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First aid is the provision of initial care for an illness or injury. It is usually performed by a lay person to a sick or injured casualty until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care past the first aid intervention. It generally consists of a series of simple and, in some cases, potentially life-saving techniques that an individual can be trained to perform with minimal equipment.
While first aid can also be performed on animals, the term generally refers to care of human patients.
Aims
The key aims of first aid can be summarised in three key points:
Preserve life - the overriding aim of all medical care, including first aid, is to save lives
Prevent further harm - also sometimes called prevent the condition from worsening, this covers both external factors, such as moving a patient away from any cause of harm, and applying first aid techniques to prevent worsening of the condition, such as applying pressure to stop a bleed becoming dangerous.
Promote recovery - first aid also involves trying to start the recovery process from the illness or injury, and in some cases might involve completing a treatment, such as in the case of applying a plaster to a small wound.
First aid training also involves the prevention of initial injury and responder safety, and the treatment phases.
Key skills
In case of tongue fallen backwards, blocking the airway, it is necessary to hyperextend the head and pull up the chin, so that the tongue lifts and clears the airway.Certain skills are considered essential to the provision of first aid and are taught ubiquitously. Particularly, the "ABC"s of first aid, which focus on critical life-saving intervention, must be rendered before treatment of less serious injuries. ABC stands for Airway, Breathing, and Circulation. The same mnemonic is used by all emergency health professionals. Attention must first be brought to the airway to ensure it is clear. Obstruction (choking) is a life-threatening emergency. Following evaluation of the airway, a first aid attendant would determine adequacy of breathing and provide rescue breathing if necessary. Assessment of circulation is now not usually carried out for patients who are not breathing, with first aiders now trained to go straight to chest compressions (and thus providing artificial circulation) but pulse checks may be done on less serious patients.
Some organizations add a fourth step of "D" for Deadly bleeding or Defibrillation, while others consider this as part of the Circulation step. Variations on techniques to evaluate and maintain the ABCs depend on the skill level of the first aider. Once the ABCs are secured, first aiders can begin additional treatments, as required. Some organizations teach the same order of priority using the "3Bs": Breathing, Bleeding, and Bones (or "4Bs": Breathing, Bleeding, Brain, and Bones). While the ABCs and 3Bs are taught to be performed sequentially, certain conditions may require the consideration of two steps simultaneously. This includes the provision of both artificial respiration and chest compressions to someone who is not breathing and has no pulse, and the consideration of cervical spine injuries when ensuring an open airway.
Preserving life
In order to preserve life, all persons require to have an open airway - a clear passage where air can move in through the mouth or nose through the pharynx and down in to the lungs, without obstruction. Conscious people will maintain their own airway automatically, but those who are unconscious (with a GCS of less than 8) may be unable to maintain a patent airway, as the part of the brain which autonomously controls in normal situations may not be functioning.
If the patient was breathing, a first aider would normally then place them in the recovery position, with the patient leant over on their side, which also has the effect of clearing the tongue from the pharynx. It also avoids a common cause of death in unconscious patients, which is choking on regurgitated stomach contents.
The airway can also become blocked through a foreign object becoming lodged in the pharynx or larynx, commonly called choking. The first aider will be taught to deal with this through a combination of ‘back slaps’ and ‘abdominal thrusts’.
Once the airway has been opened, the first aider would assess to see if the patient is breathing. If there is no breathing, or the patient is not breathing normally, such as agonal breathing, the first aider would undertake what is probably the most recognized first aid procedure - Cardiopulmonary resuscitation or CPR, which involves breathing for the patient, and manually massaging the heart to promote blood flow around the body.
Promoting recovery
The first aider is also likely to be trained in dealing with injuries such as cuts, grazes or broken bones. They may be able to deal with the situation in its entirety (a small adhesive bandage on a paper cut), or may be required to maintain the condition of something like a broken bone, until the next stage of definitive care (usually an ambulance) arrives.
