Deliberate hypotensive anesthesia with labetalol in reconstructive surgery for scoliosis

Anesthesia for surgical reconstruction of scoliosis presents a great challenge for anesthesiologists. One of the main concerns is massive bleeding. Hypotensive anesthesia has been advocated for the purpose of diminishing operative blood loss. On the other hand, some authors reported that the blood loss mostly depends on surgical technique, rather than anesthetic technique. We hereby evaluate the efficacy of deliberate hypotensive anesthesia and compare its merits and faults with that of normotensive anesthesia in scoliosis surgery performed by a single surgical and anesthetic team.

The effect of deliberate hypotensive anesthesia on intraoperative blood loss, blood transfusion, and length of surgery in patients who underwent Cotrel Duvosset Instrumentation for scoliosis was assessed. Twenty patients (Group A) were given isoflurane as the main anesthetic agent and their blood pressure was maintained at the preoperative level. These patients were compared with twenty patients (Group B) who were anesthetized with isoflurane and their intraoperative mean blood pressure was lowered and controlled at 50 mmHg by intravenous labetalol. All these forty operations were done by a single surgical and anesthetic team. The results were analyzed by the Student's t-test.

Deliberate hypotensive anesthesia was found to significantly decrease the average blood loss by nearly 55 per cent, reduce the need for transfusion by nearly 53 per cent, and shorten the average operating time by over one hour. No complications attributable to the specific anesthetic technique occurred.

The findings of this study suggest that deliberate hypotensive anesthesia with labetalol and isoflurane may be of benefit in scoliosis surgery by reducing blood loss, the need of blood replacement and operating time.