Effects of Manual Rib Cage Compressions on Expiratory Flow and Mucus Clearance During Mechanical Ventilation*

Abstract

Hard manual rib cage compression improved mucus clearance in animals positioned in the anti-Trendelenburg position. The technique appeared to be safe. Conversely, soft manual rib cage compression was not effective and potentially unsafe. These findings corroborate the predominant role of peak expiratory flow on mucus clearance.

Expiratory Rib Cage Compression in Mechanically Ventilated Subjects: A Randomized Crossover Trial

“…3 Our study showed that ERCC improves expiratory flow but has little effect on secretion removal and respiratory mechanics in mechanically ventilated patients with pulmonary infection. These results are in agreement with previous studies that found no benefits with ERCC in animal models [8][9][10] and in mechanically ventilated patients. 4,12 …”

“…4 The use of this mechanical variable made the interpretation of respiratory mechanics difficult because this parameter is influenced not only by the elastic properties of the respiratory system (which depend on the recruitment or de-recruitment of lung periphery), but also by its resistive and inhomogeneous components (which depend on other factors, such as the patterns of secretion distribution in the airways). 17 Nevertheless, these authors also postulated that ERCC can cause any degree of pulmonary collapse, which is in agreement with the study of Martí et al, 10 who found a reduction in C st after ERCC in an animal model. In our study, C st and C eff did not change immediately after ERCC, but presented a small increase after a hyperinflation maneuver compared with CTRL.…”

“…6,7 Previous animal studies showed no beneficial effects of ERCC on respiratory mechanics and gas exchange. [8][9][10] Moreover, Unoki et al 9 postulated that the airway and alveolar collapse may be exacerbated, which agrees with the results of Martí et al, 10 who found a reduction in static compliance after applying the maneuver in an animal model. These authors also found an increase in mucus clearance with "hard expiratory rib cage compression" (brief and strong bilateral compressions); however, this was not observed in critical care patients, as reported by Unoki et al 4 Although there is no clear evidence for the physiological or airway clearance benefits of ERCC in humans, Berti et al 11 found a positive effect on the duration of mechanical ventilation, as well as on the ICU discharge rate and Murray score when using ERCC along with manual hyperinflation.…”

“…10,20,30,31 According to these studies, transitory bronchial constriction, variable secretion distribution patterns in patients' airways, mucociliary activity, and individualized response to the applied intervention could explain the unchanged respiratory resistance observed after the use of airway clearance techniques. Moreover, because of the greatest contribution of the central and intermediate airways to respiratory system resistance, if the secretions displace from the periphery to more proximal airways (but are not completely removed by suctioning), there will be an increase in these resistance parameters.…”

Expiratory Rib Cage Compressions to Improve Secretion Clearance During Mechanical Ventilation: Not Only a Matter of Squeezing the Chest—Reply

“…The first, also called directed cough or manually assisted cough, consists of "assisting the cough effort with abdominal or thoracic compression during exhalation" 4 and has been indicated to improve the peak expiratory flow in patients with weak cough. 8,9 Because the hard manual rib cage compressions in the study by Martí et al 3 were applied only in the early expiratory phase, we question whether it can be compared with a directed cough maneuver or an exogenous cough.…”