Registered Nurses' Vital Sign Assessment and Respiratory Rate Practices: A Think‐Aloud Observational Study in Adult Medical and Surgical Wards

AIM: To explore how registered nurses assess and prioritise vital signs during routine clinical care, with a particular focus on respiratory rate practice, using a think-aloud observational approach. DESIGN: Observational qualitative study. METHODS: Registered nurses performing routine vital sign observations were directly observed across adult medical and surgical wards in two metropolitan Queensland hospitals. Observation encounters were audio-recorded and transcribed verbatim to capture nurses' verbalised actions using the think-aloud technique. Brief post-observation debrief interviews explored the clinical reasoning underpinning measurement practices. Data were analysed using inductive reflexive thematic analysis, integrated with descriptive summaries of observational data and measurement sequencing. RESULTS: Fifteen nurses participated in 25 observation encounters. Blood pressure was measured first in 84% of encounters and functioned as an operational anchor for observation practice. Respiratory rate was visibly counted in only 16% of encounters, despite respiratory rate values being documented in all observation charts, raising concerns regarding discrepancies between observed and documented practice. Five themes were identified: (1) Clinical reasoning during patient assessment; (2) Blood pressure as the operational anchor of observation practice; (3) Workflow efficiency shaping observation practices; (4) Respiratory rate as a backgrounded vital sign; and (5) Knowledge-practice gap in respiratory rate assessment. Despite recognising respiratory rate as an early indicator of deterioration, nurses rarely prioritised its measurement. CONCLUSION: Vital sign assessment was embedded within broader clinical reasoning but appeared to be structured primarily by workflow efficiency and device-mediated monitoring, rather than physiological priority. Respiratory rate was routinely backgrounded, despite its recognised importance in detecting clinical deterioration. Improving the completeness and reliability of vital sign assessment may require system-level attention to workflow, monitoring and documentation practices, alongside education. RELEVANCE TO CLINICAL PRACTICE: Improving respiratory rate assessment may require addressing workflow structures and clinical routines that influence how vital signs are prioritised during bedside observations, rather than focusing on education alone. NO PATIENT OR PUBLIC CONTRIBUTION: Patients or members of the public were not involved in the design, conduct, analysis, interpretation, or reporting of this study. The study focused on the observation of registered nurses' vital sign assessment practices in adult acute care settings.