Acute kidney injury Flashcards
What is AKI?
- Sudden deterioration of renal function over hours to days
- Urea and creatinine rise rapidly
- Usually associated with oliguria or anuria
- Usually reversible, but not always
How is AKI staged using creatinine?
- Stage 1 = creatinine is 1.5-1.9 x baseline
- Stage 2 = creatinine is 2.0-2.9 x baseline
- Stage 3 = creatinine is 3.0 x baseline
How is AKI staged using urine output?
- Stage 1 = <0.5 ml/kg/hour for 6-12 hours
- Stage 2 = <0.5 ml/kg/hour for >12 hours
- Stage 3 = <0.3 ml/kg/hour for >24 hours or anuria for >12 hours
- Always stage according to most severe classification outcome
What are the pre-renal causes of AKI?
- ACEi
- Sepsis
- Hypovolaemia
- Shock
- Renal artery stenosis
- CCF
- NSAIDs (reduce production of prostaglandins)
What are the renal causes of AKI?
- Acute tubular necrosis
- Acute interstitial nephritis
- Glomerular disease
- Vasculitis
What are the post-renal causes of AKI?
- Calculus (bilateral)
- Ureteric/urethral stricture
- BPH
- Tumour
- Retro-peritoneal fibrosis
Outline how you would perform a fluid assessment on a patient
- General: colour, resp rate, dialysis machines
- Peripheral: hand temp, capillary refill time, skin turgor, HR, BP, postural BP
- Face and neck: sunken eyes, mucous membranes, JVP
- Chest and back: dull percussion, crepitations at lung bases, sacral oedema
- Abdomen and limbs: ascites, ballotable kidneys, palpable bladder, urine output, oedema
Outline how you would perform a fluid assessment on a patient
- General: colour, resp rate, dialysis machines
- Peripheral: hand temp, capillary refill time, skin turgor, HR, BP, postural BP
- Face and neck: sunken eyes, mucous membranes, JVP
- Chest and back: dull percussion, crepitations at lung bases, sacral oedema
- Abdomen and limbs: ascites, ballotable kidneys, palpable bladder, urine output, oedema
What are the complications of AKI?
- Metabolic acidosis
- Hyperkalaemia
- Volume overload
- Uraemia
What bedside investigations are done on a patient with suspected AKI?
- Bladder scan
- Urinalysis
- Microscopy
- Culture and specimen
- ECG (K+)
What blood investigations are done on a patient with suspected AKI?
- Venous blood gas
- Creatine kinase
- Immunology screen
What imaging investigations are done on a patient with suspected AKI?
- Ultrasound
- CT
- CXR
What procedures are done on a patient with suspected AKI?
- Nephrostogram
-Cytoscopy
How is pre-renal AKI managed?
- IV fluid replacement to correct hypovolaemia and optimise renal blood flow until euvolaemic
- Hold potentially nephrotoxic medication (e.g. ACEi, NSAIDs)
- Diuretics if clinically indicated
How is renal AKI managed?
- Correct electrolytes
- Renal replacement therapy
- Call nephrology
How is post-renal AKI managed?
- Urinary or suprapubic catheter
- Ureteric stents
- Nephrostomy
What is a nephrostomy?
- An opening made between the kidney and the skin on your back. It lets urine drain from the kidney.