Efeito do broncodilatador no tempo de apneia voluntária máxima em pacientes com distúrbios ventilatórios obstrutivos

Abstract

Objective: To identify the role of bronchodilators in the maximal breath-hold time in patients with obstructive lung disease (OLD). Methods: We conducted a case-control study including patients with OLD and a control group. Spirometric tests were performed prior to and after the use of a bronchodilator, as were breath-hold tests, using an electronic microprocessor and a pneumotachograph as a flow transducer. Respiratory flow curves were displayed in real time on a portable computer. The maximal breath-hold times at end-inspiratory volume and at end-expiratory volume (BHT max V EI and BHT max V EE , respectively) were determined from the acquired signal. Results: A total of 35 patients with OLD and 16 controls were included. Prior to the use of a bronchodilator, the BHT max V EI was significantly lower in the OLD group than in the control group (22.27 ± 11.81 s vs. 31.45 ± 15.73 s; p = 0.025), although there was no significant difference between the two groups in terms of the post-bronchodilator values (24.94 ± 12.89 s vs. 31.67 ± 17.53 s). In contrast, BHT max V EE values were significantly lower in the OLD group than in the control group, in the pre-and post-bronchodilator tests (16.88 ± 6.58 s vs. 22.09 ± 7.95 s; p = 0.017; and 21.22 ± 9.37 s vs. 28.53 ± 12.46 s; p = 0.024, respectively). Conclusions: Our results provide additional evidence of the clinical usefulness of the breath-hold test in the assessment of pulmonary function and add to the existing knowledge regarding the role of the bronchodilator in this test. Keywords:Respiratory function tests; Pulmonary disease, chronic obstructive; Bronchodilator agents; Apnea. ResumoObjetivo: Identificar o papel do broncodilatador no tempo de apneia voluntária máxima em pacientes com distúrbios ventilatórios obstrutivos (DVOs). Métodos: Estudo caso-controle incluindo pacientes com DVOs e grupo controle. Foram realizadas espirometrias antes e após o uso de broncodilatador, assim como testes de apneia respiratória, utilizando-se um microprocessador eletrônico e um pneumotacógrafo como transdutor de fluxo. As curvas de fluxo respiratório foram exibidas em tempo real em um computador portátil, e os tempos de apneia voluntária inspiratória e expiratória máximos (TAVIM e TAVEM, respectivamente) foram determinados a partir do sinal adquirido. Resultados: Um total de 35 pacientes com DVOs e 16 controles foram incluídos no estudo. O TAVIM sem o uso de broncodilatador foi significativamente menor no grupo DVO que no grupo controle (22,27 ± 11,81 s vs. 31,45 ± 15,73; p = 0,025), mas essa diferença não foi significativa após o uso de broncodilatador (24,94 ± 12,89 s vs. 31,67 ± 17,53 s). Os valores de TAVEM foram significativamente menores no grupo DVO que no grupo controle antes (16,88 ± 6,58 s vs. 22,09 ± 7,95 s; p = 0,017) e após o uso de broncodilatador (21,22 ± 9,37 s vs. 28,53 ± 12,46 s; p = 0,024). Conclusões: Estes resultados fornecem uma evidência adicional da utilidade clínica do teste de apneia na avaliação da função pulmonar e do papel do broncodilatador n...

Validation of a breath-holding test as a screening test for exercise-induced hypoxemia in chronic respiratory diseases

“…FVC has been shown to be a clinically useful variable associated with disease progression in ILDs, including IPF, 21,22 whereas correlations between baseline %FVC and other clinical variables, such as gas exchange, functional status, and dyspnoea, are generally weak. 21 Viecili et al reported that the breath-holding time in COPD patients was positively correlated with FVC and FEV 1 , 23 suggesting that the BHT is also useful for detecting potential lung impairments. However, the relationships between SpO 2 during the BHT and physiological parameters such as the 6MWT have not been studied.…”