How To Do an Infraorbital Nerve Block, Percutaneous

• Laceration or other surgically treated lesion of the midface

A nerve block has advantages over local anesthetic infiltration when accurate approximation of wound edges is important (eg, in facial skin repair), because a nerve block does not distort the tissue as local infiltration does.

Absolute contraindications

• History of allergy to the anesthetic agent or delivery vehicle (choose a different anesthetic)

• Absence of anatomic landmarks needed to guide needle insertion (eg, due to trauma)

Relative contraindications

• Infection in the path of needle insertion: Use procedural sedation or other anesthesia.

• Coagulopathy*: When feasible, correct prior to procedure or use a different means of analgesia

* Therapeutic anticoagulation (eg, for pulmonary embolism) increases the risk of bleeding with nerve blocks, but this must be balanced against the increased risk of thrombosis (eg, stroke) if anticoagulation is reversed. Discuss any contemplated reversal with the clinician managing the patient's anticoagulation and then with the patient.

• Adverse reaction to the anesthetic or delivery vehicle (eg, allergic reaction to the anesthetic [rare] or to methylparaben [a preservative])

• Toxicity due to anesthetic overdose (eg, seizure, cardiac arrhythmias) or sympathomimetic effects due to epinephrine (if using an anesthetic-epinephrine mixture)

• Intravascular injection of anesthetic or epinephrine

• Hematoma (eg, due to puncture of the infraorbital venous plexus)

• Neuritis

• Spread of infection, by passing the needle through an infected area

Most complications result from inaccurate needle placement.

• Nonsterile gloves

• Barrier precautions as indicated (eg, face mask, safety glasses or face shield, cap and gown)

• Antiseptic solution (eg, chlorhexidine, povidone-iodine, alcohol)

• Injectable local anesthetic* such as lidocaine 2% without epinephrine† or, for longer-duration anesthesia, bupivacaine 0.5% without epinephrine‡

• Syringe (eg, 3 mL) and needle (eg, 25 or 27 gauge) for anesthetic injection

* Local anesthetics are discussed in Lacerations.

† To prevent vasoconstriction of the facial artery (which lies very close to the site of anesthetic deposition in this approach), epinephrine is not recommended for percutaneous infraorbital nerve block.

‡ Maximum dose of local anesthetics: Lidocaine without epinephrine, 5 mg/kg; bupivacaine, 1.5 mg/kg. NOTE: A 1% solution (of any substance) represents 10 mg/mL (1 g/100 mL).

• Document any preexisting nerve deficit before doing a nerve block.

• Stop the nerve block procedure if you are unsure where the needle is or if the patient is uncooperative. Consider sedation for patients who are unable to cooperate or remain still.

• The infraorbital nerve is a termination of the maxillary nerve, which is the 2nd branch of the trigeminal nerve.

• The infraorbital nerve exits the cranium through the infraorbital foramen, which is palpable 1 cm below the inferior border of the infraorbital ridge, directly below the pupil when the patient is looking straight ahead.

• Several cutaneous branches of the infraorbital nerve spread over the ipsilateral midface, lower lid, side of the nose, and upper lip.

Thus, an infraorbital block anesthetizes the ipsilateral lower eyelid, upper cheek, side of the nose, and upper lip.

• Position the patient inclined or supine.

• Check sensation in the infraorbital nerve distribution.

• Wear gloves and use appropriate barrier precautions.

• Palpate the infraorbital ridge and identify the infraorbital foramen (the injection site).

• Cleanse the skin site with antiseptic solution.

• Place a skin wheal of anesthetic, if one is being used, at the needle-entry site.

• Insert the needle just below the infraorbital foramen pointing slightly cephalad and advance it until paresthesia is elicited or the needle meets the maxillary bone just superior to the foramen. Do not insert the needle into the infraorbital foramen. If paresthesia occurs during insertion,withdraw the needle 1 to 2 mm.

• Aspirate to exclude intravascular placement and then slowly (ie, over 30 to 60 seconds) inject about 2 to 3 mL of anesthetic adjacent to, but not into, the infraorbital foramen. Press your finger lightly over the infraorbital rim to prevent lower eyelid swelling.

• Massage the area for about 10 seconds to hasten the onset of anesthesia.

• Allow about 5 to 10 minutes for the anesthetic to take effect.

• Ensure hemostasis at the injection site.

• Instruct patient regarding anticipated time to anesthesia resolution.

• To minimize the risk of needle breakage, do not bend the needle, insert it to its full depth (ie, to the hub), or attempt to change the direction of the needle while it is inserted.

• To help prevent nerve injury or intraneural injection, instruct patients to report paresthesias or pain during the nerve-block procedure.

• To help prevent intravascular injections, aspirate before injecting.

• Minimize the pain of injection by injecting slowly (eg, 30 to 60 seconds), warming the anesthetic solution to body temperature, and buffering the anesthetic.