Purpose: Ultrasound can be used to non-invasively and rapidly examine airway conditions, but vocal cord visualization with the traditional approaches is poor. Our aim was to compare the accuracies of front-side transverse-axis ultrasound (FTU), lateral-side longitudinal-axis ultrasound (LLU), and the combination of both approaches for vocal cord movement disorder diagnoses (e.g., vocal cord paralysis or arytenoid cartilage dislocation).
Methods: We compared FTU, LLU, and the combination of both methods for patients in the intensive care unit (ICU). We used nasal fiber-optic endoscopy to confirm vocal cord injury.
Results: Among the 120 patients examined, 24 (20%) had vocal cord paralysis. The visualization rate of vocal cords for FTU was 71.7% (assessable, 86; non-assessable, 34), that for LLU was 88.3% (assessable, 106; non-assessable, 14), and that for the combined approach was 96.7% (assessable, 116; non-assessable, 4). The sensitivities and specificities were 58.3% (14/24) and 75% (72/96) for FTU, 91.7% (22/24) and 87.5% (84/96) for LLU, and 100% (24/24) and 95.8% (92/96) for the combined approach. Visualization rates for LLU were significantly higher than for FTU (P = 0.002); FTU + LLU rates were higher than those for FTU (P = 0.001). The difference between LLU and FTU + LLU was not statistically significant (P = 0.025).
Conclusion: LLU can be used to evaluate arytenoid cartilage activity in ICUs, and the results are highly correlated with the diagnosis of nasal fiber-optic endoscopy. The combination of FTU and LLU shows promise as a rapid primary screening method for vocal cord injury.
Keywords: Airway; Arytenoid cartilage movement; Lateral-side longitudinal-axis ultrasound.