Resuscitation 50 (2001) 141–146

The use of AEDs by police officers in the City of London

Paula Ross a,*, Jerry Nolan b, Elizabeth Hill a, Jackie Dawson c, Fiona Whimster a,David Skinner a

a Bart’s City Life Sa�er, St Bartholomew’s Hospital, London, EC1A 7BE, UKb Royal United Hospital, Combe Park, Bath BA1 3NG, UK

c London Ambulance Ser�ice, London, UK

Received 19 January 2001; accepted 22 January 2001

Abstract

The Guidelines 2000 for cardiopulmonary resuscitation recommend shock delivery to victims in ventricular fibrillation within5 min of call receipt by the Emergency Medical Services. In an effort to achieve this goal, in some parts of the United States,police officers have been trained to use automated external defibrillators (AEDs). We undertook a 3-year pilot evaluation of theuse of AEDs by City of London police (CPOL) officers. Over a period of 3 years, 147 CPOL officers were trained in the use ofan AED. Four AEDs were placed on rapid response vehicles covering the City of London. An overall call-response interval targetwas set at 8 min. The CPOL attended 1103 (90%) of the total of 1232 calls to which they were summoned. The mean intervalbetween the first call received and arrival of the CPOL on scene was 8.9�4.0 min. The CPOL applied AEDs to 25 victims, 13of whom were initially in ventricular fibrillation; at least one shock was delivered to all 13. The interval between call receptionand delivery of the first shock was 5.5�2.5 min. The mean interval between switching on the AED and delivery of the first shockwas 24�12 s. Two (15%) of these victims survived to hospital discharge. This study has confirmed the feasibility of training policeofficers in the UK to use AEDs as first responders. The call received to arrival on scene interval should be reduced byimprovements in communication between LAS and CPOL. © 2001 Elsevier Science Ireland Ltd. All rights reserved.

Keywords: Automated external defibrillator (AED); Cardiac arrest; Cardiopulmonary resuscitation; Emergency medical services; First responder

Resumo

As recomendacoes para a reanimacao cardio pulmonar (RCP) 2000, recomendam a administracao de choque as vıtimas emfibrilhacao ventricular ate cinco minutos apos a recepcao da chamada do Servicos de Emergencia Medica (SEM). Na tentativade alcancar estes objectivos, em algumas areas dos Estados Unidos da America (EUA) os polıcias sao treinados para utilizaremdesfibrilhadores Automaticos Externos (DAE). Nos efectuamos um estudo piloto de avaliacao, com os Polıcias de Londres (PL).Num perıodo de tres anos treinaram-se 147 PL a utilizar um DAE. Equiparam-se quatro das viaturas de resposta rapida da cidadede Londres com DAE. Definiu-se como objectivo a chegada ao local em menos de oito minutos, em media. Os PL acorreram a1103 (90%) chamadas, num total de 1232 para que foram solicitados. O tempo medio decorrido da primeira chamada a chegadaao local dos PL foi de 8.9 min�4.0 min. Os PL aplicaram o DAE em 25 vıtimas, 13 das quais estavam inicialmente emfibrilhacao ventricular e aos quais foi administrado pelo menos um choque. O intervalo de tempo decorrido da chamada ate aoprimeiro choque foi de 5.5�2.5 min. O tempo de corrido da ligacao do DAE a administracao do primeiro choque foi de 24�12segundos. Duas destas vıtimas (15%) tiveram alta Hospitalar vivas. Este estudo confirmou a exequibilidade do treino dos PL noReino Unido, no uso de DAE para responderem em primeira linha. O intervalo de tempo entre o pedido de ajuda e a chegadaao local deve ser reduzido melhorando as comunicacoes. © 2001 Elsevier Science Ireland Ltd. All rights reserved.

Pala�ras cha�e: Ressuscitacao cardiopulmonar; Suporte basico de vida; Treino

www.elsevier.com/locate/resuscitation

* Corresponding author. Tel.: +44-20-76063669.E-mail address: info@bcls.org.uk (P. Ross).

0300-9572/01/$ - see front matter © 2001 Elsevier Science Ireland Ltd. All rights reserved.PII: S 0 3 0 0 -9572 (01 )00343 -4

P. Ross et al. / Resuscitation 50 (2001) 141–146142

1. Introduction

The most frequent cardiac arrest rhythm amongstvictims of ‘sudden cardiac death’ is ventricular fibril-lation (VF), which is usually secondary to ventriculartachycardia (VT) [1]. If untreated, VF will continueto deteriorate into asystole within 12–15 min. Electri-cal defibrillation is the most effective treatment forVF. The survival rates after VF cardiac arrest de-crease approximately 7–10% with every minute thatdefibrillation is delayed [2].

