CKD is managed in primary care long before nephrology sees it, and the exam tests that ownership. These questions cover staging by eGFR and albuminuria, the blood-pressure and glycaemic targets that slow progression, adjusting or avoiding medications as function declines, and knowing when referral is overdue.
Question 1
A 70-year-old with diabetic nephropathy takes lisinopril 20 mg daily. Today, his creatinine is stable at 1.4 mg/dL, but his potassium has increased to 5.2 mEq/L. Which action is most appropriate?
- A) Discontinue the lisinopril to prevent life-threatening cardiac arrhythmias today.
- B) Continue the lisinopril and counsel the patient on dietary modifications.✓
- C) Switch the lisinopril to a thiazide diuretic to lower potassium.
- D) Admit the patient to the hospital for continuous cardiac monitoring.
💡 Key Takeaway
Mild hyperkalemia on an ACE inhibitor is often managed with dietary restriction rather than discontinuing the renoprotective medication.
Show rationale
Mild hyperkalemia up to 5.5 mEq/L is common when treating diabetic nephropathy with an ACE inhibitor. Because the renal protective benefits of the drug are crucial and the creatinine is stable, the best initial approach is to implement a low-potassium diet rather than stopping the medication. Option A is incorrect because stopping the drug deprives the patient of essential proteinuria reduction, and 5.2 mEq/L is not acutely life-threatening. Option C is incorrect because while a thiazide might lower potassium, it lacks the specific renoprotective effects needed for diabetic nephropathy. Option D is a massive overreaction, as mild asymptomatic hyperkalemia in the outpatient setting does not require inpatient cardiac monitoring.
Question 2
A 55-year-old African American male presents for a follow-up. He has type 2 diabetes mellitus and a urine microalbumin-to-creatinine ratio of 12 mg/g. His blood pressure today is 148/92 mmHg, confirmed on repeat.
- A) Prescribe amlodipine 5 mg orally daily.✓
- B) Prescribe lisinopril 10 mg orally daily.
- C) Prescribe metoprolol 25 mg orally daily.
- D) Prescribe losartan 50 mg orally daily.
💡 Key Takeaway
African American patients without CKD should start a calcium channel blocker or thiazide for initial hypertension management.
Show rationale
For African American patients with hypertension and diabetes, but without chronic kidney disease or proteinuria, initial therapy should be a calcium channel blocker or a thiazide diuretic. Amlodipine is the best choice here. Lisinopril and losartan are indicated if the patient had an elevated urine microalbumin-to-creatinine ratio, but his is normal. Metoprolol is a beta-blocker and is not recommended as first-line therapy for essential hypertension without a specific compelling indication like heart failure or post-myocardial infarction.
Question 3
A 50-year-old with newly diagnosed hypertension is prescribed quinapril 10 mg daily. His baseline metabolic panel is completely normal. Which follow-up plan is most appropriate for monitoring this therapy?
- A) Schedule a follow-up to check renal function in two weeks.✓
- B) Schedule a follow-up to check renal function in six months.
- C) Order a comprehensive metabolic panel to be drawn tomorrow morning.
- D) Order a 24-hour urine collection to assess baseline protein excretion.
💡 Key Takeaway
Renal function and serum potassium must be evaluated one to four weeks after initiating an ACE inhibitor.
Show rationale
When initiating an ACE inhibitor, it is standard practice to evaluate the serum creatinine and potassium levels within one to four weeks to ensure the patient is not developing hyperkalemia or an unacceptable decline in renal function. Option B is incorrect because waiting six months delays the detection of potential early adverse pharmacotherapeutic outcomes. Option C is incorrect because drawing labs the very next day does not allow enough time for the medication to reach steady state and exert its hemodynamic effects on the kidneys. Option D is unnecessary because a normal baseline metabolic panel does not warrant a 24-hour urine collection for uncomplicated essential hypertension.
Question 4
A 60-year-old with type 2 diabetes and CKD has an eGFR of 35 mL/min/1.73 m2 and a UACR of 400 mg/g. Their A1c is 7.2% on metformin. What is the best addition?
- A) Add a daily sulfonylurea to the current regimen.
- B) Switch metformin to a daily DPP-4 inhibitor drug.
