Acute Kidney Injury Practice Questions

25 multiple-choice questions on Acute kidney injury for paramedic and EMT students, from Chapter 22 (Genitourinary and Renal Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. Acute kidney injury (AKI) is best defined as:

   1. A. Slow loss of function over years
   2. B. Permanent need for dialysis
   3. C. A sudden drop in kidney function
   4. D. An infection of the bladder wall
   Show answer

   Answer: C. A sudden drop in kidney function

   AKI develops over hours to days and is often reversible if the cause is treated. Chronic kidney disease develops over months to years.

2. AKI causes are grouped as prerenal, intrarenal, and postrenal. A prerenal cause is a problem with:

   1. A. The kidney tissue itself
   2. B. Blood flow to the kidneys
   3. C. Urine drainage from the kidneys
   4. D. The bladder muscle wall
   Show answer

   Answer: B. Blood flow to the kidneys

   Prerenal AKI results from poor perfusion such as dehydration, hemorrhage, sepsis, or heart failure. It is the most common type.

3. A 79-year-old with 3 days of vomiting and diarrhea has dry mucous membranes and little urine. The most likely type of AKI is:

   1. A. Intrarenal
   2. B. Postrenal
   3. C. Prerenal
   4. D. Congenital
   Show answer

   Answer: C. Prerenal

   Volume loss reduces kidney perfusion. Restoring volume often restores function before tissue damage occurs.

4. Which is an example of postrenal AKI?

   1. A. Enlarged prostate blocking urine
   2. B. Severe dehydration from vomiting
   3. C. Toxic injury from contrast dye
   4. D. Septic shock lowering perfusion
   Show answer

   Answer: A. Enlarged prostate blocking urine

   Postrenal AKI is caused by obstruction of urine outflow, such as BPH, stones in both ureters, or a blocked catheter.

5. Which is an example of intrarenal AKI?

   1. A. Hemorrhage lowering blood pressure
   2. B. A kidney stone blocking both ureters
   3. C. A kinked Foley catheter
   4. D. Muscle breakdown damaging tubules
   Show answer

   Answer: D. Muscle breakdown damaging tubules

   Rhabdomyolysis releases myoglobin that injures the tubules directly. Drugs, toxins, and prolonged ischemia also cause intrarenal AKI.

6. A man found on the floor after 2 days has dark brown urine and muscle pain. You should suspect:

   1. A. Bladder infection
   2. B. Kidney stones
   3. C. Rhabdomyolysis
   4. D. Liver failure
   Show answer

   Answer: C. Rhabdomyolysis

   Prolonged immobility crushes muscle, releasing myoglobin (causing dark urine), potassium, and acids. It can cause AKI and dangerous hyperkalemia.

7. Which home medication can cause muscle breakdown and rhabdomyolysis, especially with certain other drugs?

   1. A. A statin such as simvastatin
   2. B. Acetaminophen
   3. C. A thyroid hormone pill
   4. D. A daily multivitamin and mineral
   Show answer

   Answer: A. A statin such as simvastatin

   Statins can cause myopathy and, rarely, rhabdomyolysis, especially at high doses or with interacting drugs such as some antibiotics and antifungals. Ask statin users with muscle pain about dark urine.

8. The most common cause of acute kidney injury in critically ill patients is:

   1. A. Kidney stones
   2. B. Sepsis
   3. C. Contrast dye
   4. D. Bladder cancer
   Show answer

   Answer: B. Sepsis

   Sepsis accounts for roughly half of AKI in ICU patients, through low perfusion and direct inflammatory injury. Early recognition and treatment of sepsis helps protect the kidneys.

9. A patient with type 2 diabetes who takes metformin develops AKI from vomiting and diarrhea. The added risk from metformin is:

   1. A. Low potassium
   2. B. High blood glucose
   3. C. Hypothermia
   4. D. Lactic acidosis
   Show answer

   Answer: D. Lactic acidosis

   Metformin is cleared by the kidneys. When kidney function suddenly falls, it can build up and cause lactic acidosis, which is why 'sick day' advice is to pause metformin during vomiting illness.

10. Which combination of medications puts an older patient at high risk of AKI during an illness?

    1. A. A statin, aspirin, and vitamin D
    2. B. An inhaler, antihistamine, and antacid
    3. C. An ACE inhibitor, diuretic, and NSAID
    4. D. A multivitamin, iron, and calcium
    Show answer

    Answer: C. An ACE inhibitor, diuretic, and NSAID

    This 'triple whammy' reduces kidney perfusion from three directions, especially with dehydration.

11. A 4-year-old had bloody diarrhea a week ago and is now pale, tired, and making very little urine. You should suspect:

    1. A. Hemolytic uremic syndrome
    2. B. Simple dehydration only
    3. C. A urinary tract infection
    4. D. Appendicitis
    Show answer

    Answer: A. Hemolytic uremic syndrome

    Shiga toxin-producing E. coli can cause hemolytic uremic syndrome about a week after bloody diarrhea: anemia from red cell breakdown, low platelets, and AKI. It is a leading cause of AKI in young children.

12. Patients with AKI and fluid overload may present with:

    1. A. Dry lungs and sunken eyes
    2. B. Crackles, edema, and dyspnea
    3. C. Low blood pressure and poor skin turgor
    4. D. Excess urine and thirst
    Show answer

    Answer: B. Crackles, edema, and dyspnea

    When kidneys cannot remove fluid, it accumulates in tissues and lungs. Position upright and support breathing.

