Mouth-to-mouth resuscitation, a form of
artificial ventilation, is the act of assisting or stimulating
respiration
Respiration may refer to:
Biology
* Cellular respiration, the process in which nutrients are converted into useful energy in a cell
** Anaerobic respiration, cellular respiration without oxygen
** Maintenance respiration, the amount of cellul ...
in which a rescuer presses their mouth against that of the victim and blows air into the person's lungs. Artificial respiration takes many forms, but generally entails providing air for a person who is not
breath
Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.
All aerobic creatures need oxygen for cell ...
ing or is not making sufficient respiratory effort on their own. It is used on a patient with a beating heart or as part of
cardiopulmonary resuscitation
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore spon ...
(CPR) to achieve the internal respiration.
Pulmonary ventilation (and hence external respiration) is achieved through manual insufflation of the lungs either by the rescuer blowing into the patient's lungs, or by using a mechanical device to do so. This method of insufflation has been proved more effective than methods which involve mechanical manipulation of the patient's chest or arms, such as the
Silvester method
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore spon ...
. It is also known as expired air resuscitation (EAR), expired air ventilation (EAV), rescue breathing, or colloquially the kiss of life. It was introduced as a life saving measure in 1950.
Mouth-to-mouth resuscitation is a part of most protocols for performing cardiopulmonary resuscitation (CPR) making it an essential skill for
first aid
First aid is the first and immediate assistance given to any person with either a minor or serious illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery. It includes initial in ...
. In some situations, mouth-to-mouth resuscitation is also performed separately, for instance in near-
drowning
Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Most instances of fatal drowning occur alone or in situations where others present are either unaware of the victim's situation or unable to offer as ...
and
opiate overdoses. The performance of mouth-to-mouth resuscitation on its own is now limited in most protocols to
health professionals, whereas lay first-aiders are advised to undertake full CPR in any case where the patient is not breathing sufficiently.
History
In 1773, English physician
William Hawes
William Hawes (178518 February 1846) was an English musician and composer. He was the Master of the Children of the Chapel Royal and musical director of the Lyceum Theatre bringing several notable works to the public's attention.
Life
Hawes was ...
(1736–1808) began publicising the power of artificial respiration to resuscitate people who superficially appeared to have drowned. For a year he paid a reward out of his own pocket to any one bringing him a body rescued from the water within a reasonable time of immersion.
Thomas Cogan
Thomas Cogan (8 February 1736 – 2 February 1818) was an English nonconformist physician, a founder of the Royal Humane Society and philosophical writer.
Life
He was born at Rothwell, Northamptonshire on 8 February 1736, the half-brother of ...
, another English physician, who had become interested in the same subject during a stay at Amsterdam, where in 1767 a society for preservation of life from accidents in water was instituted, joined Hawes in his crusade. In the summer of 1774 Hawes and Cogan each brought fifteen friends to a meeting at the Chapter Coffee-house,
St Paul's Churchyard, where they founded the
Royal Humane Society
The Royal Humane Society is a British charity which promotes lifesaving intervention. It was founded in England in 1774 as the ''Society for the Recovery of Persons Apparently Drowned'', for the purpose of rendering first aid in cases of near dro ...
as a campaigning group for first aid and resuscitation.
[
Gradually, branches of the Royal Humane Society were set up in other parts of the country, mainly in ports and coastal towns where the risk of drowning was high and by the end of the 19th century the society had upwards of 280 depots throughout the UK, supplied with life-saving apparatus. The earliest of these depots was the Receiving House in Hyde Park, on the north bank of the Serpentine, which was built in 1794 on a site granted by ]George III
George III (George William Frederick; 4 June 173829 January 1820) was King of Great Britain and of Ireland from 25 October 1760 until the union of the two kingdoms on 1 January 1801, after which he was King of the United Kingdom of Great Br ...
. Hyde Park was chosen because tens of thousands of people swam in the Serpentine in the summer and ice-skated in the winter. Boats and boatmen were kept to render aid to bathers, and in the winter ice-men were sent round to the different skating grounds in and around London.
