1 Division of Pulmonary Critical Care and Occupational Medicine, University of Iowa, 200 Hawkins Dr, C-33-GH, Iowa City, IA 52242. Electronic address: michael-eberlein@uiowa.edu.
2 Division of Thoracic and Cardiac Surgery, University of Iowa, Iowa City, Iowa.
3 Department of Thoracic Surgery, University Hospital Wuppertal, University Witten/Herdecke, Wuppertal, Germany.