Basic life support

Basic life support (BLS) is the level of medical care which is used for patients with life-threatening illnesses or injuries until the patient can be given full medical care at a hospital. It can be provided by trained medical personnel, including emergency medical technicians, paramedics, and by laypersons who have received BLS training. BLS is generally used in the pre-hospital setting, and can be provided without medical equipment.

Many countries have guidelines on how to provide basic life support (BLS) which are formulated by professional medical bodies in those countries. The guidelines outline algorithms for the management of a number of conditions, such as cardiac arrest, choking and drowning. BLS generally does not include the use of drugs or invasive skills, and can be contrasted with the provision of Advanced Life Support (ALS). Most laypersons can master BLS skills after attending a short course. Firefighter, lifeguards, and police officers are often required to be BLS certified. BLS is also immensely useful for many other professions, such as daycare providers, teachers and security personnel and social workers especially working in the hospitals and ambulance drivers.

CPR provided in the field increases the time available for higher medical responders to arrive and provide ALS care. An important advance in providing BLS is the availability of the automated external defibrillator or AED. This improves survival outcomes in cardiac arrest cases.

Basic life support consists of a number of life-saving techniques focused on the medicine "CAB"s (previously known as ABC. was recently changed by the American Heart Association) of pre-hospital emergency care:

Healthy people maintain the CABs by themselves. In an emergency situation, due to illness (medical emergency) or trauma, BLS helps the patient ensure his or her own CABs, or assists in maintaining for the patient who is unable to do so. For airways, this will include manually opening the patients airway (Head tilt/Chin lift or jaw thrust) or possible insertion of oral (Oropharyngeal airway) or nasal (Nasopharyngeal airway) adjuncts, to keep the airway unblocked (patent). For breathing, this may include artificial respiration, often assisted by emergency oxygen. For circulation, this may include bleeding control or Cardiopulmonary Resuscitation (CPR) techniques to manually stimulate the heart and assist its pumping action.

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BLS in the United States

BLS in the United States is generally identified with Emergency Medical Technicians-Basic (EMT-B). However, the American Heart Association's BLS protocol is designed for use by laypeople, as well as students and others certified first responder, and to some extent, higher medical function personel. It includes cardiac arrest, respiratory arrest, drowning, and foreign body airway obstruction (FBAO, or choking). EMT-B is the highest level of healthcare provider that is limited to the BLS protocol; higher medical functions use some or all of the Advanced Cardiac Life Support (ACLS) protocols, in addition to BLS protocols.

The algorithm for providing basic life support to adults in the USA was published in 2005 in the journal Circulation by the American Heart Association (AHA).[1]

The AHA uses four-link "Chain of Survival" to illustrate the steps needed to resuscitate a collapsed victim:

Bystanders with training in BLS can perform the first 3 of the 4 steps.

Basic Life Support 2011 Guideline

Steps in resuscitation are now DRS C-A-B in this sequence

- Check for Danger

- Check for Response

- ‘S’ has been added for Send for help

- ‘A’ directs rescuers to open the Airway

- ‘B’ directs rescuers to check Breathing but no need to deliver rescue breaths

- ‘C’ directs rescuers to perform 30 Compressions to patients who are unresponsive and not breathing normally, followed by 2 rescue breaths

- ‘D’ directs rescuers to attach an AED as soon as it is available and follow prompts

The major change is that in the patient who is unresponsive and not breathing CPR commences with chest compressions rather than rescue breaths. If unwilling / unable to perform rescue breathing, then perform compression-only CPR, as any attempt at resuscitation is better than no attempt; and should be encouraged.

Adult BLS sequence

Assess:* If the patient is breathing normally, and pulse is present then the patient should be placed in the recovery position and monitored. Transport if required, or wait for the EMS to arrive and take over.

If the victim has no suspected cervical spine trauma, open the airway using the head-tilt/chin-lift maneuver; if the victim has suspected neck trauma, the airway should be opened with the jaw-thrust technique. If the jaw-thrust is ineffective at opening/maintaining the airway, a very careful head-tilt/chin-lift should be performed.

Continue chest compression at a rate of 100 compressions per minute for all age groups, allowing chest to recoil in between. For adults push up to 5 cm and for child up to 4cm. For infants up to 3cm or 1/3 of the chest diameter antero-posteriorly.Keep counting aloud. Press hard and fast maintaining the rate of at about 100/minute.Allow recoil of chest fully between each compression.After every 30 chest compressions give two rescue breaths in adult and child victim, Continue for five cycles or two minutes before re-assessing pulse.

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If an AED is available it should be activated immediately and its directives followed and (if indicated), call for clearance before defibrillation/shock should be performed. If defibrillation is performed,begin chest compression immediately after shock.

Note CPR for infants and children uses a 15:2 cycle when two rescuers are performing CPR (but still uses a 30:2 if there is only one rescuer). Two person CPR for an infant also requires the "two hands encircling thumbs" technique for the rescuer performing compressions.

Drowning

Rescuers should provide CPR as soon as an unresponsive victim is removed from the water. In particular, rescue breathing is important in this situation.

A lone rescuer is typically advised to give CPR for a short time before leaving the victim to call emergency medical services.

Since the primary cause of cardiac arrest and death in drowning and choking victims is hypoxia, it is more important to provide rescue breathing as quickly as possible in these situations, whereas for victims of VF cardiac arrest chest compressions and defibrillation are more important.

Hypothermia

Foreign body airway obstruction (choking)

BLS in the United Kingdom

Adult BLS guidelines in the United Kingdom were also published in 2005 by the Resuscitation Council (UK),[2] based on the 2005 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations (CoSTR) published in November 2005.[3]

Adult BLS sequence

These guidelines differ from previous versions in a number of ways:

These changes were introduced to simplify the algorithm, to allow for faster decision making and to maximize the time spent giving chest compressions; this is because interruptions in chest compressions have been shown to reduce the chance of survival.[4] It is also acknowledged that rescuers may either be unable, or unwilling, to give effective rescue breaths; in this situation, continuing chest compressions alone is advised, although this is only effective for about 5 minutes.[5]

Adult choking sequence

In other countries

The term BLS is also used in some non-English speaking countries (e.g. in Italy[6]) for the education of first responders.

See also

References