Effect of helium-oxygen on delivery of albuterol in a pediatric, volume-cycled, ventilated lung model

Pulmonary delivery of inhaled bronchodilators in mechanically ventilated patients is inefficient whether administered by metered-dose inhaler (MDI) or small-volume nebulizer. One of the factors that causes inefficient aerosol delivery is turbulent gas. Heliox (He:O-2) is a blend of helium and oxygen that is less dense than air, making turbulent flow less likely. We assessed the effect of 70% He:O-2 on albuterol delivery in a mechanically ventilated pediatric lung model. Albuterol was administered by MDI with spacer, collected on a filter proximal to a test lung, and measured by high-performance liquid chromatography Mean amount and percentage albuterol delivered were significantly (p<0.05) greater for 70% He:O-2 (395 +/- 29 mu g, 20 +/- 3.2%) than for 70% nitrogen:30% oxygen (241 +/- 29 mu g,12 +/- 1.7%). Thus 70% He:O-2 can increase the amount of albuterol delivered at the end of the endotracheal tube, suggesting a potential role for it in the care of critically ill ventilated patients.