Total spinal block after epidural injection into an interspace adjacent to an inadvertant dural perforation

Abstract

Puncture of the subarachnoid space is a common technical complication of epidural anesthesia with an incidence ranging from 0.2-3.0 per cent. Whether the needle should be repositioned in the epidural space of the same or an adjacent interspace for injection of the local anesthetic for epidural anesthesia is controversial. In the last 2,603 cesarean sections performed under epidural anesthesia in our institution, there have been 58 inadvertent dural punctures (2.23 per cent). In 31 of the 58 cases an injection was made through the needle at the next cephalad interspace using 75 to 85 per cent of the usual dose of local anesthetic. A test dose was used and an epidural catheter inserter in all 31 cases. Of the 31 parturients, 14 were either not in labor or were having contractions at more than 10-min intervals, and eight were having contractions every 4- to 10-min intervals. The three total spinal anesthetics occurred in a group of nine patients having contractions at intervals of less than 4 min. Taking into account the increased cephalad spread of anesthesia with increased body weight, three additional patients in labor had a high level of anesthesia defined as a level more than 2 SD above the mean. The levels were C7, C5, and T2. By chi-square analysis there was a strong probability that the high levels of sensory anesthesia were related to the frequency of uterine contractions. (P<0.01). The three cases of total spinal anesthesia are described.