Two Inhalation Methods Using a Pressurized Metered Dose Inhaler With Valved Holding Chamber to Assess Improvement in Lung Function After SABA Administration in Bronchial Asthma

Overview

Bronchial asthma is a chronic inflammatory disorder characterized by recurrent reversible episodes of breathlessness, wheezing, chest tightness and/ or cough. The prevalence of asthma in India is about 2%, and asthma is responsible for significant morbidity. A diagnosis of asthma is made in the presence of clinical symptoms with or without reversibility on spirometry assessment.1 Treatment comprises of inhaled medications that are used either as controller medication or a reliever medications. In a recent study involving asthmatic children, single maximal inhalation with breath hold was not found to be superior to tidal breathing for improvement in peak expiratory flow rates. The authors hypothesized that both the techniques would improve FEV1 similarly.

Bronchial asthma is a chronic inflammatory disorder characterized by recurrent reversible episodes of breathlessness, wheezing, chest tightness and/ or cough.1 The prevalence of asthma in India is about 2%, and asthma is responsible for significant morbidity. A diagnosis of asthma is made in the presence of clinical symptoms with or without reversibility on spirometry assessment.1 Treatment comprises of inhaled medications that are used either as controller medication or a reliever medications.1 PEF measurements are known to be affected by the technique and the equipment by which it is measured, and thus proper instructions and training are essential for the patient.1 PEF measurements have been used in the past as a surrogate to FEV1 measurements, but the correlation between them is poor and hence they should not be used interchangeably. If PEF falls below 80% of personal best, it is suggestive of inadequate disease control.1 Inhaled medications are delivered through various device either as dry powder forms or in a pressurized meter dose inhaler (pMDI). However, the drug delivery is variable and a pMDI delivers only 10-20% of the nominal dose per actuation or puff, even when used correctly.2,3 Use of spacer improves the drug delivery and the recent Indian guidelines recommends use of pMDI with a spacer as an effective drug delivery system. Tidal breathing with a pMDI with spacer is as effective as the single breath method as per the British/Scottish Intercollegiate Guidelines Network (SIGN) recommendations.4 Breath-holding is usually recommended after the aerosol inhalation, but there is limited information on the clinical importance of breath-holding in adult asthmatic patients. In a recent study involving asthmatic children, single maximal inhalation with breath hold was not found to be superior to tidal breathing for improvement in peak expiratory flow rates.5 Information on comparative efficacy of either method is limited in adult asthmatics. The authors hypothesized that both the techniques would improve FEV1 similarly. Thus, the objective of the present study is to assess improvement in lung function (FEV1) after short-acting beta-2 agonist administration in treatment-naïve adult patients with bronchial asthma with a single maximal inhalation with breath-hold versus 5 tidal breaths during inhalation using a valved holding chamber.