After a witnessed cardiac arrest due to VF, if defi-brillation is attempted in less than 8 min, the likeli-hood of survival may be in excess of 50% [3]. TheGuidelines 2000 for cardiopulmonary resuscitationhave set the goal of shock delivery within 5 min ofcall receipt by the Emergency Medical Services (EMS)[4]. If an EMS call-to-shock interval of �5 min can-not be achieved reliably, these guidelines recommendthe use of other personnel to function as first respon-ders in the community. In two centres in the UnitedStates, police officers have been trained to use auto-mated external defibrillators (AEDs) and have re-duced the time to defibrillation successfully [5–10].Our study is the first to assess the use of AEDs bypolice officers in the UK.

Unlike most of Greater London, its centre, the Cityof London, comprises mainly business accommoda-tion; it has a daytime population of approximately240 000 people, with a residential population of lessthan 5000. This demography should improve thelikelihood of a cardiac arrest being witnessed and theEMS being called relatively rapidly. The relativelyyoung age of the population in this area ought toimpact favourably on outcome after cardiac arrest[11].

Bart’s City Life Saver (BCLS) was established in1986 and is based at St Bartholomew’s Hospital inthe City of London. It is an independently fundedmedical charity. Its aims are to reduce premature andunnecessary sudden death from heart attack, acciden-tal injury and other life-threatening illnesses, primarilythrough education, training and research. Over thepast 14 years, BCLS has trained over 36 000 peoplein basic life support (BLS).

The City of London police (CPOL) maintain atarget call-response interval of 4 min to emergencycalls within the City of London. In collaboration withthe London Ambulance Service (LAS) and CPOL,BCLS undertook a 3-year pilot evaluation of the useof AEDs by police officers. In line with publishedrecommendations, a 2-h BLS course was offered toall other officers in order to strengthen all links in theChain of Survival [12].

2. Method

Starting in February 1997, over a period of 3years, 147 CPOL officers were trained in the safe andeffective use of an AED. They were instructed as firstresponders, defined as acting independently within amedically controlled system [13]. Training comprisedan initial 6-h course, followed by a 3-h recertificationevery 6 months.

Four AEDs (LifePak 500, Physio-Control UK Ltd,Basingstoke, UK) were placed on rapid response vehi-cles covering the square mile of the City of London(postcodes EC1-4), with a fifth unit situated perma-nently at the Central Criminal Court at the Old Bai-ley, a location identified previously as a high riskarea. An overall call-response interval target was setat 8 min.

Call criteria deemed indicative of a heart attack orcardiac arrest are listed in Table 1. When LAS Con-trol received a 999 call meeting any of these criteria,a paramedic ambulance was despatched by the rele-vant sector desk. An operator on the Special IncidentDesk (SID) screened every call passing through LASControl (approximately 3000 per day) and relayedany calls meeting these criteria to the CPOL (Fig. 1).All calls fulfilling the project’s location (post codesEC1-4) and call-out criteria were eligible to be sent tothe police. Communication was initially via a dedi-cated fax machine (later also via telephone) straightto the CPOL Control, who then mobilised the firstavailable crew. Although the CPOL were available ona 24-h basis, the LAS SID was staffed between 07:00and 23:00 h only.

The LAS did not downgrade calls in response toattendance by the police. Personnel from the first ve-hicle on scene commenced resuscitation and the policehanded over to the LAS on their arrival. The policedid not transport casualties to hospital.

Data on all calls attended by the CPOL were col-lected in the Utstein format [14] and entered ontoMicrosoft Excel spreadsheets. Simple descriptivestatistical analyses were applied. Times are cited asmean�S.D. Initial rhythms and times for switching

Table 1Call-out criteria 1997–2000

Cardiac arrestRespiratory arrestUnconscious — cause unknownCentral chest painChest pain — radiating into jaw/neck/left armSevere difficulty in breathingCollapse with a cardiac historyCold and clammy with cardiac historyCyanosed/peripherally blueGP diagnosis

P. Ross et al. / Resuscitation 50 (2001) 141–146 143

Fig. 1. Flow chart for activation of police first responders. LAS, London Ambulance Service; CPOL, City of London police; CAD,computer-aided dispatch.

on AEDs and delivering the first shock were takendirectly from data stored in the AED memory.

To increase public awareness surrounding the Chainof Survival, BCLS distributed 150 000 leaflets to Cityworkers, detailing the early signs and symptoms of heartattack and the need to call the emergency servicesquickly. BCLS also publicised the importance of its workwith a month-long poster campaign on the LondonUnderground.

