FEV1 and FVC for the control group (without noninvasive ventilation [NIV]), NIV with an inspiratory pressure (IPAP) of 15 cm H2O and expiratory pressure (EPAP) of 5 cm H2O, and NIV with an IPAP of 15 cm H2O and an EPAP of 10 cm H2O. FEV1 and FVC for the control group (without noninvasive ventilation [NIV]), NIV with an inspiratory pressure (IPAP) of 15 cm H2O and expiratory pressure (EPAP) of 5 cm H2O, and NIV with an IPAP of 15 cm H2O and an EPAP of 10 cm H2O. Data from Reference 21. Dean R Hess Respir Care 2015;60:880-893 (c) 2012 by Daedalus Enterprises, Inc.