Moderator:- Dr. S. P. MeenaPresenter:- Dr. Abhinav Gupta

Regional Anaesthesia for Surgery in Neck region

Regional anaesthesiaRegional anaesthesia is anaesthesia affecting only

a large part of the body, such as a limb or the lower half of the body. Regional anaesthetic techniques can be divided into central and peripheral techniques.The central techniques include so called neuraxial blockade (epidural anaesthesia, spinal anaesthesia). The peripheral techniques can be further divided into plexus blocks such as brachial plexus blocks, and single nerve blocks. Regional anaesthesia may be performed as a single shot or with a continuous catheter through which medication is given over a prolonged period, e.g. continuous peripheral nerve block. Regional anaesthesia can be provided by injecting local anaesthetics directly into the veins of an arm, i.e. intravenous regional techniques

Regional anaesthesia...Neck Surgeries, which can be performed under regional anaesthesia…

-Carotid Artery Surgeries, including endarterectomy-Percutenous Carotid Baloon Angioplasty-Thyroidectomy-Parathyroidectomy-Excision of thyroglossal and branchial cysts and thyroglossal fistula-Radical Neck Dissection-Cervical Node Biopsy-Stenomastoid release for torticolis-Chemodectoma-Tracheostomy and repair-Laryngectomy-Superficial Neck Procedures-Plastic repairs on the neck-Plastic procedure like liposuction, platysmoplasty etc.

Interesting FactTait and Caglieri suggested the use of cervical intrathecal injections for operating on the upper extremities and neck.

A. W. Morton reported success with total spinal anesthesia after lumbar puncture for operations on all parts of the body.

Thomas Jonnesco reported no adverse effects from 398 spinal anesthetics administered between vertebrae at the thoracic and lumbar levels with a novocaine and strychnine mixture. Jonnesco called the method General Spinal Anesthesia.

Introduction

Uses Of Regional Anaesthesia in Neck Surgeries...

-Post operative analgesia-Operative analgesia with GA-Operative anaesthesia.

Advantages Of Regional Anaesthesia Over GA

- Patient remains conscious- Maintain airway- Aspiration unlikely- Earlier recovery of bowel function- Reduction in surgical stress because of better

intraop analgesia- Reduced opioid requirements, so low incidence of

PONV- Smooth recovery requiring less skilled nursing care- Postoperative analgesia- Earlier discharge for outpatients

Introduction...

- Less expensive- Patients unfit for GA can be operated if emergency is

expected.- Reduced intra-operative blood loss.- Decreased chances DVT- Decreased metabolic changes, ie. for severe

respiratory impairment. - Excellent muscle relaxation.- Avoidance of rare complications like malignant

hyperthermia

Introduction...

Introduction...Disadvantages of RA compared to GA

- Patient may prefer to be asleep- Practice and skill is required for the best results- Some blocks require up to 30 minutes or more to be fully

effective- Analgesia may not always be totally effective - patient may

require additional analgesics, IV sedation, or a light general anesthetic( this will blunten the advantages of RA)

- Toxicity may occur if the local anesthetic is given intravenously or if an overdose is injected

- Patient discomfort from long operation- Patient discomfort during eliciting paresthesia- Contraindicated in confused patients.- Potential for nerve damage(although rare)- Some operations are unsuitable for regional anesthetics.

Advantages of GA over Regional

- A patent airway may be assured.- Adequate oxygenation possible.-Cardiovascular effects are usually titrable.-Familiarity for most anaesthesists.-Patient preference.

Disadvantages of GA compared to RA

- Higher prevalence of cardiovascular depression.- Depressed protective reflexes- Prolonged psychomotor impairment- Possibility of inadvertent awareness during the surgery- PONV, headache etc.

Introduction...

Introduction...Specific advantages of Regional Anesthesia of Neck..

-Identification of intra-operative laryngeal nerve injury

Specific disadvantages of Regional Anesthesia of Neck..

- Intraoperatively Airway manipulation if required may be more difficult than Preoperative manipulation.- Incase of tracheal injury, aspiration of the blood and secretions- Inadvertent Stellate Ganglion Block- Injury to important surrounding structures, like vessels and nerves.- Effects on heart rate and hemodynamic stability- Cardiac sympathectomy, which in turn depresses phasic and tonic dynamic modulation of the cardiac cycle. Therefore, causing hypotension and bradycardia

Relevant AnatomyThe Cervical Plexus..

