Bronchodilator response with use of OptiVent* versus Aerosol Cloud Enhancer† metered-dose inhaler spacers in patients receiving ventilatory assistance

Objective: This study compared the clinical effectiveness of the OptiVent (HealthScan Products, Inc, Cedar Grove, NJ) and the ACE (DHD, Inc, Canastota, NY) metered dose inhaler (MDI) in-line spacers. Design: Two-group, split-plot design with subjects serving as their own controls Setting: Data were collected in a 1000-bed urban hospital. Patients: A convenience sample of 7 intubated patients receiving mechanical ventilation. Intervention: Patients received 4 and 8 puffs of albuterol with use of both the OptiVent and ACE devices. Results: Changes in expiratory airway resistance (Raw), passive peak expiratory flow rate (PEFR), and total work-of-breathing (WOBTOT ) were determined using a Bicore monitor (Bicore Monitoring System; Irvine, Calif). With the ACE, Raw decreased an average of 20.2% and 8.8% in patients receiving 4 and 8 puffs, respectively. With the OptiVent, Raw decreased an average of 34.6% and 10.8% in patients receiving 4 and 8 puffs, respectively. Improvements in WOBTOT were less than those seen in Raw, and PEFR did not trend with the other 2 variables. The performances of the 2 spacer brands were comparable, with no statistical difference (P values > 0.05) for all 3 variables with use of the nonparametric Kolmogorov-Smirnov test. Conclusions: These data suggest that use of the OptiVent spacer yields comparable clinical results with the ACE spacer in patients receiving mechanical ventilation and merits further evaluation. (Heart Lung® 1998;27:418-23)