thumb|All forms of the recovery position share basic principles. The mouth is downward so that fluid can drain from the patient's airway; the chin is well away from the throat to keep the [[epiglottis open. Arms and legs are nested to stabilize the position of the patient.]]
In first aid, the recovery position (also called semi-prone) is one of a series of variations on a lateral recumbent or three-quarters prone position of the body, often used for unconscious but breathing casualties.
An unconscious person, a person who is assessed on the Glasgow Coma Scale (GCS) at eight or below, in a supine position (on the back) may not be able to maintain an open airway as a conscious person would. This can lead to an obstruction of the airway, restricting the flow of air and preventing gaseous exchange, which then causes hypoxia, which is life-threatening. Thousands of fatalities occur every year in casualties where the cause of unconsciousness was not fatal, but where airway obstruction caused the patient to suffocate. This is especially true for unconscious pregnant women; once turned on to their left side, pressure is relieved on the inferior vena cava, and venous return is not restricted. The cause of unconsciousness can be any reason from trauma to intoxication from alcohol.
It is not necessarily used by health care professionals in an institutional setting, as they may have access to more advanced airway management techniques, such as tracheal intubation.
Purpose
The recovery position is designed to prevent suffocation through obstruction of the airway, which can occur in unconscious supine patients. The supine patient is at risk of airway obstruction from two routes:
- Mechanical obstruction: In this instance, a physical object obstructs the airway of the patient. In most cases this is the patient's own tongue, as the unconsciousness leads to a loss of control and muscle tone, causing the tongue to fall to the back of the pharynx, creating an obstruction. This can be controlled (to an extent) by a trained person using airway management techniques.
- Fluid obstruction: Fluids, usually vomit, can collect in the pharynx, effectively causing the person to drown. The loss of muscular control which causes the tongue to block the throat can also lead to the stomach contents flowing into the throat, called passive regurgitation. Fluid which collects in the back of the throat can also flow down into the lungs. Another complication can be stomach acid burning the inner lining of the lungs, causing aspiration pneumonia.
Placing a patient in the recovery position gives gravity assistance to the clearance of physical obstruction of the airway by the tongue, and also gives a clear route by which fluid can drain from the airway.
The International Liaison Committee on Resuscitation (ILCOR) does not recommend one specific recovery position, but advises on six key principles to be followed: In 1891 he presented a paper with the title <nowiki>'</nowiki>On Stertor, Apoplexy, and the Management of the Apoplectic State<nowiki>'</nowiki> in relation to stroke patients with noisy breathing from airway obstruction (also known as stertor).
This paper was taken up by anaesthetist Frederick Hewitt from the London Hospital who advised a sideways position for postoperative patients. This thinking was, however, not widely adopted, with surgical textbooks 50 years later still recommending leaving anaesthetised patients in a supine position. By contrast, the St. John manual advocated turning the head to the side, but it was not until the 1950 40th edition of the St. John Manual that it was added "if breathing is noisy (bubbling through secretions), turn the patient into the three-quarters prone position",