Impact of Vocal Fold Dehydration on Vocal Function and Its Treatment.

Abstract

The change of vocal function after vocal fold dehydration due to dryness was discussed along with the treatment effect of different atomizing agents. Forty-eight staffs from The Central Hospital of Wuhan were recruited. All volunteers breathed dry air for vocal fold dehydration. After dry air inhalation, the subjects were randomly divided into four groups, with 12 cases each. Three groups were treatment groups, receiving 0.9% normal saline (IS), 5% hypertonic saline (HS) and double-distilled water (SW) atomizing inhalation therapy, respectively, and the last group was the control group without treatment. Voice data were collected for all subjects before and immediately after dry air inhalation using the Multi-Dimensional Voice Program (MDVP) system. Atomizing inhalation therapy was given 10 min after dry air inhalation, and voice data were collected using MDVP system at the following time points after atomizing inhalation treatment: 5 min, 20 min, 35 min, 50 min, 65 min, 80 min, 95 min, 110 min. In the control group, voice data were collected at the same time points and compared with those of treatment groups. The vocal function parameters collected before and after dry air inhalation as well as after treatment were subjected to test using SPSS 16.0 software. In the four groups, jitter (fundamental frequency perturbation), shimmer (amplitude perturbation), and amplitude perturbation quotient (APQ) were significantly increased after dry air inhalation (P<0.05). In IS, HS and SW groups, after atomizing inhalation treatment, there was an obvious reduction in jitter, shimmer and APQ, showing significant differences as compared with those after dry air inhalation (P<0.05). Moreover, these parameters were significantly lower than those in the control group (P<0.05). The jitter, shimmer and APQ in the IS group were significantly lower than those in the HS and SW groups (P<0.05). We are led to a conclusion: Vocal fold dehydration induced by dryness can reduce the stability of voice; such decreased voice stability can be improved by atomizing inhalation therapy; without proper treatment, voice stability caused by vocal fold dehydration cannot heal spontaneously; of three atomizing agents namely, IS, HS and SW, IS had the best treatment effect for decreased voice stability caused by vocal fold dehydration.