Effect of glucose concentration on the subarachnoid spread of tetracaine in the parturient.

We have studied the effect of glucose concentration on the spread of tetracaine spinal anesthesia in 40 parturient patients. Forty women undergoing cesarean section received a subarachnoid injection of tetracaine 8 mg dissolved in either 5% or 10% glucose solution. The maximum cephalad spread of analgesia [median (range)] was higher with 10% glucose [T3 (T4-C8)] than with 5% glucose [T4 (T5.5-T2)]. The time from the spinal injection to the maximum spread of analgesia (mean ± SD) was significantly shorter with 10% glucose (15 ± min) than with 5% glucose (28 ± 16 min). The cumulative dose of ephedrine was higher with 10% glucose (19 ± 10 mg) than with the 5% glucose (13± 8 mg). In tetracaine spinal anesthesia, the rate of onset of analgesia was faster and the maximum level of analgesia was higher in the 10% glucose solution than in the 5% glucose solution.