Background:Intensive care nurses are essential members of rapid response systems (RRSs) with little qualitative data available to capture what intensive care nurses do as they navigate their way around the complexity of a medical emergency call.

Objective: The study aims to describe and explain the role of the intensive care nurse within the medical emergency team (MET) of a tertiary-level hospital to develop an understanding of the intensive care nurse role, the way it is enacted, and their responsibilities within the team.

Method: A constructivist grounded theory research approach collected qualitative data from intensive care nurses who had experience attending MET calls. Data were collected through participant observation (16 MET calls), followed by 12 semistructured interviews.

Findings: A substantive theory was developed that 'keeping patient's safe' is a fundamental role of the intensive care nurse within the MET. This is derived from four key concepts: Systematic framework for decision making, Figuring it out, Directing care, and Patient safety. Each of these concepts was developed from categories that describe the role of the intensive care unit nurse on the MET. They include performing assessments and interventions, figuring it out, critical thinking, prioritising care, directing care, being supportive, and ensuring patient safety.

Conclusion: This study provides new insights into and an understanding of the ways intensive care nurses work within the MET, making a significant contribution to our existing understanding of the role.