Double-lumen tube endotracheal tubes (DLT) are commonly used for thoracic surgery procedures. If patients are thought to pose an intubation challenge many anesthesiologists will first insert a single-lumen tube into the trachea. Once the airway is secured they place the DLT using a tube exchanger. The exchange is sometimes difficult. For example, if the tip of the bronchial lumen of the DLT rubs against the arytenoid cartilage, it can impede passage over a tube exchanger. Since this depends, in part, on the design of the DLT, there is reason to think that DLTs from different manufacturers might be more or less easy to pass over a tube exchanger.
Drs. Ryan Gamez and Peter Slinger, Department of Anesthesia, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada, compared the ease with which Rusch, Mallinckrodt, and Fuji-Phycon double-lumen endobronchial tubes could be inserted through the trachea when exchanged over an airway exchange catheter using an airway simulator. The results of the authors’ comparison are published in this month’s edition of Anesthesia & Analgesia in the article titled “A Simulator Study of Tube Exchange with Three Different Designs of Double-Lumen Tubes.”
Seventeen residents or fellows with at least 3 years of anesthesia training participated in the study. Each participant inserted a standard single-lumen 8.0 endotracheal tube into the simulator trachea using a video laryngoscope. They then placed a lubricated Cook 11 F double-lumen tube exchange catheter over the single-lumen endotracheal tube, and subsequently withdrew the endotracheal tube. At this point, in random order, they inserted one size 37F DLT from each of the three manufacturers (Rush, Mallinckrodt, and Fuji-Phycon). The Fuji-Phycon DLT has a 45o bevel at the distal bronchial end and the bronchial tip is more flexible.
Time to intubate was significantly faster when the Fuji-Phycon DLT was used (median 2s) compared to both the Mallinckrodt (median 21s) and the Rusch (median 27s). Failure to intubate was highest with the Rusch DLT compared to 0 in the simulations using the Fuji and Mallinckrodt DLTs. Five insertion failures were due to the bronchial tube getting stuck on the right arytenoid, and in one instance the airway exchange catheter came out.
There are some limitations that should be noted. This was a simulator study, not an actual patient study. One of the authors was an unpaid consultant to Fuji Systems for redesign of the DLT. Only one size DLT was studied. The Fuji DLT is also nearly twice as expensive as the other two DLTs (~$110 for the Fuji-Phycon tube). In addition, it is unclear if the statistical differences found here would be clinically significant. This study is interesting, yet it will have to be repeated using actual patients.