To the Editor:—
Nasogastric tube insertion during anesthesia is often difficult. Many techniques have been proposed to aid insertion, including forward displacement of the larynx, use of a split endotracheal tube, and various kinds of forceps.1–3
The most common sites for impaction of the nasogastric tube are pyriform sinuses and the arytenoid cartilage.4Maneuvers to keep the nasogastric tube along the lateral or posterior pharyngeal wall encourages the smooth passage into the esophagus.5,6Our experience of using a gloved finger to steer the nasogastric tube along the posterior pharyngeal wall supports this premise.7
Our current effort was intended to determine whether neck flexion would facilitate nasogastric tube passage.
We recruited 60 consecutive patients with normal airways and neck movements who required intubation and nasogastric tube insertion as a part of their surgery. After obtaining informed consent from the patients, general anesthesia and muscle relaxation was achieved. The patients were then randomized to either the neck flexion or the neutral group using a sealed-envelope method. After tracheal intubation, both nares were vasoconstricted with 0.05% oxymetazoline. A well-lubricated 16-French gastric tube was inserted via one nostril for a length of 8–9 cm for females and 9–11 cm for males, with concave side hugging the floor of nasal passage. We selected this arbitrary length on the basis of distance of the upper cervical vertebrae from the anterior nares, which is 8–9 cm in females and 9–11 cm in males. We determined these distances manually during our digital method to facilitate insertion of the nasogastric tube.7In the neutral group, the gastric tube was then further passed with the patient’s head in the neutral position. In the flexion group, the patient’s neck was flexed as far forward as possible, and the gastric tube was then advanced. After two unsuccessful attempts in the assigned position, the anesthesiologist was allowed to perform any additional maneuvers desired to aid the successful passage of the tube. The number of attempts required for successful insertion was recorded for each patient.
Thirty patients were allocated to the neutral group, and 30 were allocated to the flexion group. Passage of the nasogastric tube was successful during the first attempt in 24 patients (80%) in the flexion group versus 15 (50%) in the neutral position (table 1). Three patients (10%) in the flexion group required additional maneuvers depending on the preference of the anesthesiologist to pass the tube. In contrast, 9 patients (30%) in the neutral group required additional maneuvers to pass the nasogastric tube.
These results support the observation that passage of the nasogastric tube with neck flexion is associated with a higher success rate than with the neutral position. We believe that neck flexion, in combination with the curve of the nasogastric tube, tends to keep the tube in close proximity to the posterior pharyngeal wall, facilitating its smooth passage into the esophagus. This is a simple but a useful technique and has proved useful in both the intensive care unit and the operating room.