National Board Ex- 6 Book .pmd - National Board Of Examination

13Many new supraglotticairway devices havebeen introduced andinclude airways with and withoutsealing characteristics. These canbe further subdivided into twomain groupsnamely single-useversus reusable and whether thedevice offers protection fromaspiration of gastric contents. 1The first supraglottic airwaydevice - the laryngeal mask airway(LMA) 2 was conceived anddesigned in 1981 by Dr. ArchieBrain of the United Kingdom.The important steps in thedevelopment of the LMA and itsvariants are:l First made commerciallyavailable in 1988 and wasapproved by the FDA for usein USA in 1991l Flexible LMA released in1992l Approved for resuscitation byJapanese ministry in 1992 andby European ResuscitationCouncil in 1996l Included in the difficultairway algorithm in 1993 andits role modified by Benumofin 1996l Intubating LMA released in1997l Disposable LMA released in1998l American Heart Associationapproval for its role inresuscitation in 2000Uses of LMA in Present Day AnaesthesiaBimla SharmaDepartment of AnaesthesiologySir Ganga Ram Hospital, New Delhil ProSeal LMA introduced byArchie Brain in 2000l LMA CTrach introduced inApril 2005l ProSeal LMA Supremeintroduce recentlyThe LMA family-This includesthe classic LMA (cLMA), theflexible LMA, the intubatingLMA (ILMA), the disposableLMA (LMA Unique), the ProSealLMA (PLMA) and the LMACTrach. Successful use of theLMA does not need the manyprerequisites necessary for directlaryngoscopy and trachealintubation. These supraglotticdevices have become increasinglypopular as more and moreanaesthesiologists favour theiruse for airway managementduring elective anaesthetics anddifficult airway situations as wellas in emergency situations for thefollowing reasons 3 :l There is decreased resistancein the patient’s upper airwayin comparison with theendotracheal tubel There is minimal haemodynamicinstability during placementas infraglottic structuresare notl stimulatedl No translocation of oral/nasal bacterial colonies andsecretions into the lowerrespiratory tract as isl possible while performingendotracheal intubationRecentAdvancesl Inadvertent bronchialintubation is totally avoidedl Ease of insertion and smoothawakeningFig 1. LMA FamilyClassic LMA (cLMA)- The firstmember of the LMA family, earlierknown as the standard LMAfills a niche between the facemask (FM) and tracheal tube(TT) in terms of both anatomicalposition and degree of invasiveness.It is manufactured frommedical grade silicone rubber andis reusable. The cLMA representsthe salient features of the LMAfamily. It consists of three maincomponents: an airway tube, inflatablemask and mask inflationline. The airway tube is slightlycurved to match the oropharyngealanatomy, semi rigid to facilitateatraumatic insertion andsemitransparent so that condensationand regurgitated materialis visible. A black line runs longitudinallyalong its posterior curvatureto aid in orientation. Thedistal aperture of the airway tubeopens into the lumen of an inflatablemask and is protected by84Journal of Postgraduate Medical Education, Training & ResearchVol. II, No. 5, September-October 2007