Discussion on Comparison of Four Mechanical Insufflation-Exsufflation Devices: Effect of Simulated Airway Collapse on Cough Peak Flow

This is the authors' abstract. We don't add key points for this paper.

To the Editor: In their recent publication, Terzi et al1 compared the performance of 4 mechanical insufflation-exsufflation (MI-E) devices under 2 airway conditions: stable upper airway (without collapse) and collapsed upper airway simulated using a Starling resistor. The study focused on evaluating cough peak flow (CPF) and effective cough volume (defined as the volume expired or coughed at a rate > 180 L/s). Their investigation revealed significant performance disparities among the tested MI-E devices. Notably, some demonstrated exceptionally high expiratory flow values > 700 L/min, while others exhibited values < 180 L/min at maximal power. Based on our own experience, drawing from our expertise in this domain, our team was surprised by these findings. Consequently, we decided to replicate the authors' methods for a deeper understanding. Following Terzi et al1 methodology, we evaluated 3 MI-E devices currently approved for clinical use in France: the CoughAssist E70 (Philips Respironics, Murrysville, Pennsylvania), Comfort Cough II (WILAmed, Kammerstein, Germany), and EOVE-70 (Air Liquide Medical Systems, Antony, France). We were unable to include the … Correspondence: Marius Lebret PhD, Air Liquide Medical Systems, 6 rue Georges Besse, 92160 Antony, France. E-mail: mariuslebret{at}gmail.com