3. Results

Every police officer passed all of their AED trainingassessments. Over 3 years, the CPOL managed to attend1103 (90%) of the total of 1232 calls to which they wereactivated. Sixty-three (5.7%) of these calls were ‘policegenerated’; these resulted from calls from the public orpatrolling officers contacting the CPOL Control directly.

The CPOL applied AEDs to 25 victims; the initialrhythms are listed in Table 2. One of these victims hada perfusing rhythm. Thirteen (52%) of the victims wereanalysed initially as having shockable rhythms and atleast one shock was delivered in all cases. After inspectionof the continuous ECG records from the AEDs, three ofthe victims analysed as having non-shockable rhythmsinitially were considered to be in fine VF. In one of these,the VF later increased in amplitude, which was analysedby the AED as a shockable rhythm; a shock was then

delivered. Data from this victim were not included in thedetermination of median call to shock intervals.

Four patients survived more than 24 h (three in VFinitially, and one with pulseless electrical activity). Twoof these were alive after 1 year, representing 15% of the13 casualties found initially in VF. These both resultedfrom police generated calls to elderly males found in thestreet.

The time intervals between the LAS receiving a calland the CPOL entering the data on to their computeraided despatch (CAD) system (LAS call received to CADentry) and between CPOL receiving a call and arrivingon scene (CPOL call received to on scene) are listed inTable 3. The mean interval between the first callreceived and arrival of the CPOL on scene (total calltime) was 8.9�4.0 min. In the 13 cases involving

Table 2Initial rhythms in cases where CPOL applied AED

Number (%)Initial rhythm

Shockable (VF) 13 (52)

Non-shockableAsystole 5 (20)Fine VF 3 (12)a

3 (12)Pulseless electrical activity1 (4)Perfusing rhythm

a In one case, the amplitude of the VF increased and became‘shockable’ during the resuscitation attempt.

P. Ross et al. / Resuscitation 50 (2001) 141–146144

Table 3Critical time intervalsa

Mean (S.D.) RangeN

8.9�4.0 minTotal call time 0–36 min11031042 4.0�2.3 min 0–26 minLAS call receive to CPOL

CAD entry1102bCPOL call receive to on 5.1�3.4 min 0–34 min

scene13Call receive to first shock 5.5�2.5 min 1–10 min

deliveryc

13 24�12 s 15–59 sAED on to first shockdelivery

a LAS, London Ambulance Service; CPOL, City of London police;CAD, computer aided dispatch.

b One CPOL call receive time missing.c Using the earliest of the LAS or CPOL call receive time.

Table 4Call diagnosis assigned by LAS Control according to informationfrom original call

Diagnosis PercentNumber

Chest pain 34.2379Collapse 28.3313

131 11.8OtherUnconscious 110 9.9

80 7.2Difficulty in breathingHeart attack 64 5.6

15 1.4Suspended?Purple? 9 0.8

0.5Cardiac arrest 6

4. Discussion

This study has confirmed the feasibility of trainingpolice officers in the UK to use AEDs as first respon-ders. City of London police officers were first on sceneand in a position to use an AED before the LAS inalmost half of the cases that they were asked to attend.This potential reduction in the collapse to defibrillationinterval will increase the chances of successful defibrilla-tion [2,15]. The mean call received to first shock inter-val was 5.5�2.5 min, which compares favourably withpolice defibrillation programs in the US [6–8]. Themean interval between switching the AED on anddelivery of the first shock was 24�12 s. This is signifi-cantly less than the 0.9 min (54 s) between attachmentof the AED and first shock delivery reported recentlyfor a casino security officer defibrillation program [16].

In comparison with some American studies [7], thefrequency with which CPOL officers applied AEDs waslow. Over a 3-year period AEDs were applied by policeofficers in only 25 (4.6%) of the 542 incidents at whichthey were first on scene. Of the 13 patients in shockablerhythms initially, only two (15%) survived to hospitaldischarge. In these two cases, the ‘diagnoses’ were givenas ‘unconscious’ and ‘collapse’ and, on each occasion,immediate two-person bystander CPR had been com-

initially shockable rhythms, the interval between callreceipt and delivery of the first shock was a mean of5.5�2.5 min and the interval between switching on theAED and first shock delivery was 24�12 s (Table 3).The CPOL were first on scene in 542 (49%) of the casesthey attended, significantly more frequent than the LAS(43%, P=0.0487) (Fig. 2).

The break down of the calls by diagnostic categoryassigned by the LAS Control is given in Table 4.

The mean age of the victims attended by the CPOLwas 48 (S.D. 19, range 10–95, data available from 685)and 69% were male. The majority of calls attended bythe CPOL were located in postal code area EC1 (40%)(Fig. 3), and most were in public sectors (Fig. 4).Incident times were collated into four time periods (Fig.5). The majority of calls were attended between 06:00and 18:00 h.

