Inhaled beta 2 agonists can be administered by SVN or MDI during mechanical ventilation. MDI is an effective administration technique, it avoids the problems related to SVN, and it may be less expensive than SVN. A variety of techniques can be used to evaluate bronchodilator response during mechanical ventilation. Low-tech methods are also low cost, but may lack sensitivity. High-tech approaches to evaluate bronchodilator responsiveness may be more sensitive but are also more expensive. More work is needed to determine the most appropriate and cost-effective methods to evaluate bronchodilator response in mechanically ventilated patients.