@article {Mart{\'\i}respcare.10173, author = {Joan-Daniel Mart{\'\i} and Roberto Mart{\'\i}nez-Alejos and Xabier Pilar-Diaz and Hua Yang and Francesco Pagliara and Denise Battaglini and Andrea Meli and Milan Yang and Joaquim Bobi and Monsterrat Rigol and Oystein Tronstad and Marcia Souza Volpe and Marcelo Britto Passos Amato and Gianluigi Li Bassi and Antoni Torres}, title = {Effects of Mechanical Insufflation-Exsufflation With Different Pressure Settings on Respiratory Mucus Displacement During Invasive Ventilation}, elocation-id = {respcare.10173}, year = {2022}, doi = {10.4187/respcare.10173}, publisher = {Respiratory Care}, abstract = {BACKGROUND: Mechanical insufflation-exsufflation (MI-E) has been proposed as a potential strategy to generate high expiratory flows and simulate cough in the critically ill. However, efficacy and safety of MI-E during invasive mechanical ventilation are still to be fully elucidated. This study in intubated and mechanically ventilated pigs aimed to evaluate the effects of 8 combinations of insufflation-exsufflation pressures during MI-E on mucus displacement, respiratory flows, as well as respiratory mechanics and hemodynamics.METHODS: Six healthy Landrace-Large White female pigs were orotracheally intubated, anesthetized, and invasively ventilated for up to 72 h. Eight combinations of insufflation-exsufflation pressures (+40/-40, +40/-50, +40/-60, +40/-70, +50/-40, +50/-50, +50/-60, +50/-70 cm H2O) were applied in a randomized order. The MI-E device was set to automatic mode, medium inspiratory flow, and an inspiratory-expiratory time 3 and 2 s, respectively, with a 1-s pause between cycles. We performed 4 series of 5 insufflation-exsufflation cycles for each combination of pressures. Velocity and direction of movement of a mucus simulant containing radio-opaque markers were assessed through sequential lateral fluoroscopic images of the trachea. We also evaluated respiratory flows, respiratory mechanics, and hemodynamics before, during, and after each combination of pressures.RESULTS: In 3 of the animals, experiments were conducted twice; and for the remaining 3, they were conducted once. In comparison to baseline mucus movement (2.85 {\textpm} 2.06 mm/min), all insufflation-exsufflation pressure combinations significantly increased mucus velocity (P = .01). Particularly, +40/-70 cm H2O was the most effective combination, increasing mucus movement velocity by up to 4.8-fold (P \< .001). Insufflation pressure of +50 cm H2O resulted in higher peak inspiratory flows (P = .004) and inspiratory transpulmonary pressure (P \< .001) than +40 cm H2O.CONCLUSIONS: MI-E appeared to be an efficient strategy to improve mucus displacement during invasive ventilation, particularly when set at +40/-70 cm H2O. No safety concerns were identified although a transient significant increase of transpulmonary pressure was observed.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/early/2022/08/30/respcare.10173}, eprint = {https://rc.rcjournal.com/content/early/2022/08/30/respcare.10173.full.pdf}, journal = {Respiratory Care} }