1. Beth Israel Deaconess Medical Center, Department of Anaesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, USA

2. Barrow Neurological Institute, Phoenix, USA

3. Valley Anaesthesiology and Pain Consultants, Phoenix, AZ; University of Arizona College of Medicine-Phoenix, Department of Anesthesiology, Phoenix, AZ; Creighton University School of Medicine, Department of Anesthesiology, Omaha, USA