Chapter 73 Head and Neck Blocks Flashcards
Absolute contraindications include
patient refusal,
local infection and sepsis, and increased intracranial pressure
(trigeminal ganglion block).
Relative contraindications
coagulopathy, anticoagulant therapy, history of facial trauma,
and pre-existing neurologic deficits. Allergy to medications used can be absolute or relative depending on the severity of the allergy.
The trigeminal ganglion resides in
the middle cranial fossa. It is situated in a fold of dura mater that forms
an invagination around the posterior two-thirds of the ganglion. This region is referred to as Meckel’s cavity and contains cerebrospinal fluid.
trigeminal ganglion bounded by
medially by the cavernous sinus and optic and trochlear
nerves; superiorly by the inferior surface of the temporal lobe of the brain; and posteriorly by the brain stem.
trigeminal ganglion formed by
the fusion of a series of cell bodies
that originate at the mid-pontine level of the brainstem
trigeminal ganglion divisions
ophthalmic (V1),
maxillary (V2), and mandibular (V3).
The ophthalmic
division is located
dorsally, the maxillary branch intermediate,
and the mandibular branch ventrally. The ophthalmic
division leaves the ganglion and passes into the orbit
through the superior orbital fissure.
ophthalmic
division further divides into
the supraorbital, supratrochlear, and nasociliary nerves which innervate the forehead and the nose.
The maxillary division exits the middle cranial fossa via
foramen
rotundum, crosses the pterygopalatine fossa, and enters
the orbit through the inferior orbital fissure.
Branches of maxillary division
infraorbital, superior alveolar, palatine and
zygomatic nerves which carry sensory information from the maxilla and overlying skin, the nasal cavity, palate,
nasopharynx and meninges of the anterior and middle cranial fossa
The mandibular division exits through
foramen ovale and divides into the buccal, lingual, inferior alveolar and auriculotemporal nerves. These nerves carry sensory input from the buccal region, the side of the head and scalp, and the lower jaw including teeth, gums, anterior two-thirds of the tongue, chin, and lower lip.
The motor component of V3 innervates
the several muscles
including the masseter, temporal, and medial and lateral pterygoids.
The ganglion interfaces with the autonomic
nervous system via
the ciliary, sphenopalatine, otic, and
submaxillary ganglia. It also communicates with the oculomotor, facial, and glossopharyngeal nerves
MAXILLARY NERVE BLOCK
most common indication
regional anesthesia for surgery of the upper jaw, but is also effective for acute postoperative pain control. it is indicated for the diagnosis and
treatment of chronic pain in the distribution of the maxillary division of the trigeminal nerve
MAXILLARY NERVE BLOCK
Technique
Place the patient in
the supine position. Palpate the mandibular notch located below the zygoma and anterior to the temporomandibular
joint. Under sterile conditions, anesthetize the skin over the notch. Insert the block needle (usually a
22-gauge, 8–10 cm, short-bevel or a same-size curved, blunt needle) in a horizontal plane through the mandibular notch until bone (lateral pterygoid plate) is touched (typically 4–5 cm). Withdraw the needle and redirect it anteriorly and superiorly
through the pterygomaxillary fissure into the
pterygopalatine fossa. Advance the needle approximately 0.25 to 0.5 cm at which depth a paresthesia is usually
perceived in the upper lip or teeth.
MAXILLARY NERVE BLOCK
Technique (Fluoroscopy)
If performed under
fluoroscopy, the needle is angled toward the superior portion of the pterygopalatine fossa, which appears as a
“V” on the lateral image. On an anteroposterior image, the needle tip should be above the level of the middle turbinate. Inject 3 to 5 ml of local anesthetic. If fluoroscopy
is used, 0.5 to 1.0 ml of contrast can be injected first to rule out intravascular placement of the needle
Neurolytic
blocks can be done with
6% phenol or absolute alcohol. After appropriate placement of the needle, up to 1.0 to 1.5 ml of the neurolytic solution is injected in 0.1-ml aliquots. The needle should then be flushed with 0.5 ml
of saline prior to removal.
Pulsed radiofrequency lesioning
can also be performed after a successful diagnostic block. Sensory stimulation is performed at 50 Hz, 1 V. Paresthesia in the upper teeth should be perceived at less than 0.3 V. Once confirmed, two or three 120-sec pulsed radiofrequency cycles are administered at 45V
MANDIBULAR NERVE BLOCK
Indications
regional anesthesia for surgery of the lower jaw, but is also effective for acute postoperative pain control. it is indicated for the diagnosis and treatment of chronic pain in the distribution of the mandibular division of the trigeminal nerve
MANDIBULAR NERVE BLOCK
area to anesthetize or treat pain is
the lower jaw and tongue.
