Angelica Floripedes do Amaral, Antonio Luiz Rodrigues-Junior, Joao Terra Filho, Helio Vannucchi, Jose Antonio Baddini Martinez
Med Sci Monit 2008; 14(10): CR524-529
Magnesium (Mg) use has the potential to promote bronchodilatation and to improve lung function in obstructive diseases. IV administration of Mg during exacerbations of chronic obstructive pulmonary disease (COPD) has led to improved peak flow. This study aimed to investigate the effects of acute IV Mg loading on respiratory parameters of stable COPD patients.
Material and Method: This was a randomized, double-blind, placebo-controlled crossover study. Twenty-two male COPD patients (64+/-6 years old, FEV1: 49+/-20%) received an IV infusion of 2 g of magnesium sulfate or placebo on two distinct occasions. Spirometry and mouth maximal respiratory pressures were obtained before and 45 minutes after the infusions.
Results: Mg use led to significant changes in functional respiratory capacity (-0.48 l, 95%CI: -0.96, -0.01), inspiratory capacity (0.21 l, 95%CI: 0.04, 0.37), maximal inspiratory pressure (10 cmH2O, 95%CI: 1.6, 18.4), and maximal expiratory capacity (10.7 cmH2O, 95%CI: 0.20, 21.2). The treatment was also associated with a marginally significant decrease in residual volume (-0.47 L, 95%CI: -0.96, 0.02, p=0.06).
Conclusions: Acute IV Mg loading in stable COPD patients was associated with a reduction in lung hyperinflation and improvement of respiratory muscle strength. The clinical potential for chronic magnesium supplementation in COPD deserves further investigation.
Keywords: Total Lung Capacity - drug effects, Respiratory Muscles - drug effects, Respiratory Mechanics - drug effects, Respiratory Function Tests, Middle Aged, Placebos, Pulmonary Disease, Chronic Obstructive - physiopathology, Male, Magnesium - therapeutic use, Lung - physiopathology, Humans, Forced Expiratory Volume - drug effects, Double-Blind Method, Aged