1. Department of Anesthesia, Critical Care and Pain Medicine; Massachusetts General Hospital; Harvard Medical School; Boston MA USA
2. Department of Anesthesia; Massachusetts Eye and Ear Infirmary; Boston MA USA
3. Anesthesia Associates of Ann Arbor; Wayne State University; Detroit MI USA
4. Valley Anesthesiology and Pain Consultants; Phoenix AZ USA
5. Wayne State University School of Medicine; Detroit MI USA
6. Departments of Anesthesiology, Critical Care Medicine and Pediatrics; The Johns Hopkins University; Baltimore MD USA