MANDIBULAR NERVE BLOCK
Technique
once the lateral pterygoid plate has been touched with the block needle, withdraw it and redirect in a slightly caudal and posterior direction until a paresthesia is produced in the lower lip, lower jaw, or ipsilateral tongue or ear. The depth should not be more than 0.1 to
0.25 cm beyond the depth at which the lateral pterygoid plate was contacted. The total distance should not exceed 5.5 cm. After proper positioning, inject 2 to 3 ml of local anesthetic, remove the needle, and apply an ice pack to the side of the
face
MANDIBULAR NERVE BLOCK
using fluoroscopy
Since this technique involves blocking the nerve as it exits the
foramen ovale, a submental, oblique view can be obtained in order to verify the position of the needle tip in relation to foramen ovale. The needle tip should be adjacent to, or overlie, the shadow of the foramen ovale. To
rule out intravascular or intrathecal injection, instill 0.5 to 1.0 ml of contrast. If negative, inject the aforementioned
volume of local anesthetic. Chemical neurolysis can be
achieved using 6% phenol, 50% glycerol, or absolute alcohol. After a successful diagnostic block and after proper
positioning of the needle, up to 1.0 ml of the neurolytic solution is injected in 0.1-ml increments. Flush the needle with 0.5 ml normal saline before removing it.
MANDIBULAR NERVE BLOCK
For pulse
radiofrequency lesioning
perform sensory and motor stimulation at 50 Hz, 1 V, and 2 Hz, 2 V, respectively, to
check needle position. Paresthesia should be obtained at less than 0.3 V, and masseter contraction should be apparent at less than 0.6 V. Two to three 120-sec pulsed cycles
should be carried out at 45 V.
the most common indication for trigeminal
ganglion blockade
Tic douloureux (Trigeminal neuralgia (TN))
Indications for trigeminal
ganglion blockade
Secondary trigeminal neuralgias from injury to the major divisions or the distal branches of the ganglion, in the treatment of chronic, intractable cluster
headaches. Persistent idiopathic facial pain (formerly atypical facial pain)
MANDIBULAR NERVE BLOCK
Technique
Place the patient on the table in the supine position with the head slightly extended. Light sedation with midazolam and fentanyl is usually required. Sterilely prepare and drape the appropriateside, leaving the eye exposed. Utilizing continuous or
pulsed fluoroscopy, locate foramen ovale by rotating the C-arm image intensifier obliquely away from the nose approximately 20 to 30 degrees, and then angle the C-arm image intensifier approximately 30 to 35 degrees in the
caudocephalad direction to bring the foramen ovale into view.
MANDIBULAR NERVE BLOCK
Technique
Raise a skin wheal directly over the shadow of the foramen which will be ~2 to 2.5 cm lateral to the corner of the mouth. Insert a short, 16- or 18-gauge
angiocatheter through the skin wheal and advance to the hub. Insert a gloved finger into the oral cavity to confirm that the buccal mucosa has not been breached. Re-glove
before proceeding. Insert a 20- or 22-gauge, curved, blunt
block needle through the angiocatheter and advance a few
centimeters. Obtain a fluoroscopic image to check the trajectory
of the needle. The goal is to advance the needle in a coaxial fashion toward the foramen ovale. With respect to external
landmarks, the trajectory of the needle will be in a plane
slightly superior to the external auditory meatus and medially
toward the pupil in the midline. Advance the needle in 1- to 2-cm increments until bone is touched. Obtain a lateral image to check the position of the needle. If the foramen
has not been traversed, adjust the needle tip (usually posterior) and advance through the foramen a distance of
0.5 to 1.0 cm.
MANDIBULAR NERVE BLOCK
After a negative aspiration for CSF or blood
inject 0.5 to 1.0 ml of nonionic, water-soluble contrast to confirm position and filling of
Meckel’s cavity. Any vascular runoff requires repositioning of the needle. If cerebrospinal fluid is obtained, the needle tip can be withdrawn until fluid is no longer appreciated
MANDIBULAR NERVE BLOCK
If an abundant cerebrospinal fluid leak is present
the remainder of the procedure should be halted. With a significant
leak, a high spinal block can be caused with even low volumes of local anesthetic. A small leak of cerebrospinal fluid may or may not cause a high spinal and if present, the pain
practitioner should proceed with caution.
MANDIBULAR NERVE BLOCK
Drug and Dosing
Inject local anesthetic
in volumes of 0.25 to 0.5 ml at a time, up to 1 to 2 ml, and observe for effect. Remove the needle and apply
an ice pack to the cheek to decrease swelling.
For conventional radiofrequency lesioning, a 3- to 5-mm active-tip needle is placed. The target depth of the needle tip depends on the division of the trigeminal nerve that needs to be lesioned
The mandibular division is rostral
and lateral; the maxillary division is intermediate; and
the ophthalmic division is mostly cephalad and medial.
Location of the needle tip on the appropriate division/s is determined by
the response to sensory and motor stimulation (50 Hz, 1 V, and 2 Hz, 2 V, respectively) of
the ganglion. Paresthesia should be perceived at less than
0.3 V, with little to no muscle contraction of the masseter
muscle at 0.6 to 1.0 V.
conventional
radiofrequency
If no contraction is seen, then the tip of the needle is on
the ophthalmic or maxillary divisions.
conventional
radiofrequency
Once the patient senses paresthesia in the painful area
inject 0.5 ml of 0.25% bupivacaine or 0.2% ropivacaine with steroid. Wait 30 to 60 sec and begin lesioning at 60° C for 90 sec.
conventional
radiofrequency
For lesioning of
the ophthalmic division, assess the
corneal reflex during
and after each lesion. Lesioning is typically started at temperatures
of 55 to 65° C to preserve this reflex. One or two lesions are recommended. If the corneal reflex diminishes, lesioning should be stopped.