The anterior rami of the upper four cervical nerves unite by a series of loops to form the cervical plexus, whose function is the supply of the skin and muscles of the neck and the innervation of the diaphragm.

Formation of the plexusThe loops are three in number, C1–2, C2–3 and C3–4, with a further loop (C4–5) often present to connect the cervical plexus with the brachial plexus.

They lie on the scalenus medius and legato scapulae muscles under the cover of the sternocleidomastoid muscle.

BranchesThe branches of the cervical plexus can be

divided into four groups.1 Communicating branches, which pass to

the hypoglossal nerve, to the vagus and to the cervical sympathetic chain.

2 Superficial branches, which supply cutaneous fibres to the neck.

3 Deep branches, to the neck muscles.4 The phrenic nerve.

Relevant Anatomy...

Relevant Anatomy...The superficial cervical plexusInnervates the skin of the anterolateral neck through anterior primary rami of C2 through C4.

Individual nerves emerge as four distinct nerves from the posterior border of the sternocleidomastoid muscle.

The lesser occipital nerve usually is a direct branch from the main stem of the second cervical nerve. The larger remaining part of this stem then unites with a part of the third cervical nerve to form a trunk that arises as the greater auricular and the transverse cervical nerves.

Superficial Cervical Plexus Banches

Ascending Branches

Occipitalis major

Auricularis magnus

Superficialis colli

Phrenic

Suprasternal

Descending Branches

Supraclavicular

Supra-acromial

Relevant Anatomy...Another part of the third cervical nerve runs downward to unite with a major part of the fourth to form a supraclavicular trunk, which then divides into the three groups of supraclavicular nerves.

The supraclavicular nerves (C3, 4), on careful palpation, can be rolled over the subcutaneous anterior border of the clavicle.

Relevant Anatomy...The deep cervical plexus

This supplies the anterior vertebral muscles, i.e. the recti capitis, longus capitis and longus cervicis, as well as giving contributions to scalenus medius (main innervation from roots of branchial plexus).

In addition, branches pass to levator scapulae (C3, 4) and to two muscles whose principal innervation is from the spinal accessory nerve: sternocleidomastoid (C2, 3) and trapezius (C3, 4).

The fourth cervical nerve may send a branch downward to join the fifth cervical nerve and participate in the formation of the brachial plexus.

The superficial cervical plexus block.Distribution Of Anaesthesia..Skin of anterolateral neck.

Position Of the Patient..The patient is in the supine or semi-sitting position with the head facing away from the side to be blocked.

Equipments required  - Sterile towels and 4"x4" gauze packs- 20 mL syringe(s) with local anesthetic- Sterile gloves and marking pen- 1½ cm-long, 22-gauge, short bevel needle

The superficial cervical plexus block...Anatomic landmarks

A line extending from the mastoid to C6 is drawn. The site of needle insertion is marked at the midpoint of the line connecting the mastoid process with Chassaignac's tubercle of C6 transverse process. This is the location of the branches of the superficial cervical plexus as they emerge behind the posterior border of the sternocleidomastoid muscle.

The superficial cervical plexus block...

After skin cleansing with an antiseptic solution, a skin wheel is raised at the site of needle insertion using a 25-gauge needle.

The needle is inserted perpendicularly just behind the posterior border of sternocleidomastoid. The needle depth be subcutenous and superficial to the deep cervical fascia.After negative blood aspiration, 5 mL of anaesthetic is injected. Two additional injections are made as the needle is directed superiorly and inferiorly at 30-45o .The most caudal injection usually blocks the supraclavicular nerves, while the most cephalic blocks greater auricular.

This injection technique should be adequate to achieve blockade of all four major branches of the superficial cervical plexus.

The superficial cervical plexus block...

The goal of the injection is to infiltrate the local anesthetic subcutaneously and behind the sternocleido-mastoid muscle.

Attention should be paid to avoid deep needle insertion.

Paresthesia is occasionally elicited during needle insertion. However, paresthesia is nonspecific and should not be routinely sought.

The deep cervical plexus blockA deep cervical plexus block is essentially a paravertebral block of the C2, C3, and C4 spinal nerves as they emerge from the foramina of the respective vertebrae.

Blockade of the deep cervical plexus also results in the blockade of the superficial cervical plexus.

A deep cervical block is often accidentally accomplished when a larger volume of local anesthetic is used in the interscalene brachial plexus block.

The most common clinical use for this block includes a carotid endarterectomy and removal of cervical lymph nodes.

