Telephone-assisted cardiopulmonary resuscitation in a simulated environment: A pilot exploratory study evaluating first responder adherence and dispatcher performance.

Background: Out-of-hospital cardiac arrest (OHCA) remains a major public health challenge, and telephone-assisted cardiopulmonary resuscitation (T-CPR) is a key strategy to improve survival. However, real-time analyses of dispatcher-rescuer interaction are scarce. Methods: A pilot study was conducted in the Valencian Community (Spain) using simulated OHCA scenarios to evaluate first responder adherence to T-CPR instructions and dispatcher performance. This exploratory study included six untrained lay callers and six dispatchers (five nurses, one physician) who participated in simulated emergency calls routed through the regional emergency coordination center (CICU). All calls were audiovisually recorded and analysed using a checklist derived from ERC 2021/AHA 2020 guidelines. Technical CPR parameters were collected from a manikin with QCPR technology. Results: Time to cardiac arrest recognition varied widely (50 s-3:48 min), with overall delays exceeding 5 min in two cases. Basic instructions (supine position, hand placement) were consistently communicated, but only 50 % of dispatchers emphasized correct compression depth. Interruptions in CPR occurred in four of six cases. Lay responders reliably followed simple instructions but struggled with technical aspects: only 33.3 % achieved adequate compression depth and rate. Significant correlations were observed between compression depth, rate, and rescuer age (ρ = -0.868; p = 0.025). AED use was systematically omitted. Conclusions: This pilot study highlights variability in dispatcher recognition times and inconsistencies in communication of critical CPR parameters. First responders adhered better to simple than technical instructions. Findings underscore the need for structured, standardized protocols and enhanced dispatcher training to optimize T-CPR effectiveness.