Effects of nebulized beta 2-adrenergic agonists on pulmonary mechanics in anesthetized patients with chronic obstructive pulmonary disease.

We evaluated the effects of nebulized beta 2-adrenergic agonists on pulmonary mechanics in patients with COPD undergoing peripheral surgery with a standardized general anesthetic technique. Thirty males with COPD were randomized into one of three groups. Group I (control group; n = 10) received nebulized saline 3 ml, Group II (n = 10) received nebulized albuterol (2.5 mg in 3 ml), and Group III (n = 10) received nebulized metaproterenol (15 mg in 3 ml). At 20 min after tracheal intubation, the study drugs were nebulized over 20 min. Datex Capnomac Ultima monitor was used to measure pulmonary mechanics on a breath-by-breath basis. There was no difference between the three groups with respect to demographic data and preoperative respiratory parameters. A similar degree of DPH occurred with the initiation of mechanical ventilation in all three groups. Patients receiving nebulized bronchodilators (Groups II and III) displayed a significant decrease in DPH and an increase in total dynamic compliance. However, there were no differences in DPH and total dynamic compliance between Groups II and III. We conclude that nebulization of either albuterol or metaproterenol can alleviate DPH resulting from mechanical ventilation in anesthetized patients with COPD.