Effects of positive expiratory pressure on pulmonary clearance of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid in healthy individuals

Abstract

Objective: To evaluate the effects of positive expiratory pressure (PEP) on pulmonary epithelial membrane permeability in healthy subjects. Methods: We evaluated a cohort of 30 healthy subjects (15 males and 15 females) with a mean age of 28.3 ± 5.4 years, a mean FEV 1 /FVC ratio of 0.89 ± 0.14, and a mean FEV 1 of 98.5 ± 13.1% of predicted. Subjects underwent technetium-99m-labeled diethylenetriaminepentaacetic acid ( 99m Tc-DTPA) radioaerosol inhalation lung scintigraphy in two stages: during spontaneous breathing; and while breathing through a PEP mask at one of three PEP levels-10 cmH 2 O (n = 10), 15 cmH 2 O (n = 10), and 20 cmH 2 O (n = 10). The 99mTc-DTPA was nebulized for 3 min, and its clearance was recorded by scintigraphy over a 30-min period during spontaneous breathing and over a 30-min period during breathing through a PEP mask. Results: The pulmonary clearance of 99m Tc-DTPA was significantly shorter when PEP was applied-at 10 cmH 2 O (p = 0.044), 15 cmH 2 O (p = 0.044), and 20 cmH 2 O (p = 0.004)-in comparison with that observed during spontaneous breathing. Conclusions: Our findings indicate that PEP, at the levels tested, is able to induce an increase in pulmonary epithelial membrane permeability and lung volume in healthy subjects.

Aerosolised micro and nanoparticle: formulation and delivery method for lung imaging

“…As seen in Table 3, nebulised 99m Tc-DTPA is mainly used to investigate the effect of particular pulmonary delivery equipment, e.g. positive expiratory pressure device, on the aerosol performance of lung deposition [97,[100][101][102][103][104][105]. Other studies with 99m Tc-DTPA focus on distinguishing different lung diseases [74,106,107], understanding the physiology of lung disease [108], and investigating the new application of ventilation scintigraphy [109].…”