Bedside sonographic control for positioning enteral feeding tubes: a controlled study in intensive care unit patients

Abstract

Background and study aim: The correct placement of an enteral feeding tube in the duodenum in critically ill patients is usually controlled radiographically. However, a direct bedside method that obviates the need for exposure to radiation would be preferable. The aim of this study was to demonstrate the usefulness of bedside sonographic position control for placing enteral feeding tubes in critically ill patients.

Patients and methods: After placement of the enteral feeding tube, the position of the tip was determined using bedside transabdominal ultrasound. Native ultrasound was enhanced by injection of air bubbles into the feeding tube. The tube was regarded as being correctly positioned when the tube was visualized within the second or third parts of the duodenum. Plain abdominal radiographs with contrast served as the gold standard test.

Results: A total of 76 consecutive examinations were analyzed. In 12 patients, access to the upper abdominal wall was not possible because of open wounds; in another 13 patients who had undergone extensive abdominal surgery, the duodenum could not be identified and so no conclusion could be reached regarding the position of the tube. In 51/76 patients (67 %) ultrasound identified the duodenum and it was possible to determine the position of the tube (46 true positives and 2 true negatives); the position was incorrectly diagnosed in three patients. The sensitivity was 96 % (95 %CI 87 % - 98 %) and the specificity was 50 % (95 %CI 36 % - 65 %), with a positive predictive value of 94 %.

Conclusions: Bedside sonographic control of the positioning of enteral feeding tubes is very sensitive and can be a valuable alternative to radiological control, especially in patients without open abdominal wounds, external installations, or extensive abdominal surgery.