Original article
Emergency response time after out-of-hospital cardiac arrest

https://doi.org/10.1016/j.ejim.2011.04.003Get rights and content

Abstract

Objectives

To investigate the emergency response time after out-of-hospital cardiac arrest (OHCA) in four cities in Serbia.

Methods

A prospective, two-year, multicenter study was designed. Using the Utstein template we recorded out-of-hospital CPR (OHCPR) and analyzed the time sequence segment of the variables in OHCA and CPR gold standards. Multivariable logistic regression models were developed using emergency response time as the primary independent variable and survival to return of spontaneous circulation (ROSC), survival to hospital discharge (HD), and one-year survival (1y) as the dependent variable. ROC curves represent cut off time dependent survival data.

Results

During the study period, the median time of recognition OHCA was 5.5 min, call receipt was 1 min and the call–response interval was 7 min. The median time required to verify OHCA and ALS onset was 10 min. ALS was carried on for 30.5 min (SD = 21.3). Abandonment of further CPR/death occurred after 29 min. The first defibrillation shock was performed after 13.3 ± 9.0 min, endotracheal tube was placed after 16.8 ± 9.4 min and the first adrenaline dose was injected after 18.9 ± 9.3 min. Higher survival (ROSC, HD, 1y) rate was found when CPR is performed within the first 4 min after OHCA.

Conclusion

The emergency response time within 4 min was associated with improved survival to ROSC, HD and 1y after OHCA. Despite the fact that our results are in accordance with the findings published in other papers, there is still a need to take all appropriate measures in order to decrease the emergency response time after OHCA.

Introduction

The time from out-of-hospital cardiac arrest (OHCA) to definitive outcome (survival or death) endlessly flows and is the most elusive variable. Precise determination of the timing of the situation course is needed for an accurate medical documentation and follow-up of the outcome of recent advances in out-of-hospital cardiopulmonary resuscitation (OHCPR) [1]. The standard report Utstein template [2] (Fig. 1), includes two major categories of variables for the record of OHCPR: event variables and outcome variables. Time points and event-to-event intervals were the least precise and the most susceptible to subjectiveness while completing the Utstein template.

Four subsequent time clocks activate from the moment of OHCA and they represent the time of the emergency response [3] (Fig. 2). There are some points in time which should be recorded as compulsory criteria during OHCA. These are [2]:

  • 1.

    Time of collapse/time of recognition. Despite its importance, data regarding this time point are the most imprecise of all, especially if it is a matter of unwitnessed OHCA. The time of collapse can be reported only by a witness to the event. However, in a state of panic, the witness can hardly remember to look at the watch and memorize the time. The time of recognition is the time when a person who did not witness OHCA is found by a third party.

  • 2.

    Time of call receipt. Modern dispatch centers for EMS record this time automatically, as well as the time at which the operator forwarded the call to the team on the field. These data are memorized within the listing at the dispatch center.

  • 3.

    Time of departure and arrival of vehicle at the scene. This is the time at which the vehicle stops at the resuscitation scene. Slow reception of relevant data from the caller, or a delayed activation of the emergency team can result in prolonged interval between the alarm and the departure of the EMS vehicle.

  • 4.

    Time of confirmed OHCA.

  • 5.

    Time of duration of CPR. ROSC is an intermediate outcome which can be of a transient nature. Patients who never re-established spontaneous circulation should also be noted.

  • 6.

    Time of abandoning CPR attempts/death at the intervention site. The time at which CPR efforts were terminated outside the hospital (in the field, during transport or in the ER) should be recorded as a separate entity.

  • 7.

    Time of departure from the scene and arrival to ED.

  • 8.

    Time of awakening. These time points were deleted because of their imprecise definitions and the practical difficulties encountered in documenting the times accurately.

