Nasogastric intubation is a medical process involving the insertion of a plastic tube (nasogastric tube or NG tube) through the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passe ...

, down the oesophagus, and down into the

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

. Orogastric intubation is a similar process involving the insertion of a plastic tube (orogastric tube) through the mouth. Abraham Louis Levin invented the NG tube. Nasogastric tube is also known as Ryle's tube in Commonwealth countries, after

John Alfred Ryle John Alfred Ryle (1889–1950) was a British physician and epidemiologist. He was born the son of Brighton medical doctor R J Ryle and brother of the Oxford philosopher Gilbert Ryle. He was educated at Brighton College and Guy's Hospital where ...

Uses

A nasogastric tube is used for feeding and administering drugs and other oral agents such as

activated charcoal "Activated" is a song by English singer Cher Lloyd. It was released on 22 July 2016 through Vixen Records. The song was made available to stream exclusively on ''Rolling Stone'' a day before to release (on 21 July 2016). Background In an inter ...

. For drugs and for minimal quantities of liquid, a

syringe A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside ...

is used for injection into the tube. For continuous feeding, a gravity based system is employed, with the solution placed higher than the patient's stomach. If accrued supervision is required for the feeding, the tube is often connected to an electronic pump which can control and measure the patient's intake and signal any interruption in the feeding. Nasogastric tubes may also be used as an aid in the treatment of life-threatening eating disorders, especially if the patient is not compliant with eating. In such cases, a nasogastric tube may be inserted by force for feeding against the patient's will under restraint. Such a practice may be highly distressing for both patients and healthcare staff. Nasogastric aspiration (suction) is the process of draining the stomach's contents via the tube. Nasogastric aspiration is mainly used to remove gastrointestinal secretions and swallowed air in patients with gastrointestinal obstructions. Nasogastric aspiration can also be used in poisoning situations when a potentially toxic liquid has been

ingested Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract, such as through eating or drinking. In single-celled organisms ingesti ...

, for preparation before surgery under

anaesthesia Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), a ...

, and to extract samples of gastric liquid for analysis. If the tube is to be used for continuous drainage, it is usually appended to a collector bag placed below the level of the patient's stomach; gravity empties the stomach's contents. It can also be appended to a suction system, however this method is often restricted to emergency situations, as the constant suction can easily damage the stomach's lining. In non-emergency situations, intermittent suction is often applied giving the benefits of suction without the untoward effects of damage to the stomach lining. Suction drainage is also used for patients who have undergone a

pneumonectomy A pneumonectomy (or pneumectomy) is a surgical procedure to remove a lung first successfully done in 1933 by Dr. Evarts Graham. This is not to be confused with a lobectomy or segmentectomy, which only removes one part of the lung. There are two ...

in order to prevent anesthesia-related vomiting and possible aspiration of any stomach contents. Such aspiration would represent a serious risk of complications to patients recovering from this surgery.

Types

Types of nasogastric tubes include: * Levin catheter, which is a single lumen, small bore NG tube. It is more appropriate for administration of medication or nutrition.Nasogastric Tube
Last authored: Dec 2009, David LaPierre * Salem Sump catheter, which is a large bore NG tube with double lumen. This avails for aspiration in one lumen, and venting in the other to reduce negative pressure and prevent gastric mucosa from being drawn into the catheter. * Dobhoff tube, which is a small bore NG tube with a weight at the end intended to pull it by gravity during insertion. The name "Dobhoff" refers to its inventors, surgeons Dr. Robert Dobbie and Dr. James Hoffmeister, who invented the tube in 1975.

Technique

Before an NG tube is inserted, it must be measured from the tip of the patient's nose, loop around their ear and then down to roughly below the xiphoid process. The tube is then marked at this level to ensure that the tube has been inserted far enough into the patient's stomach. Many commercially available stomach and duodenal tubes have several standard depth markings, for example , , and from distal end; infant feeding tubes often come with 1 cm depth markings. The end of a plastic tube is lubricated (local anesthetic, such as 2% xylocaine gel, may be used; in addition, nasal vasoconstrictor and/or anesthetic spray may be applied before the insertion) and inserted into one of the patient's anterior nares. Treatment with 2.0 mg of IV midazolam greatly reduces patient stress. The tube should be directed straight towards the back of the patient as it moves through the nasal cavity and down into the throat. When the tube enters the

oropharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...

