Anesthesia During Neurophysiologic Monitoring in Scoliosis Patients

Study Overview
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Brief Summary
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When patients have spinal surgery, electrodes are placed on the body to measure motor evoked potentials (MEP) and somatosensory evoked potentials (SSEP). Many hospitals only use IV anesthesia because they feel that measuring MEP and SSEP is easier using IV anesthesia. At this hospital the investigators typically use inhaled anesthesia and are able to successfully measure MEP and SSEP. This is a study to find out if one method of anesthesia is better than the other for measuring MEP and SSEP.

Official Title
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Anesthesia During Neurophysiologic Monitoring in Scoliosis Patients: Volatile Agents Versus Total Intravenous Anesthesia

Conditions
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Idiopathic Scoliosis

Intervention / Treatment
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* Drug: propofol
* Drug: Desflurane


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with idiopathic scoliosis. Exclusion Criteria: Patients with neuromuscular scoliosis.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Total intravenous anesthesia (TIVA)<br> | Drug: propofol<br>* Propofol adjusted to maintain the bispectral index at 40-60.<br>* Other names: Diprivan;|
| Active Comparator: Inhaled anesthesia<br> | Drug: Desflurane<br>* Desflurane adjusted to maintain the bispectral index at 40-60.<br>* Other names: Suprane;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amplitude Required to Elicit the MEP | Compare the data obtained from neuromonitoring including the amplitude required to elicit the MEP from patients receiving general anesthesia with an inhalational anesthetic agent to those receiving total intravenous anesthesia (TIVA). | at time of surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amplitude of the SSEPs | SSEPs (somatosensory evoked potentials) are most commonly elicited by bipolar transcutaneous electrical stimulation applied on the skin over the trajectory of peripheral nerves of the upper limb (e.g., the median nerve) or lower limb (e.g., the posterior tibial nerve), and then recorded from the scalp. The amplitude is the voltage of the electrical stimulation recorded. | day of surgery | 
| Latency of the SSEP's | SSEPs (somatosensory evoked potentials) are most commonly elicited by bipolar transcutaneous electrical stimulation applied on the skin over the trajectory of peripheral nerves of the upper limb (e.g., the median nerve) or lower limb (e.g., the posterior tibial nerve), and then recorded from the scalp. Latency is the time interval between the stimulation and response. | day of surgery |