Mr Smith has his bloods repeated the next morning:
- Urea is 24.5 mmol/L
- Creatinine 340 µmol/L
- Potassium 4.2 mmol/L
- Sodium 142 mmol/L
You look at Mr Smith’s fluid balance chart. His urine output has been recorded every hour and after the initial 1.8 litres was drained, he has passed between 200 and 250 ml/hour.