Final answer:
To ensure the correct placement of a nasogastric tube after throat surgery, the nurse should measure the pH of the gastric aspirate which should be acidic, indicating the tube is in the correct position.
Step-by-step explanation:
To ensure the correct placement of a nasogastric tube following throat surgery, the nurse is recommended to measure the pH of the gastric aspirate. This is because the gastric contents are acidic and, therefore, the pH level should be low (typically less than 5.5). By confirming the aspirate's pH, clinicians can be more certain that the tube is positioned within the stomach.
Other methods such as auscultation of bowel sounds and checking for respiratory distress can be supplemental to pH testing but are less reliable for confirming placement. A test feeding is not an initial step for confirming placement due to the potential risk of complications if the tube is misplaced. Pulling back on the tube is not a method to ensure correct placement; instead, it may potentially dislodge a correctly positioned tube or cause harm.