Effect of High-Frequency Chest Wall Oscillation on the Central and Peripheral Distribution of Aerosolized Diethylene Triamine Penta-acetic Acid as Compared to Standard Chest Physiotherapy in Cystic Fibrosis: Study

Furthermore, there is evidence that HFCWO removes secretions by generating differences between expiratory and inspiratory flow and velocity. Several studies have suggested that HFCWO is as effective as SCPT. In addition to the airway clearance effect, HFCWO has been shown to enhance nitrogen washout, suggesting that alveolar ventilation may be increased during HFCWO as well. so
More than 50 patients in our Adult Cystic Fibrosis Center use HFCWO as their primary means of ACT, Of these patients, we found that 80% began administering their aerosolized medications during vest treatments in order to simplify their regimen and save time. The majority of patients not using HFCWO use SCPT delivered by a home caregiver as their primary ACT. Patients using this therapy require sequential administration of airway clearance followed by certain aerosolized medications. Surveyed HFCWO patients reported that combining this therapy with aerosolized medications resulted in a 25 to 50% reduction in daily treatment time. Recognition of this practice in our patients raised concerns about the effect of HFCWO on pulmonary distribution of aerosolized medications.
Distribution of aerosols can be influenced by numerous factors, such as particle diameter and inertia, airway geometry, respiratory rate, and delivery system, thus impacting the overall effectiveness of drug delivery to the periphery of the lung. In CF patients with obstructive lung disease, bronchiectasis and mucus impaction result in flow limitation. This increases local turbulence and significantly increases central deposition. HFCWO increases inspiratory and expiratory flow rates and may exacerbate central deposition, leading to decreased clinical efficacy of aerosolized medications. In addition, the circumferential nature of the vest worn with HFCWO may limit inspiration and also add to central deposition. While one initial investigation found no effect of HFCWO on peripheral deposition in normal subjects, this has not been tested in patients with CF or other obstructive diseases. With patients frequently combining the use of aerosols with HFCWO, we sought to investigate whether there was a significant effect on distribution of aerosolized medications.

This entry was posted in Cystic Fibrosis and tagged aerosol, airway clearance, central to peripheral deposition ratio, chest physiotherapy, cystic fibrosis, high-frequency chest wall oscillation, pulmonary, Xe.