CDN Exam Flashcards

Q: What is the passing score for the CDN exam?

The CDN passing standard is a scaled score of 95, which NNCC indicates corresponds to roughly 70-74% correct depending on the exam form. The test has 150 multiple-choice questions over 3 hours. Results are reported as pass or fail with a scaled score.

Q: What are the eligibility requirements for the CDN exam?

You need an active, unrestricted RN license; at least 2,000 hours of nephrology nursing practice within the prior 2 years; and 20 contact hours of approved nephrology continuing education in that same period. NNCC manages authorization and scheduling through PSI after application approval.

Q: Which CDN content area is tested most heavily?

Hemodialysis is the largest blueprint domain at about 51-53% of scored content — more than half the exam. Kidney disease concepts account for roughly 27-29%, peritoneal dialysis about 15-17%, and kidney transplant plus acute therapies about 4-5% combined.

Q: How long is CDN certification valid?

CDN certification is valid for 3 years from the last day of the month you pass. Recertification requires meeting NNCC continuing practice and education requirements or retaking the exam. A one-time reduced-fee retake is available if you do not pass on the first attempt.

Q: How should I weight CDN flashcard study time?

Spend roughly half your review on hemodialysis — vascular access, machine safety, adequacy, complications, and water treatment. About one-quarter on kidney disease pathophysiology, electrolytes, and anemia. The remainder on peritoneal dialysis and smaller transplant/acute-therapy topics that still appear on every form.

Q: What is the CDN exam fee?

The standard CDN exam fee is $350 ($300 for partner members such as ANNA). A non-refundable processing fee is included. A one-time retake is $200 ($175 partner). An optional NNCC online practice exam is available for an additional fee.

Question 1

CKD GFR staging — what ranges define Stages 3a, 3b, 4, and 5?

Accepted Answer

Stage 3a: GFR 45-59 mL/min/1.73 m²; Stage 3b: GFR 30-44; Stage 4: GFR 15-29 (severe reduction); Stage 5: GFR below 15 or on dialysis (kidney failure). Staging guides planning for renal replacement therapy and complication management.

Question 2

Prerenal vs intrinsic (ATN) vs postrenal AKI — how does urine output and FENa help distinguish them?

Accepted Answer

Prerenal AKI: low urine sodium, FENa under 1%, responds to volume. Acute tubular necrosis: muddy brown casts, FENa over 2%. Postrenal AKI: obstruction history, hydronephrosis on imaging, may have fluctuating output. Nursing priority is identifying reversible causes quickly.

Question 3

Nephrotic syndrome — what four findings define it?

Accepted Answer

Heavy proteinuria (typically over 3.5 g/24 h), hypoalbuminemia, generalized edema, and hyperlipidemia. Results from increased glomerular permeability. Nurses monitor fluid balance, infection risk, and thrombosis risk from urinary protein loss.

Question 4

Nephritic syndrome — hallmark urinalysis and clinical picture

Accepted Answer

Hematuria with dysmorphic red cells and red-cell casts, hypertension, oliguria, and variable proteinuria (usually not nephrotic-range). Reflects glomerular inflammation. Differs from nephrotic syndrome, which features massive protein loss with relatively little hematuria.

Question 5

CKD-mineral and bone disorder (CKD-MBD) — why does phosphorus rise and calcium fall?

Accepted Answer

Failing kidneys excrete phosphorus poorly and cannot activate vitamin D to calcitriol. Hyperphosphatemia and hypocalcemia stimulate parathyroid hormone, causing bone resorption and vascular calcification. Diet, binders, and vitamin D analogs are core management tools.

Question 6

Anemia in CKD — where is erythropoietin produced and why do levels fall?

Accepted Answer

Erythropoietin is made by peritubular interstitial cells in the renal cortex. Nephron loss reduces EPO production, causing normocytic anemia. Treatment includes iron repletion and erythropoiesis-stimulating agents when indicated, with blood pressure and hemoglobin targets monitored.

Question 7

Hyperkalemia ECG progression and first cardiac stabilizer

Accepted Answer

Peaked T waves appear first, then PR prolongation, QRS widening, and loss of P waves — progressing toward ventricular fibrillation. IV calcium gluconate or calcium chloride stabilizes the myocardial membrane immediately while definitive lowering therapy is prepared.

