Mr.Comartin has returned to the surgical unit with a nasogastric (NG) tube in place.How can the nurse confirm that the NG tube is in the stomach?

A) Listen over the stomach for a swishing sound when air is injected into the NG tube
B) Ask Mr.Comartin to swallow and check him to see if the gag reflex is present
C) Check the NG tube aspirate for acidity using a pH strip
D) Connect the NG tube to suction and observe the aspirate

Checking the acidity of the NG tube aspirate using a pH strip is the most reliable method to confirm if the NG tube is in the stomach. If the aspirate is acidic (pH less than 5), it indicates that the tube is in the stomach. This is because stomach contents are acidic due to the presence of hydrochloric acid. Other methods such as listening over the stomach or connecting the NG tube to suction may not always provide accurate results. Checking for the gag reflex or asking the patient to swallow can confirm the placement of the tube in the esophagus, but not in the stomach.