Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Apr 2004
Case ReportsStrategies for managing decreased motor evoked potential signals while distracting the spine during correction of scoliosis.
Surgical correction of kyphoscoliosis may result in spinal cord injury and neurologic deficits. Monitoring somatosensory evoked potentials (SSEPs) and transcranial motor evoked potentials (MEPs) intraoperatively may allow for early detection and reversal of spinal cord injury. ⋯ Acute reduction or loss of MEP or SSEP signals during spinal distraction presents a crisis for the operative team: should distraction be immediately relieved? The authors describe three patients who showed a decrease in evoked potential signals under hypotensive, hemodiluted conditions at the stage of spinal distraction. Each case illustrates a different strategy for successful management of these patients.
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J Neurosurg Anesthesiol · Apr 2004
Buprenorphine-soaked absorbable gelatin sponge: an alternative method for postlaminectomy pain relief.
There have been several reports of instillation of buprenorphine in the intact epidural space in an attempt to control postoperative pain, but none in which an absorbable gelatin sponge soaked with buprenorphine is placed directly in the epidural space. In the present study, carried out on 30 patients (study group) undergoing noncervical laminectomies, 0.3 mg buprenorphine diluted to 5 mL with normal saline soaked into an absorbable gelatin sponge was placed in the epidural space under direct vision. In 30 other patients (control group) undergoing laminectomies, absorbable gelatin sponge soaked with 5 mL normal saline was placed in the epidural space. ⋯ The authors observed that changes in pulse rate, mean arterial pressure, and respiratory rate were not statistically significant between the control and the study groups. The pain relief score, duration of pain relief (14.8 +/- 0.77 hours in the study group vs. 0.66 +/- 0.15 hours in the control group), and sedation were significantly better in the study group. No patient demonstrated any respiratory depression (respiratory rate <12/min), bradycardia, pruritus, or neurologic pressure symptoms, although the incidence of nausea was higher in the study group.
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J Neurosurg Anesthesiol · Jan 2004
ReviewEffects of anesthetic agents and physiologic changes on intraoperative motor evoked potentials.
Motor evoked potentials (MEPs) have shown promise as a valuable tool for monitoring intraoperative motor tract function and reducing postoperative plegia. MEP monitoring has been reported to contribute to deficit prevention during resection of tumors adjacent to motor structures in the cerebral cortex and spine, and in detecting spinal ischemia during thoracic aortic reconstruction. ⋯ Understanding the effects of anesthetic agents and physiologic alterations on MEPs is imperative to increasing the acceptance and application of this technique in the prevention of intraoperative motor tract injury. This review is intended as an overview of the effects of anesthetics and physiology on the reproducibility of intraoperative myogenic MEP responses, rather than an analysis of the sensitivity and specificity of this monitoring method in the prevention of motor injury.