Stratification of sedation risk--a challenge to the sedation continuum.

We detail the limitations of the current paradigm of the sedation continuum - a tool ubiquitous to all sedation care settings and now a quarter century old. Definitions in this existing taxonomy are based on patient responsiveness to verbal and/or tactile stimuli, and the inherent subjectivity of this focus has both challenged the reliable assessment of adverse event risk and precluded clear delineation of sedation boundaries, e.g., what is the dividing line between moderate and deep sedation? We present the rationale to support a broadening of this sedation continuum precept to include an objective mechanism to predict the ongoing risk of serious adverse events, and then propose sequential steps for the development of such a restructured framework. This process, while ambitious, would yield a clear and consistent language to facilitate quality assurance, provide an objective framework for standardized sedationist training and credentialing, and permit inclusion into computerized decision-support algorithms to facilitate more precise sedative delivery. It is important to clearly delineate this goal now to permit design and initiation of the requisite research.