Bedside Spirometry, Dyspnea Severity and Inflammatory Markers for Predicting Noninvasive Ventilation Requirement in Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

OBJECTIVE: To evaluate the association of bedside spirometry, dyspnea severity, and inflammatory markers with noninvasive mechanical ventilation (NIMV) requirement in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). SUBJECTS AND METHODS: This prospective observational study included adults presenting to the emergency department (ED) with AECOPD. Bedside forced expiratory volume in one second (FEV₁% predicted) and peak expiratory flow (PEF% predicted) were measured before treatment. Dyspnea was assessed using the Visual Analog Scale (VAS). Neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, eosinophil-to-basophil ratio, arterial pH, and arterial partial pressure of carbon dioxide (PaCO₂) were obtained. Spirometry and VAS were repeated at three hours. The primary outcome was NIMV requirement during emergency department observation. Secondary outcomes included ICU admission. Mortality was analyzed descriptively because of limited events. RESULTS: Among 211 patients, 91 (43.1%) required NIMV. NIMV requirement was associated with lower baseline and third-hour FEV₁% and PEF% and higher VAS scores. Higher neutrophil-to-lymphocyte ratio and systemic immune-inflammation index were associated with ICU admission. Seven patients (3.3%) died within 30 days and had higher neutrophil-to-lymphocyte ratio and systemic immune-inflammation index values and lower eosinophil-to-basophil ratio. In multivariable analysis including arterial pH and PaCO₂, the PaCO₂ was found to be independently associated with NIMV requirement. CONCLUSIONS: Lower FEV₁% and PEF% values and greater dyspnea severity were associated with NIMV requirement, whereas inflammatory markers were associated with ICU admission and showed an association with 30-day mortality. Bedside spirometry may also provide complementary information alongside clinical assessment and arterial blood gas analysis in patients with AECOPD.