The aim of this paper is to explore the literature relating to critical care outreach services and the use of early warning scoring systems to detect developing critical illness. Several studies have identified how suboptimal care may contribute to physiological deterioration of patients with major consequences on morbidity, mortality and requirement for intensive care. In a review of adult critical care services, the Department of Health (DOH) (England) recommended in 2000 that outreach services be established to avert admissions to Intensive Care, to enable discharges and to share critical care skills. A literature search was carried out of the BIOMED and NESLI databases using the key words "outreach", "early warning signs/systems" and "suboptimal care". The literature review was limited to the past 10 years, and primary research articles of particular relevance were included in the review. The literature is examined within the context of recent findings relating to the provision of suboptimal care within general wards prior to cardiac arrest and/or admission to Intensive Care Units (ICU), and subsequent government initiatives. Discussion. The discussion explores the potential contribution of critical care outreach services and early warning scoring systems to the care of patients in acute general wards, including the role that education can have in developing the knowledge base and assessment skills of ward nurses. The paper concludes that further study is required to evaluate the effectiveness of critical care outreach services and early warning scoring systems, and that ward staff need to be educated to identify those patients at risk of developing critical illness. Finally, it is suggested that nurses' decision-making in relation to calling the outreach team requires further investigation.