BackgroundEarly warning systems and rapid response teams have been widely implemented in hospitals worldwide to facilitate early recognition and response to patient deterioration. Unfortunately, evidence suggests that these interventions have made little impact on unexpected cardiac or respiratory arrest, hospital mortality, unplanned admission to intensive care units, or hospital length of stay. These programs depend on nurses recognizing at risk patients and initiating a timely response. Although physiologic abnormalities commonly precede serious adverse events, nurses often fail to recognize or respond effectively. Clinical judgment is a critical component in the effective response to deterioration, yet little is known about factors that influence nurses' clinical judgment in these situations. Noticing, interpreting, and responding are aspects of clinical judgment and are essential to preventing further patient deterioration and serious adverse events. ObjectiveTo describe medical-surgical nurses' perceptions of factors that influenced their clinical judgment in situations of patient deterioration. DesignA qualitative descriptive design using individual, semi-structured interviews. Tanner's Clinical Judgment Model served as the framework for interview questions and data analysis. ParticipantsA purposive sample of 20 medical-surgical registered nurses were recruited from 10 adult medical-surgical units at an academic medical center hospital in the United States. MethodsTelephone interviews occurred between March and July 2018. A directed approach to content analysis was used to code the transcribed data and identify themes. ResultsEight themes related to each aspect of clinical judgment emerged from the analysis: Knowing the patient, Experience matters, Lots of small points where the system can fail, Making sense of the data, Something doesn't go together, Caught in the middle, Culture of teamwork, and Increased nursing workload. An overarching theme was Nurses' keen sense of responsibility. Findings revealed that factors within the nurse, the patient, and the work environment influence each component of noticing, interpreting, and initiating an effective response to deteriorating patients. ConclusionsFindings have implications for health care systems regarding interventions to support timely recognition and response to deterioration. Nurses' clinical judgment and factors that influence each aspect (noticing, interpreting, and responding) should be a key consideration in organizational efforts to improve the overall response to patient deterioration. Research is needed to enhance understanding of the contextual factors that impact nurses' clinical judgment to inform interventions to support timely recognition and response.