Correlação entre a capacidade vital lenta e o tempo máximo de fonação em adultos saudáveis

Can We Use the Maximum Phonation Time as a Screening of Pulmonary Forced Vital Capacity in Post-COVID-19 Syndrome Patients?

OBJECTIVE

To verify the accuracy of the maximum phonation time of the vowel /a/ (MPT/a/), fricative /s/ (MPT/s/), number counting (MPTC), and number reached in this count (CN) to estimate forced vital capacity (FVC) in patients with post-COVID-19 syndrome.

METHOD

Cross-sectional study involving adult patients, who were admitted to the intensive care unit and referred to the Post-COVID-19 Rehabilitation Outpatient Clinic. Voice function was assessed using a Vocal Handicap Index (VHI) self-assessment questionnaire and MPT tests. To perform the phonatory tests, the patients remained in a standing posture and were instructed to inhale as much air as possible and, during a single exhalation, at usual pitch and loudness, sustain the emission of /a/ and /s/; and in another breath, to perform the ascending numerical count, starting from the number one up to the highest number they could reach. Pulmonary function was assessed by spirometry. The receiver operating characteristic (ROC) curve was plotted, and FVC values lower than the normal limit by Z-score (fifth percentile) were classified as impaired lung function. The predictive values and likelihood ratios were calculated.

RESULTS

A total of 70 patients participated, with 20-30% having a high VHI. Approximately 24% had an FVC impairment and significantly low values of MPT/a/, MPT/s/, MPTC, and CN. The test results showed overall accuracy of 70% and the cutoff points of 9.69, 6.78, 10.60, and 13, respectively, with high sensitivity, predictive negative value and low specificity, predictive positive value, and positive likelihood ratio.

CONCLUSIONS

Our results suggest that the MPT has moderate discriminatory power for FVC impairment, indicating that it is not a reliable indicator of pulmonary function in the population studied. Therefore, in patients with an MPT of less than 10.60 seconds, or a CN lower than 13, other criteria should be added to improve the diagnostic accuracy and support the decision to perform more complex investigations.

Maximum Phonation Times as Biomarkers of Lung Function

PURPOSE

To verify whether measurements of maximal phonation times are biomarkers of forced vital capacity in patients with chronic obstructive pulmonary disease, and to characterize the vocal aspects of these patients, taking into account variables, such as age, body mass index, use of bronchodilators, presence of symptoms, and quality of life related to voice.

METHODS

Complete records of 25 subjects with chronic obstructive pulmonary disease, both sexes, aged 31 to 85 years, evaluated by forced vital capacity, maximum phonation times of /a/, and numerical count and number reached at this count, Vocal Symptom Scale, Voice Quality of Life. Data were presented descriptively and statistically analyzed using Student's t test for independent samples and Mann-Whitney U test. A significance level of 5% was accepted. The receiver operating characteristic curve was plotted and the standardized value of forced vital capacity <80% was considered as an indicator of pulmonary dysfunction.

RESULTS

Patients exhibited reduced maximum phonation times for /a/, numeric counting, and reached digits in counting; discrepancies in Vocal Signs and Symptoms and Voice Quality of Life Scale scores. Numeric counting times of up to 12.5 seconds indicated that forced vital capacity may be impaired.

CONCLUSION

The patients with chronic obstructive pulmonary disease examined in this study exhibited vocal deviations as evidenced by reduced maximum phonation times of /a/, numeric counting, and the digit reached during counting, as well as deviations in vocal self-assessment. Maximum phonation time in numerical counting was considered a biomarker of pulmonary function impairment.

Single breath counting technique to assess pulmonary function: a systematic review and meta-analysis

