Figure 5. The variation between individual chemosensitivity (b coefficients) for each of the six study occasion. Chemoreceptor output is expressed as (Hz)= a + b (PaO(2)-1)(mmHg). As shown, there was a large variation in the effect of vecuronium on the chemosensitivity during isocapnic hypoxia. A significant depression in the mean chemosensitivity (b coefficient) was found, comparing 0.1 mg and 0.5 mg vecuronium to control (P < 0.05) and by comparing 90 min to 30 and 60 min (P < 0.05). At 90 min, the mean chemosensitivity did not differ from control measurements (not significant).