[Locating the site of resistance to the endotracheal tube in fiberoptic oral intubation and maneuvers to overcome it: a mannequin simulation study].

OBJECTIVE

To determine the most common tracheal points of resistance during orotracheal insertion of a fiberoptic tube in a mannequin by applying a maneuver algorithm to overcome the resistance.

METHOD

Four study groups were established to compare 2 types of endotracheal tube: a standard tube and a reinforced flexible tube with an internal diameter of 7.5 mm. The tubes were used on their own or in combination with a Williams airway intubator. Two fiberoptic bronchoscopes were used, one to perform the test intubation and the other to observe the location of resistance and the effectiveness of the maneuvers for overcoming it. The degree of resistance was scored using a modified Jones scale, from 0 (intubation without resistance) to 4 (intubation impossible); location of resistance and time required for each intubation were also recorded.

RESULTS

A total of 250 oral intubations were performed. Resistance was encountered in 75.2% of the cases. The main locations of obstruction were the right arytenoid cartilage and the posterior commissure. In 89.6% of the cases, intubation of the trachea was achieved without maneuvering or with a 90 degrees counterclockwise rotation. Statistically significant differences were found in resistance and intubation time when the reinforced flexible tube was used with the Williams intubator.

CONCLUSIONS

Rotating the tube 90 degrees counterclockwise was an effective maneuver for overcoming resistance. The combination of a reinforced flexible tube and a Williams intubator was associated with less resistance and shorter intubation times.