Comparison of the clinical performance of the flexible laryngeal mask airway in pediatric patients under general anesthesia with or without a muscle relaxant: study protocol for a randomized controlled trial

Abstract

Background: The insertion of a laryngeal mask airway (LMA) is difficult in children due to the unique features of their airways. Muscle relaxants have been reported to facilitate LMA insertion in adults; however, there is a lack of evidence supporting this in children. This trial is designed to assess the feasibility of LMA insertion with and without the use of muscle relaxants in pediatric patients under general anesthesia.

Methods/design: This is a prospective, double-blind, single-center, parallel-arm, non-inferiority, randomized controlled trial to be conducted with participants aged 2-7 years who are undergoing elective ophthalmic surgery under general anesthesia. Participants are randomly assigned to one of two groups based on whether muscle relaxants are used (MR group, n = 64) or not used (Saline group, n = 64) prior to LMA insertion. The primary outcome is the oropharyngeal leak pressure (OLP) at a fixed gas flow of 3 L/min. The secondary outcomes are intubation time for successful insertion, ease of insertion and mask bagging, intubation attempt for successful insertion, successful insertion rate on the first attempt, fiberoptic view of the LMA position, postoperative complications, and changes in hemodynamic and ventilatory parameters.

Discussion: We will compare the OLPs to determine whether the muscle relaxant provides better conditions for the manipulation of the LMA. This is the first randomized controlled trial to investigate whether muscle relaxants are beneficial to the clinical performance of LMA insertion in pediatric patients under general anesthesia. This trial will be a resource for improving the process and safety of pediatric LMA insertion under general anesthesia.

Trial registration: ClinicalTrials.gov, NCT03487003 . Registered on 18 April 2018.

Keywords: Flexible laryngeal mask airway; Muscle relaxant; Oropharyngeal leak pressure; Pediatric airway; Rocuronium.

Conflict of interest statement

Ethics approval and consent to participate

As indicated in the section “Study design,” Institutional Review Board of Daegu Catholic University Medical Center approved this research protocol (version 1.2, reference number: CR-18-027, validated in 18 April, 2018). This trial is conducted according to the World Medical Association Declaration of Helsinki. As indicated in the “Methods” section, we will obtain written informed consents from all the legal guardians or parents of the participants prior to any study-related procedures.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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Figures

Fig. 1

SPIRIT flow diagram: schedule of enrollment, interventions, and assessments. *Including mean blood pressure and heart rate, † Including ventilator parameter changes such as peak inspiratory pressure (PIP) and expiratory tidal volume to set tidal volume ratio (TVe/TVs) before and at the end of surgery, ‡including respiratory adverse events (coughing, laryngospasm, bronchospasm, postoperative stridor, and desaturation; SpO2 <95%), gastric insufflation, excessive secretion, postoperative nausea and vomiting, sore throat and bloody tinge on the LMA surface; T1 at preoperative waiting area, T2 after the loss of consciousness is achieved, T3 insertion of LMA, T4 cessation of anesthetics, T5 extubation, T6 PACU arrival, T7 PACU discharge. mYPAS modified Yale Preoperative Anxiety Scale, BIS bispectral index, ETsevo % end-tidal sevoflurane concentration, TOF train of four, OLP oropharyngeal leak pressure, FOB fiberoptic bronchoscopy, FLACC Face, Legs, Activity, Cry, and Consolability

Fig. 2

CONSORT flow chart