Training
First aid scenario training in progressMuch of first aid is common sense. Basic principles, such as knowing to use an adhesive bandage or applying direct pressure on a bleed, are often acquired passively through life experiences. However, to provide effective, life-saving first aid interventions requires instruction and practical training. This is especially true where it relates to potentially fatal illnesses and injuries, such as those that require cardiopulmonary resuscitation (CPR); these procedures may be invasive, and carry a risk of further injury to the patient and the provider. As with any training, it is more useful if it occurs before an actual emergency, and in many countries, emergency ambulance dispatchers may give basic first aid instructions over the phone while the ambulance is on the way.
Training is generally provided by attending a course, typically leading to certification. Due to regular changes in procedures and protocols, based on updated clinical knowledge, and to maintain skill, attendance at regular refresher courses or re-certification is often necessary. First aid training is often available through community organizations such as the Red Cross and St. John Ambulance, or through commercial providers, who will train people for a fee. This commercial training is most common for training of employees to perform first aid in their workplace. Many community organizations also provide a commercial service, which complements their community programmes.
Specific disciplines
There are several types of first aid (and first aider) which require specific additional training. These are usually undertaken to fulfill the demands of the work or activity undertaken.
Aquatic/Marine first aid - Usually practiced by professionals such as lifeguards, Professional mariners or in diver rescue, and covers the specific problems which may be faced after water-based rescue and/or delayed MedEvac.
Battlefield first aid - This takes in to account the specific needs of treating wounded combatants and non-combatants during armed conflict.
Hyperbaric first aid - Which may be practiced by SCUBA diving professionals, who need to treat conditions such as the bends.
Oxygen first aid - Providing oxygen to casualties who suffer from conditions resulting in hypoxia.
Wilderness first aid is the provision of first aid under conditions where the arrival of emergency responders or the evacuation of an injured person may be delayed due to constraints of terrain, weather, and available persons or equipment. It may be necessary to care for an injured person for several hours or days.
Conditions that often require first aid
Also see medical emergency.
Altitude sickness, which can begin in susceptible people at altitudes as low as 5,000 feet, can cause potentially fatal swelling of the brain or lungs.[5]
Anaphylaxis, a life-threatening condition in which the airway can become constricted and the patient may go into shock. The reaction can be caused by a systemic allergic reaction to allergens such as insect bites or peanuts. Anaphylaxis is initially treated with injection of epinephrine.
Battlefield First aid - This protocol refers to treating shrapnel, gunshot wounds, burns, bone fractures, etc. as seen either in the ‘traditional’ battlefield setting or in an area subject to damage by large scale weaponry, such as a bomb blast or other terrorist activity.
Bone fracture, a break in a bone initially treated by stabilizing the fracture with a splint.
Burns, which can result in damage to tissues and loss of body fluids through the burn site.
Choking, blockage of the airway which can quickly result in death due to lack of oxygen if the patient’s trachea is not cleared, for example by the Heimlich Maneuver.
Childbirth.
Cramps in muscles due to lactic acid build up caused either by inadequate oxygenation of muscle or lack of water or salt.
Diving disorders, drowning or asphyxiation.[6]
Gender-specific conditions, such as dysmenorrhea and testicular torsion.
Heart attack, or inadequate blood flow to the blood vessels supplying the heart muscle.
Heat stroke, also known as sunstroke or hyperthermia, which tends to occur during heavy exercise in high humidity, or with inadequate water, though it may occur spontaneously in some chronically ill persons. Sunstroke, especially when the victim has been unconscious, often causes major damage to body systems such as brain, kidney, liver, gastric tract. Unconsciousness for more than two hours usually leads to permanent disability. Emergency treatment involves rapid cooling of the patient.
Heat syncope, another stage in the same process as heat stroke, occurs under similar conditions as heat stroke and is not distinguished from the latter by some authorities.
Heavy bleeding, treated by applying pressure (manually and later with a pressure bandage) to the wound site and elevating the limb if possible.
Hyperglycemia (diabetic coma) and Hypoglycemia (insulin shock).
Hypothermia, or Exposure, occurs when a person’s core body temperature falls below 33.7°C (92.6°F). First aid for a mildly hypothermic patient includes rewarming, but rewarming a severely hypothermic person could result in a fatal arrhythmia, an irregular heart rhythm.
Insect and animal bites and stings.
Joint dislocation.
Poisoning, which can occur by injection, inhalation, absorption, or ingestion.
