In this study, the investigators will utilize ultrasonography to identify midline bony landmarks including spinous processes, laminae, and intervertebral interspaces prior to the initial needle placement and compare this to standard palpation of the bony thoracic spine for thoracic epidural placement. The investigators will evaluate and compare the two needle localization techniques by the following outcomes: time to identify the epidural space by loss of resistance, needle passes, skin punctures, recovery room pain scores, and epidural success.