Cases of the Week

Question 1

What are the causes of acute renal failure?

Answer 1

pre-renal; intrinsic renal or post-renal

Question 2

What are the pre-renal causes of ARF?

Answer 2

reduced renal perfusion- hypovolaemia-severe diarrhoae; sepsis; haemorrhage; cardiac eg MI; drugs eg NSAIDs

Question 3

What happens if renal perfusion isn’t treated?

Answer 3

intrinsic renal failure occurs- acute tubular necrosis

Question 4

What causes intrinsic renal failure?

Answer 4

acute tubular necrosis (untreated pre-renal); acute glomerulonephritis- eg vasculitis; acute interstital nephritis; rhabdomyolysis

Question 5

Why can rhabdomyolysis cause renal fialure?

Answer 5

some of the products of muscle breakdown are toxic to renal tubules

Question 6

What causes post-renal ARF?

Answer 6

obstruction of the urinary tract

Question 7

What are the complications of ARF?

Answer 7

hyperkalaemia, metabolic acidosis and fluid overload

Question 8

What does hyperkalaemia cause?

Answer 8

cardiac arrhythmia

Question 9

What is the purpose of an US of the kidneys?

Answer 9

to check for obstruction and to check the size of kidneys

Question 10

What is the significance of small kidneys on usS?

Answer 10

would indicate that the patient had pre-existing CKD

Question 11

What is the treatment for hyperkalaemia?

Answer 11

10ml calcium gluconate 10%; 10 units actrapid insulin with 50ml glucose 50% ; 2.5mg salbutamol neb

Question 12

What is purpose of the calcium gluconate?

Answer 12

stabilses the myocardium

Question 13

What is the purpose of neb salbutamol?

Answer 13

beta-agonists cause potassium to enter cells

Question 14

What needs to be looked at once inital treatment of hyperkalaemia is completed?

Answer 14

none of the inital treatment removes K from the body so need to see if hte patient is able to excrete potassium- i.e are they producing urine- catheter

Question 15

What is the treatmnet for patients unable to excrete potassium

Answer 15

haemodialysis

Question 16

Why do NSAIDs cause pre-renal ARF?

Answer 16

cause vasoconstriction compromising blood supply

Question 17

What are the signs of hyperkalaemia on ECG?

Answer 17

peaked T waves–broadenin of QRS– lose P waves

Question 18

What hsould be done if proteinuria is found in the urine?

Answer 18

quantify by sending a urine sample for PCR

Question 19

What is a protein:creatinine ratio of 100mg/mmol equal to?

Answer 19

1G per day of protein excretion

Question 20

What are the indications for referral to the renal unit with CKD?

Answer 20

stage 3 with PCR >100mg/mol; nephrotic syndrome; stage 3 CKD with progression (GFR falling by >20% over 6 months; stage 3 in younger people; stage 4; haematuria (after exclusion of urological causes )

Question 21

What are the features of nephrotic syndrome?

Answer 21

proteinuria; hypo-albuminaemia; oedema and hyperlipidaemia

Question 22

What are hte causes of nephrotic syndrome?

Answer 22

glomerular problems

Question 23

What investigations need to take place before a renal biopsy?

Answer 23

blood count and coag screen and renal ultrasound

Question 24

Why does a blood count and coag screen need to take place?

Answer 24

thromocytopaenia and coag defects are CI to renal biopsy

Question 25

What are the CI to renal biopsy?

Answer 25

thrombocytopaenia; coag defects; small kidneys; uncontrolled HT; untreated UTI; presence of single kidney- relative CI

Question 26

What is the treatment for minimal change nephropathy?

Answer 26

steroids and PPI

Question 27

What glomerulonephritis presents after a URTI with rusty coloured urine?

Answer 27

IgA nephropathy

Question 28

What are the differences between nephritic and nephrotic syndromes?

Answer 28

BP is normal in nephrotic whilst elevated in nephritic; urine shows proteinuria in nephrotic whilst haematuria in nephritic and GFR shows a greater decrease in nephritic than nephrotic syndrome

Question 29

What are the signs of fluid overload?

Answer 29

increased BP; JVP; lung creps; peripheral oedema; gallop rhythm