• UEC (main renal function test)
• Urine specimen tests
• Proteinuria

<aside> 💡 ACUTE

1. Establish if AKI: Urea (increase), creatinine (increase), eGFR (decreased)
2. Differentiate pre/post renal and intrinsic renal:

• urea: creatinine ratio (in UEC) remember to equate units (urea x 1000)
  • 40-100 normal

  • 100 = pre or post renal (slow filtrate favours reabsorption)

  • intrinsic may be normal or low
• Urine Na concentration
  • low in pre renal <20mmol/L
  • high in ATN >40mmol/L
• urine osmolality
  • increased in pre renal >500mmol/L
  • decreased in ATN <350mmol/L
• urine amount
  • Pre-renal: oliguria <400mL/day
  • Intra-renal: normal or ↓ ATN can be oliguric or nonoliguric. Oliguria may be followed by diuretic phase
  • Post-renal: oliguria or anuria (<50mL/day). May be followed by diuretic phase after relief of obstruction </aside>

<aside> 💡 Albumin: Creatinine ratio

• Normal: ACR < 3
• Microalbuminuria: ACR 3-30 (early G dmg)
• Macroalbuminuria: ACR >30 (sig. G dmg)
• Nephrotic range’ proteinuria ACR >250 or PCR >300, >3.5g/day </aside>

<aside> 💡 CKD (kidney dmg/<60mL/min GFR for at least 3 months) damage: biopsy, USS, albuminaemia, haematuria

1. Stage: (eGFR, ACR)
2. Identify cause: USS, urine micro, urine ACR, FBC, ESR, CRP, fasting lipids and glucose
3. Identify complications

Urine findings in CKD

• Proteinuria (albumin)
• Broad waxy casts
• Isotonic urine
  • Urine osmolality of ~300mmol/L
  • Urine specific gravity ~1.010 </aside>

Renal physiology

CKD

Electrolytes in renal failure

nephrotic syndrome

GFR/eGFR