Theory
What is the most common cause of AKI?
Hypovolaemia
A 77-year-old woman is brought in by ambulance after being found on the floor early in the morning. She states that she tripped and fell in the evening and could not get up or get help. The following U&E's were taken:
Na+ 135 mmol/l K+5.7 mmol/l Creatinine 347 mmol/l Urea9.8 mmol/l Creatine kinase 14,550 I/U
What is the most likely cause of this clinical picture?
A. Syndrome of inappropriate ADH secretion
B. Rhabdomyolysis
C. Proximal myopathy
D. Urinary tract infection
E. Urinary retention
B- Rhabdo. Myoglobin released from muscle tissue from long lay on the floor is toxic to the kidneys, and will, therefore, produce acute kidney injury. The raised creatinine kinase, and to some degree, the raised potassium levels are typical features of rhabdomyolysis.
A 78-year-old man is admitted to a medical ward with community-acquired pneumonia (CAP). Blood tests during the third day as an inpatient finds he has developed an acute kidney injury (AKI), with eGFR dropping from 58 to 26ml/min/1.73 m2 and creatinine rising from 122 to 196umol/L.
Which of the following of his regular medications should be stopped?
A. Atorvastatin
B. Bisoprolol
C. Finasteride
D. Ramipril
E. Tamsulosin
D- ACEi should be stopped in AKI as nephrotoxic.
A urine output of ≤?ml/hr for 6 hours or more is a criteria for AKI diagnosis.
0.5ml/hr
An 18-year-old student presents to the emergency department after noticing blood in his urine that morning, but he has no dysuria. Some constant mild flank pain and myalgia are present. He has had a cold for a few days but normally, he is healthy, has no known allergies and does not take any medications.
He has a temperature of 37.9ºC but observations are otherwise normal. Physical examination is normal besides some bilateral flank tenderness.
Urine dipstick:
pH6.0 Protein negative Leucocytes negative Nitrites negative Blood positive Ketones negative Glucose negative.
What is the most likely diagnosis?
A. IgA nephropathy
B. Lupus nephritis
C. Post-streptococcal glomerulonephritis
D. Renal stones
E. Urinary tract infection
A- IgA nephropathy, classical presentation as visible haematuria closely after a URTI. Post-strep would be 1-2 weeks after URTI.
A 25-year-old man is injured in a road traffic accident. His right tibia is fractured and is managed by fasciotomies and application of an external fixator. Over the next 48 hours his serum creatinine rises and urine is sent for microscopy, muddy brown casts are identified. What is the most likely underlying diagnosis?
A. Acute interstitial nephritis
B. Acute tubular necrosis
C. Glomerulonephritis
D. IgA Nephropathy
E. Thin basement membrane disease
B- Acute tubular necrosis. Muddy brown casts + worsening renal function = acute tubular necrosis.
Which of these isn't a criteria for AKI?
A. A rise in serum creatinine of 26mmol/l or more within 48 hrs
B. A serum creatinine of over 250mmol/l
C. A fall in urine output to under 0.5ml/kg/hr for over 6 hours.
D. A 50% or greater rise in serum creatinine known to have occurred in the past 7 days.
B- AKI is about the change ie in urine or creatinine. Someone could have a serum creatinine of over 250mmol/l long term, indicating CKD rather than an AKI.
A 23-year-old man presents to his GP, asking to be screened for a condition that runs in his family. He explains that his brother and father have both suffered from kidney problems and have been told that the condition is hereditary. Additionally, he says that his brother suffered from a 'bleed on the brain' at a young age.
Examination is unremarkable and he is well in himself.
Given the likely diagnosis, which investigation is most appropriate?
A. Computed tomography (CT) of abdomen/pelvis
B. Computed tomography (CT) of head
C. Genetic testing
D. Magnetic resonance imaging (MRI)
E. Ultrasound
A 74-year-old man with stage IV chronic kidney disease secondary to type II diabetes mellitus is admitted to the acute medical assessment ward with symptoms of breathlessness and reduced exercise tolerance. He is otherwise systemically well. His blood results are as follows:
Haemoglobin80 g/l
Mean Corpuscular Volume90 fl
Mean Corpuscular Haemoglobin30 pg
Urea17 mmol/l
Creatinine300 µmol/l
eGFR8 ml/min/1.73m2
Given the likely cause of this patient's anaemia, which of the following compounds is the patient most likely to be deficient of?
