BLSD Prevention of Sudden Death: What Is the Difference Between Lay People and Medical Professionals?

Between Lay People and Medical Professionals?

M. S

, N. M

, C. R

, E. F

, C. L

, A. C

, L. D’A

D

S

, A. C

, M. C

Sudden death (SD) is a real concern for medicine today, especially as it can occur in people with no signs of disease at all. It can be the first symptom of an underlying problem. The substrate for cardiac arrest is ventricular fibril- lation (VF) or tachycardia (VT) in about 75% of cases, bradyarrhythmias in 20%, and atrioventricular dissociation in 5%. In the United States, more than 350 000 new cases of cardiac arrest are recorded annually, while in Italy it strikes more than 60 000 people every year, with a 10% overall mortality, 20% of this in people with no signs of disease at all. Survival to hospital dis- charge after out-of-hospital cardiac arrest (OHCA) remains poor, generally only in the 5% to 20% range, from the best of emergency response centres.

The chances of surviving a cardiac arrest are strongly dependent on the speed of intervention and, especially, on correct execution of the four funda- mental operations that represent the ‘chain of survival’. The first step is acti- vation of the emergency system, if the patient is unconscious, immediately followed by basic cardiopulmonary resuscitation known as ‘basic life sup- port’ (BLS) [1–4], which consists of sequences of chest compression and arti- ficial ventilation. Defibrillation, the third step (BLSD), is the only treatment that can stop VF/VT, while advanced cardiac life support (ACLS) is the last step, all according the ILCOR and AHA Guidelines 2000 [2, 5].

Since its discovery, external defibrillation has been the cornerstone of emergency cardiac care (ECC) and the principal intervention in most suc- cessful resuscitations from full cardiac arrest. The most effective interven- tion for VF is rapid defibrillation. In certain environments, survival rates can approach 80–100% when defibrillation is achieved within the first few min- utes of a cardiac arrest. Despite efforts to bolster emergency medical care by

1

Department of Cardiology, University Federico II, Naples;

Health Management,

University Federico II, Naples, Italy

broadening training in defibrillation to include emergency medical techni- cians in addition to paramedics, response times for OHCA remain unaccept- ably long. The development in Italy of semi-automatic external defibrillators (AEDs) is due to Monteleone’s law promulgated on 3 April 2001, which allows non-medical personnel to use semi-automatic defibrillators if trained.

Further technological developments in recent years have made these devices more portable and simpler to use. With these improvements and the recogni- tion that time to defibrillation is one of the most critical, if not the most important, factors in clinical outcome, AED use by laypersons has developed widespread support [6, 7]. More widespread use of AEDs may significantly affect response times to OHCA and therefore affect survival.

The AED identifies VF in cardiac arrest victims and provides the means to deliver defibrillation shocks. The operator is required neither to make judgements regarding the cardiac rhythm nor to confirm the need for defib- rillator shocks. Recent advances have enhanced the ease of use of AEDs, including instructional verbal prompts, simplified displays, and icons to help in proper pad placement. An emphasis on human-factors design has simpli- fied the steps that the user has to perform. In addition, the application of more effective low-energy biphasic waveforms to these devices as a means of energy delivery has significantly reduced their size and enhanced their portable nature. The clinical utility of biphasic waveform use in victims of OHCA has been well demonstrated. More efficient use of energy by biphasic waveform AEDs leads to smaller capacitors and batteries. This contributes to the significantly smaller overall size of the newest AEDs.

The impetus for support of the broader use of AEDs derives from obser-

vations that the single most important factor determining outcome from car-

diac arrest is time to defibrillation. Providing defibrillation to a cardiac

arrest victim improves survival by about 10% per minute during the first 10

min of the arrest. Use of AEDs by trained lay people has been shown to

improve survival from OHCA. Likewise, use of AEDs in OHCA by medical

professionals has significantly improved response times and yielded survival

rates as high as 58%. Even if lay people can be trained effectively to the use

of AED, they cannot use the manual defibrillator as the medical practitioner

does, and showed a longer time of utilisation for the defibrillation than the

time spent by the medical practitioner (Fig. 1). Moreover, recently a com-

pletely automatic trainer defibrillator has been introduced that allows us to

train lay people in the use of the new device. Anyway Monteleone’s law men-

tions only the use of AEDs and not about the automatic one, which by con-

trast can be used by the medical practitioner. Moreover, the AHA has recent-

ly approved the use of defibrillator even for children between 1 and 8 years,

using the specific paediatric patches.

