3. Measurement of plasma and urine concentrations

Substance   Method   Units
Na+, K+   Flame photometry   µmole / ml
Cl-   Electrometric   µmole / ml
HCO3-   Evolution of CO2   µmole / ml
Creatinine   Colourimetric   µmole / l


Note:        
urine output of X = [X] urine x urine flow
µmole / min   µmole / ml   ml / min

Note:        
Total solute (Osmolal) output = [osmolality] urine x urine flow
µosmole / min   µosmole / g H20   ml / min