RT Journal Article SR Electronic T1 Effects of Mechanical Insufflation-Exsufflation With Different Pressure Settings on Respiratory Mucus Displacement During Invasive Ventilation JF Respiratory Care FD American Association for Respiratory Care SP 1508 OP 1516 DO 10.4187/respcare.10173 VO 67 IS 12 A1 Joan-Daniel Martí A1 Roberto Martínez-Alejos A1 Xabier Pilar-Diaz A1 Hua Yang A1 Francesco Pagliara A1 Denise Battaglini A1 Andrea Meli A1 Milan Yang A1 Joaquim Bobi A1 Monsterrat Rigol A1 Oystein Tronstad A1 Marcia Souza Volpe A1 Marcelo Britto Passos Amato A1 Gianluigi Li Bassi A1 Antoni Torres YR 2022 UL http://rc.rcjournal.com/content/67/12/1508.abstract AB 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 ± 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.