Evaluation of Laryngeal Mask Airway Use in Pediatric Bronchoscopy: A 10‐Year Retrospective Study

Authors: Yasar Gokhan Gul, Sedat Oktem, Pelin Karaaslan, Tumay Uludag Yanaral

Abstract

Background

The effectiveness and safety of laryngeal mask airway (LMA) use in pediatric flexible bronchoscopy remains insufficiently documented, particularly regarding age‐specific outcomes. This study aimed to evaluate LMA compared to mask ventilation during pediatric flexible bronchoscopy, focusing on oxygenation parameters and complications across different age groups.

Methods

This retrospective study analyzed 212 pediatric patients (1–12 years) who underwent flexible bronchoscopy between 2014 and 2023. Patients were stratified into early childhood (1–5 years, n = 153) and late childhood (5–12 years, n = 59) groups. Primary outcomes included oxygen saturation levels and desaturation events. Secondary outcomes included total anesthesia time and complications.

Results

LMA use resulted in significantly higher intraoperative SpO2 levels in both early (94.4% vs. 92.6%, p < 0.001) and late childhood (93.9% vs. 92.3%, p = 0.038). Early childhood LMA group showed lower complication rates (7.9% vs. 19.5%, p = 0.037) and fewer desaturation events (7.9% vs. 22.1%, p = 0.031). Although procedure duration was longer with LMA use (p < 0.001), it was associated with fewer interruptions and more stable oxygenation.

Conclusions

LMA provides superior oxygenation and fewer complications compared to mask ventilation during pediatric bronchoscopy, particularly in early childhood. Despite longer procedure times, the improved safety profile supports LMA as an effective airway management option for pediatric bronchoscopy.

Introduction

Pediatric flexible bronchoscopy is an essential diagnostic tool for evaluating upper and lower airways in children. The success of this procedure depends on effective airway management and has two primary preventing hypoxemia and maintaining an uninterrupted procedure [1, 2]. These dual objectives become even more critical in children with airway abnormalities. One of the unique challenges of the procedure is the requirement for the anesthesiologist and bronchoscopist to share the same anatomical space [2, 3]. The anesthesiologist must maintain adequate oxygenation while avoiding interference with the bronchoscopist's field of view. Consequently, conventional airway security methods such as endotracheal intubation cannot be utilized. What makes airway management even more complex in the pediatric population is their distinct physiological characteristics. The risk of oxygen desaturation during FOB is notably higher in pediatric populations, especially in young children, where the onset is more rapid than in adults [4, 5]. This physiological feature demands special attention in anesthetic management. Establishing the delicate balance between maintaining adequate anesthetic depth and preserving saturation levels presents a technical challenge.

Traditionally, airway management during fiberoptic bronchoscopy (FOB) has relied on face masks or endotracheal tubes. However, these methods have limitations in terms of practicality and potential for airway trauma. The Laryngeal Mask Airway (LMA), first introduced in 1983, offers a promising alternative [6]. Since its first use in FOB in 1989, LMA has gained acceptance as a safe and suitable tool for airway management during bronchoscopy in pediatric populations [6, 7]. Compared to endotracheal tubes, LMA provides a larger inner diameter, facilitating the use of larger bronchoscopes and auxiliary tools. It also offers advantages such as shared airway access, better maintenance of oxygen saturation, and reduced physical trauma [7]. Despite these advantages of LMA, experience with LMA use in pediatric bronchoscopy remains limited in the literature. Therefore, further studies evaluating the efficacy and safety of LMA in pediatric FOB are needed. This study aims to investigate airway management strategies in pediatric FOB by reviewing our institutional experience. Through a retrospective analysis of cases from our center over the past decade, we hope to better understand the effectiveness and safety of different airway management techniques, with a particular focus on oxygen saturation levels and complications. We believe our findings may contribute to the growing body of evidence regarding airway management approaches during pediatric bronchoscopy and could help inform clinical practice in this challenging area.

