandated fixed maximum exists; dialyzers are reused as long as they pass TCV (≥80%), blood leak, and visual inspection criteria at each reprocessing.
Question 6: A blood leak test on a reprocessed dialyzer involves:
- Testing patient blood for dialysate contamination
- Applying pressure to the blood compartment and checking for leaks into the dialysate side (Correct answer)
- Checking for visible blood in the dialysate during treatment
- Measuring urea clearance only
Correct answer: Applying pressure to the blood compartment and checking for leaks into the dialysate side
The blood leak test pressurizes the blood compartment of the dialyzer and checks whether any fluid crosses into the dialysate compartment, indicating membrane rupture.
Certified Hemodialysis Technologist/Technician Exam Dialyzer Reprocessing and Reuse 1
According to AAMI guidelines, a dialyzer should be rejected for reuse if the total cell volume (TCV) falls below what percentage of the original volume?