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: Patient Protocol

Immediately following Xe administration, 4 mL or approximately 40 mCi of 99mTc diethylene triamine penta-acetic acid (DTPA) was nebulized. Aerosolization of DTPA yields particle sizes of 1 to 5 |j,m, similar to nebulized medications, and is commonly used as a radiolabeled aerosol for determining regional pulmonary distribution. DTPA was nebulized (Pari LC Plus; Pari Respiratory Equipment; Richmond, VA) for 15 min. All nebulizations were performed with the compressor (Pulmo-Aide; DeVilbiss Health Care; Somerset, PA) to eliminate droplet size variability. This system generates aerosol particles with a mass-median aerodynamic diameter of < 5 |j,m with an operating pressure of 12 to 18 pounds per square inch and flow of 5 to 7 L/min. The nebulizer, generator, and collection system was designed to eliminate positive pressure and to simulate, as closely as possible, clinical administration of aerosolized medications used at home. Patients used a nose clip and a large mouthpiece, and were instructed on standard aerosol technique using slow, deep inhalations and normal exhalations. Esophageal and gastric deposition was minimized during DTPA administration by discouraging swallowing and rinsing immediately after the procedure. All images were obtained in the sitting position to reach a pixel count of one million by a large-field-of-view gamma camera fitted with a low-energy, all-purpose collimator.
All patients underwent spirometry measurement by registered respiratory therapists (RRTs) using standards approved by the American Thoracic Society immediately before undergoing the study protocol. In a randomized crossover fashion, patients were selected to receive either SCPT immediately prior to Xe and DTPA or to undergo HFCWO during Xe and DTPA administration. The study days were separated by at least 72 h to ensure adequate decay time for DTPA, and no more than 10 days to ensure stable pulmonary function. An RRT experienced in treating CF patients completed the SCPT arm of the study using a chest percussion protocol designed for CF patients at the University of Kansas Medical Center. The protocol utilized a clapping technique in a number of different positions, including sitting, lying flat, and laying in a head-down position on the right and left sides with the therapist clapping different areas of the chest wall. The total SCPT therapy took approximately 30 min to complete. HFCWO was administered by an RRT with specific training in its operation using a frequency setting of 13 Hz and a pressure setting of 6. Each HFCWO therapy was delivered for a total of 20 min.

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.