PULSED RADIOFREQUENCY
not a temperature-dependent technique. It is a nondestructive method of providing
long-term pain relief
PULSED RADIOFREQUENCY
Technique
After proper positioning of the
needle tip, perform two or three pulsed radiofrequency cycles for 120 sec each at 45 V. The temperature of the needle tip rarely exceeds 42° C, thus local anesthetic is not
required. If significant masseter contraction is noted during pulsing, inject 1 to 2 ml of local anesthetic to diminish
this, or hold the patient’s mouth closed with your hand while the cycles are completed.
trigeminal
ganglion blockade.
CHEMICAL NEUROLYSIS
Chemical neurolysis has been performed with phenol and
alcohol in the past, but their use is not currently recommended. chemical neurolytic of choice is
Glycerol
trigeminal
ganglion blockade.
CHEMICAL NEUROLYSIS
Once through the foramen ovale, advance the needle until
cerebrospinal fluid is observed returning through the needle. Place the patient in a semi-sitting position with the
neck flexed. Inject water-soluble, nonionic contrast solution in 0.1-ml aliquots (up to 0.5 ml) into the trigeminal cistern. Once the cistern is visualized,
draw back the contrast material by free flow. The
flow of contrast is slower than cerebrospinal fluid. Inject the same amount of glycerol into the cistern. Flush the needle with 0.5 ml of saline prior to removal. Keep the
patient in a semi-sitting position for 2 hr. During the procedure,
patients often report pain, burning, or paresthesia
in the affected division/s
COMPLICATIONS
in relation to procedures
complications considered for all neurolytic techniques,
radiofrequency thermal lesioning had the highest number of complications (29.2%) followed by glycerol
rhizotomy and balloon compression at 24.8% and 16.1%, respectively.
COMPLICATIONS
Retrobulbar hematoma (needle is advanced into the retrobulbar space)
Exophthalmus (secondary to bleeding in the retrobulbar space)
hematoma
Masseter weakness (especially with lesioning of the mandibular division. The incidence is highest with balloon microcompression)
Loss of the corneal reflex, keratitis (likely to occur after radio frequency lesioning and glycerol neurolysis), ulceration, and hypesthesia are
observed in 3% to 15% of patients after a neurolytic procedure. Corneal anesthesia
was highest for radiofrequency rhizotomy at 7%, and was observed with glycerol rhizotomy and balloon compression
at 3.7% and 1.5%, respectively. Anesthesia dolorosa (deafferentation pain) occurs in up to 4% of patients with radiofrequency, followed by glycerol
where it occurs in 2% of cases.
Other complications
include
meningitis, dural arteriovenous fistulae, rhinorrhea, transient cranial nerve deficits, tissue sloughing, and even death
Postprocedure trigeminal nerve sensory loss
an expected occurrence after a properly performed neurolytic procedure. The incidence with radiofrequency
rhizotomy is as high as 98%, followed by balloon compression (72%) and glycerol neurolysis (60%)
SPHENOPALATINE GANGLION
The ganglion resides in the pterygopalatine fossa. The fossa
is bordered anteriorly by the maxillary sinus; posteriorly by
the medial pterygoid plate; medially by the palatine bone;
and superiorly by the sphenoid sinus.
The pterygomaxillary
fissure and pterygopalatine foramen
The pterygomaxillary
fissure allows passage of a needle into the fossa, while the
pterygopalatine foramen is located medial to the ganglion
and is just posterior to the middle turbinate. The fossa is
approximately 1 cm wide and 2 cm high and resembles a V-shaped vase on a lateral fluoroscopic image.A large venous plexus overlies the fossa.
Foramen rotundum and
the pterygoid canal
Foramen rotundum and
the pterygoid canal are located on the superolateral and
inferomedial aspect of the fossa, respectively
The maxillary artery
resides in the pterygopalatine fossa
SPHENOPALATINE GANGLION is “suspended” from the maxillary nerve by the
pterygopalatine nerves and is medial to the maxillary nerve.
Posteriorly the ganglion is connected to the
vidian nerve which is formed by the deep
petrosal (sympathetic from the upper thoracic spinal cord) and greater petrosal (parasympathetic from the superior
salivatory nucleus) nerves.
SPHENOPALATINE GANGLION has efferent
branches and forms the
superior posterior lateral nasal and
pharyngeal nerves.
exit the SPHENOPALATINE GANGLION caudally
the greater and lesser palatine nerves
Sensory fibers arise from the maxillary
nerve, pass through the SPHENOPALATINE GANGLION, and innervate the
upper teeth, nasal membranes, soft palate, and some parts of the pharynx. A small number of motor nerves are believed to
travel with the sensory trunks