- Need for positive pressure ventilation (PPV)
- No absolute contraindications
- Supraglottic Airway (SGA) device (many options exist)
- Appropriate sedation/paralytic agents, if indicated
|Mask Size||Weight (kg)||Age (yr)||LMA Length (cm)||LMA Cuff Vol (mL)||Largest ETT^ (mm)|
^Largest ETT that can pass thorough "Intubating LMA" (ILMA)
- Laryngeal nerve injury
- Hypoglossal nerve injury
- Pharyngeal edema
- There are 2 generations of supraglottic airway devices
- 1st Gen = classic LMA, other standard LMAs
- 2nd Gen = iGel, LMA Supreme, Pro-Seal LMA (PLMA)
- Second generation devices achieve improved esophageal and pharyngeal seal (causes ↑ oropharyngeal leak pressure), incorporate a "drain tube" that allows access to the esophagus and stomach, and usually have an incorporated bite block.
- Oropharyngeal leak pressure = the applied pressure at which the seal between the device and the larynx begins to leak.
- Peak inspiratory pressure needs to be less than the oropharyngeal leak pressure for effective ventilation and to prevent gastric insufflation.
- Higher failure rate with obese patients, inappropriate pt position (e.g. trendelenberg), and placement by inexperienced provider
- Apfelbaum JL, et al.; American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013 Feb;118(2):251-70
- Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Cook TM, Woodall N, Frerk C; Fourth National Audit Project. Br J Anaesth. 2011 May;106(5)
- Timmermann, A. Supraglottic airways in difficult airway management: successes, failures, use and misuse. Anaesthesia, 2011, 66(Suppl. 2), pages 45–56.
- Patel B., Bingham R. Laryngeal mask airway and other supraglottic airway devices in paediatric practice. Contin Educ Anaesth Crit Care Pain (2009) 9 (1): 6-9.