The keys to smooth NGT insertion are having all of your supplies at the bedside prior to the procedure, communicating with the patient, enlisting their assistance and providing adequate topical anesthesia. 16 , 21

Explain procedure | Anesthetize the mucosa | Prepare yourself, equipment, and patient
Insert the tube | Secure the tube | Troubleshooting

EXPLAIN THE PROCEDURE

Tell the patient in lay terms why you need to insert the NGT. Explain that you will administer medicine to numb their nose and throat, and then will insert the tube through their nostril and into their stomach. Instruct them that they will need to sip on the water and swallow when directed, in order to facilitate passage of the tube into the esophagus.

ANESTHETIZE the nasal and oropharyngeal mucosa

First assess which naris is more patent by having the patient hold each one closed in sequence and determining which (if either) is easier to breathe through. 

Look into both nares at the beginning of the procedure and note any significant abnormalities, lesions, injuries, bleeding, polyps or septal deviation.  Chose the most patent side, preferably without any of these conditions.

The patient's nasal cavity should be pre-medicated first with a vaso- constrictive spray , such as phenyl- ephrine or oxy- metazoline.  Though this step is often overlooked, it makes passage of the NGT much easier and also reduces the risk of iatrogenic epistaxis. 

 

Next, 5-10 cc of 2% lidocaine jelly is administered into the selected naris via a 10 cc syringe (without a needle) or via a pre-filled Urojet syringe.    Alternatively, 4% lidocaine may be applied to the mucosa via an atomizer (as shown in the video.) 

There are several options for anesthetizing the oropharynx including atomized lidocaine, benzocaine (e.g. Hurricane spray) and viscous lidocaine.   If benzocaine spray is used, it should be sprayed into the oropharynx just before insertion of the tube, as it is most effective immediately after administration.

Several studies have demonstrated that proper anesthesia prior to NGT insertion greatly reduces patient discomfort. Wolfe et. al. atomized 3 mls of 4% lidocaine into the oropharynx and compared it with placebo. Their results demonstrated a significant decrease in pain in the lidocaine group. 22 Holger et. al. performed a small study using swallowed 2% viscous lidocaine as topical anesthesia; their results show that patients were more comfortable when given the lidocaine, though operators found insertion more difficult. 23 Singer et. al. evaluated the combination of intranasal phenylephrine and viscous lidocaine with oropharyngeal tetracaine and benzocaine. Compared to placebo, this combination significantly decreased overall pain, nasal pain, and gagging associated with NGT insertion. 24 Whichever route of topical lidocaine you choose, be careful not to exceed toxic dose of lidocaine (4 mg/kg).  Note that 1% xylocaine = 1 gram/100cc or 10 mg/cc.  Therefore, a 70 kg adult can receive up to 28 cc of 1% xylocaine before reaching toxic levels.  Medications are absorbed very quickly across the nasal mucosa although this process is delayed when a vasoconstrictor is applied first.  While you wait for the anesthetic to take effect (approximately 5 minutes) you can begin to prepare your equipment .

PREPARE YOURSELF, YOUR EQUIPMENT, AND YOUR PATIENT

Prepare Yourself

Observe universal precautions: A face shield, protective gown, and gloves should be donned as patients may gag, spit, or vomit during the procedure.

Prepare Your Equipment

Determine the depth-of-insertion of the NGT: Measure the length from the naris to the ipsilateral ear to the xiphoid process. This measurement approximates the distance the NGT must travel to reach the stomach. Measure up this same distance from the distal tip of the NGT and note the location by the black marks inscribed on the proximal portion of the tube.

 

Remove the NGT tube from its packaging and apply Surgilube or viscous lidocaine to the distal end. Tear off a 10 cm piece of tape ( see below ) and have it ready at the bedside. Assure that the suction is working properly and that the tubing is within reach.

 

Prepare the patient

Offer reassurance. Sitting the patient upright will facilitate easy passage of the tube. Drape the patient with a towel or chux and provide a basin to collect any secretions or emesis.

INSERT THE NASOGASTRIC TUBE

Place the tip of the NGT in the selected naris at an angle PARALLEL with the floor of the nasal canal (not upright or following the angle of the nose). Ascertain that the natural curve of the NGT is in proper orientation with respect to the curve of the patient's nasal cavity-nasopharynx- esophagus. Some experts recommend bending the distal end of the tube so that it takes the natural shape of the nasal passage, down into the oropharynx. As you insert the tube, place gentle pressure on the tube as it passes through the nasal cavity; stop if you meet significant resistance.  

