Laryngeal Mask Airway Failure in Pediatric Patients

Optimal use of extraglottic airways, including the laryngeal mask (LMA), has not been fully defined using real-world data. Usage patterns and the reported incidence of failure and complications in different geographic regions vary greatly. In the adult population, an observational study involving more than 15,000 cases revealed a 1.1% incidence of laryngeal mask failure, defined as intubation after laryngeal mask removal, and 62% of patients experienced significant airway complications.

Similar data are scarce in children. Pediatric laryngeal mask studies report adverse event frequencies ranging from 0% to 10%. These data are limited by the focus on specific surgical procedures or the small sample size resulting in simple univariate or inadequate multivariate analyses. Additionally, although data on adverse events are presented, laryngeal mask failure requiring endotracheal intubation has been reported infrequently.

There are a significant number of studies identifying risk factors for misplacement of LMAs. However, there are no objective data to define misplacement of LMAs.

1-2 mL of lidocaine gel was applied evenly to the classic LMA (Intavent Direct, Maidenhead, UK) capsule. The appropriate size of the LMA device (size 1.5 for 5-10 kg and size 2 for 10-20 kg) was selected according to the manufacturer's recommendation. The LMA was placed by an experienced anesthesiologist, with the patient's head in a neutral position, with a fully deflated cuff, and the patient's mouth was opened, then held parallel to the chest, and the device was advanced along the hard palate. The cuff of the device was inflated with a sufficient amount of air according to the manufacturer's instructions. After LMA placement, patients were divided into two groups as successful (Group S) or unsuccessful (Group non-S) according to bilateral equal chest movement during inspiration, square wave capnography, absence of gastric insufflation, epigastrium auscultation and adequate tidal volume delivery. Another experienced anesthesiologist recorded the set (8 mL/kg) tidal volume (VT), expiratory tidal volume, airway peak pressure, SpO2, EtCO2 measurements in three respiratory cycles. Airway leak (ΔVT); It was calculated by subtracting expiratory VT from the adjusted VT. Airway leak, airway peak pressure, SpO2 and EtCO2 measurement were determined as possible objective predictors for LMA placement failure. Postoperative airway complications; It was determined and recorded as soft tissue trauma, laryngospasm, bronchospasm, and severe cough attack.

The aim of the study was to describe unsuccessful LMA placement in pediatric patients with objective data.

Inclusion criteria

• During surgery, the upper airway is planned to be supported with LMA by the Anesthesiologist.
• American Society of Anesthesiologists (ASA) physical status I or II

Exclusion criteria

• Surgery duration longer than 1 hour,
• Airway difficulty is expected,
• Restriction in opening the mouth,
• Airway malformation,
• Active upper respiratory tract infections,
• History of narrow airway,
• Hyperthyroidism, goiter, airway mass,
• Patients at risk of gastroesophageal reflux and aspiration of stomach contents