Letters to the Editor: Letters & Announcements
To the Editor:
The cuff leak test is a necessary step in preintubation procedures before the use of an endotracheal tube. These procedures do not include any verification of the tube lumen patency because obstruction of the tube lumen is a very rare and unexpected event. We experienced a case of insufficient ventilation caused by an intrabronchial tube obstruction resulting from a defective tube.
A patient was scheduled to undergo a video-assisted mediasternal tumor biopsy. After the induction of anesthesia with propofol, fentanyl, and vecuronium, the trachea was intubated successfully with a 32F (Lt) double-lumen endobronchial tube (Broncho-Cath™, Tyco Healthcare Mallinckrodt, Westmeath, Ireland). With both cuffs inflated, it was not possible to ventilate the right lung through the tracheal lumen although the left lung was normally ventilated through the bronchial lumen. First, we thought that it was the result of an inadequate tube placement. We inspected the carina using a bronchofiberscope inserted in the bronchial lumen and found an adequate tube placement. Then, we inserted the fiberscope into the tracheal lumen to verify the opening of the lumen and found an abnormal light reflection present at the end of the lumen; further inspection was impossible. Therefore, we extubated the tube immediately and ventilated the patient with 100% oxygen using a facemask. We found that there was an obstruction of the tracheal lumen at the end of the lumen with a membranous object (Fig. 1). Thorough examination of the tube by the manufacturer revealed this object was transparent adhesive used to attach cuffs to the tube.
A similar case has not yet been reported as far as the representatives of the manufacturer and the literature are aware. As preventive actions, the manufacturer raised its Acceptable Quality Level by one rank, and our department revised our preanesthetic safety checklist to include the inspection of the opening of the endotracheal tube to prevent similar problems. Although this was a rare case, because the method used to attach cuffs to tubes is a common procedure with the majority of tubes available at present, the same problem could occur when using any kind of endotracheal tube from any manufacturer.
It has been mentioned in a textbook that it is wise to check the free flow of air through the tube as part of the precase checkout (1); however, it is not likely that all anesthesiologists follow this recommendation. In fact, several electronic manuals for preanesthetic procedures do not require verifying the opening of the endotracheal tube before use (2,3).
We would like to raise a warning to anesthesiologists for the safety of patients.
Tomoya Irie, MD
Kiyoyasu Kurahashi, MD, PhD
Kenichi Ogawa, MD, PhD
Ryosuke Furuya, MD, PhD
Yoshitsugu Yamada, MD, PhD
Department of Anesthesiology and Critical Care Medicine
Yokohama City University Graduate School of Medicine
Yokohama, Kanagawa, Japan
1. Stone DJ, Gal TJ. Airway management. In; Miller RD, ed. Anesthesia, 5th ed. Philadelphia: Churchill Livingstone, 2000:1427.