 The Bispectral BIS Index was used to guide study drug administration; target BIS ranges were 60 to 80 for sedation and 40 to 60 for the maintenance of anesthesia. Adequate sedativehypnotic effect during surgical anesthesia was characterized by the portion of time within the target BIS Index range versus total surgical time. Following this, during postsurgical sedation, inadequate sedativehypnotic effect was characterized by the number, duration, and magnitude of BIS scores outside of the target range versus total postsurgical sedation time. During postsurgical sedation, the Modified Ramsey Scale was used as an additional clinical tool to evaluate the state of sedation, with an attempt to maintain the score between 3 and 5. 