Introduction Rapid response systems (RRSs) have been introduced to facilitate effective ‘rescue’ of seriously ill patients on hospital wards. While research has demonstrated some benefit, uncertainty remains regarding impact on patient outcomes. Little is known about the relationship between social contexts and the application of the RRS.

Design This comparative case study of the RRS within the medical services of two UK hospitals used ethnographic methods over a 12-month period in 2009, including observation (ward work and shadowing medical staff = 150 h), interviews with doctors, ward and critical care nurses, healthcare assistants, safety leads and managers (n=35), documentary review and analysis of routine data. Data were analysed using NVivo software.

Results The RRS reduced variability in recording, recognition and response behaviour. The RRS formalised understandings of deterioration and provided a mandate for escalating care across professional and hierarchical boundaries. However, markers of deterioration not assimilated into risk scores were marginalised and it was harder for staff to escalate care without the ‘objective evidence’ provided by the score. Contextual features (eg, leadership, organisational culture and training) shaped implementation, utilisation and impact of the RRS. Reporting and feedback of audit data enabled learning about ‘selected’ escalation work on the wards. Difficulties with referral upwards and across medical boundaries were reported by junior medical staff.

Conclusion Locating a RRS within a pathway of care for the acutely ill patient illustrates the role of these safety strategies within the social organisation of clinical work. There is a need to broaden the focus of inquiry from detection and initiation of escalation (where the strategies are principally directed) towards team response behaviour and towards those medical response practices which to date have escaped scrutiny and monitoring.