Predictors of suboptimal peak inspiratory flow in patients with acute exacerbation of chronic obstructive pulmonary disease in real clinical practice.

Background: Incorrect inhalation technique is one of the most common reasons for the ineffectiveness of Chronic Obstructive Pulmonary Disease (COPD) therapy, increasing the frequency of exacerbations. Selection of treatment based on Peak Inspiratory Flow (PIF) measurements or predictors of suboptimal PIF (sPIF) could optimize therapy in patients with COPD. The goal of this study was to investigate a prevalence and predictors of sPIF in hospitalized patients with acute exacerbation of COPD in clinical practice.

Methods: The study involved 72 patients hospitalized with acute COPD exacerbation. The analysis included demographic, clinical and lung function parameters. PIF was measured at the resistance level of patients' inhalation device using In-Check DIAL G16 before and after explaining the inhalation technique, as well as at medium-low resistance (R2) and high resistance (R5) at admission and on discharge.

Results: Upon admission and before explaining the inhalation technique, sPIF was observed in 52.7% of patients, while after the explanation, the proportion of patients with sPIF decreased to 19.4% (p < 0.0001). ROC analysis revealed that independent predictors of suboptimal PIF were age >70 years; FVC <73% pred.; FEV1< 35% pred.; RV > 194% pred.; RV/TLC > 70%; DLco < 36% pred. The most significant predictors of sPIF were age (OR 0.89) and FEV1 (OR 0.59).

Conclusion: When choosing dry powder inhaler for the maintenance therapy in patients with acute exacerbation of COPD, it is important to consider the patient's ability to generate the optimal PIF taking into account the patient's age and the severity of functional impairments.