The deep cervical plexus block...Distribution Of Anaesthesia..The cutaneous innervation of both the deep and superficial cervical plexus blocks includes skin of the anterolateral neck and the ante- and retro-auricular areas.

Positioning..The patient is in the supine or semi-sitting position with the head facing away from the side to be blocked.

Materials required..• Sterile towels and 4"x4" gauze packs• 20-mL syringe with local anesthetic• Sterile gloves and marking pen• 1½" 25-gauge needle for skin infiltration• 1½ cm-long, 22-gauge, short bevel needle

The deep cervical plexus block...Anatomic LandmarksThe following three landmarks for a deep cervical

plexus block are identified and marked:1. Mastoid process2. Chassaignac's tubercle of C63. Posterior border of the

sternocleidomastoid muscle

The anatomic landmarks for this block can be accentuated by asking the patient to:

- Lift the head up (tenses the sternocleidomastoid muscles)

- Reach the knee with the hand on the ipsilateral side

The deep cervical plexus block...

-A line is drawn connecting the mastoid process (MP) to Chassaignac's tubercle of C6 transverse process.

- Once this line is drawn, the insertion sites over the C2, C3, and C4 are labeled some 2-cm, 4-cm, and 6-cm caudal from the mastoid process, respectively.

-After cleaning the skin with an antiseptic solution, local anesthetic is infiltrated subcutaneously alongside the line estimating the position of the transverse processes

The deep cervical plexus block...-A needle connected to the syringe with local anesthetic is inserted between the palpating fingers and advanced at an angle perpendicular to the skin plane. The needle should never be oriented cephalad. A slight caudal orientation of the needle is the single best method to prevent the inadvertent insertion of the needle toward the cervical spinal cord.

-The needle is advanced slowly until the transverse process is contacted. At this point, the needle is withdrawn 1-2 mm, firmly stabilized, and 4 mL of local anesthetic is injected, after a negative aspiration test for blood. The needle is then removed and the entire procedure is repeated at the consecutive levels

The deep cervical plexus block...

- Goal is contact with the posterior tubercle of the transverse process. The spinal nerves at the individual levels are located just in front of the transverse process.

Failure to contact the transverse process on the first needle pass

- Withdraw the needle to the skin, redirect it 15o inferiorly, and repeat the procedure. - Withdraw the needle to the skin, reinsert the needle 1cm caudal, and repeat the above procedure.

The cervical plexus blocks...- The onset time for these blocks is 10-15 minutes. The first sign of the blockade is the decreased sensation in the area of the distribution of the respective components of the cervical plexus.

- It should be noted that due to the complex arrangement of the neuronal coverage of the various layers in the neck area as well as the cross-coverage from the contralateral side, the anesthesia achieved with cervical plexus block is rarely complete.

- While this should not be discouraging from the use of cervical plexus block, its use does require an understanding surgeon who is willing to supplement the block with the local anesthetic as necessary.- Carotid surgery also requires blockade of the glossopharyngeal nerve branches. This is easily accomplished intraoperatively by injecting the local anesthetic inside the carotid artery sheath

The cervical plexus blocks...- Although the placement of deep cervical block may be associated with moderate patient discomfort, excessive sedation should be avoided. - During neck surgery the airway management may be difficult due to the shared access to the head and neck with the surgeon. - -Surgeries like carotid endarterectomy require that the patient be fully conscious, oriented and cooperative during the entire surgical procedure.

- A subcutaneous midline injection of the local anesthetic extending from the thyroid cartilage distally to the suprasternal notch will block the branches crossing from the opposite side. This injection can be considered as a "field" block.

Local Analgesics  Onset (min)

Anesthesia (hrs)

Analgesia (hrs)

2% Lidocaine (+HCO3; +

epinephrene)10-15 2-3 3-6

0.5% Ropivacaine

10-20 3-4 4-10

0.25% Bupivacaine (+ epinephrene)

10-20 3-4 4-10

- A superficial cervical plexus block requires 10-15 mL of local anesthetic (3-5 mL per each redirection/ injection). Most patients benefit from the use of a long-acting local anesthetic.

