Which method is not a reliable way to confirm NG tube placement?

• A. Radiological X-ray
• B. Checking Gastric Aspirate for pH Less Than 7
• C. Instilling Air and Listening with a Stethoscope Over Fundus
• D. Determining the Presence of Carbon Dioxide

Answer: (C)

Verifying NG tube placement is essential to prevent aspiration and ensure feeds reach the stomach. Injecting air and listening with a stethoscope over the fundus is not reliable because sounds can be transmitted from surrounding structures and across the abdomen, so you can hear a “clip” even when the tube isn’t in the stomach. This method can give a false sense of accuracy and misses misplacements in the esophagus or trachea.

Radiologic X-ray is the most dependable way to confirm placement because it visually shows the tube’s path and the tip’s exact location, providing direct evidence of correct gastric placement. Checking the aspirate’s pH offers a practical bedside cue: a low gastric pH supports gastric placement, though medications and feeds can alter pH and reduce reliability. Detecting carbon dioxide in the tube can help identify tracheal placement quickly—presence of CO2 suggests the tube may be in the airway, while its absence supports not being in the airway—but it isn’t definitive for confirming gastric location and should be used in conjunction with other methods.

So, the air-and-stethoscope method is not reliable for confirming NG tube placement; imaging or corroborating bedside tests provide much more dependable information.