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 1.2 cm 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.