A randomized clinical trial of magnesium sulphate as a vehicle for nebulized salbutamol in the treatment of moderate to severe asthma attacks

Abstract

Although it is well known that intravenous administration of MgSO 4 as an adjunct to conventional therapy is effective in treating asthma attacks, the effect of nebulized MgSO 4 as a vehicle for salbutamol has been less evaluated. The aim of this study was to compare the effects of nebulized salbutamol administrated through either MgSO 4 or isotonic saline solution on the ‘peak expiratory flow rate’ (PEFR), other respiratory and clinical parameters, and hospitalization rate of patients suffering from moderate to severe asthma attacks. Twenty-six patients with asthma attack were enrolled in the study in a randomized single blind fashion. After obtaining initial peak expiratory flow measurements (PEFR) and clinical evaluation, all patients received 1 mg/kg corticosteroids and oxygen therapy and then either isotonic MgSO 4 (2.5 ml, 6.3%)+salbutamol (2.5 ml) or saline (2.5 ml)+salbutamol (2.5 ml) through a jet nebulizer (group 1 ( n=14) vs group 2 ( n=12), respectively). The nebulizations were repeated every 20 min for the first hour and every hour for the rest of 4 h. The PEFR measurements and clinical assessment were performed after nebulization at 20th, 60th, 120th, 180th and 240th minutes. Patients were discharged when PEFR reached the target level of 70% of predicted. The baseline PEFRs and clinical parameters were similar between groups 1 and 2 (50.2±18.5 vs 44.1±13.9, respectively, p>0.05). The mean% increase in PEFR at different measurement levels was similar between the groups. When the treatment response was evaluated within the groups, group 2 showed statistically significant increase in PEFR (% of predicted) 1 h earlier than group 1 (60th vs 120th minute, p=0.003 vs p=0.007). The mean duration of achieving target-PEFRs was 105.7±72.1 min for group 1 and 118.3±96.7 min for group 2 ( p>0.05). This study suggested that the additional usage of MgSO 4 to nebulized salbutamol has no beneficial effect on the treatment of asthma attacks.