<qa>  What is the desired sedative dosedose range and dosing paradigm of AQURandomized, open label, multi-center, adaptive dose ranging study, in which several dose levels of AQUAVAN Injection and fentanyl citrate injection will be investigated to produce a desired sedation level in patients undergoing elective colonoscopy. A desired sedative dosedose range and dosing paradigm will be identified based on pre-set criteria using the Modified Observers Assessment of AlertnessSedation OAAS. The desired sedative dosedose range and dosing paradigm of AQUAVAN Injection is defined as one that consistently provides mild to moderate sedation Modified OAAS between 2 and 4 inclusive in a majority of patients who are pre-medicated with fentanyl citrate injection. 