Project title

A comparison of the effects of manual hyperinflation and ventilator hyperinflation on restoring end-expiratory lung volume after airway suctioning


Amanda Corley, Oystein Tronstad, Lawrence Caruana, Amy Spooner, Matthew Linnane & John Fraser


Over 75% of patients admitted to The Prince Charles Hospital ICU require mechanical ventilation. Endotracheal suctioning is an essential procedure carried out to maintain airway patency and remove secretions in mechanically ventilated patients; however, endotracheal suctioning is associated with significant alveolar collapse and lung-de-recruitment. In our recent study, we assessed the effects of suctioning on end-expiratory lung volume and found that even 30 minutes after suctioning, significant lung de-recruitment persists.

Re-recruitment of the lung can be achieved by manual hyperinflation (MHI) or ventilator hyperinflation (VHI) and these techniques are commonly used in the critical care setting. Recent studies have found that VHI is at least as effective as MHI in the areas of maintaining oxygenation, facilitating sputum clearance and improving lung compliance, however, no studies have investigated the efficacy of either MHI or VHI in restoring lung recruitment following suctioning. Therefore, there is a significant gap in the evidence in this area which must be addressed before we can establish which method is the safest and most effective way to restore lung volume in mechanically ventilated patients post suctioning.

Electrical impedance tomography (EIT) is a relatively new, non-invasive, radiation-free imaging technique that can be used easily and safely at the bedside to provide real-time dynamic images of regional lung ventilation. By using EIT in this study, we can accurately assess end expiratory lung impedance (EELI) and determine which recruitment method is most effective in restoring lung volumes in mechanically ventilated patients after suctioning.

Research Plan

This study aims to determine which method of hyperinflation (MHI or VHI) post suctioning restores end-expiratory lung volume most effectively; and the effects of MHI and VHI on oxygenation and lung compliance.


Corley A, Sharpe N, Caruana LR, Spooner AJ, Fraser JF. Lung volume changes during cleaning of closed endotracheal suction catheters: a randomised crossover study using electrical impedance tomography. Respir Care. 2014 Apr;59(4):497-503. doi: 10.4187/respcare.02601.

Figure 1