AKI

Question 1

Prerenal causes

Answer 1

Ischaemia e.g.

Hypovolaemia secondary to vomiting / diarrhoea
Renal artery stenosis

Question 2

Intrinsic causes

Answer 2

Damage to glomeruli, renal tubules or interstitium of kidneys. This may be due to toxins or immune-mediated GN.

Examples: 
GN
ATN
AIN (acute interstitial nephritis)
Rhabdomyolysis 
Tumour lysis syndrome

Question 3

Postrenal

Answer 3

Obstruction e.g.

Kidney stone in ureter or bladder
Benign prostatic hyperplasia
External compression of ureter

Question 4

RF

Answer 4

CKD
Other organ failure / chronic disease e.g. heart failure, liver disease, DM
History of AKI
Use of drugs with nephrotoxic potential within the past week
Use of iodinated contrast agents within the past week
Age 65 and over

Oliguria (urine output less than 0.5ml/kg/hr), neurological or cognitive impairment which may mean limited access to fluids

Question 5

Preventing AKI

Answer 5

Identify those at risk
IV fluids if at risk of AKI and having contrast
Temporarily stopping drugs

Question 6

Symptoms and Signs

Answer 6

Reduced UO
Pulmonary and peripheral oedema
Arrhythmias (secondary to changes in potassium and acid base balance)
Features of uraemia (pericarditis or encephalopathy)

Question 7

Detection

Answer 7

U&Es
Urinalysis
Renal ultrasound (within 24h) if no identifiable cause

Question 8

Detection

Answer 8

Rise in creatinine of 26 micromol/litre or greater within 48h
50% or greater rise in serum creatinine known or presumed to have occurred within the past 7 days
A fall in UO to less than 0.5 ml/kg/hr for more than 6 hours in adults

Question 9

Management

Answer 9

Supportive
Careful fluid balance
Review meds
Role for loop diuretics if significant fluid overload
Prompt tx of hyperkalaemia 

Severe AKI / cause not known - review by nephrologist
Suspected AKI due to urinary obstruction - review by urologist

RRT when not responding to above