Table 2. Population Model Parameter Estimates for Normoxia Ventilation at a Fixed Petco^{2}of 45 mmHg and the Ventilatory Response to Acute Hypoxia

* Parameter not included in the statistical model.

â€ C^{50}is an extrapolated value.

C^{25}and C^{50}= concentrations causing 25% and 50% reduction of responses; %CV = percent coefficient of variation; DODR = dose driving rate; k^{el}= drug elimination rate; Petco^{2}= end-tidal pressure of carbon dioxide; PK/PD analysis = pharmacokineticâ€“pharmacodynamic analysis using pharmacokinetic data from the literature (see table 1); t^{1/2}k^{e0}= blood effect-site equilibration half-life.