Nerve Block: Infraorbital

Background

Infraorbital nerve (shown in middle right) with V2 facial sensory distribution.

Trigeminal nerve anatomy, with maxillary (V2) branch leading to trigeminal nerve.

• Infraorbital nerve is a branch of the maxillary nerve, which is a branch off the trigeminal nerve (CN V2).
  • Travels through the orbit and enters the infraorbital canal to exit onto the face through the infraorbital foramen.
• Infraorbital nerve innervates the ipsilateral lower eyelid, side of the nose, and upper lip
• Regional blocks provide anesthesia without distorting soft tissues as in local infiltration

Indications

• Trauma or need to perform painful procedure on areas innervated by infraorbital nerve

Contraindications

• Infection overlying injection site
• Previous allergic reaction local anesthetic
• Distortion of anatomical landmarks

Equipment Needed

• Local anesthesic
• 5-10 mL syringe
• Blunt fill needle
• 25-27ga needle
• Chlorhexidine or betadine
• Gauze
• Sterile gloves
• Sterile drape

Procedure

Intraoral approach

1. Place patient in supine position or seated
2. Apply anesthetic soaked q-tip to the mucosa opposite the upper second premolar (bicuspid) for 1 minute allowing for topical anesthesia
3. Draw up 2-5cc of anesthetic into syringe
4. Palpate the infraorbital foramen by having the patient look straight ahead and draw an imaginary line vertically from the pupil toward the inferior border of the infraorbital ridge, keep your finger on the foramen
5. Retract the cheek and introduce the needle into the mucosa ~ 0.5cm from the buccal surface
6. Advance the needle, keeping it parallel to the long axis of the bicuspid) until it is near the foramen (~1.5-2.5 cm)... do not advance too far as you may enter the orbit
7. Aspirate, and if no blood, inject 4-5 cc of anesthetic slowly

Extraoral Approach

1. Place patient in supine position or seated
2. Draw up 2-5cc of anesthetic into syringe (avoid epinephrine as you are very close to the facial artery while doing the block via this approach)
3. Palpate the infraorbital foramen (step 5 above)
4. Prep the overlying skin with betadine
5. Insert the needle through the skin, subcutaneous tissue, and muscle
6. Aspirate, if no blood, inject anesthetic slowly (the tissue will swell)
7. Remove the needle and massage the area for 10-15 seconds

Field Block

• If the nerve block does not work you can do a field block which will generally achieve the same effect
• Inject 5 cc of local anesthetic into the upper buccal fold in an arc like distribution and then massage into the area for a few seconds

Complications

• Bleeding/hematoma
• Infection
• Inadvertent intravascular injection
• swelling of face/eyelid
• allergic reaction to anesthetic
• damage to nerves/vessels

See Also

• Nerve blocks (main)
• Local anesthetic systemic toxicity

References

• Amsterdam J and Kilgore K. Regional Anesthesia of the Head and Neck. In: Roberts and Hedges' Clinical Procedures in Emergency Medicine. 6th ed. Philadelphia, PA: Elsevier; 2014.