QuestionSBA
QuestionChoice
Metformin is a very unlikely cause of AKI in this patient. Metformin is not inherently nephrotoxic so is not a cause of AKI. It is, however, important to be aware of metformin in AKI as most metformin excretion is performed by the kidneys, therefore the risk of toxicity is increased when kidney function is impaired.
10000374
d
Metformin
QuestionChoice
Nephrolithiasis is not a likely cause of AKI in this patient. Kidney stones classically present with acute renal colic which manifests as acute, severe loin-to-groin pain. There is no pain reported in this patient which makes obstructive nephrolithiasis an unlikely diagnosis. Furthermore, the presence of clinical fluid depletion and ongoing high volume vomiting should indicate an underlying cause of hypovolaemia.
10000375
e
Nephrolithiasis
QuestionChoice
Although ACE inhibitors can cause AKI, it is not the most likely cause here. ACEis cause AKI by dilating the efferent renal arteriole, thereby reducing glomerular hydrostatic pressure. However, hypovolaemia is a far more likely underlying cause, given the acute history of fluid loss from vomiting and the subsequent clinical manifestation of hypovolaemia.
10000372
b
Ramipril
QuestionChoice
Another important risk factor for AKI, diabetic nephropathy is important to keep in mind. Diabetic nephropathy is a significant risk factor for chronic kidney disease, which in turn increases the risk of AKI. However, this patient's diabetes is well-controlled and CKD caused by diabetes would likely have been identified on admission blood tests. On top of this, the acute history of vomiting is a far more likely cause of AKI, given the clinical evidence of fluid depletion.
10000373
c
Diabetic nephropathy
QuestionChoice
This patient's acute kidney injury (AKI) has occurred secondary to hypovolaemia caused by her recent history of vomiting. Hypovolaemia and hypotension are common causes of pre-renal AKI and may be caused by sepsis, fluid loss, or poor fluid intake (especially in frail patients). AKI should be diagnosed in patients featuring any of the following:

* Rise in serum creatinine of ≥26µmol/L within 48 hours
* Rise in serum creatinine to ≥1.5x baseline within 7 days
* A fall in urine output to <0.5ml/kg/hr for more than 6 hours
10000371
a
Hypovolaemia
Concept
Chapter
2693
3752
Acute Kidney Injury
Topic
142
Nephrology
12621
You are asked to assess a 44-year-old female patient on the ward who has not improved since admission. She was admitted 2 days ago with a 24-hour history of high volume vomiting. This has continued throughout her admission, for a total of 3 days.


On examination her mucosal membranes are dry and she has reduced skin turgor.


After bedside observations, you note that she has a blood pressure of 98/71 mmHG, a heart rate of 132 bpm, and a temperature of 36.5C. Blood tests reveal that her creatinine has increased by 40µmol/L since admission (normal range 60-120 µmol/L).


She has a 2-year history of hypertension and well-controlled diabetes for which she takes ramipril and metformin respectively. Which of the following is the most likely cause of her acute kidney injury?
a