Fig. 2. Analysis of first on scene in those cases attended by theCPOL. Fig. 3. Location by postcode of cases attended by the CPOL.

P. Ross et al. / Resuscitation 50 (2001) 141–146 145

Fig. 4. Sector location of cases attended by the CPOL.

Guidelines 2000 [4]. There were two main reasons forthis relatively long call to arrival of CPOL interval. Themost important reason was the average delay of 4.0 minbetween reception of a call by LAS Control and trans-mission to the CPOL. The fax/phone system used bythe LAS was clearly unacceptable. This has now beenreplaced by a fast computer link between the twocontrol rooms, which automatically identifies any callfulfilling the location and diagnostic criteria. Relevantcalls are now transmitted from the LAS call-takerdirectly to the CPOL control room. This system ex-cludes the SID, which should significantly reduce thenumber of ‘missed’ calls, as well as providing compre-hensive 24-h cover. The new system is expected toreduce the overall call-response interval by alerting thepolice as much as 3 min earlier.

Another reason for the relatively long LAS call toarrival of CPOL interval was that the CPOL call-re-sponse interval of 5.1 min was outside the CPOL 4-mintarget call-response interval to any immediate (Grade 1Response) call within the city boundaries. This is ex-plained simply by the fact that 39% of calls attended bythe CPOL originated in Metropolitan Police areas,which were outside the CPOL territory and conse-quently less familiar and further away. The Metropoli-tan Police is a separately administered force. Fortypercent of all calls originated from postal code areaEC1 and a significant proportion of this area is coveredprimarily by the Metropolitan Police. It would be ratio-nal to consider training key Metropolitan Police officersto carry and use AEDs.

There were other weak links in the communicationsystem, in addition to the 4-min delay in transmissionof a call from the LAS Control to the CPOL. SpecialIncident Desk operators were expected to identify rele-vant calls from several thousand that they reviewedmanually each day. Furthermore, the LAS SID wasstaffed between 07:00 and 23:00 h only. The combinedresult of these weaknesses was that the LAS failed tosend 65% of potential calls (those fulfilling both diagno-sis and location criteria) to the CPOL. Indeed, the twolong-term survivors from this project resulted from callscoming directly from the CPOL rather than via theLAS.

Despite the weaknesses in the current communicationsystem, this study has shown that the use of police firstresponders will reduce overall response times. The re-sponse times from this project have contributed to thetarget ambulance response times set by the government(ORCON). This CPOL first responder scheme, alongwith other similar schemes [17], will contribute to meet-ing the new performance standard of 75% of immedi-ately life-threatening calls being reached within 8 minby the year 2000–2001 [18]. First responders in thecommunity will be essential if the CPR Guidelines 2000recommendation of a call-to-shock interval of �5 minis to be achieved [4].

menced. Both casualties had a return of spontaneouscirculation after one shock and survived with goodcerebral and overall performance.

There are number of reasons for the low incidence ofAED use by CPOL officers. Inevitably, the specificityof the information given to the LAS Control by thepublic is poor. Only six (0.5%) of the calls attended byCPOL were assigned to the category of ‘cardiac arrest’by LAS control; these were all confirmed as cardiacarrests subsequently. Lay people cannot be expected todiagnose a cardiac arrest reliably, thus, the criteria forfirst responder activation must be kept broad. In-evitably, the majority of calls to which the CPOLattend will not be cardiac arrests. The adoption andinstallation of an Advanced Medical Priority DespatchSystem (AMPDS) by the LAS may improve the specifi-city of the call out criteria.

For those 13 cases attended to first by CPOL andwho were initially in VF, the mean call received to firstshock interval was 5.5�2.5 min. For all cases attendedby CPOL, however, the mean interval between recep-tion of the call by LAS control and arrival of the CPOLon scene was 8.9�4.0 min. This is significantly longerthan the target of 5 min recommended in the CPR

Fig. 5. Incident times. AM1, 24:00–06:00 h; AM2, 06:01–12:00 h;PM1, 12:01–18:00 h; PM2, 18:01–23:59 h.

P. Ross et al. / Resuscitation 50 (2001) 141–146146

The CPOL AED program will continue to be auditedand it is hoped that improvements in the communica-tion systems will be reflected by an increased number oflong-term survivors following defibrillation by CPOLofficers.

Acknowledgements

We would like to thank the City of London Policefor their participation in this study. The Corporation ofLondon and the Special Trustees for St Bartholomew’sHospital, London, funded this study. Leaflets detailingthe early signs and symptoms of heart attack werefunded partly by British Telecom.

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