RT Journal Article SR Electronic T1 Role of Diaphragm Ultrasound When NIV Fails in COPD Exacerbations JF Respiratory Care FD American Association for Respiratory Care SP 1600 OP 1602 DO 10.4187/respcare.07523 VO 64 IS 12 A1 Hameeda Shaikh A1 Franco Laghi YR 2019 UL http://rc.rcjournal.com/content/64/12/1600.abstract AB