A double blind comparison of lidocaine 2% with or without glucose for spinal anesthesia

The aim of the study was to compare lidocaine 2% plain to lidocaine 2% with glucose 8% for spinal anesthesia. Forty male patients scheduled for urologic surgery participated. The patients were randomly divided into two groups: the plain (P) group received 4 ml of glucose-free lidocaine 2%, the heavy (H) group received 4 ml of lidocaine 2% containing 8% glucose. After the injection, the patients remained in the sitting position for three minutes before they were placed supine. The onset and maximum level of sensory blockade were similar with both preparations (T7-T8). In both groups there were respectively 3 (P) and 4 (H) patients who did not acquire a sensory level above T10. There was a tendency towards a longer duration of sensory blockade in the P group. The patients in both groups developed an almost complete motor blockade within approximately 10 minutes. Duration of complete motorblockade of the lower extremities was significantly shorter for the H group: 59.1 +/- 6.5 minutes (mean +/- SEM) than the P group: 89.5 +/- 6.4 minutes. We consider lidocaine 2% with or without glucose a suitable agent for subarachnoid anesthesia for short procedures. As hyperbaric lidocaine results in a more rapid recovery of motor blockade, it may have advantages for patients in day-case settings.