A Method to Improve Use of a Preformed Nasal Tube for Fiberoptic Nasal Intubation

Abstract

To the Editor: Preformed nasal tubes (PNT) are commonly selected for nasal-tracheal intubation in patients undergoing head and neck surgery because they are easy to secure, provide convenient surgical access, and help reduce pressure on the nares.1 However, there are some limitations with such tubes. First, passing a fiberoptic bronchoscope (FOB) through the PNT is often difficult because of its preformed distal acute curve, particularly when an adult version FOB, such as Olympus LF-TP FOB with an outer diameter of 5.1 mm, is used. Second, when the PNT is threaded over a FOB, the FOB can be deformed (Fig. 1A) and rotational movement applied to the body of the FOB is not easily transmitted to its anterior flexible tip, reducing maneuverability of the FOB.2 Third, after the FOB is inserted into the trachea, the deformation described may cause difficulty in advancing the PNT over the FOB. Fourth, the PNT is longer than the conventional endotracheal tube and the distal end of the PNT will be impacted in the nares before the FOB’ tip is inserted into the trachea. To overcome these limitations, we have adapted a simple technique to improve use of the PNT in fiberoptic nasal intubation.Figure 1.: (A) The distal insertion tube of the fiberoptic bronchoscope (FOB) is deformed (1) because of the distal curve of the Portex® cuffed preformed nasal tubes (PNT). When a size 7.5 mm Portex® cuffed PNT and a FOB with the insertion tube of 60 cm are used, moreover, the distance between the FOB’s tip and the distal end of the PNT is only 14 cm. (B) The PNT is cut at the midpoint of the distal curve (2) to become the two portions: the internal portion (4) and outer portion (4). A short metallic tube is preformed to a curvature similar to the distal curve of the PNT (3). (C) The precurved metallic tube is inserted into the cut end of the outer portion (6). The internal portion is loaded on the FOB (7). (D) After intubation, the internal and outer portions are rejoined by the precurved metallic tube (8).The PNT is cut at the midpoint of the distal curve dividing into the internal and outer portions. The cut site is located approximately 2 cm distal to the site of attachment of the external inflation tube of the cuff. A 4-cm long metal tube (with walls 1 mm thick) bent to a curvature similar to the distal curve of the PNT (Fig. 1B) is inserted into the cut end of the outer portion. When a size 7.5 mm Portex® cuffed PNT and a FOB with the insertion tube of 60 cm are used, the distance between the FOB’s tip and the distal end of the internal portion is 22 cm (Fig. 1C). This allows the FOB to be inserted into the trachea sufficiently far before the distal end of the internal portion is impacted on the nares.3 After the FOB is inserted into the trachea, the internal portion is advanced over the FOB into the trachea. After the FOB is removed, the cut end of the internal portion is connected to the precurved metallic tube (Fig. 1D). The reconstituted preformed tube is connected to the circle breathing system by the standard endotracheal tube connector. After local ethics committee approval and written informed consent, we have used this technique in more than 500 adult patients undergoing head and neck surgery requiring nasal-tracheal intubation. No kinking, partial obstruction, increased airway resistance, or separation of the reconstituted tube occurred and the original profile of the PNT is preserved allowing it to be readily positioned over the patient’s forehead to facilitate surgical access. Fu S. Xue, MD Ya C. Xu, MD Xu. Liao, MD Department of Anesthesiology Plastic Surgery Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing, People’s Republic of China [email protected]