Indications and assessment of response to inhaled bronchodilator therapy in mechanically ventilated patients

Purpose: To evaluate albuterol-Metered-Dose-Inhaler (MDI) responsiveness in critically ill patients. Methods: Thirty-eight consecutive mechanically ventilated patients who received albulterol-MDI for 3 days were treated and evaluated using the method of Dhand (Am J R CCM 1997; 156:3-10). Indications were defined as: History of COPD, asthma, previous bronchodilation use or wheezing or auto-peep a 4. A response to an individual treatment was defined as a decrease in auto-peep > 1 or resistance > 5 or an increase in pulse oximetric saturation > 3%. These response criteria were based upon paired measurements derived from mechanically ventilated patients not receiving bronchodilator therapy. A continued response was defined as a ≥ 25% response rate to all the treatments in the three day period. Results: Of the 38 patients, 28 met at least 1 indication criterion, and 13 had a continued response to treatment for the 3 day period. For the 13 patients with a continued response, 12/13 met at least 1 indication criterion and 12/13 had a response to the first treatment. Of the 25 patients without a continued response, 22/25 did not respond to the first treatment, and 10/25 did not meet with indication criteria. Conclusions: The lack of a measurable response to treatment was predicted by the absence of indication criteria and/or failure to respond to the first treatment, the latter being the best predictor. Clinical Implications: Response to albuterol-MDI can be predicted from the first dose response.