Acute Kidney Injury Flashcards
An AKI is defined as a rapid reduction in kidney function over what period of time?
Hours - days
An AKI can be diagnosed if there is a rise in creatinine by more than what in a 48h period?
26micromol/litre
An AKI can be diagnosed if the creatinine level rises by more than what times the baseline level?
1.5 x baseline
A stage 1 AKI can be diagnosed if an individual’s urine output has been < 0.5ml/kg/hour for how long?
More than 6 consecutive hours
What is the staging system used for AKIs?
KDIGO staging
An increase in serum creatinine 1.5-1.9x baseline indicates which stage of AKI?
Stage 1
A stage 2 AKI can be diagnosed if an individual’s urine output has been < 0.5ml/kg/hour for how long?
More than 12 consecutive hours
What is the serum creatinine criteria for a stage 2 AKI?
Serum creatinine 2 - 2.9 x baseline
A stage 3 AKI can be diagnosed if serum creatinine is more than 3 x baseline value, or if the serum creatinine is greater than what value?
354micromol/litre
What is the urine output criteria for diagnosing a stage 3 AKI?
< 0.3ml/kg/hour for > 24 hours OR anuria for 12 hours
What other factor would indicate a stage 3 AKI, irrespective of the serum creatinine or urine output?
The need for RRT
What is the mechanism of a pre-renal AKI?
Renal hypoperfusion
What are some examples of pre-renal causes of an AKI?
Hypovolaemia, hypotension, sepsis
What is the mechanism of a post-renal AKI?
Urinary tract obstruction
What are some examples of post-renal causes of an AKI?
Tumours, stones, prostatic enlargement
Untreated pre-renal AKI can lead to what complication, causing a renal AKI?
Acute tubular necrosis
What investigations should be performed to identify any life-threatening hyperkalaemia in individuals with an AKI?
U&E and ECG
Which five bedside tests should be done in all individuals with an AKI?
Urinalysis, urine microscopy, bloods, ABG and ECG
If signs of infection are present in an individual with an AKI, what additional blood test should be done?
Blood cultures
If a systemic cause of AKI is suspected, what additional investigations should be performed?
Blood film and immunology tests
What is the first line imaging test for an AKI if necessary?
Renal ultrasound
What is the second line imaging test for an AKI if necessary?
CT-KUB
If there is an AKI with complete anuria, the cause is most likely to be what?
Obstructive
What is the first line management for a patient with an AKI and anuria?
Catheterisation
What are the two urgent indications for a renal biopsy in individuals with an AKI?
Suspected rapidly progressive GN or positive immunology
You should not perform a renal biopsy if what type of AKI is suspected?
Post-renal
Which patients with an AKI should undergo a myeloma screen?
Those aged > 50 with hypercalcaemia and anaemia
What does a myeloma screen involve?
Protein electrophoresis and urine testing for Bence-Jones proteins
How should fluids be given in patients with an AKI?
250ml bolus’ of crystalloid, reassessing fluid status after each one
Senior help should be sought if a patient with an AKI has shown no improvement after receiving how much fluid?
1 litre
Fluids containing what should be avoided in patients with an AKI?
Potassium
Which drugs should always be withheld in patients with an AKI?
Gentamicin, ACE inhibitors/ARBs, NSAIDs
When should metformin be withheld in patients with an AKI?
If creatinine is > 150micromol/l
How should fluid status be monitored in patients with an AKI?
Fluid status should be assessed hourly, a fluid balance chart should be completed daily and daily weights should be taken
How often should U&Es be tested in a patient with an AKI?
Daily
How should AKIs be treated in order to be resolved?
Treat the underlying cause
What happens to T waves and P waves in an ECG of someone with hyperkalaemia?
T waves are tall and tented, P waves are small or absent
What happens to the PR interval in an ECG of someone with hyperkalaemia?
Increased
What happens to the QRS complex in an ECG of someone with hyperkalaemia?
Broadened
What is the immediate treatment to protect the myocardium in individuals with hyperkalaemia?
10mls 10% calcium gluconate IV over 2 minutes (repeat until ECG improves)
What is the immediate treatment to move potassium back into cells in individuals with hyperkalaemia?
IV insulin (10 units Actrapid) and 50mls 50% dextrose over 30 minutes
As well as insulin and dextrose, what other treatment can be used to shift potassium back into cells in individuals with hyperkalaemia?
Nebulised salbutamol
What are the 4 major complications of an AKI, that are usually indications for the need for RRT?
Hyperkalaemia, pulmonary oedema, uraemia, acidaemia
What drug is used to treat acute pulmonary oedema?
Furosemide
What drug can be used to manage acidaemia?
Sodium bicarbonate
Which type of renal replacement therapy is used in haemodynamically stable patients with an AKI?
Haemodialysis
Which type of renal replacement therapy is used in haemodynamically unstable patients with an AKI?
Haemofiltration
A potassium level of greater than what indicates the need for RRT in patients with an AKI?
7mmol/l
A pH of less than what indicates the need for RRT in patients with an AKI?
7.2
Overdoses with which drugs may require the need for RRT?
Barbiturates, lithium, alcohol (and ethylene glycol), salicylates and theophylline
