Research Article

Effect of Use of Entropy Monitoring on Consumption of Sevoflurane Inhalational Agent in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery: A Randomized, Double Blind, Controlled Study

Abstract

Background: Airway management in young children is challenging because of distinct anatomical and physiological characteristics. Operating table height may influence laryngeal view, intubation success, and operator ergonomics. This randomized clinical trial evaluated the effects of four operating table heights on laryngeal visualization, intubation success and time, and ergonomic parameters in children.
Methods: In this four-group randomized clinical trial, 180 children aged 2–6 years with ASA physical status I–II were allocated using block randomization to four table-height groups: umbilical (U), rib (R), xiphoid (X), and nipple (N) levels. Outcomes included Cormack–Lehane laryngeal view grade, intubation success and time (confirmed by capnography), operator ergonomic angles measured with a digital goniometer, and operator comfort assessed on a four-point scale. Data were analyzed using SPSS version 26, and statistical significance was set at p < 0.05.
Results: First-attempt intubation success was 100% across all groups. The mean intubation time was 25.4 ± 5.2 seconds, with no significant intergroup differences
(p = 0.72). More than 97% of patients in all groups had a grade 1 laryngeal view. During mask ventilation, significant differences in neck and lumbar flexion were observed between groups (both p < 0.001). During intubation, knee flexion differed significantly among groups (p = 0.001). Overall, the umbilical level was associated with more favorable ergonomic angles compared with the other heights.
Conclusion: In children aged 2–6 years, operating table height did not significantly affect intubation success or time, but it did influence certain ergonomic parameters for the operator. Umbilical height was associated with more favorable ergonomic positioning and may be a practical option for pediatric direct laryngoscopy. Further multicenter studies are recommended to confirm these findings.

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Keywords
Airway management Direct laryngoscopy Tracheal intubation Ergonomics Children
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Honarmand A, Shafa A, Shahhosseini S, Montasery M, Safavi M, Nazemroaya B, Abtahi SM. Effect of Use of Entropy Monitoring on Consumption of Sevoflurane Inhalational Agent in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery: A Randomized, Double Blind, Controlled Study. Arch Anesth & Crit Care. 2026;.