Predictors of suboptimal peak inspiratory flow in patients with COPD exacerbation

Abstract

Incorrect inhalation technique is one of the main causes of ineffective inhaled therapy in patients with chronic obstructive pulmonary disease (COPD), leading to increased frequency of exacerbations and hospitalizations. Measuring peak inspiratory flow (PIF) and determining its optimal values for a specific dry powder inhaler (DPI) can significantly assist in selecting COPD maintenance therapy. The aim of this study was to determine the frequency and predictors of suboptimal PIF among patients hospitalized due to COPD exacerbation. Methods. The study included 100 patients with COPD exacerbation requiring hospitalization. The analysis comprised basic demographic, clinical, and functional patient characteristics at admission and discharge. PIF was assessed using an IngalOk device at resistance levels corresponding to the DPIs used by patients as maintenance therapy. Measurements were taken before and after training on proper inhalation technique upon hospital admission, as well as before discharge. Results. At admission, suboptimal PIF values were initially recorded in 46% of patients. However, this rate decreased to 20% (p < 0.0001) after training in proper inhalation technique. ROC analysis identified independent predictors of suboptimal PIF such as age > 70 years, FVC < 70% pred., FEV 1 < 30%pred., RV/TLC > 70%pred.. The most significant predictors were age (OR – 0.79; 95% CI – 0.68 – 0.91; p = 0.001) and FEV1pred. (OR – 1.15; 95% CI – 1.09 – 1.25; p = 0.002). Conclusion. The likelihood of suboptimal PIF values should be considered when selecting an optimal inhalation device for maintenance therapy in patients with COPD exacerbation, especially in the elderly, among patients with very severe bronchial obstruction and patients with pulmonary hyperinflation.