Before administering a tube feeding to a toddler, which of the following methods should the nurse use to check the placement of a nasogastric (NG) tube
A．Abdominal X-rays.
B．Injection of a small amount of air while listening with a stethoscope over the abdominal area.
C．A check of the pH of fluid aspirated from the tube.
D．Visualization of the measurement mark on the tube made at the time of insertion.
参考答案：C
解析：Intestinal, gastric, and respiratory fluids have different pH values. Therefore, checking the pH of fluid aspirated from the tube is the most reliable technique for checking proper NG tube placement without taking X-rays before each feeding. X-rays can't be performed multiple times every day. Because auscultation of air can be heard when the tube is in the esophagus as well as in the stomach, this isn't the best test for checking placement. Observing the insertion measurement mark isn't a good check either because the mark may remain the same even though the tube has migrated up or down into the esophagus, lungs, or intestines.