Nasogastric Intubation and Fe... Health Article

Definition

Nasogastric intubation refers to the process of placing a soft plastic nasogastric (NG) tube through a patient's nostril, past the pharynx and down the esophagus into a patient's stomach.

Purpose

Nasogastric tubes are inserted to deliver substances directly into the stomach, remove substances from the stomach or as a means of testing stomach function or contents.

The most common purpose for inserting a nasogastric tube is to deliver tube feedings to a patient when they are unable to eat. Patients who may need a NG tube for feedings include: premature babies, patients in a coma, patients who have had neck or facial surgery or patients on mechanical ventilation. Other substances that are delivered through a NG tube may include ice water to stop bleeding in the stomach or medications to neutralize swallowed poisons.

Another purpose for inserting a nasogastric tube is to remove substances from the stomach. A NG tube is used to empty the stomach when accidental poisoning or drug overdose has occurred. A NG tube is used to remove air that accumulates in the stomach during cardiopulmonary resuscitation (CPR). It is used to remove stomach contents after major trauma or surgery to prevent aspiration of the stomach contents. Placing a NG helps prevent nausea and vomiting by removing stomach contents and preventing distention of the stomach when a patient has a bleeding ulcer, bowel obstruction or other gastrointestinal diseases.

A NG tube may be inserted to take samples of stomach contents for laboratory studies and to test for pressure or motor activity of the gastrointestinal tract.

Precautions

Do not use force when inserting a NG tube. If resistance occurs, rotate and retract the tube slightly and try again. Forcing the tube can cause traumatic injury to the tissue of the nose, throat or esophagus.

Always check the tube positioning before giving feedings. If the tube is out of place the patient may aspirate the feeding solution into the lungs.

Keep the patient in an upright or semi-upright sitting position when delivering a tube feeding to enhance peristalsis and avoid regurgitation of the feeding.

Check patients who are receiving continuous feedings via a pump or gravity hourly or according to the medical settings policy, to assure that the tube is in position, the formula is flowing at the correct rate and the patient is comfortable with no signs of distention or distress.

Cap or clamp off the NG tube when not in use to prevent backflow of stomach contents or accumulation of air in the stomach.

If a patient has severe sinus conditions, nasal obstruction or has had facial surgery, it may be necessary to place a oral-gastric tube to avoid further nasal trauma.

If the amount of gastric aspirate is large prior to a bolus or intermittent feeding, notify the physician and follow the protocol of the medical setting for re-instilling the gastric aspirate. The feeding size may need to be decreased if the patient is not digesting it.

NG tube placement is meant to be a short-term solution for feeding problems. Patients that require long term tube feeding should have surgical placement of a gastrostomy tube or gastrostomy button. Long-term NG tube usage can cause nasal erosion, sinusitis, esophagitis, gastric ulceration, esophageal-tracheal fistula formation, oral infections and respiratory infections.

Description

To insert a nasogastric tube, have the patient tilt his head slightly back and gently ease the lubricated tubing into the nares. As the tube rounds the bend into the throat, have the patient tilt his head forward into a neutral upright position, hold his breath and swallow. Gently rotate the tubing 180 degrees to redirect the curve of the tube. Ease the tubing down the throat past the closed epiglottis. Gravity and swallowing will help move the tube down the esophagus as you gently continue to advance the tube. The patient can assist by swallowing and can even take sips of water to help move the tubing down into the stomach. Advance the tubing until you reach the marker tape that you applied when measuring the distance to the patient's stomach. Secure the tubing with tape and check the tubing for placement. If the patient gags during the procedure, stop advancing the tube and allow the patient to rest. If the tubing comes out of the mouth, retract the tubing and try again. If the patient is unconscious, advance the tube between respirations to avoid placing the tube into the trachea. If the patient becomes cyanotic, coughs or displays any signs of respiratory distress, remove the tubing, allow the patient to rest and begin again.

Once the NG tube is inserted, there are several methods for checking tube placement. Ask the patient to talk. If the patient cannot make sound, the tube has passed through the vocal cords and into the trachea. Remove the tube and start again. If the patient can talk, use a flashlight to look into the patient's mouth to view the tubing. It should appear straight in the back of the throat with no coiling into the mouth. Next, connect a 30 or 60cc catheter tip syringe to the end of the NG tube and aspirate to see if stomach contents return into the tubing. Stomach aspirate is often clear or yellow appearing but this depends upon what is in the patient's stomach. Stomach aspirate has a pH of 1-4 and an effective way to establish that the tube is in the stomach is to check the pH of the aspirate. Methods for checking tube placement, however, vary according to the medical setting. Follow the medical setting policy for checking tube placement. Another, more traditional method for checking tube placement is to draw 10-20 cc of air into the syringe, place the stethoscope over the patient's stomach and quickly inject the bolus of air into the stomach. A whooshing sound should be audible through the stethoscope over the stomach if the tube is in the stomach. If the tube is in the esophagus or trachea, the air sounds will be absent or muffled. The most accurate way to check for tube placement is an x ray of the abdomen. The NG tube is radiographic and will show up clearly on the x ray. A chest x ray is rarely done for NG tube placement because of the cost, but if performed for other purposes the radiologist will usually note the positioning of the NG tube on the report.