Low Flow Anesthesia in Children Undergoing Strabismus Surgery

Summary

Emergence agitation (EA) involves restlessness, disorientation, excitation, non-purposeful movement, inconsolability, thrashing, and incoherence during early recovery from general anesthesia. Sevoflurane and desflurane have increased the incidence of EA in children. A proposed explanation for this is that sevoflurane and desflurane cause differential recovery rates in brain function, due to differences in clearance of inhalational anesthetics from the central nervous system; whereas audition and locomotion recover first, cognitive function recovers later, resulting in EA. Low-flow anaesthesia (LFA) occurs when the fresh gas flow (FGF) is significantly lower than the patient's minute volume. In a low-flow system, the recirculated fraction should amount to at least 50% after carbon dioxide (CO2) absorption.In LFA using minimal FGF (250-500 mL/min), if the vaporizer is turned off 10-15 minutes before the end of the operation and the FGF is not changed, the inhaled anesthetic agent concentration gradually and slowly decreases to zero and the inhaled agent consumption decreases even more. In a study conducted on infants undergoing cleft lip-palate surgery, it was shown that the incidence of postoperative agitation were statistically lower in infants who administered 0.5 L/min FGF.

Strabismus surgery is one of the most frequently performed ophthalmologic operations in children and is associated with moderate postoperative pain and a high incidence of EA (40-86%). The incidence of EA after strabismus surgery is high, especially due to visual disturbances; however, the pathogenesis of this condition remains unclear. In our study, the effects of different FGFs administered in children undergoing strabismus surgery on EA and anesthetic agent consumption will be investigated.

Conditions

• Low Flow Anesthesia
• Sevoflurane
• Strabismus
• Emergence Delirium

Interventions

DRUG

Sevoflurane; In our study, the effects of sevoflurane in different FGFs administered in children undergoing strabismus surgery on EA and anesthetic agent consumption will be investigated.

Low-flow anaesthesia is generally adminstered as nitrogen wash-out, a period of higher flow rate in combination with a high vaporizer setting for initial saturation, and subsequent reduction of fresh gas flow and adjustment of the vaporizer to maintain the desired end-tidal anesthetic agent concentration (Etaa).In the initial wash-in phase, the vaporizer setting is adjusted to 6% for desflurane and 2.5-3% for sevoflurane, with FGF=4 L/min, until the Etaa concentration is 1-1.3 MAC. In another method, the vaporizer setting is adjusted to 12-18% for desflurane and 6-8% for sevoflurane, with FGA=1 L/min. Reducing the FGF during the wash-in period prevents unnecessary depth of anesthesia and reduces the consumption of inhalational anesthetics. In LFA using minimal FGF (250-500 mL/min), if the vaporizer is turned off 10-15 min before the end of the operation and the FGF is not changed, the inhaled anesthetic agent concentration gradually and slowly decreases to zero.

Sponsors & Collaborators

• Cukurova University

  lead OTHER

Principal Investigators

• Feride Karacaer, Assoc Prof · Cukurova University

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

3 Years

Max Age

10 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-11-04

Primary Completion

2025-06-04

Completion

2025-07-04