Diagnostic Accuracy of Using Point-of-care Ultrasonography for Confirming Nasogastric Tube Placement

A portable wireless ultrasound system (Vscan Air, General Electric Healthcare) with dual probes-linear array (3-12 MHz) for neck scanning and curved array (2-5 MHz) for subxiphoid scanning-will be used. The linear probe is placed transversely on the anterior neck, slid left at the thyroid level to focus on the esophagus, then rotated for longitudinal views. The curved probe is applied subxiphoid, using the liver as a landmark, and tilted left to image the stomach. A positive result is confirmed by visualizing the NGT shadow in the esophagus and stomach, followed by dynamic upsurge fogging after injecting 50cc of air. Ultrasonography and X-ray results will be compared.

This study will employ chest radiography as the reference standard for verification of correct nasogastric tube placement. Radiographic imaging will be conducted following NGT insertion and interpreted by physicians to verify positional accuracy.