Delivery efficiency of metered dose aerosols given via endotracheal tubes

Anesthesiology. 1989 Jun;70(6):1008-10. doi: 10.1097/00000542-198906000-00021.


The authors studied the efficiency of delivery of the inhaled bronchodilator metaproterenol when delivered via an endotracheal tube (ETT) using a metered dose inhaler (MDI). They found that the percentage of drug exiting the ETT varied with tube size, ranging from 3.0 +/- 1.9 for a 6.0 mm ETT to 6.5 +/- 4.4 for a 9.0 mm ETT (mean +/- SEM, P less than 0.05). The efficiency of delivery was also affected by whether the MDI was activated before or after initiation of gas flow through the ETT, with activation into a flowing stream significantly more efficient. The authors conclude that an MDI can deliver a dose of drug to the trachea, but delivery efficiency is lower than reported for MDI delivery in spontaneously breathing patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Inhalation / instrumentation
  • Aerosols
  • Bronchodilator Agents / administration & dosage*
  • Efficiency
  • Humans
  • Intubation, Intratracheal*
  • Metaproterenol / administration & dosage*
  • Respiratory Therapy / instrumentation*


  • Aerosols
  • Bronchodilator Agents
  • Metaproterenol