Article: Insert the lubricated end of the tube into the clearest nostril, aiming the end of the tube straight back as you feed it in.  The patient must continue looking straight at you. Direct the tube down and toward the ear on that side of the head. Do not allow the tube to feed upward and into the brain. Stop if you feel resistance. Pull the tube out and try the other nostril. Never force the tube inward. If you have coated the patient's throat with anesthetic throat spray, ask the patient to open his or her mouth and watch for the other end of the tube.  For patients who were not treated with throat spray, opening the mouth might be too painful. Instead, you should simply ask the patient to indicate when he or she feels the tube at the back of the throat. As soon as the tube hits the top of the throat, guide the patient's head so that the chin touches the chest. This can help encourage the tube into the esophagus, rather than into the trachea. Give the patient a glass of water with a straw. Ask him or her to take small sips and swallows as you continue guiding the tube downward.  If the patient is unable to drink water for any reason, you should still encourage him or her to dry swallow as you feed the tube into the throat. For infants, give the patient a pacifier to encourage him or her to suck and swallow during the process. Continue feeding the tube into the patient's throat until the marked measurement reaches the patient's nostril.  If you meet resistance further into the throat, slowly rotate the tube as you advance it. This should help. If the tube still gives considerable resistance, pull it out and try again. Never force it in. Stop immediately and remove the tube if you notice a change in the patient's respiratory status. This can include choking, coughing, or difficulty breathing. A change in respiratory status suggests that the tube has been inserted into the trachea by mistake.  You should also remove the tube if it comes out of the patient's mouth.

What is a summary?
Insert the tube into the chosen nostril. Check the back of the throat. Instruct the patient to swallow. Stop once you reach the measured mark.