Free CNN Exam Flashcards

There is no degree requirement. NNCC's role-based update (effective Summer 2026) removed the former baccalaureate (BSN) requirement; you only need a full, unrestricted RN license plus the required nephrology experience and continuing education. Both CNN and CDN are now open to all RNs regardless of degree.

At least 2,500 hours of nephrology nursing practice as an RN within the 2 years prior to application (in areas such as home dialysis, acute kidney injury, critical care, CKD management, or kidney transplant).

The CNN certification is valid for 3 years. Recertification requires a full, unrestricted RN license, at least 1,500 hours of nephrology experience during the cycle, and 45 contact hours of continuing education (minimum 15 nephrology-specific) — or passing the exam again, which waives the CE requirement.

The exam consists of 150 multiple-choice questions with a 3-hour time limit. The passing standard is a scaled score of 95 (corresponding to approximately 70% correct).

Concepts of Kidney Disease is the largest area at approximately 38%, followed by Hemodialysis (~30%), Peritoneal Dialysis (~22%), Transplant (~5%), and Acute Therapies (~5%). A revised blueprint effective September 1, 2026 reweights these to Concepts of Kidney Disease 30%, Acute Inpatient Therapies 25%, Peritoneal Dialysis 20%, Home Hemodialysis 15%, and Transplant 10%.

EPO is produced by peritubular interstitial cells in the renal cortex. It stimulates the bone marrow to produce red blood cells. In CKD, destruction of these cells leads to anemia.

A FENa < 1% indicates prerenal azotemia (kidneys conserve sodium due to hypoperfusion). A FENa > 2% indicates ATN (tubular damage impairs sodium reabsorption, causing sodium loss in urine).

Stage 3a: GFR 45–59 mL/min; Stage 3b: GFR 30–44 mL/min; Stage 4: GFR 15–29 mL/min (severe reduction); Stage 5: GFR < 15 mL/min (kidney failure, dialysis indication).

1) Severe proteinuria (> 3.5 g/24h), 2) Hypoalbuminemia (< 3.0 g/dL), 3) Generalized edema, and 4) Hyperlipidemia. It results from increased glomerular permeability.

Kidneys fail to excrete phosphorus and cannot convert vitamin D to its active form (calcitriol). Hypocalcemia and hyperphosphatemia result, stimulating parathyroid hormone (PTH) release, which resorbs calcium from bone.

Peaked T waves appear first, followed by PR prolongation, QRS widening, and loss of P waves. IV Calcium Gluconate must be given immediately to stabilize the cardiac cell membrane.

They block angiotensin II, preventing efferent arteriolar constriction, which is necessary to maintain glomerular filtration pressure when renal perfusion is compromised. This can precipitate acute kidney injury (AKI).

Category A1 (Normal/mild): < 30 mg/g; Category A2 (Moderate): 30–300 mg/g; Category A3 (Severe): > 300 mg/g. Severe albuminuria is a key predictor of CKD progression.

AIN is usually drug-induced (NSAIDs, antibiotics, PPIs) causing immune-mediated tubulointerstitial inflammation. The classic triad is fever, rash, and arthralgia (often with eosinophiluria).

Asterixis (flapping tremor), encephalopathy/confusion, metallic taste, nausea/vomiting, anorexia, pericarditis, and uremic frost on the skin. These indicate urgent need for renal replacement therapy.

Diffusion, which is the movement of solutes down a concentration gradient from blood to dialysate. It is optimized by maximizing concentration gradients, countercurrent flow, and dialyzer surface area.

Fluid is removed by convection/ultrafiltration, which is driven by a hydrostatic pressure gradient (transmembrane pressure, TMP) created by the dialysis machine across the semipermeable membrane.

Single-pool Kt/V (spKt/V) target is ≥ 1.4 per session (minimum delivered 1.2). The Urea Reduction Ratio (URR) target is ≥ 70% (minimum delivered 65%).

An AVF uses native vessels, offering the lowest infection and thrombosis rates. It takes 6–12 weeks to mature (vein wall thickens and dilates to handle high blood flow).

A palpable thrill (continuous vibration) and an audible bruit (low-pitched, continuous rushing sound). A high-pitched, systolic-only bruit suggests stenosis; absence of both indicates thrombosis.

Rapid clearance of urea decreases blood osmolality, causing water to shift into brain cells, leading to cerebral edema. It is prevented by limiting solute clearance during initial treatments (lower Qb, shorter time).

Place patient in Trendelenburg position (unless contraindicated), reduce or stop ultrafiltration (UF), administer a normal saline bolus (100–250 mL) as prescribed, and check vitals.

It occurs when blood flow is diverted from the distal extremity into the low-resistance access. Signs include coldness, pain, paresthesias, pallor, and weak distal pulses in the access limb.

The AAMI limit is < 0.1 mg/L (or 0.1 ppm). Excess chloramines pass through the dialyzer membrane, causing hemolysis (rupturing red blood cells) and methemoglobinemia.

Carbon tanks remove chlorine and chloramines through adsorption. Dialysis systems require two tanks in series. Chloramine testing must be performed before the first patient shift and every 4 hours from the sample port between the tanks.

