OBJECTIVES: Patients in intensive care units (ICUs) are generally sedated for prolonged periods. The level of sedation has an important bearing on outcomes. Sedation management guidelines and protocols seek to improve the management of sedation to keep it within appropriate levels. We sought to further establish the impact of improvements or changes in sedation practice, such as the introduction of guidelines, reinforcement of protocols, or practices such as daily interruption of sedation, on outcomes including mortality, morbidity and hospital costs and resource use. METHODS: We conducted a systematic review of the literature. We searched Medline, Embase and Cinahl databases, and hand-searched ASA, ESA and ISPOR conferences for observational and economic studies and clinical trials which examined the impact of different sedation practices on outcomes. All studies were downloaded into an electronic database. Abstracts were reviewed and data were extracted twice by independent reviewers, with any discrepancies resolved by a third person. We extracted and analysed data from studies showing the impact of improvements or changes in sedation practice on outcomes, including cost, resource use, mortality and morbidity. RESULTS: Improvements in sedation practice generally included more regular monitoring of sedation level, with guidelines for staff as to the optimal sedation level. Such improvements were associated with improvements in safety, including mortality, incidence of nosocomial infections, and recall after sedation, and with a lower length of stay, lower duration of mechanical ventilation, and lower use of anaesthetics. CONCLUSIONS: Improvements in sedation practice are associated with better outcomes in terms of patient morbidity and hospital resource use. In general these improvements involve more regular monitoring of sedation, and more strenuous efforts to keep the level of sedation within optimal levels, demonstrating the importance of effective monitoring of sedation level.