The efficacy of 1.5% lidocaine with 7.5% dextrose and epinephrine as an epidural test dose for obstetrics

In obstetric patients, the subarachnoid injection of 2 ml of 1.5% lidocaine in 7.5% dextrose resulted in perineal (S-2) sensory block within 2 min. This block was easily differentiated from the slower onset of sensory loss observed following epidural injection. In addition, unintentional iv injections of the test dose were detected by transient increases inmaternal heart rate following administration of the test dose containing 15 μg epinephrine. We conclude that 2 ml of 1.5% lidocaine in 7.5% dextrose with 15 μg epinephrine will aid the differentiation between subarachnoid, epidural, and iv injection.