Question 8

Uremic symptoms indicating urgent need for dialysis

Accepted Answer

Asterixis, confusion or encephalopathy, pericarditis, intractable nausea or vomiting, refractory hyperkalemia, pulmonary edema unresponsive to diuretics, and severe metabolic acidosis. These are clinical indications for emergent renal replacement therapy beyond routine outpatient scheduling.

Question 9

Albuminuria categories by urine albumin-to-creatinine ratio (ACR)

Accepted Answer

A1 normal to mildly increased: under 30 mg/g. A2 moderately increased: 30-300 mg/g. A3 severely increased: over 300 mg/g. Higher categories predict faster CKD progression and cardiovascular risk; repeat testing confirms persistence.

Question 10

Metabolic acidosis in advanced CKD — typical anion gap and compensatory response

Accepted Answer

Retention of organic acids produces a normal anion-gap or elevated anion-gap metabolic acidosis depending on cause. Lungs compensate with Kussmaul respirations (deep, rapid breathing). Severe acidosis contributes to muscle wasting, bone disease, and hyperkalemia.

Question 11

Contrast-induced nephropathy prevention in at-risk patients

Accepted Answer

Use lowest effective contrast volume, avoid nephrotoxic combinations when possible, and ensure periprocedural hydration per protocol. Hold metformin around contrast when eGFR is reduced. Monitor creatinine after exposure; at-risk patients include CKD, diabetes, and dehydration.

Question 12

ACE inhibitors and ARBs in bilateral renal artery stenosis — why are they risky?

Accepted Answer

Angiotensin II normally constricts the efferent arteriole to maintain glomerular filtration pressure. Blocking that mechanism with bilateral stenosis can precipitate acute kidney injury. Report acute creatinine rise after starting these drugs.

Question 13

Fluid overload vs hypovolemia assessment in dialysis patients

Accepted Answer

Overload: hypertension, pulmonary crackles, jugular distension, edema, weight gain above dry weight. Hypovolemia: hypotension, tachycardia, poor access flow, cramps, dizziness. Accurate pre-dialysis weight compared to dry weight guides ultrafiltration goals.

Question 14

Protein and phosphorus dietary counseling in CKD Stage 4-5

Accepted Answer

Moderate protein restriction may be recommended to reduce uremic toxin production while maintaining adequate nutrition. Phosphorus restriction and binder timing with meals limit CKD-MBD. Dietitian collaboration is essential; malnutrition worsens outcomes.

Question 15

Diffusion during hemodialysis — what drives solute removal?

Accepted Answer

Solutes move down a concentration gradient from blood across the semipermeable membrane into dialysate. Countercurrent dialysate flow maintains the gradient along the fiber length. Small molecules such as urea and potassium clear faster than larger ones.

Question 16

Ultrafiltration during hemodialysis — how is fluid removed?

Accepted Answer

Hydrostatic pressure across the membrane exceeds oncotic pressure, forcing plasma water out of blood while solutes remain. The ultrafiltration rate (mL/h) multiplied by treatment time equals fluid removed. Excessive UF rate risks hypotension and cramping.

Question 17

Kt/V — what does it measure and typical adequacy target?

Accepted Answer

Kt/V quantifies dialysis dose: clearance (K) times treatment time (t) divided by urea distribution volume (V). A single-pool Kt/V of at least 1.2 per session (or equivalent URR) is a common adequacy benchmark for thrice-weekly in-center hemodialysis.

Question 18

URR (urea reduction ratio) — minimum adequate value

Accepted Answer

URR compares pre- and post-dialysis BUN: (pre minus post) divided by pre, times 100. A URR of at least 65% is widely used as an adequacy threshold for conventional hemodialysis schedules. Low URR signals insufficient clearance or shortened treatments.

Question 19

Preferred long-term hemodialysis vascular access and why

Accepted Answer

Native arteriovenous fistula (AVF) is preferred: lowest infection and thrombosis rates, longest patency, and lowest long-term cost. Requires maturation (often 6-12 weeks) before cannulation. Plan access well before anticipated dialysis start.

Question 20

AV graft vs tunneled catheter — key tradeoffs

Accepted Answer

AV graft uses synthetic conduit; cannulation possible sooner than fistula but higher thrombosis and infection risk than AVF. Tunneled cuffed catheter is for temporary or bridge access — highest infection and central stenosis risk; avoid as permanent access when possible.

Question 21

Steal syndrome after AV access — signs and concern

Accepted Answer

Distal hand ischemia from diversion of arterial flow into the access: pain, numbness, cool pale fingers, weak pulse distally. May require surgical revision. Assess neurovascular status before and after access creation and during dialysis.

