Laryngeal mask airway

From Wikipedia, the free encyclopedia

1 Invention and development
2 Use
3 Guide to use
4 References

[edit] Invention and development

The LMA was invented in the 1980s by the British anaesthetist, Dr. Archie Brain. Since their introduction twenty plus years ago as a safe, effective alternative to the endotracheal tube doctors and the emergency medical community around the world have chosen to use LMA's over 150 million times. Over 2,500 publications and hundreds of clinical studies have tested and proved a wide variety of uses. The LMA airway has become the most respected supraglottic airway device worldwide.^{[citation needed]}

[edit] Use

The laryngeal mask airway (LMA) is used in anaesthesia and in emergency medicine for airway management. It is a tube with an inflatable cuff that is inserted into the pharynx. It causes less pain and coughing than an endotracheal tube, and is much easier to insert. However, it does not protect the lungs from aspiration, making it unsuitable for anybody at risk of this complication.

It is useful in situations where a patient is trapped in a sitting position, suspected of trauma to the cervical spine (where tilting the head to maintain an open airway is contraindicated), or when intubation is unsuccessful.

The laryngeal mask airway is a device that sits tightly over the top of the larynx. It avoids tracheal intubation and can be used with spontaneous respiration or artificial ventilation. However, it may not protect the airway from the aspiration of regurgitated material. It has found favour in day case surgery. Patients who have been treated with the laryngeal mask airway claim it does not irritate the throat as intubation typically does.

If an LMA is not suitable or appropriate, an endotracheal tube may be used to facilitate ventilation and prevent aspiration.

[edit] Guide to use

The LMA comes in three sizes, based on a persons weight the doctor or emergency medical technition can either use a 3, 4 or 5. The cuff of the mask is deflated before insertion and lubricated. The patient is now anaesthetised; alternatively, they may present unconscious. The neck is extended and the mouth opened widely. The apex of the mask, with its open end pointing downwards to the tongue, is pushed backwards towards the uvula. It follows the natural bend of the oropharynx and comes to rest over the pyriform fossa. At this point - gauged by experience - the cuff around the mask is inflated with air to create the seal. Air entry is confirmed by auscultating in the axillae.

[edit] References

Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2000; 102 (suppl 1): I95–I104.[Medline]

Asai T, Morris S. The laryngeal mask airway: its features, effects and role. Can J Anesthesiol. 1994; 41: 930–960.[Abstract]

Brain A, Denman WT, Goudsouzian NG. Laryngeal Mask Airway Instruction Manual. San Diego, Calif: LMA North America Inc; 1999.

Brimacombe R, Brain AIJ, Berry A. Nonanesthetic uses.In: The Laryngeal Mask Airway: A Review and Practice Guide. Philadelphia, Pa: Saunders; 1997: 216–277.

Rothrock J. Alexander's - Care of the Patient. Missouri; Saunders; 2003; 236.