Acute Kidney Injury

Question 1

Define AKI

Answer 1

Syndrome of decreased renal function occuring over hours - days

Question 2

What are the parameters measured for decrease renal function?

Answer 2

• Serum creatinine
• Urine output

Question 3

What are the NICE criteria for AKI?

Answer 3

• Rise in creatinine of >26 micromol/L in 48 hours
• Rise in creatinine of >1.5 x baseline in 7 days
• Urine output of < 0.5ml/kg/hour for > 6 hours

Question 4

What staging system do you use for AKI?

Answer 4

The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines

Question 5

What are the RF for AKI?

Answer 5

• Diabetes
• CKD
• IHD/CCF
• >75
• Sepsis
• Medictaions
  
  • ACEi - causes Fibromuuscular Dysplasia
  • ARBs
  • NSAIDs
  • Abx

Question 6

Describe the different stages of AKI

*think serum creatinine and UO

Answer 6

• 1
  
  • Serum Cr 1.5-1.9 x baseline
  • < 0.5mL/kg/hr for 6-12 hrs
• 2
  
  • Serum Cr 2.0-2.9 x baseline
  • < 0.5mL/kg/hr for > 12 hrs
• 3
  
  • Serum Cr > 3.0 x baseline
  • < 0.3mL/kg/hr for > 24 hrs

Question 7

What are the commonest cause of AKI?

Answer 7

1. Sepsis
2. Major surgery
3. Cardiogenic shock
4. Hypovolaemia
5. Drugs
6. Hepatorenal syndrome
7. Obstruction

Question 8

What are the pre-enal causes of AKI?

*think dec. vascular volume, dec cardiac output, systemic vasodilation, renal vasoconstriction

Answer 8

• Dec vascular output
  
  • Haemorrhage, D&V, burns, pancreatitis
• Dec cardiac output
  
  • Cardiogenic shock, MI
• Systemic vasodilation
  
  • Sepsis, drugs
• Renal vasoconstriction
  
  • NSAIDs, ACE-i, ARB, hepatorenal syndrome, cyclosporin

Question 10

What are renal causes of AKI?

* think glumerular, interstitial, vessels

Answer 10

• Glomerular
  
  • Glomerulonephritis
  • Acute Tubular Necrosis
• Interstitial
  
  • Infection
  • Infiltration - sarcoid
  • Drug reaction
    
    • aminoglycoside, cisplatin, amphotericin
• Vessels
  
  • Vasculitis
  • Haemolytic Uraemic Syndrome
  • Thrombotic Thrombocytopenic Purpura
  • DIC

Question 11

What are the post renal causes of AKI?

Answer 11

• Bladder Outlet obstruction
• Stones
• renal tract malignancy
• stricture

Question 12

What are the life threatening cx of AKI?

Answer 12

• Pulmonary oedema
• Hyperkalaemia
• Metabolic acidosis
• Uraemia

Question 14

What Ix would you order for AKI?

Answer 14

Bedside

• Urine dipstick
• MCS
• Urine PCR

Bloods

• FBC, U&E, LFT, Bone profile, CRP, CK
• platelets
• Ix intrinsic renal disease
  
  • immunoglobulins, autoantibodies (ANCA. ANA, anti-GBM)
  • Anti-streptolysin O Titres - if post-strep GN sus

Imaging

• Renal USS

Question 15

How would you broadly Mx AKI?

Answer 15

• Tx underlying cause for all
• Prerenal
  
  • correct volume depletion
  • inc renal perfusion
• Renal
  
  • Refer to biopsy and specialist tx for intrinsic renal disease
• Post renal
  
  • catheter
  • nephrostomy
  • urological intervention

Question 16

What are the indications for urgent dialysis?

*Think AEIOU

Answer 16

• Acidosis (<7.2)
• Electrolyte imbalance - hyperkalaemia (>6.5)
• Ingestion of drugs (BLAST)
• Overload fluid
• Uraemia (pericarditis, encephalopathy, gastritis)
• BLAST
  
  • Barbiturates
  • Lithium
  • Alcohol
  • Salicylates
  • Theophylline

Question 17

What drugs to stop in AKI?

*DAMN AKI

Answer 17

• Diuretics
• Aminoglycosides and ACE inhibitors
• Metformin
• NSAID
  
  • Aspirin can continue at 75 mg for secondary prevention of ACS