Placement of Nasal Oxygen Catheters

Hypoxemia is defined as partial pressure of blood oxygen (PaO₂) below 80 mm Hg or an arterial blood hemoglobin saturation of less than 95%.¹ Severe hypoxemia is defined as PaO₂ below 60 mm Hg.^2,3 Hypoxemia may occur due to a low fraction of inspired oxygen (FiO₂), hypoventilation, or venous admixture.³ Any patient with hypoxemia requires oxygen therapy.

Supplemental oxygen can be delivered noninvasively or invasively. Noninvasive methods include flow-by oxygen, oxygen face masks, oxygen hoods, and oxygen tents or cages. Invasive techniques use nasal prongs, nasal oxygen catheters, nasopharyngeal oxygen catheters, and transtracheal oxygen catheters. Noninvasive methods deliver oxygen less effectively than invasive techniques, and the method of oxygen supplementation will be dependent on patient needs, available equipment, skill and clinical experience, and the level of FiO₂ required.³

Nasal oxygen catheters are an effective delivery tool for patients that require oxygen therapy for more than 12 to 24 hours.⁴ 

An FiO₂ level of 40% to 80% may be achieved using unilateral or bilateral nasal oxygen catheters.^4-7 Bilateral nasal catheters will allow a higher oxygen flow and can deliver 60% oxygen with a flow rate of 100 mL/kg and up to 80% oxygen at 200 mL/kg.⁷ However, high oxygen flow rates may cause patient discomfort, irritation, and sneezing. The size of the catheter may be a determinant to the flow rate of oxygen able to be administered. To avoid pulmonary oxygen toxicity, an FiO₂ of more than 50% should not be administered for more than 24 to 72 hours.⁴ It is unlikely that pulmonary oxygen toxicity will occur with a unilateral nasal oxygen catheter as an FiO₂ of more than 50% is difficult to achieve and sustain with this method of oxygen delivery. Because of the high FiO₂ achievable with bilateral catheters, care must be taken if high flow rates are used over an extended period of time because oxygen toxicity may occur.

Catheter placement is relatively simple and requires minimal equipment. Depending on the animal’s physical status, sedation may be of benefit if the patient will not tolerate the procedure. Use of nasal oxygen catheters may be contraindicated in patients with coagulopathies, increased intracranial pressure, head trauma, or nasal pathology.⁸

The following images demonstrate the steps needed to appropriately place a nasal oxygen catheter.

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Figure 1 The following materials are needed for nasal oxygen catheter placement:

• Oxygen source and extension tubing

• Tubing adapter

• Nasal oxygen catheter or feeding tube, 5-6 French (Fr), 8-12 Fr for medium- to large-breed dogs

• Tape or alternate supplies for securing the nasal oxygen catheter (eg, suture material, skin stapler)

• Lidocaine 2% topical solution or a topical ophthalmic anesthetic

• Lidocaine 2% jelly

• Oxygen humidifier

• Elizabethan collar (as needed)

1 / 11

Figure 1 The following materials are needed for nasal oxygen catheter placement:

• Oxygen source and extension tubing

• Tubing adapter

• Nasal oxygen catheter or feeding tube, 5-6 French (Fr), 8-12 Fr for medium- to large-breed dogs

• Tape or alternate supplies for securing the nasal oxygen catheter (eg, suture material, skin stapler)

• Lidocaine 2% topical solution or a topical ophthalmic anesthetic

• Lidocaine 2% jelly

• Oxygen humidifier

• Elizabethan collar (as needed)

This article originally appeared in the July 2017 web issue of Veterinary Team Brief.