title: Effect of laryngeal mask airway on esophageal motility during general anesthesia.
abstract: OBJECTIVE
  To determine whether the Laryngeal Mask Airway (LMA) triggers the pharyngo-esophago-gastric reflex during general anesthesia by comparing the esophageal motility of patients with the LMA and endotracheal tube (ETT) in place.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  Operating room and recovery room of a tertiary-care referral hospital.
  
  
  METHODS
  50 adult ASA physical status I and II patients scheduled for elective orthopedic surgery.
  
  
  METHODS
  All patients received a standardized general anesthetic technique, then were allocated randomly to the LMA (n = 30) or ETT (n = 20) groups.
  
  
  RESULTS
  The esophageal manometric inputs were recorded continuously using an ambulatory esophageal manometric recorder and divided into five perioperative phases (preanesthesia, induction, surgery, LMA, or ETT rejection and arousal phase). The LMA or ETT was removed at the end of the surgery, when the patient was awake. An awake state was defined as the presence of the following clinical signs: swallowing, bucking, struggling, straining, and restlessness. The esophageal peristaltic wave percent and esophageal contraction frequency were significantly decreased during induction, surgery, and the LMA or ETT rejection and arousal phases compared with the preanesthetic phases in both the LMA and ETT groups. However, there were no significant group differences in any corresponding perioperative phases.
  
  
  CONCLUSIONS
  During the general anesthetic period before the arousal phase in this study, a LMA does not provoke significantly different esophageal peristalsis compared with an ETT. Thus, the LMA is unlikely to stimulate the pharyngo-esophago-gastric reflex during that period.
authors.affiliation: Department of Anesthesiology, Wonkwang University School of Medicine, Iksan City, Cheonbuk, South Korea.
authors.forename: Yong
authors.initials: Y
authors.lastname: Son
authors.forename: Soo-Kyung
authors.initials: SK
authors.lastname: Park
authors.forename: Young-Pyo
authors.initials: YP
authors.lastname: Cheong
authors.forename: Yoo-Sun
authors.initials: YS
authors.lastname: Choi
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Ahn
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Suck-Chei
authors.initials: SC
authors.lastname: Choi
authors.forename: Kyung-Kun
authors.initials: KK
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General; D017558:Elective Surgical Procedures; D015154:Esophageal Motility Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D017214:Laryngeal Masks / Q000009:adverse effects*; D008297:Male; D019637:Orthopedic Procedures; D011446:Prospective Studies