David Roberts

We evaluated the effect of dexamethasone on vomiting after elective tonsillectomy in 133 healthy children aged 2-12 yr in a randomized, stratified, blocked, double-blind, placebo-controlled study. General anesthesia was induced by inhalation of N2 O and halothane or intravenously (IV) with propofol. Anesthesia was maintained with N2 O and halothane. Dexamethasone 150 micro g/kg up to a maximum dose of 8 mg, or placebo, was administered IV before surgery. All patients received 1.5 mg/kg codeine intramuscularly (IM) intraoperatively. Perioperative IV fluids, management of emesis, postoperative pain and hospital discharge criteria were all standardized. The groups were similar with respect to number, age, weight, length of surgery, and estimated intraoperative blood loss. Dexamethasone reduced the overall incidence of vomiting from 72% (placebo) to 40% (P < 0.001). Vomiting, both in-hospital and postdischarge, was decreased by the prophylactic administration of dexamethasone. Each episode of inhospital vomiting prolonged discharge by 13 +/- 2 min, mean +/- SD (P < 0.001). In conclusion, dexamethasone markedly decreased vomiting by healthy children after elective tonsillectomy in an ambulatory hospital setting. (Anesth Analg 1996;83:913-6)

This paper presents a mixed reality (MR) system that results from the integration of a telepresence system and an application to improve collaborative space exploration. The system combines free viewpoint video with immersive projection technology to support nonverbal communication (NVC), including eye gaze, interpersonal distance, and facial expression. Importantly, these features can be interpreted together as people move around the simulation, maintaining a natural social distance. The application is a simulation of Mars, within which the collaborators must come to agreement over; for example, where the Rover should land and go. The first contribution is the creation of an MR system supporting contextualization of NVC. Two technological contributions are prototyping a technique to subtract a person from a background that may contain physical objects and/or moving images and a lightweight texturing method for multiview rendering, which provides balance in terms of visual and temporal quality. A practical contribution is the demonstration of pragmatic approaches to sharing space between display systems of distinct levels of immersion. A research tool contribution is a system that allows comparison of conventional authored and video-based reconstructed avatars, within an environment that encourages exploration and social interaction. Aspects of system quality, including the communication of facial expression and end-to-end latency are reported.