Observed laryngeal responses during non-invasive ventilation in healthy volunteers

<bold>Background:</bold> Non-invasive ventilation (NIV) is a vital method for managing respiratory failure. The larynx may resemble a malfunctioning valve and obstruct free airflow. While transnasal fiberoptic laryngoscopy (TFL) effectively observes the laryngeal responses, less invasive techniques would be preferable. Laryngeal point of care ultrasound (L-POCUS) emerges as a potential alternative. Prior to integrating L-POCUS into the assessment of NIV-dependent patients, it is imperative to investigate the feasibility of this method. <bold>Aims:</bold> To evaluate the viability of L-POCUS for monitoring and characterizing laryngeal responses during NIV, and to compare with those acquired through TFL. <bold>Method:</bold> In this cross-sectional investigation, thirty healthy participants (19 female) participated in concurrent video-recorded TFL and L-POCUS during NIV treatment (S-mode, IPAP 20, EPAP 4). L-POCUS was performed thrice using anterior, right and left approaches, and the analyses focused on the last five breaths. Two blinded evaluators independently described and scored both TFL and L-POCUS recordings, subsequently comparisons were made between their findings. Interrater-reliability was assessed for the last ten recordings. <bold>Results:</bold> All participants were successfully assessed using the L-POCUS approaches. The visualization rate was 99.1% for TFL compared to 81.7% for L-POCUS. The overall concordance rate for the laryngeal responses was 84.6%; with 88.9% and 88.3% for movements of vocal folds and aryepiglottic folds, respectively. Interrater reliability showed substantial agreement. <bold>Conclusion:</bold> L-POCUS proved to be a viable approach for characterizing laryngeal responses during NIV, exhibiting a strong concordance with TFL.