CPR in Remote Environments
If the casualty is unconscious and not breathing, they are already dead.
Clinically, this statement is not strictly true as there may be other signs of life which the lay rescuer may not be able to determine but this seemingly callous assumption is made for several reasons, not just for the casualty’s benefit, but for everyone’s:
- There are several reasons why the casualty may not be breathing, the worst case scenario is that they are in Cardiac Arrest - an inability of the heart to circulate blood either due to an absence of electrical activity or chaotic, uncoordinated electrical activity. If this is the case they will need resuscitation to return normal circulation. This is time critical. If the casualty is not breathing for any other reason, without oxygen they will eventually go into Cardiac Arrest. Time spent deciding if they are dead or not or the reason behind why they are not breathing is wasted time. In either case, the treatment is the same.
The exception to this is Drowning and Children which will be discussed in a separate article.
- The best possible outcome is the casualty is successfully resuscitated and makes a full recovery but the absolute worst outcome is that they stay dead. It cannot get any worse.
- It is not your fault. Because of the misconception that CPR will ‘bring them back to life’ it is a typical for a First Aider to place blame on themselves when a casualty is not successfully resuscitated: “Maybe I did something wrong?” or “Maybe I should have done it better?”
By changing our perspective, any failure to successfully resuscitate can never be seen as anyone’s fault. They didn't die, they stayed dead.
So why do we do CPR?
CPR on its own is highly unlikely to successfully resuscitate a casualty in Cardiac Arrest but it may introduce and circulate oxygen to delay cardiac and cerebral ischemia. CPR also has a specific role in a combination with a sequence of other interventions known as the Chain of Survival.
In 1988 Mary Newman coined the phrase “The Chain of Survival” at a national conference on Citizen CPR(1) which formed the basis for her 1989 article “The Chain of Survival Takes Hold”.(2)
This model demonstrates the sequential protocol for treating any casualty who is assumed to be in Cardiac Arrest for the very simple aim of increasing their chance of recovery. Like any chain, it is only as strong as is weakest link; in terms of successful resuscitation the weakness in each link is time delay.
As soon as it is recognised that the casualty is not breathing, contact the emergency services and / or summon a defibrillator. While Basic Life Support is concerned with resuscitation of a casualty in Cardiac Arrest the protocol is triggered by the absences of breathing. Checking for the absence of a carotid pulse is not only an unreliable indicator of cardiac arrest for the lay rescuer.(3) it is also time consuming - a delay of 2 minutes in the initial call for help reduces survival rates by 50%.(4)
Regardless of cause, if the casualty is not breathing they are either in cardiac arrest or they will be soon! Immediately summon a defibrillator or call for help.
Effective CPR will circulate approximately 25-33% blood volume (5, 6) – not enough to sustain life but enough to delay tissue cell death. The chance of survival decreases by 50% after only 4 minutes delay of CPR. (4)
60% of Cardiac Arrests are caused by Heart Attack (Myocardial Infarction) with 50-80% of these casualties being in Ventricular Fibrillation.(7, 8) This is a shockable rhythm which may be reverted by defibrillation. CPR alone will never revert the heart’s electrical activity to a normal rhythm but effective CPR may keep the heart in this shockable state for a minutes longer. (9)
Once help has been called or a defibrillator summoned, start CPR.
Defibrillation is the only method that exists pre-hospital to depolarize the abnormal electrical activity in the heart and yes, this is time critical too! From the moment the heart goes into arrest, every cell in the body is being deprived of oxygen, including heart tissue. Prolonged cardiac hypoxia causes irreversible damage which if left untreated will cause the heart to stop completely. Once there is an absence of electrical activity, defibrillation with an AED will not work. Pre-hospital survival rates decrease by 50% with a delay of 7 minutes from collapse. (4)
As soon as it is practical, stop CPR, turn on the defibrillator and follow the instructions.
If a second rescuer is available they prepare the defibrillator without interrupting your CPR.
Early Advanced Care
While timely CPR and Defibrillation will increase the casualty’s chance of recovery they by no means guarantee it. Whether normal circulation has resumed or not, the casualty will need Advanced Life Support; advanced interventions, drugs and techniques. A defibrillator may be able to return normal electrical activity to the heart and, as a result, normal circulation but it does not deal with the root cause of the arrest which may still be present. One estimate of the maximum time limit for Advanced Care is 30 minutes and 90 minutes for transport to definitive care. (10)
Resuscitation in Remote Environments
In a remote environment we may be able to summon help and commence CPR quickly but without the remaining links of the chain in place, within their respective time limits, the chance of recovery is negligible.