Materials and Methods

Study Design and Population

We conducted a retrospective analysis of clinical records for all pediatric patients who underwent FOB at our hospital between January 2014 and December 2023. The study was approved by the institutional ethics committee (IMU Ethics and Research Committee; 26.04.2024, Approval No: E‐10840098‐202.3.02‐2655). Due to the retrospective nature of the study, the requirement for informed consent was waived by the ethics committee, in accordance with national research ethics guidelines. The study included patients aged 1–12 years with a medical indication for bronchoscopy. The patients were stratified into two age groups (1–5 years and 5–12 years) based on developmental differences in airway anatomy and respiratory physiology. This age‐based stratification was chosen because younger children (1–5 years) typically have smaller airways, higher oxygen consumption, and lower functional residual capacity compared to older children (5–12 years), which may affect their response to different airway management techniques. Additionally, these age groups represent distinct developmental stages in terms of airway maturity and respiratory reserve. Regarding respiratory comorbidities, patients with well‐controlled asthma (ASA II) were included in the study. However, those with active bronchospasm or severe airway hyperreactivity requiring emergency intervention were excluded. Patients with documented severe reactive airway disease or those who had experienced bronchospasm within 48 h prior to the procedure were also excluded from the study population. Other exclusion criteria included ASA III or higher, intrinsic and idiopathic coagulopathy, known allergy to any of the study medications, severe hypoxemia due to severe cardiac disease, and incomplete medical records.

Data Collection

We extracted the following data from clinical follow‐up forms and the hospital information management system. The data encompassed a range of crucial factors, including patients' demographic details, their American Society of Anesthesiologists (ASA) physical status classification and the indications that led to the bronchoscopy procedure. Additionally, we collected detailed information about the anesthesia administered, the total anesthesia time, and any complications that occurred either during the operation or in the post‐operative period.

Patient Grouping

Patients were categorized into two groups based on the airway management technique used during FOB: Group Patients who underwent FOB with LMA.Group Patients who underwent FOB with standard mask ventilation.

Anesthesia and Bronchoscopy Procedure

All patients were examined by an anesthesiologist at least 24 h prior the procedure, and informed consent was obtained. A standardized fasting protocol was 6 h for solids and formula, 4 h for breast milk, and 2 h for clear liquids [8].

The bronchoscopy procedures were performed by pediatric pulmonologists with at least 5 years of experience in pediatric FOB. The standard anesthesia protocol included routine monitoring of peripheral oxygen saturation (SpO2), end‐tidal CO2, electrocardiography, heart rate, and non‐invasive blood pressure.

Premedication drugs were given in the form of midazolam 0.05 mg/kg (oral) approximately 30–45 min prior to anesthesia induction. Anesthesia was induced using sevoflurane and/or propofol (2 mg/kg), which was then further supplemented with intravenous (IV) fentanyl (1–2 µg/kg). After pre‐oxygenation, Group 1 patients received an appropriately sized LMA, while Group 2 patients continued with standard mask ventilation. For Group 1, a mouth catheter was connected between the LMA and breathing circuit. In both groups, a 3.8 mm fiberoptic bronchoscope was inserted, and local anesthetic (2% lidocaine) was sprayed topically on the vocal cords. Anesthesia was maintained with sevoflurane (1–2 minimum alveolar concentration [MAC]) and propofol boluses (0.5–1 mg/kg) as needed, titrated to maintain stable hemodynamics (heart rate and blood pressure within ±20% of baseline), with manual ventilation used to control anesthesia depth. Baseline arterial oxygen saturation (SpO2) together with hemodynamic parameters in the form of heart rate, systolic & diastolic blood pressure was recorded every 5 min throughout the procedure. Episodes of desaturation occurred during the procedure were managed in both groups by halting the procedure and assisting the ventilation till SpO2 returned to normal. Post‐procedure, the LMA was removed under deep anesthesia once spontaneous breathing resumed. All patients were closely monitored for at least 30 min, tracking vital signs and potential complications in the post‐anesthesia care unit (PACU).

Outcome Measures

The primary outcome measures of this study were oxygen saturation (SpO2) levels and desaturation events during airway management in pediatric patients, specifically analyzed according to the developmental stages of early childhood (1–5 years) and late childhood (5–12 years). SpO2 values were recorded and analyzed at three time points (preoperative, lowest intraoperative value, and postoperative) to account for age‐specific physiological differences. Desaturation events were categorized into two groups with age‐appropriate mild desaturation (SpO2 90%–92% lasting less than 1 min) and severe desaturation (SpO2 < 90% lasting more than 1 min or any episode requiring intervention) [4]. Due to the known differences in airway anatomy and respiratory physiology between age groups, with younger children having smaller airways, higher oxygen consumption, and lower functional residual capacity, we specifically analyzed the frequency and severity of desaturation events within each age group. Secondary outcome measures included total anesthesia time and the incidence of age‐specific respiratory complications (bronchospasm, laryngospasm, bleeding) which were evaluated considering the distinct developmental characteristics of each age group. These outcome measures were designed to assess both the procedural efficacy and safety profile of LMA and face mask use.