Discomfort can be diminished by very slow (1 mm at a time) insertion once the tube enters the narrow mid-nasopharynx.  Rapid insertion often leads to patient discomfort, more gagging, and the need to pull back and start over.  The operator will generally feel mild resistance as the tube abuts the posterior pharyngeal wall.  Continuous gentle pressure usually will allow the tube to bend into the throat and be properly positioned to continue its journey to the lower pharynx. The patient may gag once the tube has passed from the nasopharynx into the oropharynx, and it may be necessary to pause for a few moments.

 

Next, instruct the patient to sip water through the straw, and advance the tube as the patient swallows. Coordinating the passage of the tube with the swallowing mechanism helps to avoid tracheal intubation and facilitates passage of the tube into the esophagus.   (Demonstrated in the flouroscopy video .)  Once in the esophagus, rapidly insert the tube up to the predetermined desired length.

If the patient begins to cough steadily, becomes dyspneic, desaturates, or is unable to speak during this portion of the procedure, you should be suspicious of tracheal insertion and immediately withdraw the tube several centimeters (see Complications section below for further discussion.) Difficulties in passing the tube are discussed in the Troubleshooting section below.

SECURE THE TUBE

At this point you can secure the tube to the patient's nose with tape. Take a 5-7 cm strip of adhesive tape and tear it vertically for ½ of the length of the tape. The wide section is placed across the patient's nose, and the two "tails" are then wrapped in opposite directions around the NGT.

TROUBLESHOOTING

Nasal obstruction | Failure to pass into esophagus | Unconscious patient | Hemorrhage / coagulopathy

Nasal Obstruction

It is important to chose the most patent side  by having the patient alternatively breath through each nostril independently.  The presence of polyps are generally not considered a contraindication to this procedure, but it may be made easier by the application of a topical vasoconstrictor first, allowing a minute or 2 for the medication to take effect.   If the tube meets with significant obstruction, continuous, gentle pressure often allows passage.  If the tube cannot be passed through either side, it may be necessary to insert the tube orally.  If a tube is absolutely necessary, the oral route can be used.  The technique is generally the same as for nasal insertion although greater attention to topical anesthesia is necessary as most patients find this procedure to be extremely uncomfortable.  Oral tubes are generally not recommended for long term use, except in intubated patients.  They may be helpful for diagnostic purposes when they can be removed in a short time.

Failure of Tube to Pass Into Esophagus / Curling of the Tube

Difficulty may be encountered in passing the tube from the oropharynx into the esophagus, especially if the tube tends to curl. Occasionally the NGT will curl 180 ° and the distal tip will protrude through the oral cavity. Several remedies are possible. Maneuvers to increase the rigidity of the tube may be employed. After several attempts at passage, NGTs tend to become more flexible, and using a new NGT may increase your chances of successful passage. Some authorities 15 , 21 recommended cooling the NGT in an ice bath to increase rigidity. Care must be utilized when using this technique as injuries to the soft tissues of the pharynx and esophagus are more likely with a cooled, rigid tube (see Complications section for further discussion.) Flexing the neck (in patients without cervical spine injury) brings the esophagus into a more anterior position and may facilitate passage as well.  Bending the tube in the direction it will ultimately take may be helpful.  The tube is inserted with the convex side up initially and then, as it reaches the lower pharynx, it is rotated 180 degrees so that the tube passes posteriorly and into the esophagus.

Unconscious Patient

These patients are unable to assist you by swallowing, and passage into the esophagus may be difficult. Furthermore, in the supine patient gravity may cause the esophagus to collapse and impede passage, causing the NGT to curl. 21 If the patient does not have intact airway reflexes, it is possible to insert a laryngoscope into the oropharynx and directly visualize the tube. This visualization alone may be enough to facilitate passage. If further manipulation is required, a Magill forceps or the operators fingers may be inserted into the posterior oral cavity to help advance the tube. Anteriorly-directed traction on the mandible (using either the jaw-thrust maneuver or gentle manual traction on the patient's lower teeth and chin) will often open the esophagus and allow the tube to pass through. A variation of this technique utilizes anterior traction on the thyroid cartilage to open the esophagus. It should be noted that in the intubated patient, the Salem or Levin tube may be passed orally.

Hemorrhage / Coagulopathy

Bleeding disorders do not generally represent a contraindication to tube placement.  However, bleeding after insertion may sometimes be signigicant.  The likelihood of major bleeding can be diminished by application of a vasoconstrictor to the entire nasal mucosa by atomization and the waiting several minutes for the medication to take effect.

   

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