Pediatric orogastric and nasogastric tubes: a new formula evaluated

We sought to compare the traditional method of determining depth of gastric tube insertion, by measuring from the external landmarks of the nose or mouth, to the earlobe, to the xiphoid process (NEX method), with a graph for determining depth of gastric tube insertion that is based on patient height (graphic method).

A prospective, randomized, double-blinded study comparing NEX and graphic methods for gastric tube depth of insertion was undertaken. This study included a convenience sample of pediatric emergency department patients in need of gastric intubation. Patients were block randomized, and their gastric tubes were placed to the depth derived from the particular method employed. Alternate depth of insertion was measured on all patients. Abdominal radiographs were used to determine the distance that the end of the tube was from the center of the stomach.

Forty-four patients each were in the NEX and graphic groups. The mean distance from the center of the stomach was -1.12 cm (SD 1.36) for the graphic group, compared with 1.31 cm (SD 3.39) for the NEX method. The difference between the 2 methods was 2.43 cm (95% confidence interval [CI] 1.33 to 3.54). Using absolute values, the mean distance from the center of the stomach was 1.26 cm (SD 1.23) for the graphic group compared with 2.60 cm (SD 2.51) for the NEX method. Using these values, the difference between the groups is 1.34 cm (95% CI 0.50 to 2.18).

When compared with the NEX method, the graphic method demonstrates a significant ability to more consistently and accurately determine the depth of pediatric gastric tube insertion.