Inhibitory effect of gas anesthetics on neurophysiological monitoring in young children

JRCT ID: jRCT1041220109

Registered date:25/12/2022

Basic Information

• Recruitment status: Pending
• Health condition(s) or Problem(s) studied: Spinal cord diseases
• Date of first enrollment: 25/12/2022
• Target sample size: 20
• Study type: Interventional

Intervention(s)

At our center, for pediatric spinal surgery with intraoperative neuromonitoring as a routine practice, the standard anesthetic regimen is propofol (4-10 mg/kg/h) + remifentanil (0.2-1.0 mcg/kg/min) + sevoflurane [expiratory concentration 0.3-0.5 minimum alveolar concentration (MAC)]/desflurane (0.3-0.5 MAC) after a slow induction with sevoflurane. After intubation, the patient is placed in the supine position and a neuromonitoring device is attached to measure the control current. The following research methods were employed to avoid exceeding the scope of this normal clinical practice.

For general anesthesia induction, either slow induction with sevoflurane or rapid induction with propofol is performed based on the presence of a preoperatively placed peripheral venous route (standard general anesthesia). Here, anesthesia induction is performed with 5-8% sevoflurane, 2-3 mg/kg propofol, and 2 mcg/kg fentanyl under 40% nitrous oxide, and intubation is performed (the usual method of anesthesia induction at our center). At the end of airway clearance, propofol (4 mg/kg/h) and remifentanil (0.5 mcg/kg/min) (hereafter TIVA) are started as the base general anesthesia (this is the same as the usual anesthesia flow). In the desflurane addition group (group D), sevoflurane administration is discontinued and desflurane is started to achieve the target concentration. Once the concentration of anesthetics in the expired gas has stabilized, neuromonitoring potentials (motor evoked potentials (MEPs), somatosensory evoked potentials (SEPs), bulbocavernous reflexes (BCRs)) are assessed. (BCR) potential diagrams are recorded and stored.
Gas anesthetics (sevoflurane and desflurane) are then discontinued and a washout of at least 20 minutes is performed. The end-expiratory sevoflurane concentration is monitored to ensure that it is less than measurable (3 L/min minute ventilation volume). A second round of monitoring is then performed on the same patient under TIVA anesthesia alone, and each (MEP, SEP, BCR) potential diagram is recorded and stored. All of these recordings will be done as part of the normal surgical process of recording potential control prior to the start of surgery, and given the time required to prepare for the start of surgery, a significant delay in the start of surgery is not anticipated due to the study.

About the Interventions
The two interventions in this study are as follows.
(i) TIVA [propofol (4 mg/kg/h) and remifentanil (0.5 mcg/kg/min)
Sevoflurane (age-adjusted MAC=0.2) will be added
(ii) TIVA [propofol (4 mg/kg/h) and remifentanil (0.5 mcg/kg/min)
Desflurane (age-adjusted MAC = 0.2) will be added

After the usual (above) induction of general anesthesia, confirm that the exhaled concentration of the inhaled anesthetic has reached 0% under TIVA anesthesia, then perform neuromonitoring under TIVA anesthesia (X minutes after the start of administration) and record and store potentials. Sevoflurane or desflurane will then be administered, and after the exhaled concentration stabilizes at an age-adjusted MAC=0.2, neuromonitoring will be performed again in the same patients, and potentials will be recorded and stored.

Twenty patients will be pre-randomized by computer into two groups (sevoflurane and desflurane groups).

Outcome(s)

• Primary Outcome: Percentage of reducing the amplitude in the neuromonitoring results on the patient's upper limbs.
• Secondary Outcome: None

Key inclusion & exclusion criteria

• Age minimum: Not applicable
• Age maximum: < 3age old
• Gender: Both

Include criteria

Patients younger than 2 years old who undergoing elective spinal surgery
Initial surgery case

Exclude criteria

Patients with preoperative immobility of lower limbs
Patients who are contraindicated to use inhalational anesthetics or propofol
Patients or patient's families do not agree with study participation
Patients who show unstable hemodynamics
Patients who show any signs of insufficient anesthesia

Related Information

• Primary Sponsor: Kojima Fumio Taiki