The society distributed money-rewards, medals, clasps and testimonials, to those who saved or attempted to save drowning people. It further recognized "all cases of exceptional bravery in rescuing or attempting to rescue persons from asphyxia
Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that ca ...
in mines, wells, blasting furnaces, or in sewers where foul gas may endanger life."
Insufflations
Insufflation, also known as 'rescue breaths' or 'ventilations', is the act of mechanically forcing air into a patient's respiratory system. This can be achieved via a number of methods, which will depend on the situation and equipment available. All methods require good airway management to perform, which ensures that the method is effective. These methods include:
* Mouth-to-mouth - This involves the rescuer making a seal between his or her mouth and the patient's mouth and 'blowing', to pass air into the patient's body
* Mouth-to-nose - In some instances, the rescuer may need or wish to form a seal with the patient's nose. Typical reasons for this include maxillofacial injuries, performing the procedure in water or the remains of vomit in the mouth
* Mouth-to-mouth and nose - Used on infants (usually up to around 1 year old), as this forms the most effective seal
* Mouth-to-mask – Most organisations recommend the use of some sort of barrier between rescuer and patient to reduce cross infection risk. One popular type is the 'pocket mask'. This may be able to provide higher tidal volumes than a Bag Valve Mask.
Adjuncts to insufflation
Most training organisations recommend that in any of the methods involving mouth-to-patient, that a protective barrier is used, to minimise the possibility of cross infection (in either direction).
Barriers available include pocket masks and keyring-sized face shields. These barriers are an example of personal protective equipment
Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, e ...
to guard the face against splashing, spraying or splattering of blood or other potentially infectious materials.
These barriers should provide a one-way filter valve which lets the air from the rescuer deliver to the patient while any substances from the patient (e.g. vomit, blood) cannot reach the rescuer. Many adjuncts are single use, though if they are multi use, after use of the adjunct, the mask must be cleaned and autoclave
An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizati ...
d and the filter replaced. It is very important for the mask to be replaced or cleaned because it can act as a transporter of various diseases.
The CPR mask is the preferred method of ventilating a patient when only one rescuer is available. Many feature inlets to support supplemental oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...
, which increases the oxygen being delivered from the approximate 17% available in the expired air of the rescuer to around 40-50%.
Efficiency of mouth-to-patient insufflation
Normal atmospheric air contains approximately 21% oxygen when inhaled. After gaseous exchange
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a b ...
has taken place in the lungs, with waste products (notably carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
) moved from the bloodstream to the lungs, the air being exhaled by humans normally contains around 17% oxygen. This means that the human body utilises only around 19% of the oxygen inhaled, leaving over 80% of the oxygen available in the exhalatory breath.
This means that there is more than enough residual oxygen to be used in the lungs of the patient, which then enters the blood.
Oxygen
The efficiency of artificial respiration can be greatly increased by the simultaneous use of oxygen therapy. The amount of oxygen available to the patient in mouth-to-mouth is around 16%. If this is done through a pocket mask with an oxygen flow, this increases to 40% oxygen. If either a bag valve mask
A bag valve mask (BVM), sometimes known by the proprietary name Ambu bag or generically as a manual resuscitator or "self-inflating bag", is a hand-held device commonly used to provide positive pressure ventilation to patients who are not breathi ...
or a mechanical ventilator is used with an oxygen supply, this rises to 99% oxygen. The greater the oxygen concentration, the more efficient the gaseous exchange will be in the lungs.
See also
* Mechanical ventilation
Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move a ...
- using mechanical devices to assist or replace spontaneous breathing
* Medical emergency
A medical emergency is an acute injury or illness that poses an immediate risk to a person's life or long-term health, sometimes referred to as a situation risking "life or limb". These emergencies may require assistance from another, qualified ...
References
External links
Expired Air Resuscitation
Basic first aid advice from the Australian New South Wales ambulance service
Two page pamphlet detailing EAR
UK resuscitation council website - contains information on the latest approved guidelines
{{Emergency medicine
First aid
Respiration
Emergency medical procedures