A nurse is teaching a client who has a prescription of a nasogastric tube (NG) to treat a pyloric obstruction. Which of the following rationales for the use of the nasogastric tube should the nurse include in the teaching?

Pyloric obstruction involves a mechanical blockage at the stomach outlet, leading to the accumulation of gastric contents. Knowledge of gastrointestinal decompression and the therapeutic purpose of nasogastric tubes in managing increased intragastric pressure and preventing emesis is required here. Choice A rationale Pyloric obstruction causes gastric stasis and distension because contents cannot enter the duodenum. Nasogastric intubation provides decompression by removing accumulated secretions and gas, which relieves pressure, prevents vomiting, and reduces the risk of aspiration in the client. Choice B rationale Providing nutrition via tube feeding is contraindicated in pyloric obstruction. Because the outlet of the stomach is blocked, any enteral formula introduced would accumulate in the stomach, worsening distension and significantly increasing the risk of reflux or aspiration. Choice C rationale While gastric pH can be measured via a nasogastric tube, it is not the primary therapeutic rationale for tube placement in a client with a mechanical obstruction. Decompression is a critical intervention to ensure safety and comfort. Choice D rationale Administering oral medications through a nasogastric tube is ineffective during an obstruction. The medication cannot pass the pylorus to be absorbed in the small intestine, and it adds volume to an already overfilled and pressurized stomach.