Efeito da nebulização nos parâmetros laríngeos: Videolaringoscopia Digital de alta velocidade

Abstract

ABSTRACT

Introduction: Laryngeal hydration is a common recommendation in clinical practice from medical doctors and speech therapists in order to maintain and improve vocal performance. Hydration occurs in two ways: internal hydration, also called systemic, which occurs after the ingestion of water or water with electrolytes and through the external hydration, also called superficial, obtained through the nebulization of water or saline and provides moisture at the epithelial surfaces of the vocal folds that are important to keep them functional and with good malleability. The level of laryngeal hydration modifies the viscosity of the superficial layer of mucous secretion and modifies the biomechanical and aerodynamic properties of the vocal folds with an impact on phonation. One of the forms of laryngeal image evaluation is high-speed videolaryngoscopy (HSV). It is an instrument that allows the evaluation of the mucondulatory movement of the vocal folds cycle by cycle, enabling the diagnosis of laryngeal changes, establishing image patterns such as videokymography (DKG) and obtaining quantitative data. Such data and images are useful for analysis and comparisons of interventions and treatments. Objective: To verify the effects of nebulization with 0.9% saline solution on the laryngeal parameters analyzed by digital videokymography (DKG) in women and men with or without laryngeal alteration submitted to HSV. Material and method: This is a clinical, comparative intra-subject study. 59 young adults, non-voice professionals, dysphonic and non-dysphonic were selected. Thirty of them were female and twenty-nine were male. The participants were submitted to HSV before and after nebulization with 0.9% saline solution for 10 minutes. The images obtained were analyzed by DKG, with pre and post nebulization analysis, at the anterior, middle and posterior thirds of the vocal folds. The parameters analyzed were: minimum opening (AbMin), maximum opening (AbMax), average opening (AbMed), dominant frequency of the variation in the opening of the right and left vocal folds (Freq-R and Freq-L), dominate amplitude of the variation of the opening of the right and left vocal folds (AmpAb-R and AmpAb-L) and percentage of vocal fold closure (Fech -%). Variables were analyzed by means of absolute and relative frequency distribution of categorical variables and measures of numerical synthesis of quantitative variables. Based on the analysis of the distribution of quantitative variables using the Kolmogorov-Smirnov test, the statistical test to be used in the comparison of the pre- and post-nebulization groups (Student's Paired T Test and Wilcoxon Test) was defined. The Intraclass Correlation Coefficient (ICC) was used in the PAST © program to assess the concordance of the videokymographic variables analyzed by two evaluators, obtaining moderate to excellent agreement. Results and discussion: Women without laryngeal alterations showed statistically significant more changes after nebulization, with a decrease in maximum opening, average opening, opening amplitude of the left vocal fold, opening amplitude of the right vocal fold and an increase in the percentage of closure in the anterior third of the vocal folds. These results indicate a decrease of the lateral excursion of vocal folds during phonation after superficial hydration. In women with laryngeal alterations, the parameters that changed after nebulization were the increased frequency of opening the left vocal fold and the right vocal fold in the topography at the posterior third. In men, nebulization did not change the studied variables in a statistically significant way, except for the amplitude of the right vocal fold in men with laryngeal alterations, at the analysis of the posterior third of the vocal folds. The digital videokymography obtained by high-speed videolaryngoscopy provided quantitative and objective data for the evaluation of laryngeal dynamics. Conclusion: After superficial hydration of the larynx through nebulization with saline solution, women without laryngeal alterations showed a decrease in vocal fold amplitude during phonation. Men without alterations did not show evidence of changes in laryngeal parameters after nebulization. The results of this research suggest that superficial hydration modifies the laryngeal dynamics differently between the sexes.