Acute Kidney Injury (AKI) Flashcards
What is the current definition of acute kidney injury?
Increases in serum creatinine by > 26.5 umol/l within 48hrs or >1.5umol/l within the 7 days prior
Urine volume is more than 0.5 ml/kg/h for 5 hrs
What are the stages of AKI?
AKI 1, 2 and 3
Stage 3 is 3 x baseline serum creatinine and <0.3 ml/kg/h for more than 24hrs or anuria for more than 12hrs
What is the incidence of AKI?
One in five people admitted to hospital each year as an emergency have an AKI
What are the immediate dangerous consequences of AKI?
Acidosis
Electrolyte imbalance
Intoxication TOXINS
Overload
Uraemic complications
AEIOU
What are the short and long term outcomes of AKI?
Short term - death, dialysis and length of stay
Long term - death, CKD, dialysis and CKD related CV events
What increases mortality?
Small rises in creatinine
In the long term, what is the risk of death?
Over 10 years is increased by 2 fold with AKI
If eGFR on discharge is less than 60 then 1.5x
What is normal baseline for creatinine?
80umol/l
Too late to act if creatinine is over 400
Even 120 will cause significant kidney injury
What are the pre-renal causes of AKI?
Cardiac failure, haemorrhage, sepsis, vomiting and diarrhoea
What are the post-renal causes of AKI?
Tumours, prostate disease and stones
(obstruction)
What are the intrinsic causes of AKI?
Glomerulonephritis, vasculitis, radiocontrast, myeloma, rhabdomyolysis and rugs (NSAIDs and gentamicin)
What are AKI risk events?
Sepsis, toxins, hypotension, hypovolaemia (haemorrhage, vomiting, and diarrhoea), and major surgery
What is the STOP AKI prevention care bundle?
Sepsis - screen and treat promptly
Toxins - avoid (gentamicin, NSAIDs and IV iodinated contrast)
Optimise - BP and volume status
Prevent harm - daily U+Es, fluid balance and med review
What is suggested if sepsis is suspected?
Blood cultures, urine output monitoring, fluids, antibiotics, lactate level and oxygen saturation monitoring
What is the medicine sick day rules?
When you are unwell with vomiting or diarrhoea, fever, sweats and shaking then STOP medicines - ACE inhibitors, ARBs, NSAIDs, diuretics and metformin
Restart when well
How is AKI diagnosed?
Increase in creatinine - >26/5 in 48hrs or >1.5 within 7 days
Reduced urine output - <0.5ml/kg/hr for 6hrs or <300mls in 12 hrs
What could be caused by AKI - volume status?
Hypovolaemia - give boluses of fluid IV
Euvolemic - give maintenance fluid
Hypervolemia - senior review
What investigations and assessments are needed in AKI?
History, examination, drugs, insults, renal function, urine dipstick, FBC, USS, blood gas, and blood tests
What can be included in history?
Past medical history, FH, drug exposure, pre/post renal factors, uraemic symptoms and timing of symptoms - SOB, urine output and vomiting
What is included in blood tests?
U+Es, bicarb, LFTs, bone and FBC
Clotting
What is included in AKI review?
Bloods
Ultrasound
Medicines
Plan for fluid maintenance - fluid balance chart and daily weights
What is included in AKI follow up?
Record
Repeat bloods - check if renal function has returned to baseline and if not then think other diagnosis
Treatment and medication review - do they need to restart diuretics, antihypertensive or other meds
What are the potential indications for RRT?
Acidosis, electrolyte imbalance (hyperkalaemia), intoxication (lithium), overload and uraemic complications
How does an ECG look when patient has hyperkalaemia?
Peaked T waves - usually earliest sign
Tall tented T waves
P waves widen and flatten, PR segment lengthens and P waves eventually disappear
What are later changes to an ECG with hyperkalaemia?
Prolonged QRS interval with bizarre QRS morphology
High grade AV block
Any kind of conduction block
Sinus bradycardia or slow AF
Then cardiac arrest - asystole, VF or PEA
What is the treatment for hyperkalaemia?
Stabilise myocardium - calcium gluconate
Shift K intracellularly - salbutamol or insulin-dextrose
Remove - diuresis, dialysis and anion exchange resins
