The comparison of insertion depth for orotracheal intubation between standard polyvinyl chloride tracheal tubes and straight reinforced tracheal tubes.

STUDY OBJECTIVE: To investigate whether these properties of reinforced tubes cause difference in insertion depth compared to standard polyvinyl chloride tracheal tubes.

DESIGN: A randomized controlled trial.

SETTING: Operation room.

MATERIALS: Standard polyvinyl chloride tracheal tubes, reinforced tubes.

INTERVENTIONS: Seventy-six adult patients undergoing surgery under general anesthesia were randomly allocated with standard tube (n=38) or reinforced tube (n=38) intubation. The endotracheal tube was fixed at the right canine with a predetermined insertion depth using the formula: endotracheal tube insertion length (cm)=0.1977 × [body height (cm)] - 12.7423.

MEASUREMENTS: The distances between the tracheal tube tip and the carina using fiberoptic bronchoscope.

MAIN RESULTS: The mean tip-to-carina distance of reinforced tube was about 1.2cm longer than that of standard tube (P<.001).

CONCLUSIONS: The insertion depth of straight reinforced tracheal tubes can be shorter than that of standard polyvinyl chloride tracheal tubes due to different tube pathways in the upper airway.