Undoubtedly, many public arenas exist in which response times by trained medical personnel may be unacceptably long. The AHA estimates that wider use of AEDs by first-line responders could avert 20 000 to 100 000 deaths per year. Several studies show that AEDs can be used safely and effectively by rescuers with minimal or no previous training in their use, although speed, compliance, and safety can still be improved. These studies support the idea that the use by citizens of publicly accessible AEDs is feasible, and that organised AED training should also focus on community responders and on- site responders. The initial programmes on the use of AEDs by people other than medical professionals involved community responders such as police officers and fire-fighters [8–11]. More recently data have become available from studies based on on-site schemes in which AEDs have been placed in strategic locations such as airports and casinos, or a hybrid approach with on-site AED location plus involvement of community responders [12–15].

Several studies suggest that a tiered response system increases survival rates even if it reduces the time to shock only by 1 or 2 min [16, 17]. Overall sur- vival rates in the various studies vary from less than 3% to over 50%. Time to shock varies remarkably among studies, ranging approximately from an esti- mated 2 to 11 min.

In seeking a reduction of the time from the onset of VF to defibrillation, deployment of AEDs in public places is a very attractive option. Two large- scale observational studies involving airlines have been carried out [13–17].

Fig. 1. Time from beginning of the scenario to delivery of AED shock. Mean time to defibrillation was 88 ± 7 s for lay people and 67 ± 9 s for the medical professionals (MP)

0 20 40 60 80 100 120

Mean time of intervention

MP

Lay people

p <0.0001

Both studies reported remarkable results for treatment of witnessed VF, with greater than 55% survival, and confirmed that time to shock is a major determinant of success. However, a high incidence of unwitnessed cardiac arrest and non-shockable rhythms also occur. Identification and training of the medical practitioner, community, on-site, and home responders should be guided by analysis of the local environment.

A new area of debate centres on whether cardiopulmonary resuscitation (CPR) is an important component of training for rescuers who are not healthcare professionals. Some studies indicate that survival can increase when rescuers use an AED without delivery of BLS [18]. However, other stud- ies show that BLS can increase survival significantly if combined with early defibrillation [19]. Some authors, however, have not questioned the potential value but rather the feasibility of CPR undertaken by lay people. Concern has been raised about reluctance among lay people to perform CPR on a stranger using mouth-to-mouth ventilation due to aversion or fear of infection.

Therefore concern exists that linking CPR administration to defibrillation may limit the acceptance of AEDs. The use of chest compressions only as a substitute for CPR may represent an acceptable alternative for lay people, but this needs further research.

In conclusion, AEDs have developed concurrently with our understand- ing of time to defibrillation as a crucial factor determining the outcome of cardiac arrest [20–23]. Historically, the complexity and size of AEDs dictated that they could be used only by trained medical professionals. Recent tech- nological developments and emphasis on human-factors design have made these devices much more portable and straightforward to use. These factors have supported the notion of a broader use of AEDs, including by lay per- sons. The absolute differences between lay people and medical professionals, however, were small and may be of little clinical relevance. Furthermore, lay subjects demonstrated proficiency in electrode placement and safety precau- tions with the AED system used. These findings suggest that use of this AED by untrained lay people may be feasible. The utility of a simplified training program may be in helping a user perform under the pressure and anxiety of an actual emergency rather than learning a complex operational task.

Otherwise it is very important that a BLSD course also includes CPR tech- nique.

