[1] Univ Copenhagen & Capital Reg Denmark, Ctr Clin Educ, DK-2100 Copenhagen, Denmark
[2] Univ Copenhagen, Gentofte Hosp, Dept Pulmonol, Hellerup, Denmark
[3] Univ Copenhagen, Herlev Hosp, Dept Surg Gastroenterol, DK-2730 Herlev, Denmark
[4] Leiden Univ, Med Ctr, Dept Pulmonol, Leiden, Netherlands
[5] Univ Amsterdam, Acad Med Ctr, Dept Pulmonol, NL-1105 AZ Amsterdam, Netherlands
[6] Univ Toronto, Dept Anesthesia, Toronto, ON, Canada