Spinal Anesthesia with Bupivacaine for Lumbar Laminectomy

Bae, Jung In; Cheun, Jae Kyu

Abstract

Spinal anesthesia has been virtually abandoned in general practice for lumbar laminectomy because of the fear of airway obstruction and the difficulty of sedation in the prone position. Nontheless, spinal anesthesia offers obvious benefits to the surgeon such as a clear surgical field with less bleeding. The objective of this study was to evaluate the effects of bupivacaine as a spinal anesthetic for lumbar laminectomy. Spinal anesthesia was induced to 25 random patients who were scheduled for lumbar laminectomy. This spinal anesthetic was isobaric 0.5% bupivacaine mixed with 1:300,000 epinephrine. A spinal tapping was made in a sitting position at the interspace above or below the surgical area depending on the patients height and then 3 ml of local anesthetic was injected. Next, each patient was laid down in a supine position for 3 minutes and then turned him around in a prone position. Each patient was then given a deep sedation using thiopental or nembutal until the operation was over. Arterial blood gases were analysed for the evaluation of ventilatory function. P.CO2 were 39.3+/-3.9mmHg preoperatively and 50.39+/-6.8 mmHg at 1 hour during operation. P.O2 were 94.4+/-11.2mmHg preoperatively and 83.57+/-14.4 mmHg at 1 hour during operation. PH were 7.40+/-0.02 preoperatively and 7.30+/-0.04 at 1 hour during operation. The duration of motor paralysis was 3-3.5 hours which waa suitable for the lumbar laminectomy. We observed no serious complications. This study showed that spinal anesthesia using bupivacaine with sedation in the prone position for laminectomy caused slight hypoventilation but it was a tolerable amount. Furthermore, the duration of anesthetic effect of bupivacaine was suitable for laminectomy. Consequently, we concluded that bupivacaine can be a good choice of spinal anesthetic agents for laminectomy.