References

1. American Heart Association (1992) Guidelines for cardiopulmonary resuscitation and emergency cardiac care, part I: Introduction. JAMA 268:2171–2183

2. American Heart Association in collaboration with the International Liaison

Committee on Resuscitation (ILCOR) (2000) Guidelines 2000 for cardiopulmonary

resuscitation and emergency cardiovascular care. An international consensus on science. Circulation 102(Suppl I):I-l–I-384

3. Handley JH, Monsieurs KG, Bossaert LL (2001) European Resuscitation Council guidelines 2000 for adult basic life support. Resuscitation 48:199–205

4. Monsieurs KG, Handley JH, Bossaert LL (2001) European Resuscitation Council guidelines 2000 for automated external defibrillation. Resuscitation 48:207–209 5. Robertson C, Steen P, Adgey J et al (1998) The European Resuscitation Council

guidelines for advanced life support. Resuscitation 37:81–90

6. Cummins RO, Doherty A, Hein K et al (1997) Teaching citizens to use an AED dur- ing the AHA HeartSaver course: active vs passive learning and long-term retention of skills. Circulation 96(Suppl I):I365

7. Priori SG, Bossaert LL, Chamberlain DA et al (2004) Policy conference: ESC–ERC recommendations for the use of automated external defibrillators (AEDs) in Europe. Eur Heart J 3:1–9

8. Cummins RO, Hazinski MF, Kerber RE et al (1998) Low-energy biphasic waveform defibrillation: evidence-based review applied to emergency cardiovascular care guidelines. Circulation 97:1654–1667

9. Tunstall-Pedoe H, Bailey L, Chamberlain DA et al (1992) Survey of 3765 cardiopul- monary resuscitations in British hospitals (the BRESUS study): methods and over- all results. BMJ 304:1347–1351

10. Fromm RE Jr, Varon J (1997) Automated external versus blind manual defibrilla- tion by untrained lay rescuers. Resuscitation 33:219–221

11. Myerburg RJ, Fenster J, Velez M et al (2002) Impact of community-wide police car deployment of automated external defibrillators on survival from out-of-hospital cardiac arrest. Circulation 106:1058–1064

12. Caffrey SL, Willoughby PJ, Pepe PE et al (2002) Public use of automated external defibrillators. N Engl J Med 347:1242–1247

13. Page RL, Joglar JA, Kowal RC, et al (2000) Use of automated external defibrillators by a US airline. N Engl J Med 343:1210–1216

14. Davies CS, Colquhoun M, Graham S et al (2002) Defibrillators in public places: the introduction of a national scheme for public access defibrillation in England.

Resuscitation 52:13–21

15. Valenzuela TD, Roe DJ, Nichol G et al (2000) Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos. N Engl J Med 343:1206–1209 16. Van Alem AP, Vrenken RH, de Vos R et al (2004) Use of automated external defibril-

lator by first responders in out-of-hospital cardiac arrest: prospective controlled trial. BMJ 328:396

17. Stotz M, Albrecht R, Zwicker G et al (2003) EMS defibrillation-first policy may not improve outcome in out-of-hospital cardiac arrest. Resuscitation 58:277–282 18. Capucci A, Aschieri D, Piepoli MF et al (2002) Tripling survival from sudden car-

diac arrest via early defibrillation without traditional education in cardiopul- monary resuscitation. Circulation 106:1065–1070

19. Wik L, Hansen TB, Fylling F et al (2003) Delaying defibrillation to give basic car- diopulmonary resuscitation to patients with out-of-hospital ventricular fibrilla- tion: a randomized trial. JAMA 289:1389–1395

20. Santomauro M, Ottaviano L, D’Ascia C et al (2002) Sudden cardiac death preven- tion through hospital early defibrillation: Naples experience. Ital Heart J 1(Suppl 1):92–95

21. Santomauro M, Ottaviano L, Borrelli A et al (2002) Organization Project for Early

Semiautomatic in Hospital Defibrillation (Heart Project). Progress in Clinical Pacing, Rome, 3–6 December 2002, p 46

22. Santomauro M, Ottaviano L, Borrelli A et al (2003) Sudden cardiac death preven- tion through hospital early defibrillation. Naples experience. Pacing Clin Electrophysiol 26:S186

23. Santomauro M, Ottaviano L, Borrelli A et al (2003) Organization Project for Precocious Semiautomatic in Hospital Defibrillation (Naples Heart Project). In:

Gulizia M (ed), New Advances in Heart Failure and Atrial Fibrillation, Springer

Milan, pp 139–149