Data analysis
Data were entered in Microsoft excel and the same was analyzed using a statistical package for social sciences SPSS version 20.0 (IBM Corporation, Armonk, NY, USA). Statistical comparisons were made using percentile and mean differences. Descriptive statistics calculated for background variables. Since the data do not follow a normal distribution, the Kruskal Wallis test (Non-parametric) was performed to determine the association between the concentration of salbutamol and other background characteristics. Statistical significance was set at a p-value ≤ of 0.05.