1. Anesthesiology Research Laboratory, Departments ofAnesthesiology and
2. Physiology, and
3. Department of Anesthesiology and Intensive Care Medicine, University Hospital Münster, 48129 Münster, Germany
4. Department of Biomedical Engineering, Marquette University, Milwaukee 53233;
5. Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee 53226;
6. Research Service, Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295; and