Prevalence- 5% on ward
- 15% critically ill
- 40% mortality if on RRT
Aetiology - 80% pre-renal
- 10-20% renal
- 10% post-renal
Definitions - RIFLE
- Working
- Acute onset
- Deterioration in function
- Retention of nitrogenous and non-nitrogenous substances:
- Urea, cretinine
- Potassium, water, protons
- May be associated with a urine production problem
- Anuria (< 50 ml/day)
- Oliguria (< 300 ml/day)
Killers - Fix urgently, before taking history - Potassium
- Check ABG
- Wide QRS and flat P is a peri-arrest situation => Crash call
- Calcium gluconate
- Skin necrosis => Check the cannula
- Acts fast (seconds) but only lasts 10 mins
- Insulin-dextrose
- Lasts 4-6 hours => Don't forget to hand over and recheck
- Acidosis
- Check ABG
- 100 ml of 8.4% NaHCO3
- Fluid
- ABG, CXR, SpO2
- Diuretics
- Furusemide 40 mg or 80 mg if acute-on-chronic
- Try max. 2 boluses
- Monitor urine o/p
- GTN
- CPAP
- Keeps alveloi open and pushes fluid out
- Dialysis
Aetiologies - Pre-renal
- Hypovolaemia
- Sepsis
- Renal artery stenosis or thrombosis
- Renal
- HTN
- Diabetes
- Drugs (big 5)
- Diuretics
- NSAIDS
- ACEi
- Aminoglycosides
- Contrast
- GN
- Rhabdomyolysis
- Multiple myeloma
- Post-renal
- BOO
- Strictures
- Cervical cancer (in resource-poor settings)
- Anti-cholinergics
Investigations - Bloods
- FBC
- Anaemia of chronic disease
- WCC
- CRP, ESR
- Cultures
- U+Es
- Group + save
- Glucose
- CK
- Bone profile
- PSA
- LFTs
- Plasma electrophoresis
- Autoantibodies if suspicion (2nd line)
- Urine
- Dip
- UPCR
- cf Nephrotic range > 3 g/24hr
- Microscopy
- MC+S
- Electrophoresis
Management - Hypovolaemia
- Fluid challenge
- Monitor urine o/p
- No response indicates the hypovolaemia has caused ATN => Need dialysis
- Sepsis
- Fluid challenge
- No response indicates fluid is all going to interstitial space
- => Need inotropes +/- RRT
- Renal cause
- Obstruction
- Catheter (everyone should have one anyway, for monitoring)
Notes - Acute-on-chronic kidney injury causes a big jump in creatinine for a small reduction in GFR
- Completely the opposite to the usual situation
- When checking for the killers the key investigation is ARTERIAL BLOOD GAS
- Patient may look and sound well, even though the killers are marching forwards
- Sort them out straight away, before taking history
- It's the CHARGE that normally keeps proteins in the glomerulus
- Dysmorphic RBCs have been squeezed out of the glomerulus
- Golden hour for antibiotics
- Uraemia can cause pericarditis and tamponade
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