13. Uremia, the buildup of waste products, can cause:

    1. A. Heat intolerance and sweating
    2. B. Excess urine and thirst
    3. C. Jaundice and dark urine
    4. D. Confusion, nausea, itching
    Show answer

    Answer: D. Confusion, nausea, itching

    Uremic toxins affect the brain, gut, and skin. Severe uremia can cause pericarditis, bleeding problems, and seizures. Heat intolerance points to the thyroid, excess urine and thirst to high glucose, and jaundice to the liver.

14. A patient with AKI has a pericardial friction rub and chest pain. You should suspect:

    1. A. Acute myocardial infarction only
    2. B. Pneumothorax
    3. C. Esophageal spasm
    4. D. Uremic pericarditis
    Show answer

    Answer: D. Uremic pericarditis

    High urea levels inflame the pericardium. It may lead to a pericardial effusion and tamponade.

15. Which finding in a septic patient is an early warning of AKI?

    1. A. Falling urine output
    2. B. Increasing urine output
    3. C. Clear lung sounds
    4. D. Rising blood pressure
    Show answer

    Answer: A. Falling urine output

    Decreased urine output is one of the earliest signs that the kidneys are not being perfused.

16. Why must you report a crush injury's duration to receiving staff?

    1. A. It changes the tetanus dose
    2. B. It sets the pain medication dose given
    3. C. Longer compression raises AKI risk
    4. D. It decides if a splint is needed
    Show answer

    Answer: C. Longer compression raises AKI risk

    The longer muscle is compressed, the more damage and toxin release occur when it is freed, increasing AKI and hyperkalemia risk.

17. Which cause of AKI can paramedics most directly treat in the field?

    1. A. Glomerulonephritis
    2. B. Hypovolemia
    3. C. Polycystic kidney disease
    4. D. Kidney cancer
    Show answer

    Answer: B. Hypovolemia

    Restoring circulating volume with IV fluids can reverse prerenal AKI. The others need hospital treatment.

18. Contrast-induced AKI is a risk after:

    1. A. Plain chest x-rays
    2. B. CT scans with IV contrast
    3. C. 12-lead ECG monitoring
    4. D. Continuous pulse oximetry
    Show answer

    Answer: B. CT scans with IV contrast

    Iodinated contrast dye can injure kidney tubules, especially in patients with diabetes or kidney disease.

19. Why may an AKI patient be at risk of bleeding?

    1. A. The kidneys make clotting factors
    2. B. AKI raises the platelet count
    3. C. Uremia impairs platelets
    4. D. Urea acts like heparin
    Show answer

    Answer: C. Uremia impairs platelets

    Uremic toxins prevent platelets from working normally, so patients may bleed more after injury. Clotting factors are made in the liver, AKI does not raise the platelet count, and urea has no heparin-like effect.

20. In severe heart failure, kidney function often worsens because:

    1. A. Low cardiac output reduces kidney perfusion
    2. B. Heart failure raises blood flow to the kidneys
    3. C. Heart failure lowers the aldosterone level
    4. D. The kidneys stop releasing renin
    Show answer

    Answer: A. Low cardiac output reduces kidney perfusion

    In cardiorenal syndrome, poor forward flow and high venous pressure reduce kidney perfusion, causing a prerenal pattern of AKI, salt retention, and worsening edema. Renal blood flow falls rather than rises, and renin and aldosterone go up, not down.

21. For a ureteral stone to cause postrenal AKI in an adult, it usually must:

    1. A. Be larger than 1 mm in any patient
    2. B. Be made of uric acid crystals
    3. C. Lodge deep inside the wall of the bladder
    4. D. Block both kidneys or a single kidney
    Show answer

    Answer: D. Block both kidneys or a single kidney

    One healthy kidney can maintain adequate function, so a unilateral stone rarely causes AKI unless the patient has only one working kidney or both sides are blocked. Stone composition does not determine this.

22. The kidneys are vulnerable to ischemia during shock because:

    1. A. They get little flow
    2. B. They need high blood flow
    3. C. They store oxygen for later use
    4. D. They cannot change their blood flow
    Show answer

    Answer: B. They need high blood flow

    Kidneys receive a large share of cardiac output, and the tubules are very sensitive to low oxygen. They do not store oxygen, and although they can autoregulate their flow, that protection fails when pressure falls too low.

23. AKI is more likely to be fatal in:

    1. A. Healthy teens with flu
    2. B. Young athletes
    3. C. Critically ill older adults
    4. D. Patients with mild seasonal colds
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    Answer: C. Critically ill older adults

    Older adults and those with multiple illnesses have less kidney reserve and higher mortality from AKI.

24. A patient with acute kidney injury receives the usual dose of a renally cleared sedative and stays drowsy for many hours. The best explanation is that:

    1. A. The drug is building up
    2. B. AKI speeds up drug clearance
    3. C. The dose was given too slowly
    4. D. Uremia blocks the drug's effect
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    Answer: A. The drug is building up

    Drugs and active metabolites cleared by the kidneys accumulate in AKI, prolonging their effects, so many need lower doses or longer intervals. AKI slows clearance rather than speeding it, uremia does not block the drug, and a slow injection does not prolong the effect.

25. Which statement about the long-term outlook after an episode of AKI is most accurate?

    1. A. Kidney function returns to normal in all
    2. B. It does not affect later kidney health
    3. C. Recovery is impossible after AKI
    4. D. Even after recovery, CKD risk rises
    Show answer

    Answer: D. Even after recovery, CKD risk rises

    Many patients recover kidney function, but even one AKI episode raises the later risk of chronic kidney disease, kidney failure, and death. Follow-up is recommended.