title: Respiratory mechanics in COPD patients who failed non-invasive ventilation: role of intrinsic PEEP.
abstract: Non-invasive positive pressure ventilation (NPPV) is the first choice to treat exacerbations in COPD patients. NPPV can fail owing to different causes related to gas exchange impairment (RF group) or intolerance (INT group). To assess if the respiratory mechanical properties and the ratio between the dynamic and static intrinsic positive end-expiratory pressure (PEEP(i),dyn/PEEP(i),stat), reflecting lung mechanical inequalities, were different between groups, 29 COPD patients who failed NPPV (15 RF and 14 INT) were studied, early after the application of invasive ventilation. Blood gas analysis, clinical status, and mechanical properties were measured. pH was higher in INT patients before intubation (p<0.001). PEEP(i),dyn/PEEP(i),stat was found higher in INT group with (p=0.021) and without PEEP (ZEEP, p<0.01). PEEP(i),dyn/PEEP(i),stat was exponentially associated with the duration of NPPV in INT group (p=0.011). INT and RF patients had similar impairment of respiratory system resistance and elastance.
authors.affiliation: Department of Anesthesia and Intensive Care, Laboratory of Respiratory Biomechanics, University of Trieste, Cattinara Hospital, Trieste, Italy. v.antonaglia@libero.it
authors.forename: Vittorio
authors.initials: V
authors.lastname: Antonaglia
authors.forename: Massimo
authors.initials: M
authors.lastname: Ferluga
authors.forename: Guido
authors.initials: G
authors.lastname: Capitanio
authors.forename: Umberto
authors.initials: U
authors.lastname: Lucangelo
authors.forename: Fulvia
authors.initials: F
authors.lastname: Piller
authors.forename: Erik
authors.initials: E
authors.lastname: Roman-Pognuz
authors.forename: Bruno
authors.initials: B
authors.lastname: Biancardi
authors.forename: Giuseppe Davide
authors.initials: GD
authors.lastname: Caggegi
authors.forename: Walter A
authors.initials: WA
authors.lastname: Zin
mesh_terms: D000368:Aged; D006801:Humans; D063087:Noninvasive Ventilation; D011175:Positive-Pressure Respiration; D018467:Positive-Pressure Respiration, Intrinsic / Q000503:physiopathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000628:therapy; D012143:Respiratory Physiological Phenomena