It is sometimes worth attempting resuscitation, if you are willing and able, even if you suspect it may be futile:
- Your conscience is clear, safe in the knowledge that you followed protocols and did everything you reasonably could, without any “what if’s?”
- Witnessing an attempt to resuscitate the casualty is an important factor in enabling other people, especially family if they are present, to work through the grieving process.
When to stop CPR in a Remote Environment
There is no definitive guidance on when to stop CPR in a remote environment. Countries which subscribe to the International Liaison Committee on Resuscitation (including the US and UK) are advised:
- qualified help arrives and takes over,
- the victim starts to show signs of regaining consciousness, such as coughing, opening his eyes, speaking, or moving purposefully AND starts to breathe normally, OR
- you become exhausted.
In addition to this two sources state after 30 minutes in a remote environment. (11, 12)
Signs of death
It may not be appropriate to start CPR if the casualty is clearly dead; the experience may be distressing for the rescuer or those watching, it may be unethical or it may consume time, resources and effort which could be better applied elsewhere.
In Case of Death
- Locate and secure the person’s passport, identification and insurance details, medication, diary, camera, mobile phone and diary as these may be used as evidence in an inquest.
- Inform the police and, if abroad, the Embassy, consulate or High Commission; yours and theirs if different. Provide them with the contact details of the person’s next of kin.
All deaths need to be registered in the country you are visiting at the time as well as the deceased’s home country. A death certificate will need to be issued before the body or ashes can be repatriated.
- If the casualty has died from infection disease, alert the authorities as soon as possible and secure the area from humans and wildlife. Remain together as and limit travel unless absolutely necessary.
Do not move the body until you have received permission from the local police. In tribal regions where there is no police, seek permission from the Head of the tribe or village.
You should not interfere with the body to preserve evidence, however sometimes you will need to cover the body or even bury it dependant on how long it will take to be retrieved. Reasons for covering or burial include dignity, infection control and protection of the body from flooding, avalanche, wildlife etc.
- Mark and record the location accurately to aid recovery of the body
Related Article: Hypothermia Guidelines
Related Article: Defibrillators in Remote Environments
- Newman MM (1988) “Early access, early CPR and early defibrillation: Cry of the 1988 Conference on Citizen CPR.” Journal of Emergency Medical Services. 13:30-35
- Newman M (1989). "The chain of survival concept takes hold". Journal of Emergency Medical Services. 14: 11–13.
- Eberle B, Dick WF, Schneider T, Wisser G, Doetsch S, Tzanova I. (1996) “Checking the carotid pulse check: diagnostic accuracy of first responders in patients with and without a pulse.” Resuscitation. Dec;33(2):107-16.
- Waalewijn RA, de Vos R, Tijssen JG, Koster RW. (2001) “Survival models for out-of-hospital cardiopulmonary resuscitation from the perspectives of the bystander, the first responder and, the paramedic”. Resuscitation. Nov;51(2):113-22.
- American Heart Association (2005) “2005 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 7.1: Adjuncts for Airway Control and Ventilation”. Circulation. 112: IV-51-IV-57
- Jiang L, Jhang J (2011) “Mechanical cardiopulmonary resuscitation for patients with cardiac arrest.” World Journal of Emergency Medicine, 2(3)
- van Alem AP, Vrenken RH, de Vos R, et al. (2003) “Use of automated external defibrillator by first responders in out of hospital cardiac arrest: prospective controlled trial.” British Medical Journal. 327:1312.
- Whitfield R, Colquhoun M, Chamberlain D, et al. (2005) The Department of Health National Defibrillator Programme: analysis of downloads from 250 deployments of public access defibrillators. “Resuscitation” 2005;64:269-77.
- Bossaert LL (1997). "Fibrillation and defibrillation of the heart". British Journal of Anaesthesia 79 (2): 203–13.
- Vukmir R. (2006) “Survival from prehospital cardiac arrest is critically dependent upon response time.” Resuscitation. 69:229-234.
- Duff J, Gormly P (2010) "First Aid and Wilderness Medicine" Cicerone, Singapore, p.82
- Center for Wilderness Safety (2011) "Wilderness Protocol 1: CPR and Cardiac Arrest." https://www.wildsafe.com/resources/protocols/1.html Accessed 19th October 2014