Intrabronchial Malposition of Nasogastric Tube

Supine chest radiograph in an ICU patient shows the tip of an NG tube in the right lower lobe bronchus (arrow). New opacities are seen in the vicinity of the tip of the NG tube, which may represent hemorrhage or aspiration.

Facts:

• Incidence in ICU patients between 0.5% - 1.5% of all NG tube placement
• Right side more common than left, lower lobe more than intermediate bronchus or main bronchus
• In one study of 14 malpositions, nearly half of the cases had subsequent pneumothorax requiring chest tubes, and the other half experienced pneumonias at the same site
• Traditional criteria for determining proper positioning of an NG tube (i.e., sound heard over the stomach upon insufflation of air, aspiration of fluid, absence of coughing) may not work well in ICU patients who are usually obtunded, intubated, have impaired gag reflex, decreased laryngeal sensitivity and are on neuromuscular blocking agents.
• Routine radiography after placement of an NG tube in ICU patients can be helpful for detection of tube malposition
• Once detected intrabronchial NG tube malposition, one should look for evidence of pneumothorax. If not seen, a close follow up radiograph is recommended since delayed pneumothorax may occur.

Reference:

Bankier AA, Wiesmayr MN, Henk C, et al. Radiographic detection of intrabronchial malpositions of nasogastric tubes and subsequent complications in intensive care unit patients. Intens Care Medicine 1997;23:406-410.