Predictors of Suboptimal Peak Inspiratory Flow in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease in Clinical Practice.

Background: Incorrect inhalation technique is a primary cause of therapeutic failure in chronic obstructive pulmonary disease (COPD), leading to increased exacerbation frequency. Identifying predictors of suboptimal peak inspiratory flow (sPIF) can significantly enhance treatment efficacy in COPD patients. The objective of this study was to identify the prevalence and predictors of sPIF in hospitalized patients with acute exacerbation of COPD in a clinical setting.

Methods: This study enrolled 72 patients hospitalized for acute COPD exacerbation. It analyzed demographic, clinical, and lung function parameters. Peak inspiratory flow (PIF) was measured using an In-Check DIAL G16 (Alliance Tech Medical) across different resistance levels of the patients' inhalation devices, both before and after instruction in inhalation technique, and at various resistance settings (R2 and R5) upon admission and discharge.

Results: Initially, 52.7% of patients exhibited sPIF, which decreased to 19.4% following inhalation technique education (p<0.0001). Receiver operating curve analysis identified age >70 years, forced vital capacity <73% predicted (pred.), forced expiratory volume in 1 second (FEV1) <35% pred., residual volume (RV) >194% pred., RV/total lung capacity >70%, and diffusing capacity for carbon monoxide <36% pred. as independent predictors of sPIF. The most significant predictors were age (odds ratio [OR], 0.89) and FEV1 (OR 0.59).

Conclusion: Selecting a suitable dry powder inhaler for maintenance therapy in patients with acute exacerbation of COPD requires consideration of the patient's ability to achieve optimal PIF, with special attention to age and severity of functional impairment.