172 Med-Surg: Renal questions written for the NCLEX-RN, each with a rationale explaining why the correct answer is correct and why the others are not. Free, no account required. 10 examples are shown below.
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The answer: A — Acute kidney injury (contrast-induced, prerenal) secondary to cardiac catheterization with iodinated contrast in a patient with pre-existing CKD Think of it this way: Iodinated contrast dye is directly toxic to kidney tubule cells (nephrotoxic). A patient who already has CKD has fragile kidneys with reduced reserve. Add 85 mL of contrast dye, and 48 hours later the kidneys show the classic signs of contrast-induced AKI: rising creatinine, decreased urine output, and a timeline that fits perfectly. Why A is right: Classic risk factors for contrast-induced AKI are present: pre-existing CKD (baseline creatinine 1.4, eGFR 58), significant iodinated contrast exposure (85 mL), and the 48-hour post-procedure onset of oliguria with rising creatinine. This timing is the textbook presentation of CI-AKI, which typically develops within 24-72 hours of contrast exposure. Why the others are wrong: - B: Urinary obstruction from BPH would show hydronephrosis on renal ultrasound — which was normal here. Also would not follow a contrast exposure timeline. - C: Metformin was held as a precaution; metformin itself is not directly nephrotoxic. It is held to prevent lactic acidosis IF AKI develops, not because it causes AKI. - D: Glomerulonephritis presents with hematuria, proteinuria, and often systemic symptoms (fever, rash, joint pain) — not a clean 48-hour post-contrast timeline. - E: Cardiorenal syndrome requires signs of heart failure (JVD, S3 gallop, significantly elevated BNP) — which are absent here. Remember: Pre-existing CKD + iodinated contrast + rising creatinine 48 hours later = contrast-induced AKI until proven otherwise. Technical note: Prevention of CI-AKI: pre-hydration with IV isotonic saline, minimize contrast volume, choose iso-osmolar or low-osmolar agents, hold nephrotoxic medications. N-acetylcysteine (NAC) was historically given but evidence for benefit is mixed.
The diuretic phase of AKI is characterized by increased urine output (up to 3-5 L/day) as the kidneys recover. This places the client at high risk for dehydration, hypovolemia, and significant electrolyte losses (especially sodium and potassium). The nurse's highest priority is monitoring for these complications and replacing fluids and electrolytes as ordered.
The findings of decreased urine output, bounding pulse, hypertension, and pulmonary crackles are classic signs of fluid overload (volume excess). In AKI, the kidneys cannot adequately excrete fluid, leading to accumulation. This is a medical emergency requiring intervention such as diuretics or dialysis to remove excess fluid.
Active infection is a contraindication to kidney transplantation because immunosuppressive medications post-transplant would worsen the infection. Previous smoking (if quit), ABO compatibility, and controlled comorbidities are not contraindications.
A hard, cool AV graft with associated pain is indicative of graft thrombosis, which is a surgical emergency. The graft may be occluded, and the client requires immediate intervention to restore blood flow. The nurse should notify the provider immediately rather than performing assessments or interventions that could delay treatment.
Correct statements include: drinking fluids and frequent urination help flush bacteria; wiping front to back prevents fecal contamination of the urethra; and urinating after intercourse flushes bacteria that may have entered the urethra. Stopping antibiotics early leads to incomplete treatment and potential resistance.
Ureteroscopy involves passing a scope through the ureter, and ureteral perforation is a known complication of this procedure. The nurse should monitor for signs of perforation such as severe pain, fever, hematuria, and extravasation of urine. While stricture formation, retention, and avulsion are possible complications, perforation is the most common acute complication to monitor post-ureteroscopy.
During pregnancy, ESWL is contraindicated due to potential fetal harm. For a 6mm stone, conservative management with hydration and pain control is typically attempted first, as many stones pass spontaneously. Ureteroscopy is considered if conservative measures fail or if there are complications like infection or obstruction. Percutaneous nephrostomy may be used for severe obstruction.
Hyperkalemia causes muscle weakness and characteristic ECG changes (peaked T waves, widened QRS). The heart is particularly sensitive to potassium changes. Options B, C, and D are not typical findings of hyperkalemia. Hyperkalemia does not cause increased bowel sounds or respiratory alkalosis.
Calcium oxalate stones account for approximately 70-80% of all kidney stones. They are often associated with high oxalate intake, hypercalciuria, or hypocitraturia. Understanding stone types guides both treatment and prevention strategies.
