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

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.

Tracheal Tube Cuff Inflation in Oropharynx : An Useful Method in Blind Nasotracheal Intubation / 대한마취과학회지

We designed a study to determine if the tracheal tube cuff inflation in the oropharynx improves the success rate of blind nasotracheal intubation in normal, paralyzed patients because of lacking of controlled study about it. In prospective, randomized fashion, 100 ASA I or II patients undergoing elective oral surgery were studied. The trachea was intubated once keeping the tracheal tube cuff deflated throughout the maneuver and once using the technique of tracheal tube cuff inflation in the oropbarynx. A maximum of two attempts was allowed for each technique. If the first attempt was failed, the second attempt was tried with an addition of application of thyroid cartilage compression in each technique. Witb the tracheal tube cuff inflated, the success rate was significantly higher than the cuff-deflated technique(p<0.05). A application of thyroid cartilage compression increased the success rate of the blind nasotracheal intubation in each technique, but it was more useful in the cuff inflation technique(p<0.05). Time taken to intubate the trachea was longer in the cuff inflation technique. We suggest that, in normal paralyzed patients, the tracheal tube cuff inflation in the oropharynx increases the success rate of blind nasotracheal intubation.