Type A is an immediate, IgE-mediated hypersensitivity reaction (usually to ethylene oxide sterilant) causing dyspnea, hives, and anaphylaxis. Type B is a milder, complement-activated reaction causing chest and back pain 20–40 minutes into treatment.

Active hepatitis B infection (due to high transmission risk), positive HIV or hepatitis C status (per facility policy to prevent cross-contamination), and systemic infections/sepsis.

Rope ladder rotates needle sites along the length of the access to prevent aneurysm formation. Buttonhole uses constant sites and angles to create a mature tract, suitable for self-cannulation, but has a higher infection risk.

Place the patient in left lateral Trendelenburg (Durant's Maneuver). This traps the air bolus in the apex of the right ventricle, preventing it from entering the pulmonary artery and blocking outflow.

High-flux membranes have larger pores and higher ultrafiltration coefficients (KUF). They allow clearance of larger 'middle molecules' (e.g., beta-2 microglobulin) and faster fluid removal.

Dextrose (glucose monohydrate) is the osmotic agent, available in 1.5%, 2.5%, and 4.25% concentrations. Higher concentrations create a larger osmotic gradient, increasing fluid removal (ultrafiltration).

Continuous Ambulatory Peritoneal Dialysis (CAPD) is manual, with 4–5 exchanges during waking hours and long overnight dwells. Automated Peritoneal Dialysis (APD) uses a cycler machine to perform multiple exchanges overnight, leaving the day clear.

Cloudy dialysate effluent with a white blood cell count > 100/mcL (with at least 50% polymorphonuclear neutrophils), clinical symptoms (abdominal pain, rebound tenderness), and/or positive Gram stain/culture.

A PET measures the rate of solute transfer (creatinine and glucose) across the peritoneal membrane. It classifies patients as high, high-average, low-average, or low transporters. High transporters need shorter, faster dwells (like APD); low transporters need longer dwells (like CAPD).

Exit-site infection shows redness and purulence at the external opening. Tunnel infection shows pain, swelling, tenderness, and erythema along the subcutaneous pathway of the catheter, carrying a high risk of peritonitis and requiring systemic antibiotics.

Fibrin appears as white, gelatinous shreds in the effluent, often stimulated by peritoneal inflammation or peritonitis. It can block the catheter. It is treated by adding heparin (e.g., 500–1000 units/L) to the dialysate bags as prescribed.

Distended bowel loops compress the peritoneal catheter and alter its position. Management includes stool softeners and daily bowel regimens (avoiding phosphorus/magnesium-containing laxatives).

EPS is a rare, severe complication where the peritoneal membrane becomes thickened and fibrotic, leading to bowel obstruction. Symptoms include persistent nausea, vomiting, malnutrition, and ascites. It often requires stopping PD.

Maintain sterile dressings, avoid catheter manipulation, perform flush-only exchanges as ordered to prevent fibrin occlusion, and delay routine dialysis use for at least 10–14 days to allow healing and prevent leaks.

The KDOQI guideline recommends a minimum total (peritoneal + residual renal) weekly Kt/V of 1.7. This requires a 24-hour urine and dialysate collection.

1) A calcineurin inhibitor (CNI: Tacrolimus or Cyclosporine), 2) An antimetabolite (Mycophenolate Mofetil or Azathioprine), and 3) A corticosteroid (Prednisone).

Nephrotoxicity. CNIs cause vasoconstriction of the afferent arterioles, reducing GFR and raising creatinine. Levels must be monitored via periodic trough blood levels (taken just before the next dose).

Hyperacute occurs within minutes/hours (pre-existing antibodies; requires immediate graft removal). Acute occurs weeks/months post-transplant (T-cell mediated; treatable with high-dose steroids/thymoglobulin). Chronic occurs over years (progressive fibrosis; untreatable, leads to graft loss).

HHD patients must test their home water system for chlorine/chloramines prior to every treatment session and perform periodic bacterial/endotoxin cultures of the product water.

Cytomegalovirus (CMV). It typically occurs 1–6 months post-transplant (when immunosuppression is highest). Symptoms include fever, leukopenia, and organ-specific disease (pneumonitis, colitis). Prevented with valganciclovir.

Federal regulations that dialysis facilities must meet to receive Medicare reimbursement. They mandate patient rights, water quality standards, reuse safety, interdisciplinary plans of care, and quality assessment/performance improvement (QAPI) programs.

Systematically tracking clinical outcomes (adequacy, anemia, bone disease, vascular access, infections) to identify gaps, implement corrective plans (clinical audits), and improve patient safety and care processes.

Support patient autonomy, assess for depression/cognitive issues, ensure the patient understands the consequences of withdrawal, facilitate interdisciplinary support (palliative care/social work), and document the decision.

Initially within 30 days or 13 treatments of admission, then stable patients are reviewed annually. Unstable patients (e.g., frequent hospitalizations, inadequate dialysis) must be reviewed monthly.

CRRT runs continuously at lower blood/fluid flow rates, allowing slow, gentle solute and fluid removal. This prevents the rapid hemodynamic shifts and hypotension associated with intermittent HD in unstable patients.