- C) Initiate an SGLT2 inhibitor to provide renal protection.✓
- D) Refer the patient for immediate renal replacement therapy.
💡 Key Takeaway
SGLT2 inhibitors are strongly recommended for patients with type 2 diabetes, CKD, and an eGFR over 20.
Show rationale
KDIGO guidelines strongly recommend adding an SGLT2 inhibitor for patients with type 2 diabetes and CKD who have an eGFR of at least 20 mL/min/1.73 m2, due to significant cardiovascular and renal benefits. Adding a sulfonylurea (A) or switching to a DPP-4 inhibitor (B) might improve glycemic control but neither provides the targeted renoprotective effects that slow CKD progression. Referring for renal replacement therapy (D) is incorrect because an eGFR of 35 indicates stage 3b CKD, which is managed medically and does not yet require dialysis or transplantation.
Question 5
A 71-year-old female with hypertension presents for follow-up. Labs show an eGFR of 58 mL/min/1.73 m2. Her UACR is 150 mg/g on two consecutive visits. She currently takes amlodipine.
- A) Maintain the current amlodipine medication therapy alone.
- B) Add an ACE inhibitor to her regimen.✓
- C) Substitute the amlodipine with a beta blocker.
- D) Refer the patient for immediate nephrology evaluation.
💡 Key Takeaway
ACE inhibitors or ARBs are indicated for patients with hypertension and moderately increased albuminuria to protect renal function.
Show rationale
A UACR between 30 and 300 mg/g indicates moderately increased albuminuria. Adding an ACE inhibitor or ARB is the standard of care to reduce proteinuria and slow the progression of chronic kidney disease. Option A is incorrect because amlodipine, a calcium channel blocker, does not offer targeted renal protection against albuminuria. Option C is incorrect because beta blockers do not reduce proteinuria and are not first-line for uncomplicated hypertension. Option D is premature; nephrology referral is typically reserved for Stage 4 CKD (eGFR < 30) or rapidly progressing disease.
Question 6
An 85-year-old male complains of severe fatigue. His current eGFR is 12 mL/min/1.73 m², down from 14 six months ago. His UACR is 450 mg/g. What is the correct diagnostic classification for this patient?
- A) Stage 4 chronic kidney disease with moderately increased albuminuria
- B) Stage 5 chronic kidney disease with severely increased albuminuria✓
- C) Stage 4 chronic kidney disease with severely increased albuminuria
- D) Stage 5 chronic kidney disease with moderately increased albuminuria
💡 Key Takeaway
Stage 5 CKD (kidney failure) is diagnosed when the eGFR falls below 15 mL/min/1.73 m².
Show rationale
The diagnosis of Stage 5 chronic kidney disease, also known as kidney failure, is established when the estimated glomerular filtration rate falls below 15 mL/min/1.73 m². This patient's eGFR of 12, which has been persistently low for six months, confirms Stage 5 disease. Additionally, his UACR of 450 is well above the 300 mg/g threshold, placing him in the A3 category for severely increased albuminuria. Option A is incorrect because Stage 4 indicates an eGFR of 15 to 29, and moderately increased albuminuria is 30 to 300 mg/g. Option C is incorrect because it misidentifies the eGFR stage as Stage 4. Option D is incorrect because it underestimates the severity of the albuminuria, categorizing it as moderate rather than severe.
Question 7
A 55-year-old patient with hypertension and type 2 diabetes was started on lisinopril 10 mg two weeks ago. The patient's baseline serum creatinine was 1.0 mg/dL. Today, the repeat serum creatinine is 1.25 mg/dL and potassium is 4.8 mEq/L. Which action is most appropriate?
- A) Continue the current dosage and recheck the labs in six months.✓
- B) Decrease the medication dose and recheck the labs in two weeks.
- C) Discontinue the lisinopril and initiate a calcium channel blocker today.
- D) Order a renal ultrasound to evaluate for renal artery stenosis.
💡 Key Takeaway
A creatinine increase up to 30 percent after starting an ACE inhibitor is acceptable and requires no intervention.
