Quantification of Exhaled Propofol Is Not Feasible During Single-Lung Ventilation Using Double-Lumen Tubes: A Multicenter Prospective Observational Trial.

During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation.