%0 Journal Article %A Juçara Gasparetto Maccari %A Cassiano Teixeira %A Augusto Savi %A Roselaine Pinheiro de Oliveira %A André Sant’Ana Machado %A Tulio Frederico Tonietto %A Eduardo Ludwig %A Paulo José Zimermann Teixeira %A Marli Maria Knorst %T Nebulization during spontaneous breathing, CPAP and Bilevel: a randomized analysis of pulmonary radioaerosol deposition. %D 2013 %R 10.4187/respcare.02518 %J Respiratory Care %P respcare.02518 %X Rationale: There have been few reports of factors affecting aerosol delivery during noninvasive ventilation (NIV). Nebulization is a standard practice and our objective was to determine the effect of spontaneous breathing and NIV mode on 99m-Technetium (Tc) lung deposition in subjects with normal lung. Methods: Thirteen healthcare volunteers were submitted to a randomized radioaerosol nebulization with 99m-Tc during spontaneous breathing (SB), continuous positive airway pressure — CPAP (10 cmH2O) and bilevel positive pressure ventilation — Bilevel (Inspiratory/Expiratory pressures of 15/5 cmH2O). NIV was performed by a ResMed VPAP II ST-A. The radioaerosol deposition was evaluated by pulmonary scintigraphy after 10 minutes of inhalation. Regions of interest (ROI) were outlined on left lung (LL) and right lung (RL) and trachea (TRQ). The average number of counts per pixel in each ROI was determined and the ratio of lung and trachea was calculated. Measurements and Main Results: The three techniques showed comparable lung deposition. Analysis of radioaerosol deposition in the lungs showed a mean count at RL of 108.7±40 with CPAP, 111.5±15 with Bilevel, and 196.6±167 with SB. At LL, the finding values were 92.7±15 with CPAP, 98.4±14 with Bilevel and 225.0±293 with SB. There was no difference between the means of radioaerosol deposition in the RL, LL or TRQ, as well as the lung calculated ratio [LCR = (RL + LL) / TRQ], which was similar comparing ventilatory strategies. Conclusions: Based on our data, there is an equivalent deposition of inhaled substances in individuals with healthy lungs, when spontaneous breathing, CPAP and Bilevel are compared. %U https://rc.rcjournal.com/content/respcare/early/2013/09/03/respcare.02518.full.pdf