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Definition

Nasal trauma or aspiration pneumonia due to inadvertent administration in the trachea/lungs

Risk factors

 Use of a large nasogastric tube

 Use of a stiff nasogastric tube

 Inexperienced administrator

Pathogenesis

Mechanical trauma; inadvertent administration of fluid or feed material in the trachea/lungs

Prevention

A small‐bore tube can be used to reduce trauma. Use a feeding tube with guidewire, which can be left in place for several days/weeks – if such a feeding tube is used, the guidewire should be shorter than the tube to avoid trauma from the tip of the wire. Lubricant should be placed on the tube before insertion. Insertion of the tube in the trachea is common and needs to be avoided. Palpation of the ventral left neck region and trachea should be performed to ensure correct placement. In some horses (5%) the esophagus is transposed and runs along the right neck region, in which case this side of the neck has to be palpated. A cough reflex is not always elicited by incorrect placement, due to sedation or illness. Endoscopy or radiography can also be used to assess correct placement of the tube. While the tube is advanced in the esophagus, air should be blown through the tube. This is important if a small‐bore tube is used to avoid retroflection of the tube. The tube should ideally end in the distal part of the esophagus rather than in the stomach. This prevents occlusion of the tube with solid ingesta. Large bore indwelling tubes in the stomach have also been shown to delay gastric emptying. The guidewire can be left in place or removed. If it is removed it should not be thrown out, as it might be needed for replacement of the tube. If the tube is left indwelling it should be replaced every 24 hours in the opposite nostril (see Chapter 5: Complications of Nasogastric Intubation).

Diagnosis and clinical signs

Diagnosis of nasal trauma is made based on clinical signs such as nasal discharge or bleeding and can be confirmed via endoscopy. Diagnosis of aspiration pneumonia due to inadvertent administration of enteral feeding into the trachea/lungs is based on clinical signs such as fever, coughing and nasal discharge. Endoscopy and cytology of a tracheal aspirate as well as thoracic ultrasonography and radiography can aid in diagnosis.

Treatment

Nasal mucosal trauma will usually heal without treatment. Discontinuation of nasogastric intubation or using the other nostril can also help. Anti‐inflammatories (flunixin meglumine 1.1.mg/kg q12 h IV) and/or broad‐spectrum antibiotics can be necessary in severe cases. In case of aspiration pneumonia due to inadvertent administration fluids into the trachea, general treatment principles for aspiration pneumonia should be followed. These include anti‐inflammatories (flunixin meglumine 1.1.mg/kg q12 h IV) and broad‐spectrum antibiotics (e.g. gentamicin 6.6 mg/kg q24 h IV and Na‐penicillin 30,000 IU/kg q6 h IV).

Expected outcome

Nasal trauma usually heals well over time; in rare cases necrosis of the conchae has occurred (unpublished data). Prognosis for aspiration pneumonia depends on severity; if sterile fluids only are used prognosis is good, if large amounts were administered into the lungs, prognosis can be guarded.