Project title

A Pilot Study Investigating the Effects of the Cleaning of Closed Suction Catheters on Lung Volume Loss using Electrical Impedance Tomography


Amanda Corley, Nicola Sharpe, Lawrence Caruana, Amy Spooner, John F Fraser


The preservation of lung volume and Positive End Expiratory Pressure (PEEP) is vital to maintain optimal gas exchange and prevent atelectasis in mechanically ventilated patients. Suctioning is an essential aspect of airway management in these patients to prevent airway obstruction, lung collapse, atelectasis and reduce work of breathing. Closed suction catheters are used widely in our Intensive Care facility and globally. After use, the suction catheter requires cleaning with sterile normal saline which is instilled into the ‘cleaning side port’ whilst suction is being applied. If there is no valve between the patient’s airway and the cleaning port when this cleaning is taking place, the patient may experience significant lung volume loss and lung collapse during cleaning

Research Plan

This study aimed to quantify lung volume loss in mechanically ventilated patients during the cleaning of closed suction catheters without a valve; and determine if using a closed suction catheter with a valve preserves lung volume and PEEP. Ten patients were studied and it was found that during cleaning of the suction catheter without a valve, significant lung volume was lost from the lung. We also determined that the presence of a valve between the patient’s airway and the cleaning port completely protects the lung from any volume loss during the cleaning procedure.


Since the completion of this study, we have changed our closed suction catheters in the ICU to those which preserve lung volume during catheter cleaning.


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.

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