CNN Practice Questions (2026) — Free Sample Questions with Answers

Answer: D

Arrange a psychiatric referral, because refusing dialysis suggests depression: Depression should be screened for when it is suspected. But a capable patient's informed choice of conservative care is not, by itself, evidence of depression.

Explain that dialysis is the standard of care and must be started: A capable adult may decline dialysis. Pressuring the patient overrides autonomy, and dialysis may bring little survival or quality-of-life benefit for frail older adults with heavy comorbidity.

Ask the family to persuade the patient to try dialysis for a few months: A time-limited trial is something to offer the patient directly, not to push through the family. That approach undermines the patient's own decision.

Support the choice and coordinate conservative care with the palliative team: Correct. Conservative kidney management is a legitimate, planned option. The nurse supports the patient's informed choice and coordinates symptom management, advance care planning and team support.

For frail older adults with high comorbidity, conservative kidney management with interdisciplinary palliative support is an accepted alternative to dialysis that respects patient autonomy.

Answer: D

Sodium zirconium cyclosilicate by mouth: Potassium binders remove potassium from the body over hours. They do nothing to protect the heart from immediate arrhythmia when the ECG is already changing.

Regular insulin IV with dextrose: Insulin moves potassium into cells within 15-30 minutes and is given early. But it does not stabilize the cardiac membrane, which is the first priority when the ECG shows changes.

Furosemide by IV push: Loop diuretics increase potassium excretion only if the kidneys respond. That effect is slow and unreliable in stage 4 CKD.

Calcium gluconate by slow IV push: Correct. IV calcium stabilizes the myocardial cell membrane within minutes. It is given first when hyperkalemia causes ECG changes, followed by shifting agents (insulin/dextrose, albuterol) and then removal.

Hyperkalemia with ECG changes: stabilize (IV calcium), then shift (insulin plus dextrose, beta-agonist), then remove (binders, diuretics, dialysis).

Answer: B

Inadequate systemic calcium replacement: Under-replacement lowers both ionized and total calcium. Here the total calcium is rising while the ionized level falls.

Citrate accumulation from impaired metabolism: Correct. When the liver cannot metabolize citrate, calcium-citrate complexes build up. Total calcium rises, ionized calcium falls, the ratio exceeds 2.5 and an anion-gap acidosis develops. Reduce or stop the citrate per protocol and notify the prescriber.

Clotting of the hemofilter from low citrate: Filter clotting appears as rising transmembrane pressure and falling filter life. It does not produce this systemic calcium pattern.

Metabolic alkalosis from excess citrate buffer: Citrate overload with intact metabolism produces alkalosis. This patient has a rising anion-gap acidosis, which points to citrate that is not being metabolized.

During citrate CRRT, a total-to-ionized calcium ratio above 2.5, falling ionized calcium despite more calcium, and anion-gap acidosis signal citrate accumulation. Patients with liver failure and shock are at highest risk.

Answer: A

Drain and send effluent for cell count, Gram stain and culture: Correct. ISPD guidance is to confirm peritonitis (WBC >100/µL with >50% neutrophils) and collect cultures before starting empiric intraperitoneal antibiotics promptly.

Give oral antibiotics and recheck the effluent at the next visit: Intraperitoneal antibiotics are preferred, and treatment should not wait for a later visit. Starting before samples are taken also lowers culture yield.

Switch to hypertonic exchanges to flush the bacteria from the peritoneum: Rapid exchanges and hypertonic solutions do not treat infection. Specimens and antibiotics are the priorities.

Remove the PD catheter and arrange temporary hemodialysis: Catheter removal is for refractory, relapsing or fungal peritonitis. It is not the first step for a new episode.

Cloudy effluent in a PD patient means peritonitis until proven otherwise. Send effluent for cell count, Gram stain and culture, then start empiric intraperitoneal antibiotics without delay.

Answer: C

0.5 mg/L: This is five times the limit. Chloramine at this level can cause hemolysis and methemoglobinemia.

1.0 mg/L: This is close to the level in municipal drinking water and would be dangerous for dialysis water.

0.1 mg/L: Correct. ANSI/AAMI (ISO 23500) sets a maximum of 0.1 mg/L total chlorine. Test before each treatment, and do not dialyze if the result is above the limit.

4.0 mg/L: This is the EPA maximum disinfectant level for drinking water, not the standard for dialysis water.

Total chlorine in dialysis water must be no higher than 0.1 mg/L. Chloramine breakthrough causes hemolysis, so test before every treatment.

Answer: B

Acute cellular rejection from under-immunosuppression: Rejection is more likely with low or subtherapeutic drug levels. It would not explain tremor, hypomagnesemia and a supratherapeutic trough.

Calcineurin-inhibitor (tacrolimus) toxicity: Correct. A high trough with tremor, headache, hyperkalemia, hypomagnesemia, hypertension and a rising creatinine (from afferent vasoconstriction) is the classic tacrolimus toxicity picture. Report it for dose adjustment; a biopsy may still be needed to rule out rejection.

BK polyomavirus nephropathy from over-immunosuppression: BK nephropathy can raise creatinine, but it does not cause the neurologic and electrolyte effects seen here. Diagnosis needs BK viremia testing.

Renal artery thrombosis of the transplanted kidney: Graft arterial thrombosis usually occurs early after surgery with abrupt anuria. That does not match this gradual, drug-related pattern.

Rising creatinine with a high tacrolimus level, tremor, hyperkalemia, low magnesium and hypertension points to calcineurin-inhibitor toxicity rather than rejection.