The effectiveness, safety and tolerance/comfort of high-frequency chest wall oscillation (HFCWO) in prolonged mechanical ventilation patients remain unknown. This study aimed to test the hypothesis that HFCWO could produce greater clearance volume of sputum, greater improvement rates in serial changes in the chest X-ray (CXR), and greater weaning success rates after extubation in Prolonged Mechanical Ventilation (PMV) patients with intra-tracheal intubation.

For over 20 years, studies have attempted to examine the effectiveness, safety and tolerance/comfort of HFCWO in the management of surgical and non-surgical patients who had impaired bronchial secretion clearance, including those with neuromuscular disorders, chronic obstructive pulmonary disease, cystic fibrosis, and blunt thoracic trauma, or those hospitalized for critical cardiac/abdominal/thoracic surgery. However, these outcomes of HFCWO on PMV patients remain unknown.

This parallel-design, randomized controlled trial aimed to test the hypothesis that HFCWO could produce greater clearance volume of sputum, greater improvement rates in serial changes in the chest X-ray (CXR), and greater weaning success rates after extubation in PMV patients with intra-tracheal intubation. Moreover, the safety and tolerance/comfort of HFCWO in PMV patients after removal of endotracheal tubes were also evaluated.

Inclusion Criteria:

1. continuous intra-tracheal intubation and mechanical ventilator support for at least 21 days
2. age ≥20 year-old
3. having an acute or chronic pulmonary condition requiring secretion mobilization as judged by the physician
4. alert consciousness; completion of the Modified Borg Scale (MBS) and Hamilton Anxiety Scale (HAS)
5. scheduled extubation within 24 hours after enrollment
6. without any contraindication for HFCWO (i.e., recent spinal injuries which have not yet been stabilized and active hemorrhage with hemodynamic instability)

Exclusion Criteria:

1. those who had undergone tracheostomy