Laryngeal Mask Airway (LMA Classic)

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Editor(s): Lee A. Fleisher, MD, FACC, FAHA Lee A. Fleisher, MD, FACC, FAHA

Robert Dunning Dripps
Professor and Chair
Department of Anesthesiology and Critical Care

Professor of Medicine
University of Pennsylvania School of Medicine
| Robert Gaiser, MD Robert Gaiser, MD

Professor of Anesthesiology and Critical Care
Department of Anesthesiology and Critical Care
University of Pennsylvania School of Medicine

Contributor(s): Joshua H. Atkins, MD, PhD Joshua H. Atkins, MD, PhD

Associate Professor
Department of Anesthesiology and Critical Care
University of Pennsylvania School of Medicine
Philadelphia, Pennsylvania
| Acknowledgements Acknowledgements

Jeremy D. Kukafka, MD
Department of Anesthesiology and Critical Care
Univ of Pennsylvania School of Medicine
Philadelphia, PA

Infraclavicular Nerve Block: Ultrasound-Guided Technique
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Intraoperative Transesophageal Echocardiography
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Gail A. Van Norman, MD
Clinical Associate Professor
Department of Anesthesiology
Univ of Washington
Seattle, WA

Elizabeth J. Watson, MD
Post-Doctoral Fellow
Department of Anesthesiology and Critical Care
Univ of Pennsylvania School of Medicine
Philadelphia, PA

Liang Xue, BS
Research Assistant
Department of Anesthesiology and Critical Care
Univ of Pennsylvania School of Medicine
Philadelphia, PA


Note: Because of the multitude of differences in clinical application and placement technique among the LMA Classic, LMA Flexible, and LMA ProSeal and LMA Fastrach, this chapter shall deal only with use of the LMA Classic.

  • Airway management for general anesthesia with and without spontaneous ventilation
  • Rescue airway after failed intubation or ineffective mask ventilation
  • Facilitation of endotracheal intubation
  • Situations in which airway control is desirable, but tracheal intubation may be difficult or contraindicated:
    • Patients trapped in a sitting position
    • Suspected cervical spine trauma
    • Inability to extend or rotate the cervical spine due to congenital or acquired abnormalities
      • Severe rheumatoid arthritis or osteoarthritis
      • History of cervical spine fusion
      • History of atlantoaxial dislocation
      • Patients with Down syndrome

Relative Contraindications

  • Increased aspiration risk
    • Full stomach
    • Intestinal obstruction
    • Severe gastrointestinal reflux disease
    • Diabetes with gastroparesis
    • History of significant peptic ulcer disease
    • History of gastric bypass or gastric stapling operation
    • Pregnancy, particularly second and third trimester
  • Significantly reduced pulmonary compliance
  • Major trauma to maxilla, mandible, or larynx
  • Unstable cervical spine
  • Unusual operative positioning; particularly prone position
  • Major intrathoracic surgery
  • Major intraabdominal surgery
  • Morbid obesity or patients requiring high inspiratory pressures for ventilation
  • Tracheoesophageal fistula
  • Equipment for mask ventilation
  • Emergency medications, supplies, and equipment for intubation
  • Disposable or reusable LMA Classic
  • Lubricating jelly
  • Clean, dry syringe for cuff inflation/deflation
  • Tape to secure LMA after placement
  • Soft bite block

Placement of the LMA involves passage through the open oral cavity, along and against the hard and soft palate, around the curve of the palatopharyngeal junction, underneath the tongue, and past the epiglottis and tonsillar pillars. When properly positioned the distal cuff of the LMA sits in the hypopharynx just proximal to the upper esophageal sphincter, with the opening of the bowl directed over the glottic opening. During placement, the natural anatomic curves of the oral cavity and the palatopharynx are used to guide the LMA into place. Ideally, the inflated cuff makes a seal with but does not compress the arytenoid cartilages surrounding the glottis.

Large tongue, small interincisor distance (mouth opening), and large floppy epiglottis may make optimal LMA positioning more difficult. Neck flexion and cricoid pressure also serve to reduce the cross-sectional palatopharyngeal area available for manipulation during placement.

Several types of malpositioning of the LMA are common. These include (1) a "flipped tip," with the distal cuff inverted during insertion; (2) entrapment and resulting folding of the epiglottis over the airway by the distal cuff; (3) sideways rotation during placement; (4) overadvancement through the upper esophageal sphincter; (5) underadvancement into the oropharynx; and (6) anterior advancement into the glottic opening.

Sample excerpt does not include step-by-step text instructions for performing this procedure
The full content of this section includes:
  • Step-by-step text instructions for performing the procedure
  • Clinical pearls providing practical clinical tips from medical experts
  • Patient safety guidelines consistent with Joint Commission and OHSA standards
  • Links to medical evidence and related procedures

  • Assess the airway after insertion of the LMA.
  • Monitor and assess as usual the hemodynamic and respiratory function during and after anesthesia until complete recovery.
  • Assess patient for airway postoperatively for complications due to LMA insertion.

Minor Complications

  • Sore throat
  • Hoarseness
  • Laryngospasm
  • Ear pain
  • Dry mouth
  • Hiccups
  • Mouth ulceration
  • Other minor soft tissue trauma

Major Complications

  • Regurgitation of gastric contents and aspiration
  • Recurrent laryngeal nerve injury
  • Vocal cord paralysis
  • Arytenoid cartilage dislocation
  • Hypoglossal or lingual nerve injury; tongue or throat numbness
  • Dysphagia, dysarthria, dysphonia
  • Laryngeal hematoma
  • Temporomandibular joint dislocation
  • Serious soft-tissue trauma to mouth, epiglottis, lips, posterior pharyngeal wall, soft palate, uvula, or tonsils
  • Esophageal rupture
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