Ventilatory Reserve and Level of Motor Block During High Spinal and Epidural Anesthesia

Abstract

Eighteen subjects were successively given spinal anesthesia with 50 to 75 mg. lidocaine, and epidural anesthesia with 15 to 35 ml of 2% lidocaine containing 1200,000 epinephrine. Mean levels of cutaneous analgesia (pin prick) and motor block (electromyography) were T 2.3 [plus or minus] 1.8 and T5.1[plus or minus] 2.4, respectively, with spinal anesthesia, and T 3.6 [plus or minus] 1.2 and T 8.2 [plus or minus] 2.6 with epidural anesthesia. Mean inspirator capacity fell 8% with spinal anesthesia and 3% with epidural anesthesia. Mean expiratory reserve volume fell 48% with spinal anesthesia and 21% with epidural anesthesia.