title: Large cuff volumes impede posterior pharyngeal mucosal perfusion with the laryngeal tube airway.
abstract: OBJECTIVE
  The laryngeal tube airway (LTA) is a new extraglottic airway device with a large proximal cuff that inflates in the laryngopharynx and a distal conical cuff that inflates in the hypopharynx. We determine the influence of the cuff volume and anatomic location on pharyngeal mucosal pressures for the LTA.
  
  
  METHODS
  Fifteen fresh cadavers were studied. Microchip sensors were attached to the (anatomic location) anterior, lateral and posterior surface of the distal cuff (hypopharynx) and proximal cuff (laryngopharynx) of the size 4 LTA. Oropharyngeal leak pressure (OLP) and mucosal pressures were measured at 0-140 mL cuff volume in 20-mL increments. In addition, mucosal pressures for the proximal cuff were measured in three awake, topicalized volunteers.
  
  
  RESULTS
  OLP and mucosal pressure at all locations increased with cuff volume (all: P < 0.01). Mucosal pressures were highest posteriorly. Mucosal pressures only exceeded 35 cm H(2)O (pharyngeal mucosal perfusion pressure) in the anterior and posterior laryngopharynx and when the cuff volume was > 80-100 mL. Mucosal pressures were similar for cadavers and awake volunteers.
  
  
  CONCLUSIONS
  Mucosal pressures for the LTA increase with cuff volume, are highest posteriorly and potentially exceed mucosal perfusion pressure when cuff volume exceeds 80-100 mL.
authors.affiliation: Department of Anaesthesia and Intensive Care Medicine, Cairns Base Hospital, The Esplanade, Cairns 4870, Australia. jbrimacombe@austarnet.com.au
authors.forename: Joseph
authors.initials: J
authors.lastname: Brimacombe
authors.forename: Christian
authors.initials: C
authors.lastname: Keller
authors.forename: Winfried
authors.initials: W
authors.lastname: Roth
authors.forename: Alex
authors.initials: A
authors.lastname: Loeckinger
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D007830:Larynx / Q000502:physiology*; D008875:Middle Aged; D009092:Mucous Membrane / Q000502:physiology; D010614:Pharynx / Q000502:physiology*; D011312:Pressure