Metered dose inhalers for bronchodilator delivery in intubated, mechanically ventilated patients

We determined the relative efficacy of two bronchodilator aerosol delivery methods in 18 intubated mechanically ventilated patients with airways obstruction. Two treatment arms, consisting of albuterol 270 micrograms (three puffs) from a metered dose inhaler and albuterol 2.5 mg from a saline solution nebulized with an updraft inhaler, were compared in a single blind, randomized crossover design. Pulmonary function was evaluated using an interrupter technique. Changes in passive expiratory flow at respiratory system recoil pressures between 6 and 10 cm H2O provided the therapeutic endpoints. Paired measurements were made before and 30 minutes after drug delivery. The MDI and NEB resulted in similar improvements in iso-recoil flow (mean increase for both groups = 0.1 L/s). Treatment sequence, severity of obstruction, and bronchodilator responsiveness had no effect on relative efficacy. Albuterol caused a small but significant increase in heart rate that was similar following both delivery methods. We conclude that bronchodilator aerosol delivery with metered dose inhalers provides a viable alternative to nebulizer therapy in intubated mechanically ventilated patients and may result in a cost savings to hospitals and patients.