High-frequency chest wall compressions: good for the patient? Good for the clinician?

Chest physiotherapy practice may vary across intensive care units, hospitals, and countries, including the techniques used and the professionals that deliver the intervention.1 There are also variations in methods of patient referral (if required), treatment goals, and selection of interventions.1–3 Chest physiotherapy goals may include the enhanced clearance of airway secretions, the optimization of gas exchange, and/or the re-expansion of collapsed lung.4 Recent recommendations for the management of retained airway secretions in the non-intubated critically-ill patient include interventions to increase lung volume and/or increase expiratory flow.1 Other methods may include manual-assisted cough, oral and/or nasopharyngeal suctioning, or assistive devices such as mechanical in-exsufflation.1 For the intubated and ventilated patient the use of body positioning or mobilization, manual and/or ventilator hyperinflation, and airway suctioning are recommended.1 Evidence supporting these recommendations has been based on limited randomized controlled trials, observational trials, non-randomized trials, or expert opinion.1,4 Manual techniques such as chest wall percussion and chest wall vibrations/compressions (when combined with positioning and breathing exercises, often termed conventional chest physiotherapy/physical therapy or CCPT) may also have a role to facilitate secretion clearance in the intubated and ventilated patient and in the patients with chronic respiratory disease such as cystic fibrosis.5–7 High-frequency chest wall compressions (HFCWC) is a novel mechanical method applied by a vibratory vest, which induces rapid air movement in and out of the lungs to induce mucolysis and mucus clearance.8 HFCWC has been advocated as a means to standardize the delivery of chest physiotherapy and eliminate of the need for therapist administered treatments.9 Clinkscale et al9 also state that, as “conventional chest physical therapy has been associated with various complications, including hypoxemia, arrhythmias, and increased intracranial hypertension, as well as carpal tunnel syndrome for the therapists or nurses providing the treatments,”2–4 this is further justification for a randomized controlled trial comparison with HFCWC. However, Gobba et al,10 in a review of the occupational health evidence, conclude that the “available data are insufficient for an adequate evaluation of the occupational risk related to repetitive movements in health workers,” unlike the suggestion from Clinkscale et al.9 Clinkscale et al9 undertook a single-center randomized controlled trial of respiratory therapist delivered CCPT (up to 4 times per day after bronchodilator therapy, including manual chest wall percussion and vibration in postural drainage positions, combined with deep breathing and coughing for a total session time of 15–20 min) versus HFCWC (up to 4 times per day after bronchodilator therapy, in the upright position for 15–30 min, with HFCWC applied for more than 15 min at frequency of 10–15 Hz, interspersed with huffing and coughing as required). There are insufficient details of the CCPT and HFCWC therapy provided to the intubated and mechanically ventilated patient. CCPT/HFCWC was discontinued at the discretion of the respiratory therapist, based on local guidelines for both atelectasis and cystic fibrosis/bronchiectasis. Detail is lacking on the numbers of patients ventilated, ventilation modes used during interventions, and the monitoring of patientventilator synchrony (especially during the delivery of HFCWC).