Continuous Ventilation During Transnasal Fiberoptic Bronchoscope-Aided Tracheal Intubation

To the Editor: Most techniques for management of an unexpectedly difficult airway require interruption of ventilation. We suggest a transnasal technique that permits intubation of the trachea without interrupting ventilation that may be useful when multiple intubation attempts have failed in a patient who has received a muscle relaxant. Topical anesthesia is applied to the most patent nostril using a mixture of 4 mL viscous lidocaine 2% and 1 mL phenylephrine 1% poured into a 10-mL syringe and administered via a 16-gauge catheter. A 28-34 Fr soft rubber nasopharyngeal airway is inserted into the nostril as a dilator. Shortly thereafter, an uncut No. 7 or 8 endotracheal tube (ETT) is substituted for the nasal airway and inserted approximately 14 cm. A swivel elbow with suction port is used to connect the ETT to the circuit. An assistant holds the lips closed and compresses the vacant nostril to permit the patient to be manually ventilated. Optimal position is verified by inspection of the capnogram. A fiberoptic bronchoscope is advanced through the suction port and ETT past the vocal cords into the trachea until the carina is visualized Figure 1. Using the bronchoscope as a stylet, the ETT is advanced into the trachea. After confirming proper ETT placement, the bronchoscope is withdrawn.Figure 1: Sagittal section line drawing of the fiberoptic bronchoscope-assisted nasotracheal intubation.The method described above enables the patient to be ventilated continuously with O2-enriched anesthetic vapor, while the endoscopist locates and enters the trachea with the fiberscope. In situations where mask fit is problematic or soft tissue obstruction hinders ventilation by mask, the nasal tube provides a conduit free of soft tissue that may allow adequate patient ventilation even before fiberoptic endoscopy is initiated. No technique is foolproof. Ovassapian et al. [1] classified the causes of failure in awake fiberoptic nasotracheal intubation as 1) deviation of the airway; 2) decrease in space between the edge of the epiglottis and posterior pharyngeal wall; 3) bloody secretions; and 4) hyperactive airway reflexes. These problems certainly apply to the techniques described herein. Using this technique, O2-enriched anesthetic vapor can be used to ventilate the patient throughout the placement of the ETT. This makes this technique especially useful for patients in whom airway management remains problematic and the clinical situation is deteriorating. Linda Chen, MD Scott A. Sher, MD Stanley J. Aukburg, MD Department of Anesthesia University of Pennsylvania School of Medicine Philadelphia, PA 19104