Statistical Analysis

The Statistical Package for the Social Sciences version 25 (SPSS IBM Corp., Armonk, NY, USA) program was used. Normality of distribution of the variables was checked by Shapiro‐Wilk test. Independent student t test was used for comparison of the normally distributed variable between the groups. Quantitative data are given as mean ± standard deviation values. Categorical variables were grouped and compared using the χ2 test or Fisher's exact test. SpO2 values measured at different times were compared with the repeated measures ANOVA test. The data were analyzed at a 95% confidence level, and a P‐value of less than 0.05 was accepted as statistically significant.

Results

Our study evaluated 212 pediatric patients undergoing flexible fiberoptic bronchoscopy (FOB) between January 2014 and December 2023. Patients were categorized into early childhood (1–5 years, n = 153) and late childhood (5–12 years, n = 59) groups, with comparable distribution between LMA and mask ventilation procedures. Demographic analysis revealed no significant differences between groups in either age category regarding age, gender distribution, weight, or height (all p > 0.05) (Table 1).

Primary indications for bronchoscopy varied between groups, with recurrent infection/persistent infiltration being most common across both age categories, followed by foreign body suspicion and stridor in early childhood. Corresponding bronchoscopic diagnoses showed bronchial purulent secretion as the predominant finding in both groups, with detailed distributions presented in Table 2.

Oxygen saturation analysis revealed similar pre‐procedure SpO2 levels between groups in both age categories. During procedures, the LMA group maintained significantly higher SpO2 levels in early childhood (94.4% ± 2.1% vs. 92.6% ± 3.5%, p < 0.001) and moderately higher levels in late childhood (93.9% ± 2.4% vs. 92.3% ± 3.3%, p = 0.038). Post‐procedure SpO2 levels showed no significant differences between groups in either age category (Table 3, Figures 1 and 2).

Desaturation events showed significant differences in early childhood (p = 0.031), with the LMA group demonstrating better higher rates of no desaturation (92.1% vs. 77.9%), and lower rates of both mild (6.6% vs. 13.0%) and severe desaturation (1.3% vs. 9.1%). In late childhood, although similar trends were observed, with LMA showing better outcomes (no 75.9% vs. 66.7%, 20.7% vs. 23.3%, 3.4% vs. 10.0%), these differences were not statistically significant (p = 0.561) (Table 3).

Complication analysis revealed significant differences in early childhood (p = 0.037), with lower overall rates in the LMA group (7.9%) compared to mask ventilation (19.5%), particularly in laryngospasm and bleeding events. In late childhood, complication rates showed no significant differences between groups (p = 0.590) (Table 4).

Total anesthesia time was significantly longer in LMA groups across both age categories (p < 0.001). In early childhood, LMA procedures averaged 118.3 ± 23.8 min compared to mask ventilation at 95.5 ± 32.5 min. Similarly, in late childhood, LMA procedures took 113.8 ± 20.2 min versus 82.0 ± 31.7 min for mask ventilation. Notably, LMA procedures demonstrated more consistent durations with smaller standard deviations in both age groups (Table 1).

Discussion

In this retrospective study comparing LMA and mask ventilation during pediatric flexible bronchoscopy, we analyzed outcomes from procedures performed at our institution over a decade. Our analysis investigates the efficacy and safety of LMA use during FOB, focusing on the impact of LMA on oxygen saturation (SpO2) and desaturation events.

Although no significant differences in patient demographics were observed between study groups, there were notable differences in procedure indication. These likely represent the retrospective nature of our study design. Primary indications included recurrent infections, foreign body suspicion, and stridor, with variations likely reflecting clinical decision‐making processes rather than systematic selection criteria.

Our analysis revealed modest but statistically significant differences in oxygenation outcomes across different age groups, with superior oxygen saturation maintenance seen with LMA use. In early childhood, the significantly higher SpO2 levels observed in the LMA group align with findings from previous studies [9, 10]. Interestingly, this advantage extends to late childhood with only moderate significance, suggesting age‐dependent variations in the effectiveness of airway management techniques.

