Final answer:
Correct placement of an NG tube is checked by aspirating gastric contents for pH testing, listening for air gurgling using a stethoscope, and using endoscopic examination to visually confirm the tube's position.
Step-by-step explanation:
To verify if an NG tube is placed correctly, there are several methods healthcare professionals use. One common approach is to aspirate gastric contents and test the pH level to see if it matches that of the stomach. Another method is to inflate air into the NG tube and listen over the stomach with a stethoscope for air gurgling. Additionally, an endoscopic examination using a tiny camera can be conducted to directly visualize the tube's placement in the stomach or duodenum. Checking NG tube placement is critical for patient safety, as incorrect placement can lead to serious complications such as lung aspiration.