Preparing for the CNN (Certified Nephrology Nurse) exam? Procedures is one of the areas our deck drills hardest: 120 of its 1020 flashcards focus on procedures, covering topics like EBCT, Empty Bed Contact Time, RO, Fluid Balance Error. Try the sample questions below — every card is a real question-and-answer pair from the full deck.
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According to AAMI/CMS standards, what is the minimum required total Empty Bed Contact Time (EBCT) for carbon adsorption, and how must it be distributed across the tanks?
Show answer →Minimum EBCT is 10 minutes total. It must be split between at least two carbon tanks in series, with at least 5 minutes of contact time in each tank. This ensures that if the first (worker) tank fails, the second (polisher) tank provides a safety margin to remove chlorine/chloramines. Exam Tip: Total EBCT is calculated based on the maximum possible water flow rate of the system.
The Reverse Osmosis (RO) system shows a feed water conductivity of 400 μS/cm and a product water conductivity of 8 μS/cm. Calculate the percent rejection and determine if this meets the typical AAMI performance standard for RO membranes.
Show answer →Formula: [(Feed - Product) / Feed] x 100. Calculation: [(400 - 8) / 400] x 100 = 98%. This meets/exceeds the standard. RO membranes should typically maintain >95% (often >98%) salt rejection. A significant drop in % rejection indicates membrane scaling, fouling, or degradation, allowing contaminants like aluminum or fluoride to pass into the product water. Clinical Tip: Conductivity is the primary real-time indicator of RO health.
The nurse notes redness and purulent drainage at the CVC exit site, but the patient is afebrile and the tunnel is non-tender. How is this classified and managed?
Show answer →This is an Exit Site Infection. Management involves increased local care (cleaning with CHG) and topical or oral antibiotics. Unlike a tunnel infection, it does not necessarily require catheter removal unless it progresses. Rationale: Exit site infections are localized to the skin-catheter interface. Exam Tip: Tunnel infections (tenderness/redness over the subcutaneous tract) are much more serious and almost always require catheter removal.
During a routine clinic visit, a PD exit site shows mild redness (<2mm) without drainage, pain, or induration. How should the CNN classify this finding according to standard assessment protocols?
Show answer →This is classified as an Equivocal or Normal exit site depending on the time since surgery. If chronic, mild redness without other signs (purulence, swelling, crusting) often represents mechanical irritation rather than infection. Management involves improving immobilization (anchoring). Exam Tip: Distinguish between acute infection (purulent drainage) and chronic irritation. True infection usually requires at least two clinical signs (redness, crusting, swelling, pain, or drainage).
A Fluid Balance Error or Scale Inconsistency alarm occurs repeatedly. The nurse verifies that the bags are hanging freely and no clamps are closed. What is the next priority step according to 2026 safety standards?
Show answer →Priority: Check for external interference with the scales (e.g., bags touching the machine frame, lines draped over the scale arms, or empty bags not yet replaced). Rationale: CRRT scales are highly sensitive. Even a slight touch or swinging of bags can trigger an error. If the error persists after clearing obstructions, the nurse may need to restart the clock/balance or, if a hardware failure is suspected, take the machine out of service. Exam Tip: NNCC emphasizes safety—never bypass scale alarms by hanging bags elsewhere. Precise fluid balance is the primary advantage of CRRT; scale errors compromise the therapy's hemodynamic stability goal.
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Try 30 free CNN cards firstThe full CNN deck contains 1020 flashcards, and 120 of them focus on procedures. This page shows 5 free samples.
Our CNN deck dedicates 120 of 1020 cards (12%) to procedures — always cross-check the official NNCC exam outline for the current blueprint weighting.
Yes — the samples on this page are free, and the CNN preview page has 30 more free cards. Full access to all 1020 cards is a one-time $7.
Assessment
20 cards
Basics
110 cards
Diagnostics
70 cards
Management
200 cards
Pathology
280 cards
Pharmacology
160 cards
Physiology
60 cards
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