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The Use of Automated External Defibrillators and Public Access Defibrillators in the Mountains: Official Guidelines of the International Commission for Mountain Emergency Medicine ICAR-MEDCOM

      In this article we propose guidelines for rational use of automated external defibrillators and public access defibrillators in the mountains. In cases of ventricular fibrillation and pulseless ventricular tachycardia, early defibrillation is the most effective therapy. Easy access to mountainous areas permits visitation by persons with high risks for sudden cardiac death, and medical trials show the benefit of exercising in moderate altitude. The introduction of public access defibrillators in popular areas in the mountains may lead to a reduction of fatal outcome of cardiac arrest. Public access defibrillators should be placed with priority in popular ski areas, in busy mountain huts and restaurants, at mass-participation events, and in remote but often-visited locations that do not have medical coverage. Automated external defibrillators should be available to first-responder groups and mountain-rescue teams. It is important that people know how to perform cardiopulmonary resuscitation and how to use public access defibrillators and automated external defibrillators.

      Key words

      Introduction

      The automated external defibrillator (AED) is a medical heart monitor and defibrillator capable of recognizing the presence or absence of ventricular fibrillation (VF) or rapid ventricular tachycardia and determining, without intervention by an operator, whether defibrillation should be performed. If it determines that defibrillation should be performed, it automatically charges and requests delivery of an electrical impulse to an individual's heart.
      The public access defibrillator (PAD) is designed to be used by anyone without medical training. It gives verbal advice on how to apply the pads and start the automated electric shock procedure and also helps the first responder perform cardiopulmonary resuscitation (CPR) by audible instruction after or instead of shock advisement.
      Eighty percent of sudden cardiac deaths are caused by VF,
      • Sefrin P.
      Frühdefibrillation durch Ersthelfer, Risiko oder Qualitätssprung.
      and every minute of delay reduces the success of defibrillation by 10%.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      Thus, the time to the first attempt at defibrillation is the most important factor in survival of potential victims of sudden cardiac death.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      Cardiopulmonary resuscitation combined with early defibrillation represents the best therapy available for VF.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      Presently, over 75% of persons who experience cardiac arrests in urban areas do not receive adequate care.
      • Gallagher E.J.
      • Lombardi G.
      • Gennis P.
      Effectiveness of bystander cardiopulmonary resuscitation and survival following out-of-hospital cardiac arrest.
      ,
      • Stiell I.G.
      • Wells G.A.
      • DeMaio V.J.
      • et al.
      Modifiable factors associated with improved cardiac arrest survival in a multicenter basic life support/defibrillation system: OPALS Study Phase I results. Ontario Prehospital Advanced Life Support.
      Because of logistic and local reasons, this percentage may be even higher in the mountains; therefore, the numbers of successful outcomes may be lower.
      • Burtscher M.
      • Mittleman M.A.
      Time-dependent SCD risk during mountain sports with age.
      • Breitfeld L.
      • Voelckel W.
      Der plötzliche Herztod im Gebirge und halbautomatische externe defibrillatoren—grundsätzliche Überlegungen.
      • Burtscher M.
      • Pachinger O.
      • Mittleman M.A.
      • Ulmer H.
      Prior myocardial infarction is the major risk factor associated with sudden cardiac death during downhill skiing.
      Many mountain huts and restaurants are readily accessible by lifts and trail routes and thus bring a significant number of high-risk individuals to mountainous areas. There is an increasing trend to advise and encourage those with medical conditions such as hypertension, other cardiac problems, and diabetes to hike and exercise in mountainous areas, resulting in an increasing number of persons at risk.
      • Schobersberger W.
      • Schmid P.
      • Lechleitner M.
      • et al.
      Austrian Moderate Altitude Study 2000 (AMAS 2000). The effects of moderate altitude (1,700m) on cardiovascular and metabolic variables in patients with metabolic syndrome.
      Cardiac arrest is the second most common cause of death in the mountains.
      • Burtscher M.
      Risiko “plötzlicher Herztod” beim Alpinsport.
      A person's risk of cardiac arrest in the mountains increases over the age of 40, and vigorous exercise, dehydration, and hypoxia at higher altitude combined with medical problems may increase this risk.
      • Breitfeld L.
      • Voelckel W.
      Der plötzliche Herztod im Gebirge und halbautomatische externe defibrillatoren—grundsätzliche Überlegungen.
      Also, there are increasing numbers of persons at risk of sudden cardiac death performing winter sports and attending mass events.
      • Burtscher M.
      • Pachinger O.
      • Mittleman M.A.
      • Ulmer H.
      Prior myocardial infarction is the major risk factor associated with sudden cardiac death during downhill skiing.
      ,
      • Burtscher M.
      • Philadelphy M.
      • Likar R.
      Sudden cardiac death during mountain hiking and downhill skiing.
      Although CPR remains the fundamental aspect of resuscitation,
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      the use of automated external defibrillation is an effective therapy of VF and pulseless ventricular tachycardia, and is the first step in resuscitation by laymen on individuals over the age of 8 years.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      ,
      • Atkins D.L.
      • Bossaert L.L.
      • Hazinski M.F.
      • et al.
      Automated external defibrillation/public access defibrillation.
      Public access defibrillators have been shown effective in urban areas, but early defibrillation should also be feasible in the mountains.
      The AEDs and PADs are simple to use and do not require any more medical knowledge than CPR.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      Therefore, as shown by a number of successful resuscitations, the introduction of PADs in busy mountainous areas is recommended.

