Ambulance calls and prehospital transportation time of emergency patients with cardiovascular events in Osaka City.

AIM

This study investigated the association between the number of phone calls made to hospitals from ambulances requesting if they can accept prehospital emergency patients with cardiovascular events, and the prehospital transportation time.

METHODS

Using ambulance records, we retrospectively enrolled adult patients suffering acute myocardial infarction from 1998 to 2007, and out-of-hospital cardiac arrest of cardiac origin from 2000 to 2007, transported to medical institutions by the emergency medical service in Osaka City.

RESULTS

During the study period, 8,596 patients with acute myocardial infarction without arrest and 9,283 out-of-hospital cardiac arrests of cardiac origin were registered. The hospital arrival time (from patient's call until hospital arrival) increased along with the increasing number of phone calls to hospitals from ambulances for patients with acute myocardial infarction (from 23.2 min with one phone call to 39.7 min with ≥5 phone calls; for trend <0.001), and for those with out-of-hospital cardiac arrest (from 24.4 min with one phone call to 36.6 min with ≥5 phone calls; for trend <0.001). In a multivariable analysis, chronological factors such as weekend and night-time were significantly associated with an increment in the phone calls to hospitals from ambulances.

CONCLUSIONS

From ambulance records in Osaka City, we showed that the increased number of phone calls to hospitals from ambulances led to prolongation of the hospital arrival time.