Seizures, or a malfunction in the electrical activity in the brain. Three types of seizures include a grand mal (which usually features convulsions as well as temporary respiratory abnormalities, change in skin complexion, etc) and petit mal (which usually features twitching, rapid blinking, and/or fidgeting as well as altered consciousness and temporary respiratory abnormalities).
Muscle strains and Sprains, a temporary dislocation of a joint that immediately reduces automatically but may result in ligament damage.
Stroke, a temporary loss of blood supply to the brain.
Toothache, which can result in severe pain and loss of the tooth but is rarely life threatening, unless over time the infection spreads into the bone of the jaw and starts osteomyelitis.
Wounds and bleeding, including lacerations, incisions and abrasions, Gastrointestinal bleeding, avulsions and Sucking chest wounds, treated with an occlusive dressing to let air out but not in.
Artificial respiration
Artificial respiration is the act of simulating respiration, which provides for the overall exchange of gases in the body by pulmonary ventilation, external respiration and internal respiration.[1] This means providing air for a person who is not breathing or is not making sufficient respiratory effort on their own[2] (although it must be used on a patient with a beating heart or as part of cardiopulmonary resuscitation in order 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 patients chest or arms, such as the Silvester method.[3] It is also known as Expired Air Resuscitation (EAR), Expired Air Ventilation (EAV), mouth-to-mouth resuscitation, rescue breathing or colloquially the kiss of life.
Artificial respiration is a part of most protocols for performing cardiopulmonary resuscitation (CPR)[4][5] making it an essential skill for first aid. In some situations, artificial respiration is also performed separately, for instance in near-drowning and opiate overdoses. The performance of artificial respiration in 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.
Mechanical ventilation involves the use of a mechanical ventilator to move air in and out of the lungs when an individual is unable to breathe on his or her own, for example during surgery with general anesthesia or when an individual is in a coma.
Insufflations
Mouth-to-mouth insufflationInsufflation, 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 their mouth and the patient's mouth and 'blowing', in order 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.[6]
Bag valve mask (BVM) - This is a simple device manually operated by the rescuer, which involves squeezing a bag in order to expel air into the patient.
Mechanical resuscitator - An electric unit designed to breathe for the patient
Adjuncts to insufflation
A CPR pocket mask, with carrying caseMost training organisations recommend that in any of the methods involving mouth to patient, that a protective barrier is used, in order to minimise the possibility of cross infection (in either direction).[7]
Barriers available include pocket masks and keyring-sized face shields. These barriers are an example of Personal Protective Equipment 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 (eg. 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 autoclaved and the filter replaced.
The CPR mask is the preferred method of ventilating a patient when only one rescuer is available. Many feature 18mm inlets to support supplemental oxygen, which increases the oxygen being delivered from the approximate 17% available in the expired air of the rescuer to around 40-50%.
Tracheal intubation is often used for short term mechanical ventilation. A tube is inserted through the nose (nasotracheal intubation) or mouth (orotracheal intubation) and advanced into the trachea. In most cases tubes with inflatable cuffs are used for protection against leakage and aspiration. Intubation with a cuffed tube is thought to provide the best protection against aspiration. Tracheal tubes inevitably cause pain and coughing. Therefore, unless a patient is unconscious or anesthetized for other reasons, sedative drugs are usually given to provide tolerance of the tube. Other disadvantages of tracheal intubation include damage to the mucosal lining of the nasopharynx or oropharynx and subglottic stenosis.
In an emergency a Cricothyrotomy can be used by health care professionals, where an airway is inserted through a surgical opening in the cricothyroid membrane. This is similar to a tracheostomy but a cricothyrotomy is reserved for emergency access. This is usually only used when there is a complete blockage of the pharynx or there is massive maxillofacial injury, preventing other adjunts being used.[1]
Efficiency of mouth to patient insufflation
Normal atmospheric air contains approximately 21% oxygen when created in. After gaseous exchange has taken place in the lungs, with waste products (notably carbon dioxide) 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. [8]
This means that there is more than enough residual oxygen to be used in the lungs of the patient, which then crosses the cell membrane to form oxyhemoglobin.
Oxygen
Typical view of resuscitation in progress with a BVM in useThe 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 a Bag Valve Mask or mechanical respirator 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.
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