Figure 1. The time course of lidocaine serum concentration with (squares) and without (circles) salbutamol pretreatment (mean +/− SD). The peak lidocaine concentrations are less than the toxic range of 5 [micro sign]g/ml. With the continuous infusion of lidocaine after the loading dose, a nearly stable lidocaine concentration was maintained during the inhalational challenge; there is no significant difference in lidocaine concentrations at the end of the loading dose and at the end of the inhalational challenge.