Korean J Anesthesiol.  1997 Apr;32(4):539-546. 10.4097/kjae.1997.32.4.539.

The Incidence of Regurgitation above Upper Esophageal Sphincter: Laryngeal Mask Airway vs Endotracheal Tube

• Cheong YP
• Ko BC
• Son Y
• Kim TY

• KMID: 1934611
• DOI: http://doi.org/10.4097/kjae.1997.32.4.539

Abstract

BACKGROUND
From a clinical perspective, the regurgitation of the gastric contents above the upper esophageal sphincter has greater clinical relevance than gastroesophageal reflux. The authors investigated the incidence of regurgitation of gastric contents above the upper esophageal sphincter associated with the laryngeal mask airway(LMA) and the endotracheal tube(ETT) by methylene blue(50mg) gelatine capsule and pH probe in positive pressure ventilated patients during long surgical procedures .
METHODS
Sixty patients scheduled for elective orthopedic surgery with a standardized general anesthetic technique were randomly allocated to receive either a LMA(n=34) or a ETT(n=26) for airway management. For the detection of regurgitation episodes during anesthesia, a pH monitoring probe was positioned in the hypopharynx 30 minutes before induction and a methylene blue capsule was swallowed just before induction. At the end of anesthesia, the episodes of regurgitation of gastric contents above upper esophageal sphincter were analyzed according to the pharyngeal blue staining or pH< or =4.
RESULTS
There were no episodes of regurgitation of gastric contents(pH< or =4 or/and methylene blue staining) above the upper esophageal sphincter detected during the course of measurement. There was no clinical evidence of aspiration in either group.
CONCLUSIONS
In comparison with ETT, the use of LMA does not appear to result in increased incidence of regurgitation of gastric contents above upper esophageal sphincter in positive pressure ventilated patients during long surgical procedures.

Keyword

Anesthetic techniques; general; Complications; regurgitation of gastric contents; Equipment; laryngeal mask airway

MeSH Terms

Airway Management
Anesthesia
Esophageal Sphincter, Upper*
Gastroesophageal Reflux
Gelatin
Humans
Hydrogen-Ion Concentration
Hypopharynx
Incidence*
Laryngeal Masks*
Methylene Blue
Orthopedics
Gelatin
Methylene Blue