A. Vitamin B12
B. Ferritin
C. Folate
D. Erythropoietin
E. T3 / T4
D- CKD often leads to anaemia due to reduced levels of EPO.
Sepsis causes what type of shock leading to AKI?
A. Hypovolaemic
B. Cardiogenic
C. Distributive
D. Obstructive
E. Anaphylactic
C- Distributive shock. Causes massive vasodilation leading to reduced blood pressure (shock).
A 27-year-old female presents to the medical take.
She has been unable to get an appointment at her GP and is concerned as she has noticed frank haematuria for the last 8 days. She has no dysuria or frequency. She reports she has noticed four episodes of haematuria previously, but these have always resolved spontaneously after a day or two.
She reports she is usually fit and well apart from hearing aids that she has needed since birth. This does not seem unusual to her as both her younger sister also has needed hearing aids since birth.
On examination, she has an abdomen that is soft and non-tender. Her Rinne test was positive and her weber test was equally heard in both ears.
Investigations show:
Haemoglobin 127g/l
White cells 6 x 10^9/l
Platelets 376 x 10^9/l
Sodium 139 mmol/l
Potassium 5.2 mmol/l
Urea 13 mmol/l
Creatinine 292 µmol/l
Urine dip:
Blood +++
Protein +++
Leucocytes negative
Nitrites negative
What is the most likely diagnosis?
A. IgA nephropathy
B. Minimal change disease
C. Alport syndrome
D. Rapidly-progressive glomerulonephritis
E. Goodpasture syndrome
C- Alport Syndrome, as causes sensorineural hearing loss, painless haematuria and poor renal function.
A 68-year-old man is admitted to a general medical ward with reduced urine output. He has a background of severe dementia for which he takes memantine. He has no other past medical history of note and has otherwise seemed well. Renal function tests are sent:
Na+137 mmol/L(135 - 145)
K+5.9 mmol/L(3.5 - 5.0)
Bicarbonate17 mmol/L(22 - 29)
Urea16 mmol/L(2.0 - 7.0)
Creatinine130 µmol/L(55 - 120)
What is the most likely underlying cause of the acute kidney injury?
A. Acute tubular necrosis
B. Dehydration
C. Memantine toxicity
D. Renal calculi
E. Sepsis
Which of these drugs isn't nephrotoxic?
A. ARBs
B. Cisplatin
C. Aciclovir
D. Diltiazem
E. Amphotericin B
D- Diltiazem is a calcium channel blocker which is not nephrotoxic.
A 27-year-old man with a 3-month history of excessive thirst and polyuria presents to the endocrinology clinic. He has a past medical history of bipolar disorder.
Initial blood results carried about by his GP are below.
Na+140 mmol/L (135 - 145) K+ 3.6 mmol/L(3.5 - 5.0) Glucose 6 mmol/L(4-11) HbA1c 41 mmol/mol(<42)
What test would be diagnostic in this patient?
A. CT head
B. Renal tract ultrasound
C. Thyroid function tests
D. Urine osmolality
E. Water deprivation test
A 55-year-old man presents to the general practitioner for routine blood tests before he is placed on a statin. His renal function is found to be reduced and he is sent for further investigation.
Na+135 mmol/l K+4.2 mmol/l Urea15 mmol/l Creatinine 152 µmol/l
Which of the following would indicate that the cause of this man's presentation was chronic and not acute?
A. A normal parathyroid level
B. Normal kidney size on ultrasound
C. Oliguria
D. Anuria
E. Hypocalcaemia
E- Hypocalcaemia. This is because renal failure can result in reduced levels of metabolised vitamin D/1,25(OH)2D. This results in reduced calcium reabsorption in the kidneys, leading to hypocalcaemia.