Orogastric tube placement in extremely low birth weight infants

Background: Traditionally, orogastric tube (OGt) length of insertion is determined by nose-earlobe-xyphoid (NEX) measurement. Although radiography is the gold standard for verification of placement, scarce data are available for extremely low birth weight (ELBW) infants. Objective: To correlate OGt placement in ELBW infants with its position in the gastrointestinal tract by radiography and to establish clinical correlates with gastrointestinal perforations. Design/methods: Retrospective evaluation of 290 ELBW infants. The 1st (n = 290) and 2nd (n = 273) radiographs following OGt placement were evaluated. Diaphragm and OGt were referenced to the level of the 10th thoracic vertebra (T10). The lower esophageal sphincter (LES) was presumed to be at T9. Results: Most (86%) OGt were placed during the first three days of life. OGt pores and the stomach were visible in 37% and 40% of the cases respectively. The diaphragm was noted to be at T8 (14%), T9 (43%), T10 (41%) & T11 (2%). On the first radiograph, OGt were in the esophagus (4%), in the duodenum (3%), straight in the stomach (8%) and diagonal in the stomach (85%). Of all 563 radiographs evaluated, 502 (89%) OGt were diagonal in the stomach, extending below the LES for a median 3 cm (0.7-4.9 cm). In the 225 radiographs where the stomach could be visualized, the median distance from T10 to the OGt tip was 2.8 cm (1-5) while that from T10 to the greater curvature was 3.1 cm (1-5). Clinical correlates: There were 21 cases of necrotizing enterocolitis (15 of them with perforation) and 7 cases of spontaneous intestinal perforation. None of them were temporally or anatomically linked to OGt placement. Conclusions: Radiological verification of OGt placement is possible. The unpredictable level of the diaphragm, the poor visibility of OGt pores and the often gasless stomach can make radiological verification difficult. Determining OGt insertion length in ELBW infants by the NEX method results in appropriate intragastric placement in 85% of the cases. 1. Background