Figure 1.

Hypoxaemic response for the five opioid drug treatments. Left panels: time course of the median slope (upper panel) and intercept (lower panel). Right panels: mean and 95% confidence intervals of the slope and intercept for the periods before, during and after drug treatment. Repeated measures analysis of variance on these ventilatory responses with treatment and period as within subject factors with subject as the repeated measure found no significant differences between treatments or periods.

Abbreviations: M15 = morphine 15 mg, M10/O5 = morphine 10 mg + oxycodone 5 mg; M7.5/O7.5 = morphine 7.5 mg + oxycodone 7.5 mg; M5/O10 = morphine 5 mg + oxycodone 10 mg; O15 = oxycodone 15 mg. M15 (○); M10/O5 (▵); M7.5/O7.5 (▿); M5/O10 (□); O15 (⋄); before (▪); during (); after ()