An Overview of the Afferent Limb

The afferent limb of a rapid response system is responsible for monitoring the patient, detecting deterioration and triggering a clinical response. This chapter describes the observations, early warning systems and calling criteria used to identify the sick or deteriorating patient. Failures in the individual components of the afferent limb are common and frequently result in potentially avoidable, adverse clinical outcomes. We describe the essential principles and common shortfalls of the afferent limb and consider the actions required to improve its functioning including improving regular patient monitoring and assessment; ensuring the accurate measurement and recording of vital signs; and enabling the timely calling of a rapid response team. The chapter also considers the role of technology in improving the functioning of the afferent limb and includes a reflection on the effects of the COVID-19 pandemic.