Effects of age and weight on the measured rate of uptake of nitrous oxide in normal children

The effect of age on the uptake of nitrous oxide (N₂O) has been previously determined by using the time required to reach a steady state. This methodology may be inaccurate since the steady state is often not achieved during the study period. The time to reach a steady state depends on elimination half-life (t( 1/2 )) 95 per cent steady state = 5 x t( 1/2 ). We therefore developed a method to calculate the t( 1/2 ) of N₂O from the inspired and expired concentrations.