Question 22

Cannulation site rotation (rope ladder vs area)

Accepted Answer

Rotate needle sites along the access length to allow aneurysm-free healing and preserve access life. Avoid repeated puncture in one spot (area cannulation) except in buttonhole programs with strict sterile technique. Document sites each treatment.

Question 23

Heparin anticoagulation during hemodialysis — nursing considerations

Accepted Answer

Prevents circuit clotting; dose individualized by weight and bleeding risk. Monitor for access site bleeding post-treatment. Heparin is contraindicated or reduced with active bleeding; protamine sulfate reverses heparin in overdose emergencies.

Question 24

Intradialytic hypotension — common causes and immediate interventions

Accepted Answer

Causes include excessive ultrafiltration, rapid UF rate, eating during dialysis, cardiac dysfunction, and antihypertensive timing. Interventions: Trendelenburg, reduce UF, saline bolus per protocol, lower blood pump speed, and reassess dry weight.

Question 25

Muscle cramps during dialysis — prevention and treatment

Accepted Answer

Often related to rapid fluid removal, sodium shifts, or hypovolemia. Slow UF rate, adjust sodium profiling, and give normal saline per protocol. Review dry weight and dietary sodium intake. Cramps may signal excessive fluid gain between sessions.

Question 26

Dialysis disequilibrium syndrome — who is at risk and symptoms

Accepted Answer

Occurs when urea is cleared faster than the brain equilibrates, causing cerebral edema. Highest risk in first treatments or very high pre-dialysis BUN. Symptoms: headache, nausea, restlessness, seizures, decreased consciousness. Prevention includes shorter initial treatments.

Question 27

Air embolism during hemodialysis — signs and emergency actions

Accepted Answer

Sudden dyspnea, chest pain, hypotension, altered mental status, or cardiac arrest. Clamp blood lines, place patient on left side with head down, administer oxygen, and notify provider immediately. Prevention: prime lines completely and secure connections.

Question 28

Dry weight — definition and clinical use

Accepted Answer

The post-dialysis weight below which the patient develops hypotension or cramps without overt edema. It changes with nutrition status and cardiac function. Accurate dry weight is the foundation for setting ultrafiltration goals each session.

Question 29

Maximum recommended ultrafiltration rate guideline

Accepted Answer

Many protocols limit UF rate to about 10-13 mL/kg/hour to reduce hypotension and cardiac stress. Higher rates increase cramping and intradialytic events. Interdialytic weight gain control through fluid and sodium counseling reduces required UF.

Question 30

Sodium profiling during hemodialysis — purpose

Accepted Answer

Varies dialysate sodium during treatment to reduce osmotic shifts that cause cramps and hypotension while still achieving fluid removal goals. Individualized profiles balance comfort against interdialytic thirst and weight gain.

Question 31

Water treatment for hemodialysis — reverse osmosis role

Accepted Answer

RO removes dissolved ions, bacteria, and endotoxins from feed water. Dialysis water must meet AAMI/ISO purity standards because impurities cross into blood. Daily chlorine/chloramine testing and bacterial cultures per facility policy are mandatory.

Question 32

Chloramine in municipal water — dialysis hazard

Accepted Answer

Chloramine can pass carbon prefilters and cause hemolytic anemia in patients if not removed. Total chlorine testing before each shift confirms removal. Standard chlorine alone is easier to eliminate; chloramine requires specific treatment design.

Question 33

Dialysate composition — key electrolytes adjusted per prescription

Accepted Answer

Typically contains sodium, potassium, calcium, magnesium, bicarbonate (or acetate precursor), and glucose optional. Potassium bath of 0-4 mEq/L is matched to serum K and arrhythmia risk. Bicarbonate corrects metabolic acidosis during treatment.

Question 34

Blood leak detector — when does the machine alarm?

Accepted Answer

Optical sensor detects blood in effluent dialysate line, indicating membrane rupture or disconnect. Machine stops blood pump automatically. Do not bypass without investigating; patient blood loss can be rapid.

Question 35

Venous pressure alarm rise during treatment — likely causes

Accepted Answer

Needle dislodgement, kinked venous line, clot in drip chamber or fiber, or stenosis in outflow tract. Inspect access and tubing immediately. High venous pressure can indicate impending access failure.

