title: The safety and efficacy of the use of the flexible laryngeal mask airway with positive pressure ventilation in elective ENT surgery: a 15-year retrospective single-center study.
abstract: BACKGROUND
  The use of flexible laryngeal mask airway (FLMA) in elective ear, nose and throat (ENT) surgery offers significant advantages, but is frequently considered inferior to tracheal intubation (TI) for ventilation and airway protection. We investigated the safety and success rate of intraoperative FLMA use with positive pressure ventilation (PPV), and the factors responsible for FLMA failure.
  
  
  METHODS
  A 15-year single center retrospective study. FLMA failure was defined as the need for FLMA removal and TI, either during induction (primary failure), or after turning the patient over to the surgeon (secondary failure). Strict failure criteria included the inability to achieve and/or maintain all 3 essential FLMA functions, such as ventilation (tidal volume ≥6 mL/kg), airway protection from above the cuff (airway sealing pressure [ASP] >12 cm H2O), and separation of the respiratory and gastrointestinal tracts (absent gastric insufflation during PPV).
  
  
  RESULTS
  In 685 patients, FLMA was successfully inserted in 94%. Secondary failure rate was 1.5%, with half of failures observed intraoperatively. The inability to seat FLMA during induction or FLMA dislodgment were the most common reasons for failures. The number of FLMA insertion attempts and low ASP were associated with FLMA primary failure and the need for TI. There were no complications.
  
  
  CONCLUSIONS
  The results suggest an acceptably low failure rate of use of FLMA with PPV in selected ENT surgical procedures. True intraoperative FLMA failure is uncommon. We advocate observing strict criteria for adequacy of FLMA placement, and close monitoring of FLMA function intraoperatively at all times.
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA - nek@stanford.edu.|Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA - nek@stanford.edu.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Nekhendzy
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Ramaiah
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Collins
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Hendrikus J
authors.initials: HJ
authors.lastname: Lemmens
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Sam P
authors.initials: SP
authors.lastname: Most
mesh_terms: D000328:Adult; D017558:Elective Surgical Procedures; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D017214:Laryngeal Masks / Q000009:adverse effects; D013517:Otorhinolaryngologic Surgical Procedures; D011175:Positive-Pressure Respiration; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome