Summarize the following:
Use a clean, dry syringe to insert air into the NG tube. Listen for the sound it makes using a stethoscope.  Draw back the plunger of the syringe to collect 3 ml of air, then attach the syringe to the open end of the tube. Place a stethoscope over the patient's stomach, just below the ribs and toward the left side of the body. Quickly depress the plunger to insert the air into the tube. You should hear a gurgling or popping sound through the stethoscope if the tube has been positioned correctly. Remove the tube if you suspect improper placement. Use a syringe to draw stomach acid through the tube, then test the contents with pH indicator paper.  Attach an empty syringe toe the adapter at the free end of the tube. Lift the plunger to draw 2 ml of stomach contents into the tube. Wet the pH indicator paper with the collected sample and compare the color on the strip to its corresponding color chart. The pH should usually be between 1 and 5.5 Remove the tube if the pH is too high or if you otherwise suspect improper placement. Secure the placement of the tube by taping it to the patient's skin with 1-inch (2.5-cm) thick medical tape.  Attach one piece of tape to the patient's nose, then wrap the ends of that piece around the tube. Place a separate piece of tape across the tube and over the patient's cheek, as well. The tube must not be able to move around as the patient moves his or her head naturally. Before leaving the patient, make sure that he or she is as comfortable as possible.  Help the patient ease into a comfortable resting position. Make sure that the tube is not cut off or strained. Once the patient is comfortable, you should be able to remove your gloves and wash your hands. Throw the gloves away in a clinical waste bin, and use warm water and antibacterial soap to wash your hands. If the air test and stomach contents both check out, the tube is likely positioned properly. Nonetheless, it is still a good idea to arrange a chest x-ray to further confirm the placement of the tube. Do this before using the tube to deliver food or medications. The x-ray technician should promptly deliver the x-ray results, and proper placement can then be confirmed by a doctor or nurse. At this point, you should be able to use the tube to drain the stomach, insert food, and/or insert medication.  You'll need to attach a bile bag to the end of the tube if you want to drain out digestive waste fluids. Alternatively, you may need to attach the end of the tube to a suction machine. Set the machine suction and pressure as indicated for that patient's specific needs. If you need to use the NG tube for feeding or medication, you might need to remove the guide wire from inside before inserting anything into the stomach. Flush 1 to 2 ml of water through the tube before carefully pulling the guide wire straight out. Clean the wire, dry it, and store it in a safe, sterile location for later use. Regardless of what the tube is used for, you should document its usage closely. Write down the reason for its insertion, the type and size of the tube, and all other medical details dealing with the usage of the tube.

Summary:
Inject air into the tube. Aspirate from the tube. Secure the tube. Check the patient's level of comfort. Confirm the placement with an x-ray. Use the NG tube as needed.