1. Northwestern Memorial Hospital, 251 East Huron Suite F5-704, Chicago, Illinois 60611, USA
2. Fellow in Regional Anesthesiology and Acute Pain Medicine, Northwestern Memorial Hospital, 251 East Huron Suite F5-704, Chicago, Illinois 60611, USA
3. Resident in Anesthesiology, Northwestern Memorial Hospital, 251 East Huron Suite F5-704, Chicago, Illinois 60611, USA