Nasogastric intubation is a medical process involving the insertion of a plastic tube ( nasogastric tube or NG tube ) through the nose, through the throat, and down into the abdomen. Orogastric intubation is a similar process involving the insertion of a plastic tube (orogastric tube ) by mouth.
Video Nasogastric intubation
Usage
Nasogastric tubes are used to feed and administer drugs and other oral agents such as activated charcoal. For medicines and for a small amount of fluid, a syringe is used for injection into the tube. For continuous feeding, gravity-based systems are used, with solutions placed higher than the patient's abdomen. If necessary supervision is necessary for feeding, the tube is often connected to an electronic pump that can control and measure the patient's intake and signal a disturbance at the time of feeding.
Nasogastric aspiration (suction) is the process of draining the contents of the stomach through the tube. Nasogastric aspiration is primarily used to secrete gastrointestinal secretions and swallow air in patients with gastrointestinal obstruction. Nasogastric aspiration may also be used in poisoning situations when potentially toxic liquids have been ingested, for pre-surgical preparation under anesthesia, and for extracting gastric samples for analysis.
If the tube will be used for continuous drainage, it is usually added to the collector bag placed below the patient's stomach level; gravity empties the contents of the stomach. It can also be added to the suction system, but this method is often limited to emergency situations, since constant suction can easily damage the lining of the stomach. In non-emergency situations, intermittent suction is often applied to provide suction benefits without damage effects on the lining of the stomach.
Suction drainage is also used for patients who have undergone pneumonectomy to prevent vomiting associated with anesthesia and possible aspiration of the stomach contents. Such aspirations would represent a serious risk of complications for patients recovering from this surgery.
Maps Nasogastric intubation
Type
Types of nasogastric tubes include:
- Levin catheter , which is a single lumen, a small NG tube. This is more appropriate for medication or nutrition.
- Salem Sump catheter , which is a large NG tube with double lumen. This allows aspiration in one lumen, and venting in other parts to reduce negative pressure and prevent the gastric mucosa from being drawn to the catheter.
- Dobhoff tube , which is a small heavy NG tube at the end intended to pull it with gravity during insertion.
Technique
Before the NG tube is inserted, it should be measured from the tip of the patient's nose, circling their ears and then down to about 5 cm below the xifoid process. The tube is then marked at this level to ensure that the tube has been inserted far enough into the patient's abdomen. Many commercially available tube and duodenal tubes have some standard depth marks, for example 18 "(46 cm), 22" (56 cm), 26 "(66 cm) and 30" (76 cm) from the distal end; Baby food tubes often come with a 1 cm depth mark. The tip of the plastic tube is lubricated (local anesthesia, such as 2% xylocaine gel, may be used; in addition, the nasal vasoconstrictor and/or anesthetic spray may be applied prior to insertion) and fed into one of the patient's anterior nares. The tube should be directed straight toward the patient's back as it moves through the nasal cavity and down the throat. When the tube enters the oropharynx and slips down the posterior pharyngeal wall, the patient may vomit; in this situation the patient, if awake and alert, is asked to mimic swallowing or given water to sip the straw, and the tube continues to be inserted when the patient swallows. Once the tube passes through the pharynx and enters the esophagus, it is easily inserted into the stomach. The tube should be secured in place to prevent it from moving.
Great attention should be given to ensuring the tube does not pass through the larynx into the trachea and into the bronchi. A reliable method is to suck some liquid from a tube with a syringe. The liquid is then tested with pH paper (note not litmus paper) to determine the acidity of the liquid. If the pH is 4 or below then the tube is in the correct position. If this is not possible then verify the correct tube position is obtained with a chest X-ray/abdomen. This is the most reliable way to ensure proper placement of NG tubes. The use of chest x-ray to confirm the position is the expected standard in the UK, with review and confirmation of Dr./doctor. Future techniques may include measuring enzyme concentrations such as trypsin, pepsin, and bilirubin to confirm correct placement of NG tubes. Because enzyme testing becomes more practical, allowing quick and cheap measurements by the bed, this technique can be used in combination with pH testing in place of effective and less harmful X-rays. If the tube will remain in place then check the position of the tube is recommended before each feed and at least once per day.
Only smaller diameter (12 Fr or less in adults) nasogastric tubes suitable for long-term feeding, to avoid irritation and erosion of the nasal mucosa. These tubes often have a guide to facilitate insertion. If feeding is required for a longer period of time, other options, such as placement of a PEG tube, should be considered.
Properly placed NG tube functions and used for suctioning are maintained by rinsing. This can be done by dousing a small amount of salt and air using a syringe or by watering a larger amount of water or salt, and air, then assessing the air to circulate through one lumen of the tube, into the stomach, and out the other lumen. When these two flushing techniques are compared, the latter is more effective.
Contraindications
Use of nasogastric intubation is contraindicated in patients with moderate to severe neck and facial fractures due to an increased risk of airway obstruction or improper tube placement. Special care is required during insertion in these circumstances to avoid unnecessary trauma to the esophagus. There is also a greater risk for patients suffering from bleeding disorders, especially those resulting from the sub sub-mucous vein in the lower third of the esophagus known as esophageal varices that can easily rupture due to their fragility and also in GERD.
Alternative measures, such as orogastric intubation, should be considered under these circumstances, or if the patient will not be able to meet their nutritional and caloric needs for long periods of time (usually 24 hours).
Complications
Small complications include nose bleeding, sinusitis, and sore throat.
Sometimes more significant complications occur including nasal erosion where the tube is docked, esophageal perforation, damage to surgical anastomosis, lung aspiration, collapsed lung, or intracranial placement of the tube.
See also
- Forced to feed
- Tubefeeding
- Abraham Louis Levin, inventor of NG techniques
References
Source of the article : Wikipedia
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