      Recommendations for the Use of AEDs in the Mountains

      Ideally a PAD or AED should be available wherever a cardiac arrest occurs. In practice, PADs should first be placed in:
      • Areas of highest probability of use, such as popular ski areas
        • Burtscher M.
        • Mittleman M.A.
        Time-dependent SCD risk during mountain sports with age.
        ,
        • Burtscher M.
        • Pachinger O.
        • Mittleman M.A.
        • Ulmer H.
        Prior myocardial infarction is the major risk factor associated with sudden cardiac death during downhill skiing.
        ,
        • Burtscher M.
        • Philadelphy M.
        • Likar R.
        Sudden cardiac death during mountain hiking and downhill skiing.
      • Highly frequented mountain huts and larger restaurants in the mountains
      • Remote and highly frequented locations without medical coverage
      • Mass-participation events in the mountains
      Automated external defibrillators should be used by first-responder groups, according to International Liaison Committee on Resuscitation guidelines.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      Moreover, mountain-rescue teams should be equipped with AEDs.

      Requirements for the Introduction of PADs in the Mountains

      The introduction and use of PADs in the mountains aims to reduce the frequency of cardiac deaths.
      • Burtscher M.
      • Mittleman M.A.
      Time-dependent SCD risk during mountain sports with age.
      ,
      • Burtscher M.
      Risiko “plötzlicher Herztod” beim Alpinsport.
      Knowledge of and ability to perform CPR as well as knowledge of the use of a PAD are essential to improve the outcome of resuscitation.
      • Sefrin P.
      Frühdefibrillation durch Ersthelfer, Risiko oder Qualitätssprung.
      ,
      • Weißmann A.
      • Sefrin P.
      Kardiopulmonale reanimation 2000. Eine Gegenüberstellung aktueller Richtlinien.
      ,
      American College of Sports Medicine and American Heart Association joint position statement.
      Automated external defibrillators in health/fitness facilities.
      Frequent practice of both CPR and PAD use leads to a higher resuscitation success rate.
      American Heart Association
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 4: the automated external defibrillator: key link in the chain of survival.
      ,
      The American Heart Association in collaboration with the International Liaison Committee on Resuscitation
      Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support, section 2: defibrillation.
      It is important that the general population know the availability, location, and use of PADs, and they should be encouraged in CPR and PAD training. Consideration should be given to the use of a single model of defibrillator within a local region.

      Reasons for the Use of AEDs in Mountain Rescue

      In particular situations, an AED is the device of choice for the advanced medical-care provider, such as rescue teams, because it may provide monitoring ability allowing additional treatment in contrast to a PAD.
      • Breitfeld L.
      • Voelckel W.
      Der plötzliche Herztod im Gebirge und halbautomatische externe defibrillatoren—grundsätzliche Überlegungen.
      ,
      • Elsensohn F.
      Gibt es einen Platz für automatische externe defibrillatoren im Bergrettungsdienst?.
      Even though the majority of casualties in mountain rescue are caused by trauma, rescue teams are facing an increasing number of cases of VF and pulseless ventricular tachycardia where an AED is the treatment of choice.
      • Burtscher M.
      • Philadelphy M.
      • Likar R.
      Sudden cardiac death during mountain hiking and downhill skiing.

      Technical Considerations

      The storage location must meet the minimal environmental requirements set by the manufacturer. When an AED is selected, one must consider particular requirements:
      • Automated external defibrillators should apply a biphasic waveform for lower energy, less battery power, less weight,
        American Heart Association Task Force on Automatic External Defibrillation, Subcommittee on AED Safety and Efficacy
        less damage to the myocardium,
        • Xie J.
        • Weil M.H.
        • Sun S.
        • et al.
        High energy defibrillation increases the severity of post resuscitation myocardial function.
        and lower side energy to helpers who unintentionally touch the patient during shock.
        • Cummins R.O.
        • Hazinski M.F.
        • Kerber R.E.
        • et al.
        Low-energy biphasic waveform defibrillation: evidence-based review applied to emergency cardiovascular care guidelines: a statement for healthcare professionals from the American Heart Association Committee on Emergency Cardiovascular Care and the Subcommittees on Basic Life Support and Pediatric Resuscitation.
      • The display should be easily readable in bright sunshine.
      • The device must work in freezing temperatures and wet conditions. This includes the adhesion of pads.
      • The weight should be as low as possible.
      • In organized mountain rescue, an AED should have a monitor and the possibility of attachment of a pulse oximetry device, for rescue teams may be accompanied by a physician or trained paramedic with Advanced Life Support competence. However, it should be noted that blood centralization and hypothermia can result in falsely low pulse oximetry values.

      Acknowledgments

      These recommendations have been discussed and approved at the ICAR-MEDCOM meetings 2003 in Erjavceva Hut, Slovenia, and Coylumbridge, Scotland, by the following members: Borislav Aleraj (CR), Jeff Boyd (CA), Roberto Buccelli (I), Giovanni Cipolotti (I), Tore Dahlberg (N), Florian Demetz (I), Bruno Durrer (CH), John Ellerton (GB), Pawel Jonek (PL), Sylveriusz Kosinski (PL), Tim Kovacs (USA), Xavier Ledoux (F), Peter Mair (A), Walter Phleps (A), Peter Rheinberger (FL), Günther Sumann (A), Dario Svajda (HR), Iztok Tomazin (SLO), Ken Zafren (USA), Gregoire ZenRuffinen (CH), and Igor Zulian (HR).

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