Emergency ambulance dispatch: is there a case for triage?

Emergency telephone calls for an ambulance (999 calls) are usually dealt with first-come first-served. We have devised and assessed criteria that ambulance dispatch might use to prioritize responses. Data were collected retrospectively on consecutive patients presenting to an accident and emergency (A&E) department after a 999 call. An unblinded researcher abstracted data including age, date, time, caller, location, reason for call and A&E diagnosis and each case was examined for ten predetermined criteria necessitating an immediate ambulance response--namely, cardiac arrest; chest pain; shortness of breath; altered mental status/seizure; abdominal/loin pain >65 years old; fresh haematemesis; fall >2m; stabbing; major burns. 471 patients were recruited, 55% male, median age 50 years. 406 calls came from bystanders or the patients themselves, 36 from general practitioners, 8 from other hospitals and 21 from the police. 52% of patients were admitted. 44% met at least one of the above criteria. Most patients did not meet the criteria for an immediate ambulance response but might nonetheless be suitable for an urgent response. The criteria used in this study have the advantage of being based on the history provided by the caller. The introduction of a priority-based dispatch system could reduce response times to those who are seriously ill, and also improve road safety.