Angle beta & platelet activity in acute asthma - Do inhaled bronchodilators & steroids help?

Purpose: To compare pulmonary function tests (PFT) & platelet activity before & after salbutamol inhaled alone & in combination with beclomethasone & to observe the added effect of ongoing steroids in acute asthma. Methods: Twenty five young asthmatics without associated disease were studied on two occasions. On day 1, PFT and platelet activity (Aggregation, Adhesiveness, PF₃, clumps /150 WBC on smear) were recorded before & 30 minutes after inhaling salbutamol (200μg) by metered dose inhaler (MDI) with spacer. On day 2, the tests were repeated after inhaling salbutamol (200μg) plus beclomethasone (200μg). Angle Beta was calculated from the expiratory part of flow volume loop. Results: All asthmatics had a low FEF_25-75 & Angle Beta & increased platelet activity & airway resistance which improved after salbutamol inhalation. Addition of Beclomethasone corrected airway obstruction further. (Raw 64 vs.50% FEF_25-75 28.75% vs.22.21%; Angle Beta 61% vs.55%). Platelet aggregation reduced comparably on both days (17.90% vs.13.64%). Ongoing steroids improved the overall bronchodilator response. Conclusions: Beclomethasone enhances the effect of salbutamol on Angle Beta & airway resistance but not on platelet activity, while ongoing steroids potentiate bronchodilator response to these drugs further through their priming effect on airways. Clinical Implications: Angle Beta is a novel indicator of small airway obstruction. Inhaled steroids should be started early in asthma in view of their anti-inflammatory actions. Inhaled bronchodilators should be regularly administered to improve platelet activity.