Figure 3
Alternating insufflation of CO 2 and air after administration of capsaicin. Pain ratings on a numerical rating scale from 0 to 10 during nasal insufflation of CO2 with a flow of 1 l/min or compressed air for 60 sec each followed by an interval of 20 sec to change gas supply and pain rating after intranasal application of capsaicin. After 2 cycles of CO2 and air each a break of 60 sec was made to allow subject to remove nasal discharge due to intranasal capsaicin application. Time is given in minutes. Error bars are given as standard error of the mean.