and glides down the posterior pharyngeal wall, the patient may gag; in this situation the patient, if awake and alert, is asked to mimic swallowing or is given some water to sip through a straw, and the tube continues to be inserted as the patient swallows. Once the tube is past the pharynx and enters the esophagus, it is easily inserted down into the stomach. The tube must then be secured in place to prevent it from moving. There are several ways to secure an NG placement. One method and the least invasive is tape. Tape is positioned and wrapped around the NG tube onto the patients nose to prevent dislodgement. Another securement device is a nasal bridle, or a device that enters one nare, around the nasal septum, and then to the other nare where it is secured in place around the nasogastric tube. There are two ways a bridle is put into place. One method, according to the Australian Journal of Otolaryngology, is performed by a physician to pull a material through the nares and then tied with the ends shortened to prevent removal of the tube. The other method is a device called the Applied Medical Technology, or AMT, bridle. This device uses a magnet inserted into both nares that connects at the nasal septum and then pulled through to one side and tied. This technology allows nurses to safely apply bridles. Several studies have proven the use of a nasal bridle prevents the loss of the NG placement that provides necessary nutrients or suctioning. A study conducted in the UK from 2014 through 2017, determined that 50% of feeding tubes secured with tape were lost inadvertently. The use of bridle securement decreased the percentage of NGs lost from 53% to 9%. Great care must be taken to ensure that the tube has not passed through the larynx into the trachea and down into the

bronchi A bronchus is a passage or airway in the lower respiratory tract that conducts air into the lungs. The first or primary bronchi pronounced (BRAN-KAI) to branch from the trachea at the carina are the right main bronchus and the left main bronchus ...

. The reliable method is to aspirate some fluid from the tube with a

. This fluid is then tested with

pH paper A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence ...

(note not litmus paper) to determine the acidity of the fluid. If the pH is 4 or below then the tube is in the correct position. If this is not possible then correct verification of tube position is obtained with an

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 ...

of the chest/abdomen. This is the most reliable means of ensuring proper placement of an NG tube. The use of a chest x-ray to confirm position is the expected standard in the UK, with Dr/ physician review and confirmation. Future techniques may include measuring the concentration of enzymes such as

trypsin Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting these long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the di ...

pepsin Pepsin is an endopeptidase that breaks down proteins into smaller peptides. It is produced in the gastric chief cells of the stomach lining and is one of the main digestive enzymes in the digestive systems of humans and many other animals, ...

, and

bilirubin Bilirubin (BR) (Latin for "red bile") is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from t ...

to confirm the correct placement of the NG tube. As enzyme testing becomes more practical, allowing measurements to be taken quickly and cheaply at the bedside, this technique may be used in combination with pH testing as an effective, less harmful replacement of X-ray confirmation. If the tube is to remain in place then a tube position check is recommended before each feed and at least once per day. Only smaller diameter (12 Fr or less in adults) nasogastric tubes are appropriate for long-term feeding, so as to avoid irritation and erosion of the nasal mucosa. These tubes often have guidewires to facilitate insertion. If feeding is required for a longer period of time, other options, such as placement of a

PEG tube Percutaneous endoscopic gastrostomy (PEG) is an endoscopic medical procedure in which a tube (PEG tube) is passed into a patient's stomach through the abdominal wall, most commonly to provide a means of feeding when oral intake is not adequate (fo ...

, should be considered. Function of an NG tube properly placed and used for suction is maintained by flushing. This may be done by flushing small amounts of saline and air using a syringe or by flushing larger amounts of saline or water, and air, and then assessing for the air to circulate through one lumen of the tube, into the stomach, and out the other lumen. When these two techniques of flushing were compared, the latter was more effective.

Contraindications

The use of nasogastric intubation is

contraindicated In medicine, a contraindication is a condition that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a reason to use a certain tre ...

in patients with moderate-to-severe neck and facial fractures due to the increased risk of airway obstruction or improper tube placement. Special attention is necessary during insertion under these circumstances in order to avoid undue trauma to the esophagus. There is also a greater risk to patients with bleeding disorders, particularly those resulting from the distended sub-mucosal veins in the lower third of the esophagus known as

esophageal varices Esophageal varices are extremely dilated sub-mucosal veins in the lower third of the esophagus. They are most often a consequence of portal hypertension, commonly due to cirrhosis. People with esophageal varices have a strong tendency to develop s ...

which may be easily ruptured due to their friability and also in GERD(Gastro Esophageal Reflux Disease). Alternative measures, such as an orogastric intubation, should be considered under these circumstances, or if the patient will be incapable of meeting their nutritional and caloric needs for an extended time period (usually >24 hours).

Complications

Minor complications include nose bleeds,

sinusitis Sinusitis, also known as rhinosinusitis, is inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include thick nasal mucus, a plugged nose, and facial pain. Other signs and symptoms may include fever, hea ...

, and a sore throat. Sometimes more significant complications occur including erosion of the nose where the tube is anchored, esophageal perforation, damage to a surgical

anastomosis An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be norma ...

, pulmonary aspiration, a

collapsed lung A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve is ...

, damage to vocal cords or intracranial placement of the tube. Fox News Digital reported about a voluntary field correction notice dated March 21, 2022, referenced 60 injuries and 23 deaths related to misplacement of a nasogastric tube. Avanos Medical's ''Cortrak2 EAS recall'', has been classified as a Class I recall by the FDA, following these reports.

References