Coordination between respiration and swallowing during non-invasive positive pressure ventilation

Background and objective The purpose of this study was to test the hypothesis that the risk of silent aspiration is increased in non‐invasive positive pressure ventilation. Methods We analysed the coordination between respiration and swallowing, in 12 young volunteers and 10 elder volunteers, by simultaneously monitoring respiratory flow, laryngeal movement and swallowing sound in three different conditions: control, continuous positive airway pressure (CPAP), and bi‐level positive airway pressure (BiPAP). A step‐wise multiple regression analysis was performed with the occurrence rate of inspiration after swallows as the dependent variable and various correlated variables as the independent variables. Results In both subject groups, the occurrence rate of inspiration after swallow was greater with BiPAP compared with control and CPAP conditions. Repetitive saliva swallowing test count and swallow non‐inspiratory flow occurrence rate were extracted as predictor variables for risk of inspiration after swallows during BiPAP treatment. Conclusion We found that the occurrence rate of inspiration after swallow is increased with BiPAP use irrespective of age. The results suggest that swallow non‐inspiratory flow may trigger inspiratory support in the BiPAP mode, resulting in a risk of aspiration. We evaluated the coordination between respiration and swallowing during non‐invasive artificial ventilation in healthy subjects and found that the occurrence rate of inspiration after swallowing is increased while using BiPAP. The results suggest that SNIF may trigger inspiratory support during BiPAP treatment, increasing the risk of aspiration.