Nasogastric tube positioning
Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death.
Evaluation of Nasogastric tube
Plain radiograph
A correctly placed nasogastric tube should 10:
- descend in the midline, following the path of the esophagus and avoiding the contours of the bronchi
- clearly bisect the carina or bronchi
- cross the diaphragm in the midline
- have its tip visible below the left hemidiaphragm
Ideally, the tip should be at least 10 cm beyond the gastro-esophageal junction 1.
Malpositioning may include tip position:
- remaining in the esophagus
- traversing either bronchus or more distally into the lung
- coiled in the upper airway
- intracranial insertion, possible in both patients with and without skull base trauma or surgery 2
- spinal canal insertion is very rare, occurring after skull base surgery in one case report 8,9
In some circumstances fluoroscopic nasojejunal tube insertion is necessary.
Ultrasound
Point-of-care ultrasonography may be used to guide the nasogastric tube in real time with the probe placed sequentially in the following locations 7:
- anterolateral neck
- cervical esophagus typically visualized to the left, posterolateral to the trachea
- an intraluminal curvilinear echogenic interface represents esophageal placement of the tube
- epigastrium
- with a longitudinal view of the gastroesophageal junction, the nasogastric tube may be advanced into the stomach under direct visualization
- oblique and sagittal scan planes to view the tube coursing through the gastric fundus and terminating in the antrum, confirming correct placement
Complications
Overall, complications occur in 1-3% of cases, with complications leading to death occurring in approximately 0.3% of cases. Complications include 1-6,8,9:
- upper airway
- epistaxis from insertion trauma
- lower airway
- aspiration pneumonia
- pneumothorax
- hemorrhage
- empyema
- enteral
- viscus perforation and mediastinitis or peritonitis
- may further complicate with intravascular placement
- viscus obstruction
- knotting/tangling of the tube
- intramural esophageal dissection
- viscus perforation and mediastinitis or peritonitis
- intracranial and spinal canal
- meningitis
- focal neurological deficits
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