Impact of Preliminary Bronchodilator Dose in Chronic Obstructive Pulmonary Disease Patients With Suboptimal Peak Inspiratory Flow

•Investigation of the impact of a preliminary dose of pressurized metered dose inhalers (pMDIs) on COPD patients with suboptimal peak inspiratory flow rate (PIFR) using Diskus dry powder inhaler (DPI).•Prospective, randomized, case-control study design to assess the spirometric parameters before and after the administration of salbutamol through Diskus DPI with and without a preliminary dose.•Emphasis on the importance of appropriate drug deposition for improved clinical outcomes in COPD patients with suboptimal PIFR.•Comparative analysis of spirometric parameters, including Forced Vital Capacity (FVC), Forced Expiratory Volume in 6 seconds (FEV₆), Forced Expiratory Volume in 3 seconds (FEV₃), FEV₁/FVC, and FEV₁/FEV₆, among optimal and suboptimal PIFR groups with and without a preliminary dose.•Highlighting the association between suboptimal PIFR and poorer health status, indicating the need for interventions to enhance inhaler technique and ensure appropriate drug delivery. Suboptimal peak inspiratory flow rate (PIFR) is highly prevalent in patients with chronic obstructive pulmonary disease (COPD) owing to the mismatch of their PIFR with the corresponding inhaler-device resistance. This study aimed to investigate the impact of a preliminary dose of pressurized metered dose inhalers (pMDIs) on patients with COPD with suboptimal PIFR using Diskus dry powder inhalers (DPIs). A prospective, randomized, case–control study included 24 patients with COPD. PIFR was measured using the In-Check Dial G16 with low-to-medium resistance. Spirodoc was used to measure baseline spirometric data and compare it before and 30 minutes after the administration of Diskus DPI. On a different day, the study dose was given to each suboptimal patient by the same aerosol generator with preceded 2 puffs of salbutamol pMDI and re-evaluated for spirometric parameters 30 minutes after the study dose. There was a significant difference between the optimal and suboptimal groups in peak expiratory flow (2.38 ± 1.20 vs 1.49 ± 1.06 L/s, P = 0.050). PIFR showed a statistically significant difference between the optimal and suboptimal groups (71.66 ± 6.15 vs 41.25 ± 9.79 L/min, P < 0.0001). There was a significant difference in forced vital capacity (ΔFVC) between optimal and suboptimal groups without a preliminary dose (0.42 ± 0.21 vs 0.16 ± 0.11 L, P = 0.002), forced expiratory volume in 6 seconds (ΔFEV6) (0.53 ± 0.49 vs 0.17 ± 0.11 L, P = 0.022), forced expiratory volume in 3 seconds (ΔFEV