Optimum sevoflurane concentration for I-gel insertion in unpremedicated children

Area of Science:

• Anesthesiology
• Pediatric Anesthesia
• Airway Management

Background:

• End-tidal sevoflurane concentration (ET SEVO) requirements for supraglottic airway device insertion in pediatric patients are not well-established.
• The I-gel and classic laryngeal mask airway (CLMA) are commonly used supraglottic airway devices in pediatric anesthesia.

Purpose of the Study:

• To determine the median effective concentration (EC50) and the 95% effective concentration (EC95) of sevoflurane for I-gel insertion in children.
• To compare these values with those for CLMA placement in a pediatric population.

Main Methods:

• A prospective, randomized controlled study was conducted with pediatric patients aged 1.5-8 years undergoing elective cataract surgery.
• Patients received sevoflurane and oxygen anesthesia, with spontaneous breathing maintained. They were randomized to receive either an I-gel (size 2) or CLMA (size 2).
• The Dixon up-and-down method was used to determine ET SEVO, with responses (movement or no movement) recorded after device insertion.

Main Results:

• The EC50 for I-gel insertion was 0.94% (95% CI: 0.83%-1.06%), and the EC95 was 1.26% (95% CI: 1.12%-1.66%).
• For CLMA insertion, the EC50 was 1.9% (95% CI: 1.70%-2.1%) and the EC95 was 2.54% (95% CI: 2.24%-3.41%).
• These results indicate that the I-gel requires approximately half the ET SEVO compared to the CLMA.

Conclusions:

• I-gel insertion in children can be safely and effectively achieved with a significantly lower end-tidal sevoflurane concentration compared to CLMA.
• The findings suggest potential benefits of using the I-gel in pediatric anesthesia regarding anesthetic agent requirements.