The inaccurate use of the term time and interval results in confusion and false interpretation of OHCA in the available literature [2]. Interval is not the same as time as it refers to a period between two events. Various jargon terms should be rejected and the term interval should be used only for the time between two events. One of the most non-uniformed terms in CPR is the call–response interval (time of response) and represents the period from collection of the call up to the moment of stopping the emergency vehicle. This interval includes the time of calling the EMS, collection of the call, forwarding the call to the closest team, movement of the team from their base to the emergency vehicle, starting the vehicle and arrival at the intervention site. This interval is prolonged for time of approach to the patient or for the time needed to prepare the defibrillator.

Four time intervals are the “gold standard” for CPR comparison:

  • 1.

    Interval from event onset to start of CPR.

  • 2.

    Interval from event onset to first defibrillation. Early defibrillation is the milestone of successful treatment of lethal arrhythmia (VF/pulseness VT). The time interval between collapse and first defibrillation is the key variable in the follow up of a number of other elements of the emergency response.

  • 3.

    Interval from event onset to advanced airway management, is critical, but it is one of the most demanding procedures for the EMS physicians during OHCPR.

  • 4.

    Interval from event onset to first administration of adrenaline. The reports do not need to show the exact increase of the applied i.v. drug dose during OHCPR, but the application of these drugs is time dependent [2]. New evidence suggests that an early defibrillation, not only shortens the time between collapse and defibrillation in patients in VF/pulseness VT, but analogously shortens the interval between intubation and application of drugs [4].

Section snippets

Objectives

The aim of this study was to determine the emergency response time after OHCA using Utstein style template for OHCPR carried out in four cities in Serbia (Belgrade, Novi Sad, Niš and Kragujevac).

Study design

The multi-centric (Belgrade, Novi Sad, Niš, and Kragujevac), prospective study was conducted prospectively during the two-year period, from 1 January 2007 to 31 December 2008. The out-of-hospital CPR and their outcomes were recorded. The out-of-hospital emergency medical team (emergency medical doctor — EMD, nurse and driver) was providing the ALS (advanced life support) according to the CPR Guideline for 2005.

Study subjects

The study sample consisted of patients older than 18 years and experiencing sudden

Results

Using the Utstein template, the distribution of patients and the events during the out-of-hospital CPR and the follow-up were analyzed in a whole study sample, as well as for each city independently: BG (Belgrade), NI (Nis), NS (Novi Sad) and KG (Kragujevac). The data are presented in Fig. 3[5]. During the investigation, 591 patients met the inclusion criteria for study enrollment and OHCPR.

Discussion

The emergency response time guideline has its origin in an article published in 1979 that evaluated patient outcomes after out-of-hospital nontraumatic cardiac arrest [6]. The investigators reported that survival decreased significantly if basic life support and advanced life support were initiated in >.4 min and >.8 min, respectively. They therefore suggested these times as recommended guidelines for the emergency response of basic and advanced life support providers.

The key variable for a

Conclusion

The most suitable time of emergency response in OHCA is still unknown, as well as the intensity and duration of treatment by the EMS. Our study points out the need for improvements in CPR management strategies, CPR data colection, resuscitation team management, and basic and adult life support training programs. It also points out the need for basic training in the use of automated external defibrillators for all first line rescue. Rapid resuscitation performed within the first 4 min after OHCA

Learning points

  • Emergency response time includes the time of calling the EMS, collection of the call, forwarding the call to the closest team, movement of the team from their base to the emergency vehicle, starting the vehicle and arrival at the intervention site.

  • Four subsequent time clocks (patient, dispatch, ambulance, and hospital) activate from the moment of OHCA and they represent the time of the emergency response.

Contributors

Sladjana Andjelic, corresponding author, is a principal investigator. She is working in City Emergency Medical Care Center, Belgrade, Serbia, and as head of Center for education. She is a designer of internal protocol — acute stroke list as one part of examination in this study. She followed up the patients who are included in the study.

Ana Sijacki, as a mentor,attended to the propriety of the study investigation.

Panic Gordana followed up all patients admitted in intensive units.

Conflict of interest statement

We declare no conflict of interest in the preparation of this manuscript.

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