Fig. 2. Time course of total intraneural lidocaine content (nanomoles per milligram wet weight of nerve) after injection of 0.5% plain lidocaine (L; open circles) or 0.5% lidocaine with epinephrine (LE; 1:100,000; filled circles); n = 10 at each time point. The solid and dashed lines are fits to the separate data sets from 4 to 60 min using the equation, L = L^f× exp(−k (t − 4)) + L^s. Parameters of the fit are shown on the figure. k = transport rate coefficient for the rapid removal phase (washout from nerve); L^f= amplitude of the fast-decaying component; L^s= amplitude of the steady state (plateau) component, which eventually decays to the baseline value.