 Comparing sedation techniques during invasive endoscopic procedures such as ERCP and EUS is a relatively unexplored area of clinical research. In particular, the effectiveness of adjunct sedatives such as diphenhydramine and promethazine during ERCPEUS procedures has not been studied. Achieving a moderate sedation level may be ideal for ERCPEUS procedures in order to provide adequate patient comfort, amnesia, and completion of intended endoscopic procedures. The relevance of further studies in this area is apparent. In terms of clinical practice; over-sedation can lead to decreased airway protection, longer post-procedural recovery times, and unnecessary drug cost; under-sedation can lead to patient anxiety, agitation, recall, and longer procedural time. 