[1] Med Univ Vienna, Dept Anesthesiol Intens Care Med & Pain Therapy, A-1090 Vienna, Austria
[2] Landesklinikum Krems, Dept Pulmonol, Krems An Der Donau, Austria
[3] Landesklinikum Krems, Dept Anesthesiol Intens Care & Emergency Med, Krems An Der Donau, Austria