Question 36

Arterial pressure alarm (negative pressure) — common causes

Accepted Answer

Access recirculation, needle against vessel wall, suction from blood pump too high, or line kink on arterial side. May reduce clearance and damage access. Reposition needles or reduce pump speed per protocol.

Question 37

Recirculation — definition and effect on adequacy

Accepted Answer

Treated blood returns to arterial needle without full circuit transit, lowering effective clearance. Suspected with poor Kt/V despite adequate time, high access flows, or reversed lines. Access imaging or dilution studies confirm.

Question 38

Type A vs Type B dialyzer reactions

Accepted Answer

Type A (anaphylactic): within minutes — chest pain, dyspnea, hypotension; often ethylene oxide or membrane sensitizer. Type B (complement-mediated): back pain, chest pain, often 15-30 minutes in; may resolve with continued treatment. Stop blood flow for severe Type A.

Question 39

Hepatitis B vaccination and isolation in dialysis units

Accepted Answer

All susceptible patients and staff should complete HBV vaccination series. HBsAg-positive patients dialyze in dedicated room or station with dedicated equipment per CDC guidelines. Serologic surveillance guides station assignments.

Question 40

Catheter exit-site infection vs tunnel infection

Accepted Answer

Exit-site: erythema, drainage at skin exit — often topical or oral antibiotics. Tunnel infection: tenderness along subcutaneous tract, may have drainage; higher risk of bacteremia and often requires catheter removal plus systemic antibiotics.

Question 41

CAPD vs APD (CCPD) — modality difference

Accepted Answer

CAPD uses manual bag exchanges throughout the day without a machine. APD (automated peritoneal dialysis) runs cycles overnight with a cycler. Both use the peritoneal membrane as the filter; choice depends on lifestyle, ultrafiltration needs, and residual kidney function.

Question 42

Peritoneal dialysis catheter break-in period

Accepted Answer

New catheters need healing time before full-volume exchanges (often 2 weeks per surgeon protocol) to reduce leaks and infection. Low-volume dwells may start earlier. Train patients on sterile connection technique before independent exchanges.

Question 43

Peritonitis in PD — cloudy effluent and first steps

Accepted Answer

Cloudy dialysate with abdominal pain and fever suggests peritonitis. Send effluent for cell count, Gram stain, and culture before broad antibiotics per protocol. Do not routinely remove catheter unless refractory or fungal infection.

Question 44

Ultrafiltration failure in long-term PD — clinical consequence

Accepted Answer

Membrane transport changes reduce fluid removal, causing volume overload and possible modality failure. May require increased hypertonic dwells temporarily or transition to hemodialysis. Monitor daily weights and blood pressure closely.

Question 45

Dwell time and exchange volume — effect on clearance

Accepted Answer

Longer dwells improve small-solute clearance early but may reduce ultrafiltration as osmotic gradient dissipates. Prescription balances exchanges per day, dwell duration, and glucose concentration to meet adequacy (Kt/V or PET results).

Question 46

PET (peritoneal equilibration test) — what it determines

Accepted Answer

Classifies membrane transport as low, low-average, high-average, or high transporter. High transporters clear small solutes quickly but may need shorter dwells; low transporters may need longer dwells. Guides individualized PD prescription.

Question 47

Hernia risk with PD — patient teaching points

Accepted Answer

Increased intra-abdominal pressure from dialysate volume raises inguinal and umbilical hernia risk. Avoid heavy lifting, treat constipation, and report bulges or pain. Surgical repair may be needed before continuing PD safely.

Question 48

PD solution glucose concentration — ultrafiltration mechanism

Accepted Answer

Hypertonic dextrose creates osmotic gradient pulling fluid into peritoneal cavity. Higher concentrations remove more fluid but accelerate membrane changes and metabolic load. Icodextrin solutions provide sustained ultrafiltration for long dwells.

Question 49

Kidney transplant acute rejection — nursing monitoring focus

Accepted Answer

Watch rising creatinine, decreased urine output, fever, graft tenderness, and hypertension. Biopsy confirms rejection type. Immunosuppressant levels and adherence are critical; teach patients never to stop medications without transplant team approval.

Question 50

CRRT vs conventional hemodialysis in critically ill patients

Accepted Answer

Continuous renal replacement therapy runs 24 hours with gentler fluid and solute shifts — preferred in hemodynamically unstable ICU patients. Conventional HD is intermittent with higher UF rates. Nursing monitors anticoagulation, filter clotting, and fluid balance hourly on CRRT.

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