Inserting an NG tube
Whether you've never inserted an NG tube or have done so dozens of times, you know that this common bedside procedure is not without risk. To ensure your patient's safety, you need to know the reason for the insertion order and be aware of the potential pitfalls and how to avoid them.
Primarily intended for short-term use—typically 48 – 72 hours—NG tubes serve both therapeutic and diagnostic purposes. They are inserted in patients immediately after major surgery to help keep the stomach empty and prevent postop vomiting and used to feed and administer meds in critically ill patients. In addition, nasogastric tubes are routinely used to collect gastric contents for lab analysis and to aspirate the gut in case of a GI bleed or a drug overdose.
While the indication helps determine which type of tube you'll use, inserting it involves the same basic steps. This review will help you proceed safely the next time you receive an order that begins, "Insert NG tube."
Prepare the patient
The two most commonly ordered NG tubes—the Levin and the Salem sump—both range in size from 12 – 18 F for adults and are 42 – 50 inches long. The Levin, a flexible, soft rubber or plastic tube with a single lumen and holes at the tip and along the distal side, is typically used for decompression, lavage, or feeding; it's not used for suctioning because it could adhere to and irritate the stomach's mucosal surface.
The Salem, which is made of clear, firm plastic, has two lumens; the second, smaller lumen serves as an air vent (also called a sump port or, more commonly, a pigtail). The vent allows atmospheric air to continually flow into the stomach, preventing the tip of the NG tube from adhering to the gut wall, making this tube ideal for use with suction. Like the Levin tube, the Salem sump has holes along its distal side, but air only flows through the hole in the tip.
Depending upon the particular needs of your patient, you'll obtain the appropriate NG tube and gather all the equipment at the bedside. You'll need an emesis basin, towel, tissues, water-soluble lubricant, non-sterile gloves, an irrigation set (if required), safety pin, and ice chips or a cup of water with a straw. If suction will be used, make sure it's set up and working properly.
Next, explain to your patient that you'll gently insert the tube into his stomach. Tell him that he may experience momentary discomfort, such as coughing, gagging, or tearing, but it's essential that he swallow as directed to ease tube insertion.
If he has a deviated septum or other nasal deformity from a past surgery or trauma, use a penlight to see which of his nares is the most patent. Another option: You can occlude one nostril at a time and observe his breathing. You'll then use the nostril with the best airflow.
When you're ready, help your patient into a high Fowler's position, supporting his head and shoulders with a pillow. Cover his chest with the towel and put the tissues and emesis basin within his reach.
To determine the length required to reach the stomach, extend the end of the tube from the tip of his nose to his earlobe, then down to the xiphoid process. Mark the distance with a piece of tape. The average length for an adult is 22 – 26 inches.
Put on gloves and coil the end of the tube around your index finger to produce a flexible curve to ease insertion. Coat approximately four inches of this curved end with a water-soluble lubricant to minimize injury to the nasal passages. Oil-soluble substances such as petroleum jelly are contraindicated because they can't be absorbed by the pulmonary mucosa and may cause pneumonia if accidentally introduced into the trachea.
Insert the tube
To perform the procedure, instruct the patient to hold his head straight up with his neck slightly hyperextended and facing forward. Grasp the end of the tube above the lubricant. With the curve pointing downward, carefully insert the tube along the floor of the nostril, on the lateral side.