Overview of the fluorescein isothiocyanate dextran 4000 Da (FD-4) infusion with two steady states. Data are presented as mean FD-4 values by arterial microdialysis (solid line) with mean values in steady state (filled triangles), bronchial microdialysis (long dash line) with mean values in steady state (filled circles) and ureacorrected bronchial microdialysis (dash-dot line) with mean values in steady state (open circles). The circles and the triangles represent the time where the microdialysis vials were exchanged for the steady state samples. The gray area is a graphical presentation of the intravenous FD-4 infusion. The infusion was started with an intravenous bolus of 10 μg/kg over 10 minutes. In the low steady state an infusion of FD-4 at 5 μg/kg/hour was maintained. After the low steady state a new intravenous FD-4 bolus of 10 μg/kg over 10 minutes was infused. In the high steady state an infusion of FD-4 at 10 μg/kg/hour was maintained.