Pressurized Aerosol versus Jet Aerosol Delivery to Mechanically Ventilated Patients

Abstract

SUMMARY The purpose of this study was to compare deposition of aerosol to the lung from a metered-dose inhaler (MOl) and aerosol holding chamber and from a jet nebulizer in ventilator­ dependent patients. Twenty-one patients were entered into the study, all receiving assisted ventila­ tion and inhaled bronchodilators because of airflow limitation. The average age was 68 yr; there were 10 men and 11 women. The patients were randomized to receive either 4 puffs (800 J.1g) of radiolabeled fenoterol by MOl of 1.75 ml (1,750 J.1g) of radiolabeled fenoterol solution by nebulizer. Imaging of lung fields was made by a portable scintillation camera at 5-min intervals during the study. Results showed that 20 patients completed the study, 9 receiving fenoterol by MOl, and 11 by jet nebulizer. Fourwe~ excluded from analysis because of previous pneumonectomy, two from each group. Lung depositl'on measured as apercent of given dose from either system was 5.65 ± 1.09 (mean ± SEM) for MOl plus extension chamber and 1.22 ± 0.35 for jet nebulizer (p < 0.001).There­ fore, this trial shows significantly greater efficiency of aerosol deposition to the lung In ventilator­ dependent patients when using an MOl plus aerosol holding chamber than when using a jet neb­ ulizer. AM REV RESPIR DIS 1990; 141:440-444