The reduction in desaturation events observed in our study represents one of the key advantages of LMA use. In the literature, hypoxemia rates during bronchoscopy range widely, making our findings particularly noteworthy [4, 5, 6, 7, 8, 9, 10, 11, 12]. In early childhood, the vast majority of LMA cases were completed without desaturation events, demonstrating substantial improvement over mask ventilation. The dramatic reduction in severe desaturation events with LMA use represents a significant safety advantage. The decrease in mild desaturation events particularly enables uninterrupted and more efficient procedure completion, providing significant advantages in both patient safety and procedure quality. These findings, consistent with observations by Naguib et al. [9], strongly support LMA as an effective option for maintaining stable oxygenation during pediatric bronchoscopy.

The analysis of complications by age groups provides important findings. Several large‐scale studies conducted in different pediatric settings have demonstrated that flexible bronchoscopy can be safely performed with no procedure‐related mortality, even in children [13, 14, 15, 16]. In our study, the LMA group demonstrated significantly lower complication rates compared to mask ventilation, suggesting an enhanced safety profile. Notably, no cases of bronchospasm were observed in the LMA group compared to mask ventilation. Although the LMA group showed lower complication rates in late childhood, this difference did not reach statistical significance. The age‐dependent pattern of laryngospasm demonstrates that airway management technique effectiveness varies among age groups, aligning with Naguib et al.'s [9] observation that FOB with LMA is associated with lower complication rates. These findings indicate that LMA use provides safer airway management, particularly in early childhood, and that age‐specific factors play a crucial role in technique selection.

Total anesthesia time was significantly longer in the LMA group across both age categories, despite superior oxygenation, fewer desaturation events and lower complication rates. These findings likely reflect additional time needed for LMA insertion, waiting for adequate anesthesia depth before removal, and potentially more comprehensive examinations enabled by stable oxygenation [8, 10]. This trade‐off between procedure length and stability appears clinically acceptable, particularly given the reduced risk of procedure interruption due to desaturation.

Our reported anesthesia durations (90–120 min) exceed those typically reported at major pediatric centers, reflecting institutional factors including academic teaching environment requirements, comprehensive documentation protocols, and our specific LMA management approach requiring deep anesthesia for safe removal. While these institutional factors may limit the direct applicability of our duration‐related findings to centers with more streamlined protocols, the safety benefits regarding desaturation events and complications remain clinically relevant across different practice settings.

Our data demonstrated clear age‐dependent variations in the effectiveness of airway management techniques. The more pronounced benefits of LMA in early childhood suggest that age‐specific approaches to airway management during bronchoscopy may be warranted [9, 11]. This finding is particularly relevant given the higher baseline risk of respiratory complications in younger children [4, 12].

However, LMA use in diagnostic bronchoscopy has important limitations. The LMA may adversely affect upper airway evaluation and disrupt natural airway dynamics, potentially compromising diagnostic accuracy [12]. Therefore, oxygenation benefits must be balanced against diagnostic limitations, requiring individualized patient assessment rather than routine adoption.

Our findings demonstrate that LMA use in pediatric bronchoscopy provides clinically meaningful safety advantages through significant reductions in desaturation events and respiratory complications, particularly in early childhood. While procedure durations are extended, the improved oxygenation stability and reduced complication rates represent important clinical benefits. However, the decision to use LMA should be individualized, considering both the safety advantages and potential limitations in upper airway evaluation required for comprehensive diagnostic assessment. These results support LMA as a valuable option in the anesthesiologist's armamentarium for specific clinical scenarios where maintaining stable oxygenation is prioritized.

The main limitations of our study include being a single‐center experience, its retrospective design, and the lack of long‐term outcome evaluations. Future research recommendations include comparative studies between different LMA types, evaluation of long‐term outcomes, cost‐effectiveness analyses, and comparative studies in specific patient groups.

Author contributions

Yasar Gokhan Gul: methodology, conceptualization, investigation, data curation, resources. Sedat Oktem: investigation, validation, writing – review and editing, resources. Pelin Karaaslan: conceptualization, resources. Tumay Uludag Yanaral: conceptualization, investigation, writing – original draft, methodology, validation, visualization, writing – review and editing, software, formal analysis, project administration, data curation, supervision, resources.

Funding

The authors received no specific funding for this work.

Conflicts of Interest

The authors declare no conflicts of interest.