Show rationale
An increase in serum creatinine of up to 30 percent is an expected hemodynamic response when initiating an ACE inhibitor due to efferent arteriole dilation. The patient's creatinine went from 1.0 to 1.25, which is a 25 percent increase and well within the acceptable range. Option B is incorrect because a dose reduction is unnecessary for an expected physiologic response. Option C is incorrect because discontinuing the drug deprives this diabetic patient of vital renal protection. Option D is incorrect because evaluating for bilateral renal artery stenosis is only indicated if the creatinine increases by more than 30 percent. Continuing the medication and monitoring routinely is the safest and most appropriate management plan for this patient.
Question 8
A 72-year-old female presents with severe acute gastroenteritis lasting three days. Her comprehensive metabolic panel demonstrates a BUN of 45 mg/dL and a creatinine of 1.5 mg/dL. Her baseline creatinine is 0.9 mg/dL. Which diagnosis best explains these laboratory findings?
- A) Intrinsic acute tubular necrosis
- B) Prerenal acute kidney injury✓
- C) Advanced chronic kidney disease
- D) Postrenal obstructive nephropathy
💡 Key Takeaway
A BUN to creatinine ratio greater than 20:1 in the setting of volume depletion indicates prerenal acute kidney injury.
Show rationale
This patient's presentation of severe volume loss from gastroenteritis combined with a BUN to creatinine ratio of 30:1 strongly indicates prerenal acute kidney injury. In prerenal states, decreased renal perfusion prompts increased urea reabsorption relative to creatinine, typically elevating the ratio above 20:1. Intrinsic acute tubular necrosis usually presents with a ratio of less than 15:1 because the damaged tubules cannot effectively reabsorb urea. Advanced chronic kidney disease would show long-standing structural changes and a relatively normal ratio rather than this acute, disproportionate BUN elevation. Postrenal obstructive nephropathy typically requires a history of urinary retention, prostatic hypertrophy, or nephrolithiasis, none of which are present here.
Question 9
A 68-year-old female requires treatment for severe restless legs syndrome. She is intolerant to dopamine agonist therapy and has an estimated glomerular filtration rate of 28. Which intervention is most appropriate?
- A) Initiate a renally adjusted gabapentin dose.✓
- B) Prescribe a standard pregabalin starting dose.
- C) Start a standard gabapentin enacarbil dose.
- D) Recommend a renally adjusted ropinirole dose.
💡 Key Takeaway
Alpha-2-delta ligands require strict renal dose adjustments in patients with chronic kidney disease.
Show rationale
For patients who cannot tolerate dopamine agonists, alpha-2-delta ligands are the preferred alternative. However, medications like gabapentin and pregabalin undergo renal clearance and require strict dose reductions in the setting of chronic kidney disease. Initiating a renally adjusted gabapentin dose ensures safe symptom management while preventing medication toxicity and excessive somnolence. Prescribing a standard pregabalin or gabapentin enacarbil dose is unsafe for a patient with an estimated glomerular filtration rate of 28, as it will lead to rapid drug accumulation. Recommending ropinirole is incorrect because the patient has a documented intolerance to dopamine agonist therapy.
Question 10
A 64-year-old female with type 2 diabetes has an eGFR of 42 mL/min/1.73 m2 and a urine albumin-to-creatinine ratio of 350 mg/g. She is currently taking metformin monotherapy. Which medication should the nurse practitioner plan to initiate?
- A) Add an SGLT2 inhibitor to the treatment plan.✓
- B) Add a thiazolidinedione to the daily treatment plan.
- C) Add a GLP-1 agonist to the daily treatment plan.
- D) Add a DPP-4 inhibitor to the daily treatment plan.
💡 Key Takeaway
SGLT2 inhibitors are the preferred add-on therapy for diabetic kidney disease with albuminuria.
Show rationale
For patients with type 2 diabetes, chronic kidney disease, and severe albuminuria, ADA guidelines recommend an SGLT2 inhibitor to slow kidney disease progression and reduce cardiovascular events. This patient's eGFR of 42 and elevated albumin-to-creatinine ratio make this the optimal choice. Adding a thiazolidinedione does not specifically protect renal function and can cause fluid retention. Adding a GLP-1 agonist is an acceptable alternative if SGLT2 inhibitors are contraindicated, but it is not the first-line preference for primary renal protection in the presence of significant albuminuria. Adding a DPP-4 inhibitor offers mild glycemic control without the necessary renal protective benefits required for this patient's advancing nephropathy.
