1. Volume 104, Issue 4, Pages 1108-1113 (October 1993)
Inhaled β2-Agonist and Positive Expiratory Pressure in Bronchial Asthma 
Erika Frischknecht Christensen, M.D., Ole Norregaard, M.D., Lone Winther Jensen, M.D., Ronald Dahl, M.D. 
CHEST 
Volume 104, Issue 4, Pages (October 1993)
DOI: /chest
Copyright © 1993 The American College of Chest Physicians Terms and Conditions

2. FIGURE 1
Cone spacer (Nebuhaler) PEP mask. Variable resistances can be applied onto the expiratory tube as connections of different diameters, giving positive expiratory pressure (PEP).
CHEST  , DOI: ( /chest )
Copyright © 1993 The American College of Chest Physicians Terms and Conditions

3. FIGURE 2
Difference in expiratory airway resistance, ΔRAW = Raw after-Raw before each dose, and difference in functional residual capacity; ΔFRC = FRC after-FRC before each dose; p = placebo. Mean and 95 percent confidence interval. Values for five patients on a day with repetitive placebo doses.
CHEST  , DOI: ( /chest )
Copyright © 1993 The American College of Chest Physicians Terms and Conditions

4. FIGURE 3
Difference in expiratory airway resistance ΔRAW = Raw after-Raw before each dose; p = placebo. Mean and 95 percent confidence interval.
CHEST  , DOI: ( /chest )
Copyright © 1993 The American College of Chest Physicians Terms and Conditions

5. FIGURE 4
Difference in functional residual capacity, ΔFRC = FRC after-FRC before each dose; p = placebo. Mean and 95 percent confidence interval.
CHEST  , DOI: ( /chest )
Copyright © 1993 The American College of Chest Physicians Terms and Conditions