Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death. 

Radiographic features

Plain radiograph

A correctly placed nasogastric tube should ¹⁰:

• descend in the midline, following the path of the oesophagus 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-oesophageal junction ¹.

Malpositioning may include tip position:

• remaining in the oesophagus

• 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 oesophagus typically visualised to the left, posterolateral to the trachea

  • an intraluminal curvilinear echogenic interface represents oesophageal placement of the tube

• epigastrium

  • with a longitudinal view of the gastro-oesophageal junction, the nasogastric tube may be advanced into the stomach under direct visualisation

  • 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 fatal sequelae in ~0.3% of cases. Complications include ^1-6,8,9:

• upper airway

  • epistaxis from insertion trauma

• lower airway

  • aspiration pneumonia

  • pneumothorax

  • haemorrhage

  • empyema

• enteral

  • GI perforation and mediastinitis or peritonitis

    • may further complicate with intravascular placement

  • GI obstruction

  • knotting/tangling of the tube

  • intramural oesophageal dissection

• intracranial and spinal canal

  • meningitis

  • focal neurological deficits