Blouet S, et al. - Experts tested the presumption that changing breathing pattern of COPD patients on noninvasive ventilation (NIV) could identify patients with severe acute exacerbation of COPD (AECOPD) prior to admission. A change in breathing patterns that predicts severe AECOPD could be identified by the data from NIV. For 2 consecutive days, results demonstrated an association of a respiratory rate outside the interquartile limit of the respiratory rate calculated over the 4 preceding days with an increased risk of severe AECOPD of 2.8.