Effect of dextrose concentration on the intrathecal spread of amethocaine.

Effects of solutions of 0.5% amethocaine, containing different concentrations of dextrose (0%, 1.25%, 2.5% and 5%) were studied after intrathecal injection. The cephalad extent of block was greater with all three dextrose-containing solutions (T6), compared with the isobaric solution which contained no dextrose (T11). The variability of maximum level of block within each group was similar (seven dermatomes), and the rate of onset to maximum extent of block was the same in all groups. The rate of onset to the T12 dermatome was more rapid in the patients who received solutions containing dextrose. The initial onset of effect of the solution containing 1.25% dextrose was more like that of the isobaric solution than of those containing higher concentrations of dextrose.