For the implementation of laryngeal ultrasound as a method to assess laryngeal movements in NIV users, feasibility and validity are required. This study investigated the feasibility and validity of laryngeal ultrasound in observing and characterizing laryngeal movements during ongoing NIV in healthy adult volunteers, compared to the findings with those obtained by TFL.
A cross-sectional study of thirty healthy awake participants (19 female) was conducted with an exploratory setup that included simultaneous video recording of TFL and laryngeal ultrasound during NIV treatment (S-mode, IPAP 20, EPAP 4). Laryngeal ultrasound was performed with three probe placements; anterior, right lateral and left lateral approach. The analyses focused on the last five breaths during NIV. Two blinded evaluators independently described and scored both TFL and laryngeal ultrasound recordings, and subsequent comparisons were made between their findings and reported as concordant/disconcordant rates. The participant's perception of the two evaluation methods was evaluated on an NRS scale of 0-10 (no discomfort-worst).
The laryngeal visualization rate was 99.1% for TFL compared to 81.7% for US. All participants were successfully assessed using laryngeal ultrasound with at least one probe placement. The overall concordance rate for the laryngeal responses to the NIV treatment was 84.6%; with 88.9% and 88.3% for movements of vocal folds and aryepiglottic folds, respectively. Discomfort was rated as zero on the NRS scale in 22/30 for laryngeal ultrasound, compared to 5/30 participants for TFL.
Laryngeal ultrasound proved to be a viable approach for characterizing laryngeal responses during NIV, exhibiting a strong concordance with TFL, and may offer valuable clinical information when applied in patients failing NIV due to suspected laryngeal closure.
Less invasive methods for monitoring laryngeal responses to treatments using positive airway pressures have not been reported previously. Laryngeal ultrasound has the potential to become a feasible and easily available method for physiotherapists to monitor laryngeal responses during NIV.
ultrasound
NIV