ABSTRACT
ABSTRACT Objective: To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. Methods: This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP); CPAP5 (CPAP at 5 cmH2O); and CPAP10 (CPAP at 10 cmH2O). We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expiratory flow rate (PEFR), and FEF25-75%) at three time points: pre-immersion; 10 min after immersion; and 10 min after the end of each protocol. Results: We evaluated 13 healthy volunteers. The CPAP10 protocol reversed the restrictive pattern of lung function induced by immersion in water, maintaining pulmonary volumes and capacities for a longer period than did the CPAP5 protocol. Conclusions: When the hemodynamic change causing a persistent lung disorder, only the application of higher positive pressures is effective in maintaining long-term improvements in the pulmonary profile.
RESUMO Objetivo: Verificar se continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas) em diferentes pressões melhora os volumes e capacidades pulmonares de sujeitos saudáveis em imersão em água. Métodos: Estudo clínico randomizado realizado entre abril e junho de 2016 com voluntárias saudáveis em uso de anticoncepcional oral. Foram aplicados três protocolos em imersão em água, todos com duração de 20 min: controle (sem aplicação de CPAP); CPAP5 (CPAP de 5 cmH2O); e CPAP10 (CPAP de 10 cmH2O). Avaliaram-se FC, SpO2, CVF, VEF1, relação VEF1/CVF em % do previsto, taxa de pico de fluxo expiratório e FEF25-75% em três momentos distintos: pré-imersão, 10 min após a imersão e 10 min após o final dos protocolos. Resultados: Foram avaliadas 13 voluntárias saudáveis. O protocolo CPAP10 foi capaz de reverter o padrão restritivo pulmonar induzido pela imersão em água em indivíduos saudáveis, mantendo normais os volumes e as capacidades pulmonares por um período mais prolongado quando comparado ao protocolo CPAP5. Conclusões: Nossos resultados indicam que, em condições cuja alteração hemodinâmica causadora do distúrbio pulmonar seja persistente, apenas a aplicação de pressões positivas mais elevadas é efetiva para manter as melhoras no quadro pulmonar por um maior tempo após a sua aplicação.
Subject(s)
Humans , Female , Adult , Young Adult , Peak Expiratory Flow Rate/physiology , Continuous Positive Airway Pressure , Immersion/physiopathology , Lung/physiopathology , Water , Body Mass Index , Physical Therapy ModalitiesABSTRACT
OBJECTIVE: To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. METHODS: This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP); CPAP5 (CPAP at 5 cmH2O); and CPAP10 (CPAP at 10 cmH2O). We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expiratory flow rate (PEFR), and FEF25-75%) at three time points: pre-immersion; 10 min after immersion; and 10 min after the end of each protocol. RESULTS: We evaluated 13 healthy volunteers. The CPAP10 protocol reversed the restrictive pattern of lung function induced by immersion in water, maintaining pulmonary volumes and capacities for a longer period than did the CPAP5 protocol. CONCLUSIONS: When the hemodynamic change causing a persistent lung disorder, only the application of higher positive pressures is effective in maintaining long-term improvements in the pulmonary profile.