INTERACTION BETWEEN BARICITY (GLUCOSE-CONCENTRATION) AND OTHER FACTORS INFLUENCING INTRATHECAL DRUG SPREAD

The effects of intrathecal injection of 0.5% bupivacaine in solutions containing various concentrations of glucose have been studied in four groups of 20 patients. When solutions containing 0.8% glucose were in jected at the L3-4 interspace the median maximum extent of block was h igher, and the range of blocks wider, with the 8% solution. All patien ts receiving 0.8% glucose had blocks between the T5 and T10 dermatomes , confirming previous work on the benefits of this concentration of gl ucose. In the two other groups 0.5% bupivacaine containing 0 or 0.8% g lucose was injected at the L2-3 interspace. In both groups of patients a wider range of blocks, with a median maximum extent that was higher , was produced. These results demonstrate how glucose concentration ma y be used to influence the spread of intrathecal solutions and how oth er factors can obscure the effect of glucose concentration.