Scoliosis
Conditions
Keywords
pediatrics, Anaesthesia, Scoliosis, Magnesium
Brief summary
The primary objective of this study is to determine whether magnesium sulfate has a clinically important effect on the amplitude and latency of somatosensory and motor evoked potentials in patients undergoing surgical correction of idiopathic scoliosis.
Detailed description
Motor and somatosensory evoked potentials are continuously monitored in the setting of scoliosis surgery to evaluate the integrity of spinal cord pathways. Detection of neural irritation or injury using motor or somatosensory evoked potentials allows the surgeon to modify technique to reverse the insult and proceed without spinal cord compromise. To facilitate evoked potential monitoring, anesthetic agents that attenuate the evoked responses must be avoided.Several different agents have been studied to try to diminish the acute opioid tolerance and/or hyperalgesia seen with remifentanil. Two studies investigated the effect of magnesium sulfate on intraoperative remifentanil-induced hyperalgesia. In both studies, post-operative pain scores and opioid consumption were decreased in those patients who received magnesium. Our aim is to establish that magnesium sulfate does not adversely affect somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) in patients undergoing correction of idiopathic scoliosis. Future clinical trials can then be performed investigating the effect of magnesium sulfate on remifentanil-induced hyperalgesia in the same population.
Interventions
DRUGMagnesium
Magnesium will be administered intravenously at a dose of 50 mg/kg bolus followed by an infusion of 10 mg/kg/hr.
Sponsors
The Hospital for Sick Children
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
12 Years to 18 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists (ASA) status I or II * Adolescent children aged 12 to 18 years undergoing surgery for idiopathic scoliosis
Exclusion criteria
* Magnesium use within the last two weeks, either intravenous or oral supplements * Patients with known electrolyte imbalances or conduction disorders. (Sodium \<135 or \>143 mmol/L OR Potassium \< 3.7 or \> 5.0 mmol/L if 12 to 15 yrs; Potassium \<3.7 or \>4.8 mmol/L if 16 to 18 yrs) * Renal, cardiac or neuromuscular disorders.(Urea \< 2.9 or \> 7.1 mmol/L OR Creatinine \>79 µmol/L if \< 13 yrs; Creatinine \> 98 µmol/L if \>= 14 yrs)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Somatosensory and motor evoked potentials | Baseline | Cortical SEPs will be measured from Cz-Fpz or Ci-Cc (10-20 system of head measurement) and the amplitudes will be taken from the first positive deflection to first negative deflection (P1-N1) after supramaximal stimulation of the posterior tibial nerves at the medial malleolus. The MEP peak-to-peak amplitudes will be measured from left and right tibialis anterior and abductor hallucis muscles. Stimulation parameters will be varied in order to achieve the maximum amplitude values. Evoked potentials will be measured before and at 10 and 30 minutes after the start of the magnesium infusion. |
Countries
Canada
Outcome results
None listed