Assessment of a new method to verify feeding tube placement by syringe aspiration in a porcine model

Background: Malpositioned feeding tubes carry the risk of serious complications. However, common bedside methods of differentiating tracheal from gastric feeding tube placement are neither accurate nor practical. Therefore, we conducted an animal study to verify feeding tube placement by syringe aspiration test. Methods: A total of 26 pigs were anesthetized and intubated with tracheal tubes in the trachea and the esophagus. The animals were divided into two groups. The animals in the mechanical ventilation group were paralysed and received mechanical ventilation. The animals in the spontaneous breathing group maintained spontaneous breathing. The feeding tubes were then inserted through the tracheal tubes, into the trachea and esophagus, so that the anterior openings of the feeding tubes were located in the trachea and esophagus. A feeding syringe was then attached and 30 ml of air was aspirated into the syringe. The ability to aspirate air without resistance was defined as a positive syringe aspiration test. If there was resistance as air was aspirated, it was defined as a negative syringe aspiration test. In the next step, 20 esophageal ventilations were given to create a distended stomach in the experimental animals, and the syringe aspiration test was repeated in the same manner described above. Results: The syringe aspiration test was positive for feeding tubes placed in the trachea and was negative for feeding tubes located in the esophagus in both the mechanical ventilation group and the spontaneous breathing group. Conclusion: The syringe aspiration test is an effective method of differentiating tracheal from esophageal feeding tube placement.