To the Editor-Despite the popularity of fiberoptic bronchoscope for nasotracheal intubation, “blind nasal” intubation still remains a necessary technique in maintaining an airway in certain conditions. [1,2] Although various methods and devices have been developed, most of the concerns are focused on the safety of operators without considering the trauma to the patients. [3–7]

We would like to present a simple, easy, inexpensive technique that would be more favorable for the patient and the operator. The whole process takes only a few minutes and is faster than placing the fiberoptic bronchoscope. It is an ideal technique for the patients on whom the use of fiberoptic bronchoscope is impossible because of copious bloody secretions.

The patient is prepared for an awake intubation as described elsewhere. [1,2] An appropriate size of endotracheal tube is inserted through the nostril until the tip of the endotracheal tube reaches the oropharynx where the nonturbulent smooth breathe sounds can be heard. At that point, instead of directly passing the endotracheal tube into the larynx blindly as the conventional method describes, a soft suction catheter is inserted (Professional Medical Products, Inc, Suction Catheter with control port, 14-French TM) through the tube into the trachea. The predetermined length of the catheter is advanced to reach the end of the endotracheal tube. The patient is asked to take deep respirations, and the catheter tip is advanced slowly while applying gentle suction. The catheter tip will go into the trachea easily. After the catheter tip is advanced > 10 cm from the tip of the endotracheal tube, the catheter is connected to the gas sampling tubing of the capnograph, and the control port is sealed. The capnograph confirms the placement of the catheter tip in the trachea with reassuring CO2wave forms. If the catheter tip is placed in the esophagus, very small (if any) CO2wave forms will be noticed on the capnograph. The operator will also feel more resistance as the catheter tip passes through the esophagus. If the patient has not been adequately topicalized, the patient will cough as the tip of the catheter approaches the glottis. The operator also may feel some degree of resistance while advancing the catheter through the glottis. Once the catheter tip is placed in the trachea, the endotracheal tube can be passed over the catheter to the trachea using the Seldinger technique.

Reasons for successful placement of the catheter in the trachea appear to be as follows:

First, the nasopharyngeal route is a natural airway; air passes directly from via the oropharynx to the trachea. This explains why a nasogastric tube, intended to be placed in the esophagus, often goes to the trachea and why a fiberoptic bronchoscope inserted through the nasopharyngeal route often enters the trachea without much guidance. Second, we have noticed that while working to clear copious bloody secretions under direct laryngoscopy for difficult intubation, the soft suction catheter tip tends to move toward the trail of secretions that is coating the glottis and eventually finds its way to the trachea. Finally, strong inspiratory air movement on awake patients may further facilitate the catheter tip to move into the trachea.

Don S. Lee, M.D., M.P.H.

Associate Professor

Charles I. Yang, M.D.

Resident; Department of Anesthesiology; George Washington University Medical Center; 901 23rd Street, NW; Washington, DC 20037–0170

(Accepted for publication April 1, 1997.)

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