AKI Flashcards
(17 cards)
Define AKI
Sudden loss of renal function, characterised by either abnormal urine output or increased urea and creatinine in the urine
What are the stages of AKI
1: 1.5-1.9x baseline Cr OR UO : <0.5 ml/kg/h for 6-12 hours
2: 2-2.9x baseline Cr OR UO : <0.5 ml.kg/h for <12 hours
3: 3x baseline or increase to >4.0mg/dl OR UO <0.5 ml/kg/h for >24 hours
Pre-renal aetiology for AKI
Impaired perfusion due to: Shock Hypovolaemia (sepsis, major haemorrhage, vomiting/diarrhoea, congestive HF) Trauma Renal artery stenosis Drugs e.g. NSAIDs, ACEi
Renal aetiology of AKI
Glomerulonephritis (glomerular) Interstitial nephritis (interstitial) Acute tubular necrosis (tubular) Drugs and nephrotoxic contrast Vascular
Post-renal aetiology of AKI
Enlarged prostate Kidney stones Calcified ureter Cancer Fibrosis Urethral stricture
Risk factors for AKI
>75 Underlying kidney disease DM Sepsis Exposure to nephrotoxins Major surgery
Give examples of nephrotoxins
Aminoglycosides
Vancomycin
Piperacillin-taxobactam
Symptoms of AKI
Malaise Anorexia Nausea/vomiting Pruritus Dizziness Drowsiness, convulsions, coma Symptoms of the cause
Pre: -
Renal: rash, bruising
Post: frequency, urgency, hesitance, flank pain, haematuria
Signs of AKI
Oedema
Pre-renal: tachycardia
Renal: Rash, petechiae, ecchymoses, oedema, protein uria
Post: haematuria, distended palpable bladder
Investigations for AKI
Dipstick: Protein +, haematuria +
Bladder scan: >150ml when void
ECG: check for hyperkalaemia
U+Es: raised Cr
FBC: normal or low Hb: deranged WCC
ABG/VBF: assess acid-base status
USS: exclude renal obstruction
CXR: monitor fluid overload
What features would point towards a CKI instead of AKI
Anaemia suggests chronic
Kidneys <9cm suggests chronic
Hypocalcaemia and hyperphosphataemia suggests chronic
What is the significance of trimethoprim in AKI
Can lead to a rise in serum creatinine that does reflect any change in GFR
What is the short-term management for AKI
- Diuretic for pulmonary oedema
- Oxygen or CPAP for low sats
- Calcium gluconate or chloride for hyperkalaemia -> insulin + dextrose
- IV fluids for hypovolaemia
- Manage hyper-uraemia
- Treat the cause
What is the management plan for AKI if it progresses
Dialysis short-term
Ultimately transplant
Complications of AKI
Metabolic acidosis Water retention Hyperkalaemia Hyponatraemia Toxin accumulation e.g. urea
Prognosis of AKI
Mortality is 20% untreated and 60% with BG disease
Biphasic recovery (oliguria -> polyuria)
Prognosis depends on number of involved organs
Management for pre-, Renal and post- AKI
Pre - IV fluids
Renal - treat underlying cause, supportive
Post - Catheter and pro referral
