EXECUTIVE SUMMARY:Aim This systematic review investigates the essential components of an effective and feasible scoring system to assess patients following anaesthesia and surgery, thereby enhancing patient safety through timely and appropriate discharge from the Post-Anaesthetic Care Unit. The findings of the evidence synthesis will be used to inform the development of a Post-Anaesthetic Care Unit discharge tool.Methods A systematic review of quantitative research conducted in adult populations on post-anaesthetic discharge assessment strategies utilised in post-anaesthetic care units following any type of surgical procedure. An extensive literature search was constructed to identify all relevant studies published between 1970 and 2010. Studies were appraised and data was extracted by two reviewers using the standardised critical appraisal and data extraction tools from the Joanna Briggs Institute.Results A total of eight studies were included in the review. One randomised controlled trial and four observational studies provided evidence on the effectiveness and feasibility of discharge assessment tools. All studies identified pain, conscious state, and nausea and vomiting as important variables to consider in assessing a patient's readiness for discharge from the post-anaesthetic care unit. Two additional observational studies and a retrospective records analysis investigated the recovery of patients in the post-anaesthetic care unit, providing data on psychomotor and cognitive recovery following anaesthetic.Conclusion There was general agreement amongst the studies that post-anaesthetic care unit discharge assessment should consider levels of pain, conscious state, and nausea and vomiting. Although vital signs were included in all the discharge assessment tools, there was variation in the specific vital signs included within tools, with blood pressure being the only vital sign consistently used. The value of including urine output, oral intake or psychomotor testing in assessing readiness for post-anaesthetic care unit discharge was inconclusive and therefore requires further investigation.Implications for practice Based on the evidence from studies at moderate to high risk of bias analysed in this systematic review, the following recommendations are considered important for the assessment of the readiness of adult patients to be discharged from the post-anaesthetic care unit:• Assessment of pain, conscious state, blood pressure and nausea and vomiting should be made before discharging a patient. Assessment of other vital signs should be considered before discharging a patient from post-anaesthetic care unitImplications for research The synthesised evidence suggests there is limited consensus on criteria for post-anaesthetic care unit discharge assessment and further investigation using sound methodologies is required, especially with regard to patient outcomes. The following recommendations can be made:• Further research should investigate the validity and reliability of assessment variables on post-anaesthetic care unit discharge tools, the implementation of validated post-anaesthetic care unit discharge criteria for assessment of patient readiness for discharge, and, the relationship between post-anaesthetic care unit discharge assessment and patient safety.