Influence of change in lateral decubitus on pulmonary aerosol deposition

CONTEXTUALIZACAO: O decubito lateral apresenta as maiores mudancas em relacao a ventilacao pulmonar regional e e utilizado na rotina da fisioterapia respiratoria. OBJETIVOS: Avaliar a influencia do decubito lateral na deposicao pulmonar de radioaerossol durante a inalacao em individuos jovens e relacionar os efeitos desse decubito na rotina terapeutica. METODOS: Em estudo randomizado em duas fases, foram incluidos oito homens voluntarios saudaveis, com media de idade de 23,6±2,5 anos. Na primeira fase, inalou-se aerossol durante nove minutos no decubito lateral sorteado e, apos intervalo de cinco a sete dias, realizou-se a segunda fase. Para a cintilografia, inalou-se uma dose media de acido dietilnotriaminopentacetico marcado com tecnecio (DTPA - TC99m), com uma atividade radioativa em media de 25 milicuries (mCi). Ao final da inalacao, as imagens foram adquiridas em câmaras de cintilacao e analisadas por meio da divisao longitudinal e transversal dos pulmoes em regioes de interesse (ROI). Para analise estatistica, utilizou-se o teste t de Student pareado, considerando significativo p BACKGROUND: The lateral decubitus position leads to the greatest changes in regional pulmonary ventilation and is used in respiratory physical therapy routines. OBJECTIVES: To evaluate the influence of the lateral decubitus position on the pulmonary deposition of inhaled radioaerosol particles in young people and report the effects of the decubitus position on routine therapy. METHODS: Eight healthy male volunteers, mean age 23.6±2.5 years, were included in a randomized study in two phases. In the first phase, aerosol was inhaled for nine minutes in a randomly-selected lateral decubitus position and after an interval of 5 to 7 days, the second phase was conducted. Pulmonary scintigraphy was carried out by inhalation of 25 mCi of 99mTc-DTPA. Following inhalation, images were acquired with scintillation cameras and regions of interest (ROI) were investigated in the longitudinal and cross-sectional divisions of the lungs. Statistical analysis included a paired Student's t-test with a significance level of p