Pulmonary function is usually assessed by measuring Vital Capacity (VC) using equipment such as a spirometer or ventilometer, but these are not always available to the population, as they are relatively expensive tests, difficult to transport and require trained professionals. However, the single breath counting technique (SBCT) appears as a possible alternative to respiratory function tests, to help in the pathophysiological understanding of lung diseases. The objective is to verify the applicability of the SBCT as a parameter for evaluating VC. This is a systematic review registered in the International Prospective Register of Systematic Reviews (CRD42023383706) and used for PubMed®, Scientific Electronic Library Online, LILACS, EMBASE, and Web of Science databases of articles published until January 2023. Methodological quality regarding the risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 and National Institutes of Health tools. Eleven of a total of 574 studies were included, of these, nine showed a correlation between VC and SBCT (weak in healthy, moderate in neuromuscular and strong in hospitalized patients). One study of hospitalized patients accurately identified a count value of 21 for a VC of 20 ml kg-1(Sensitivity = 94% and Specificity = 77%), and another estimated a count lower than 41 for a VC below 80% of predicted in patients with neuromuscular dystrophy (Sensitivity = 89% and Specificity = 62%), and another showed good intra and inter-examiner reproducibility in young, adult, and elderly populations. A meta-analysis of three studies showed a moderate correlation in subjects with neuromuscular diseases (r= 0.62, 95% CI = 0.52-0.71,p< 0.01). A high risk of bias was identified regarding the justification of the sample size and blinding of the evaluators. SBCT has been presented as an alternative to assess VC in the absence of specific equipment. There is a clear relationship between SBCT and VC, especially in neuromuscular and hospitalized individuals. New validation studies conducted with greater control of potential bias risks are necessary.

Estimation of forced vital capacity using speech acoustics in patients with ALS

In this study, we present and provide validation data for a tool that predicts forced vital capacity (FVC) from speech acoustics collected remotely via a mobile app without the need for any additional equipment (e.g. a spirometer). We trained a machine learning model on a sample of healthy participants and participants with amyotrophic lateral sclerosis (ALS) to learn a mapping from speech acoustics to FVC and used this model to predict FVC values in a new sample from a different study of participants with ALS. We further evaluated the cross-sectional accuracy of the model and its sensitivity to within-subject change in FVC. We found that the predicted and observed FVC values in the test sample had a correlation coefficient of .80 and mean absolute error between .54 L and .58 L (18.5% to 19.5%). In addition, we found that the model was able to detect longitudinal decline in FVC in the test sample, although to a lesser extent than the observed FVC values measured using a spirometer, and was highly repeatable (ICC = 0.92-0.94), although to a lesser extent than the actual FVC (ICC = .97). These results suggest that sustained phonation may be a useful surrogate for VC in both research and clinical environments.

Perceptual and acoustic evaluation of speech production in Down syndrome: A case series

People with Down syndrome (DS) can experience difficulties with speech production that can impact on speech intelligibility. In previous research, both perceptual and acoustic analysis has shown that people with DS can have difficulties with speech production in the areas of respiration, phonation, articulation, resonance and prosody. However, these studies have investigated various aspects of speech production separately. No study has examined all components of speech production in one single study and considered how these components, if impaired, may impact on speech intelligibility in DS. This paper presents the data of three male speakers with DS and three age- and gender-matched controls as a case series. The participants' speech samples were analysed using a number of perceptual and acoustic parameters, across the major components of speech production - respiration, phonation, articulation, resonance, and prosody. Results showed that different areas of speech production were affected in each participant, to different extents. The main perceptual difficulties included poor voice quality, monopitch, and monoloudness. Acoustic findings showed a higher mean F0, lower harmonics-to-noise ratio and longer voice onset times. These preliminary findings show that people with DS can present with mixed profiles of speech production that can affect speech intelligibility. When assessing speech production in DS, clinicians need to evaluate all components of speech production and consider how they may be impacting intelligibility.

Correlação entre a capacidade vital lenta e o tempo máximo de fonação em idosos

RESUMO Objetivos: verificar a relação existente entre a capacidade vital lenta e o tempo máximo de fonação em idosos. Método: o estudo foi do tipo analítico e observacional, de corte transversal, realizado na Universidade aberta a Terceira Idade na instituição de origem, no período de junho a outubro de 2014. Participaram 61 idosos do sexo feminino, não tabagistas. Foram excluídos portadores de Doença Pulmonar Obstrutiva Crônica e/ou doenças respiratórias, indivíduos com problemas neurológicos ou de audição e profissionais da voz. Todos os participantes foram avaliados quanto à capacidade vital lenta e tempo máximo de fonação. Foram coletados ainda os seguintes dados: sexo, peso, estatura, idade e índice de massa corpórea. Resultados: os dados demonstram que os valores de capacidade vital lenta e tempo máximo de fonação estão reduzidos na terceira idade. Além disso, existe uma correlação positiva entre a capacidade vital lenta e o tempo máximo de fonação do /s/ e /z/ no sexo feminino. Conclusões: com o envelhecimento, medidas de respiração e voz podem estar reduzidas. Além disso, existe uma associação entre a capacidade vital lenta e o tempo máximo de fonação em mulheres idosas, sugerindo a influência que a respiração exerce sobre a fonação nesta população específica.