Cases of the Week Flashcards
What are the causes of acute renal failure?
pre-renal; intrinsic renal or post-renal
What are the pre-renal causes of ARF?
reduced renal perfusion- hypovolaemia-severe diarrhoae; sepsis; haemorrhage; cardiac eg MI; drugs eg NSAIDs
What happens if renal perfusion isn’t treated?
intrinsic renal failure occurs- acute tubular necrosis
What causes intrinsic renal failure?
acute tubular necrosis (untreated pre-renal); acute glomerulonephritis- eg vasculitis; acute interstital nephritis; rhabdomyolysis
Why can rhabdomyolysis cause renal fialure?
some of the products of muscle breakdown are toxic to renal tubules
What causes post-renal ARF?
obstruction of the urinary tract
What are the complications of ARF?
hyperkalaemia, metabolic acidosis and fluid overload
What does hyperkalaemia cause?
cardiac arrhythmia
What is the purpose of an US of the kidneys?
to check for obstruction and to check the size of kidneys
What is the significance of small kidneys on usS?
would indicate that the patient had pre-existing CKD
What is the treatment for hyperkalaemia?
10ml calcium gluconate 10%; 10 units actrapid insulin with 50ml glucose 50% ; 2.5mg salbutamol neb
What is purpose of the calcium gluconate?
stabilses the myocardium
What is the purpose of neb salbutamol?
beta-agonists cause potassium to enter cells
What needs to be looked at once inital treatment of hyperkalaemia is completed?
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
What is the treatmnet for patients unable to excrete potassium
haemodialysis
Why do NSAIDs cause pre-renal ARF?
cause vasoconstriction compromising blood supply
What are the signs of hyperkalaemia on ECG?
peaked T waves–broadenin of QRS– lose P waves
What hsould be done if proteinuria is found in the urine?
quantify by sending a urine sample for PCR
What is a protein:creatinine ratio of 100mg/mmol equal to?
1G per day of protein excretion
What are the indications for referral to the renal unit with CKD?
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 )
What are the features of nephrotic syndrome?
proteinuria; hypo-albuminaemia; oedema and hyperlipidaemia
What are hte causes of nephrotic syndrome?
glomerular problems
What investigations need to take place before a renal biopsy?
blood count and coag screen and renal ultrasound
Why does a blood count and coag screen need to take place?
thromocytopaenia and coag defects are CI to renal biopsy
What are the CI to renal biopsy?
thrombocytopaenia; coag defects; small kidneys; uncontrolled HT; untreated UTI; presence of single kidney- relative CI
What is the treatment for minimal change nephropathy?
steroids and PPI
What glomerulonephritis presents after a URTI with rusty coloured urine?
IgA nephropathy
What are the differences between nephritic and nephrotic syndromes?
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
What are the signs of fluid overload?
increased BP; JVP; lung creps; peripheral oedema; gallop rhythm
