Venous serum albuterol, corrected for the number of puffs of albuterol administered, in mechanically ventilated patients (filled square) and nonintubated control individuals (filled circle). Serum levels were similar in both groups except at baseline and 15 min after drug administration. Note that the groups had similar patterns of systemic absorption, with the peak level occurring at 10 min and a rapid decline in serum levels thereafter. Bars represent standard error. *P <0.05 versus controls. From Duarte et al [25*].