A Randomized Clinical Trial to Compare Three Different Methods for Estimating Orogastric Tube Insertion Length in Newborns: A Single-Center Experience in China

Background: Orogastric (OG) and nasogastric (NG) tubes are frequently used in the NICU. Obtaining a relatively accurate estimated length before insertion could significantly reduce complications. While previous studies have mainly focused on the NG tube, OG tubes are more commonly used in China. Purpose: The objective was to determine whether there were differences in the rate of accurate placement among the adapted nose-ear-xiphoid (NEX) method, nose-ear-midway to the umbilicus (NEMU) method, and weight-based (WB) equation in estimating the OG tube insertion distance. Methods: A randomized, controlled, open-label clinical trial to compare the three methods was conducted in a single center. After enrollment, newborns were randomly assigned into three groups. By radiological assessment, the anatomical region for OG tube placement was analyzed. The primary metric was the tip within the gastric body, and the second metric was strictly accurate placement defined as the tube was not looped back within the stomach and the end was located more than 2 cm but less than 5 cm into the stomach, referred to as T10. Results: This study recruited 156 newborns with the majority being preterm infants (n = 96; 61.5 percent), with an average birth weight of 2,200.8 ± 757.8 g. For the WB equation, 96.2 percent (50 cases) of the OG tubes were placed within the stomach, and the rates were 78.8 percent (41 cases) in the adapted NEX and NEMU methods. The strictly accurate placement rates were highest for the WB equation at 80.8 percent (42/52), followed by the adapted NEX method at 65.4 percent (34/52), and the NEMU method at 57.7 percent (30/52). Conclusion: The WB equation for estimating the insertion depth of the OG tube in newborn infants resulted in more precise placement compared to the adapted NEX and NEMU methods.