A change in the level of sedation from conscious sedation to general anesthesia may occur inadvertently with a relatively small alteration in the dose of sedative drugs used. This continuum of sedation advocated by the ASA has also been adopted by the Tripartite Committee of the Australian and New Zealand College of Anaesthetists (ANZCA), Gastroenterological Society of Australia (GESA) and Royal Australasian College of Surgeons.3 The goals of sedation are to achieve a balance between the benefits of FDA approved Drug Library high throughput sedation (Table 3) versus potentially

avoidable risks (Table 4). Reported risks of endoscopy vary widely. A Scottish study reported a mortality rate of 153 out of a total of 33 854 patients.4 Over 90% of the deaths were in ASA grade III, IV or V cases (Table 5). In a group of almost 650 000 patients, a recent multi-national study5 reported four post-procedure deaths, only one of which was attributable to factors related to sedation, giving an anesthetic death rate of 0.0002%. It is of note that, in contrast to the Scottish study, very few Ibrutinib cases were carried out outside of ambulatory care settings and no endoscopic retrograde cholangio pancreatographies

(ERCPs) were included. In terms of cardiorespiratory morbidity of endoscopy procedures, a survey commissioned by the American Society for Gastrointestinal Endoscopy (ASGE) revealed a rate of cardiopulmonary complications of 0.54%.6 Other reported rates have varied from 0.02% to 0.37%.7 The recent multi-national study5 of 646 080 patients revealed a very low overall risk of cardiorespiratory complications; 0.1% required bag and mask ventilation for upper endoscopy and 0.01% for colonoscopy. Endotracheal intubation was required in only four patients, and only one patient sustained neurologic injuries. The wide variation in complication rates can be attributed to differences in study design, patient population, methods of sedation and definitions

of complications. In addition, some endoscopic procedures, such as ERCP have been shown to be more likely to lead to cardiorespiratory complications, particularly in elderly patients.8 The exact contribution of the sedation process to post-procedure cardiorespiratory complications MCE can be difficult to determine, particularly in patients with ASA grade IV and above. Surveys have indicated that a substantial proportion of patients in Asia, Europe and Canada undergo upper gastrointestinal endoscopy without sedation.9 This practice is not common in the USA and Australia. There is evidence that the low prevalence of unsedated endoscopy is due more to patient reluctance rather than physician preference.10 In terms of patient tolerance, a double-blind Finnish study compared intravenous midazolam alone compared with each of three other groups: a placebo-controlled no sedation group, a placebo-controlled pharyngeal local anesthetic group, and a third control group that was unblinded.