Bedside Spirometry, Dyspnea Severity, and Inflammatory Markers for Predicting Noninvasive Ventilation Requirement in...

The objective of this study was 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).

This prospective observational study included adults presenting to the emergency department (ED) with AECOPD. Bedside forced expiratory volume in 1 s (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 (NLR), systemic immune-inflammation (SII) index, eosinophil-to-basophil ratio (EBR), arterial pH, and arterial partial pressure of carbon dioxide (PaCO₂) were obtained. Spirometry and VAS were repeated at 3 h. The primary outcome was NIMV requirement during ED observation. Secondary outcomes included intensive care unit (ICU) admission. Mortality was analyzed descriptively because of limited events.

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 NLR and SII index were associated with ICU admission. Seven (3.3%) patients died within 30 days and had higher NLR and SII index values and lower EBR. In multivariable analysis including arterial pH and PaCO₂, the PaCO₂ was found to be independently associated with NIMV requirement.

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.