TY - JOUR T1 - Lung volume changes during cleaning of closed endotracheal suction catheters: a randomised crossover study using electrical impedance tomography. JF - Respiratory Care DO - 10.4187/respcare.02601 SP - respcare.02601 AU - Amanda Corley AU - Nicola Sharpe AU - Lawrence R Caruana AU - Amy J Spooner AU - John F Fraser Y1 - 2013/09/17 UR - http://rc.rcjournal.com/content/early/2013/09/17/respcare.02601.abstract N2 - Background Airway suctioning in mechanically ventilated patients is required to maintain airway patency. Closed suction catheters (CSC) minimise lung volume loss during suctioning but require cleaning post-suction. Despite their widespread use, there is no published evidence examining lung volumes during CSC cleaning. The study objectives were to quantify lung volume changes during CSC cleaning; and to determine if these changes were preventable using a CSC with a valve insitu between the airway and catheter-cleaning chamber. Methods This prospective randomised crossover study was conducted in a metropolitan tertiary intensive care unit. Ten patients mechanically ventilated with Synchronised Intermittent Mandatory Ventilation — volume control (SIMV-VC) and requiring manual hyperinflation (MHI) were included in this study. CSC cleaning was performed using two different brands of CSC (one with a valve [Ballard Trach Care-72™, Kimberly-Clark] and one without [Portex® Steri-Cath® DL, Smiths Medical]). The manoeuvres were performed in both SIMV-VC and MHI. Lung volume change was measured via impedance change using electrical impedance tomography (EIT). A mixed model was used to compare the estimated means. Results During cleaning of the valveless CSC, significant decreases in lung impedance occurred during MHI (-2563 impedance units; 95%CI 2213, 2913; p<0.001) and significant increases in lung impedance occurred during SIMV (762; 95%CI 452, 1072; p<0.001). In contrast, cleaning of the CSC with a valve insitu resulted in non-significant lung volume changes, and maintenance of normal ventilation during MHI and SIMV-VC respectively (188, 95%CI -136, 511, p=0.22; and 22, 95%CI - 342, 299, p=0.89). Conclusions When there is no valve between the airway and suction catheter, cleaning of the CSC results in significant derangements in lung volume. Therefore, the presence of such a valve should be considered essential in preserving lung volumes and uninterrupted ventilation in mechanically ventilated patients. ER -