Water Treatment and Quality Flashcards
6 cards from real CCHT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Water Treatment and Quality flashcards as text
A dialysis patient develops aluminum toxicity. Which water treatment failure is the most likely cause?
Answer: Inadequate removal of aluminum from the source water by the RO system
Aluminum toxicity in dialysis patients is primarily caused by inadequate removal of aluminum from source water, which then enters the patient's bloodstream via the dialysate. The RO system must effectively remove aluminum; failure of the RO or elevated source water aluminum can cause toxic accumulation.
What is the purpose of testing dialysis water for endotoxins?
Answer: To detect bacterial cell wall fragments that can cause inflammatory reactions even in the absence of live bacteria
Endotoxins are lipopolysaccharides derived from gram-negative bacterial cell walls. Even dead bacteria release endotoxins. When endotoxins enter the bloodstream via the dialysate, they trigger immune responses causing fever, hypotension, and systemic inflammation—even without live bacterial infection.
During a water quality check, the RO product water conductivity reading is 45 μS/cm, significantly higher than the baseline of 8 μS/cm. What does this most likely indicate?
Answer: The RO membrane is failing or bypassed, allowing solutes to pass through into the product water
A sudden increase in RO product water conductivity from 8 to 45 μS/cm (nearly 6-fold increase) indicates that the RO membrane is no longer effectively rejecting dissolved solutes. This is a significant quality failure requiring immediate investigation and potentially halting patient treatments until resolved.
What is the function of the distribution loop in the dialysis water treatment system?
Answer: To continuously circulate RO-purified water to dialysis machines, preventing stagnation and bacterial growth in supply lines
The distribution loop continuously circulates RO product water through the supply lines to all dialysis machines. Continuous circulation prevents water from becoming stagnant in the lines, which would allow bacterial biofilm to form and multiply in the piping system.
What type of water quality testing documents are required to be maintained in the dialysis facility?
Answer: Daily chlorine/chloramine logs, monthly bacteriology and endotoxin results, and annual chemical analysis, retained for at least 2 years
Facilities must maintain comprehensive water quality records including daily chlorine/chloramine logs, monthly microbiological results (bacteria and endotoxins), and annual chemical analysis for all AAMI-required contaminants. CMS Conditions for Coverage require these records to be retained and available for surveyor review.
A dialysis facility's monthly water culture result shows a bacterial count of 75 CFU/mL. What action is required?
Answer: This exceeds the action level (50 CFU/mL) and requires investigation, corrective action, and resampling
A bacterial count of 75 CFU/mL exceeds the AAMI action level of 50 CFU/mL but is below the maximum limit of 200 CFU/mL. This requires a formal investigation, corrective action (such as system disinfection), and re-testing to confirm the count returns below the action level.