- A deep cervical plexus block requires 3-5 mL of local anesthetic per level to ensure reliable blockade. Except perhaps with patients with significant respiratory disease (blockade of the phrenic nerve), most patients benefit from the use of a long-acting local anesthetic

InfectionLow risk

A strict aseptic technique is used

Hematoma

Avoid multiple needle insertions, particularly in anticoagulated patients

Keep a 5 minute steady pressure on the site when the carotid artery is inadvertenly punctured

Phrenic Nerve Blockade

Phrenic nerve blockade (diaphragmatic paresis) invariably occurs with a deep cervical plexus block

A deep cervical plexus block should be carefully considered in patients with significant respiratory disease

Bilateral deep cervical block in such patients may be considered contraindicated

Blockade of the phrenic nerve does not occur after superficial cervical plexus block

Local anesthetic toxicity

Central nervous system toxicity is the most serious consequence of the cervical plexus block. This complication occurs because of the rich vascularity of the neck, including vertebral and carotid artery vessels; it is usually caused by an inadvertent intravscular injection of local anesthetic rather then absorbtion

Careful and frequent aspiration should be performed during the injection

Nerve injuryLocal anesthetic should never be injected against resistance or when the patient complains of severe pain on injection

Spinal anesthesia

This complication may occur with injection of a larger volume of local anesthetic inside the dural sleeve that accompanies the nerves of the cervical plexus

It should be noted that a negative aspiration test for CSF does not rule out the possibility of intrathecal spread of local anesthetic

Avoidance of high volume and pressure during injection are the best measures to avoid this complication

Cervical Epidural Anaesthesia-Epidural anesthesia has been traditionally limited to procedures involving the lower limbs, pelvis, perineum, and lower abdomen.

-As clinicians have become more experienced with its application, epidural anesthesia with or without sedation has been used as the sole anesthetic or in combination with general anesthesia for a larger variety of cases.

- Dogliotti in 1933 was the first to describe cervical epidural anesthesia. # - Bonica et al described a series of cases in which cervical epidural anesthesia was used for surgery of the upper extremities.###Dogliotti AM: A new method of block anesthesia, regimental procedural anesthesia. Amer J

Surg (1933); 20 : 107## Bonica JJ, Backup PH, Anderson CE, Hadfield D, Crepps WR, Monk BF: Peridural block: Analysis of 3, 637 cases and a review. Anaesthesiology (1957) 18:719

Cervical Epidural Anaesthesia...

-Ciocatto discussed the technique of continuous epidural block for the control of severe pain due to metastatic carcinoma of the cervical spine or disc extrusion.#

-Michalek reported the use of cervical epidural anesthesia at the C6–7 level for a total parathyroidectomy with parathyroid gland implantation into the forearm. He concluded that combined procedures involving the neck and upper limbs could be safely conducted under cervical epidural blockade. ##

-Several studies have described the use of high thoracic epidural anesthesia for off-pump coronary revascularization and even for minimally invasive aortic valve replacement.

#Ciocatto E: The management of pain, Int. Anesth. Clin. (1964); 2:3 ##Anesth Analg. 2004 Dec;99(6):1833-6, table of contents.

Cervical Epidural Anaesthesia...- In patients in whom general anesthesia could lead to prolonged ventilatory care, such as those with diffuse interstitial lung disease, thoracic epidural anesthesia as the sole anesthetic has been described as a successful alternative.

- Although it is intriguing to realize that epidural blockade can be performed for procedures that in the past were limited to general anesthesia, the decision about whether to use this form of neuraxial blockade should be determined by the needs of the patient.

- Physiologically, blocks above T5 have a far greater effect on patient hemodynamics than blocks at T10 or lower. However, if the benefits of epidural blockade outweigh the risks to the patient, and the sensory blockade needed for the particular procedure can be obtained, then it is indicated.

Cervical Epidural Anaesthesia...- The epidural space is smaller than the subarachnoid space, extends from the base of the skull to the sacral hiatus, and surrounds the dura mater anteriorly, laterally, and posteriorly. The epidural space is bound posteriorly by the ligamentum flavum and laterally by the pedicles and the intervertebral foramina. It is a space filled with the fat, areolar tissue, lymphatics, veins, and nerve roots that traverse it, but no free fluid. The volume of fat is greater in obese individuals and less in the elderly.

1. Anterior epidural space, 2. Posterior epidural space, 3. Ligamentum flavum,4. Blood vessels in the epidural space, 5. Pedicles, 6. Nerve roots, 7. Transverse process, 8. Vertebral body, 9. Spinal cord

Cervical Epidural Anaesthesia...-The interlaminal space at C6 and C7 is slit-like but easily accesible when the neck is flexed. The ligamenta flavum in the cervical spine is thinner than at other levels, the epidural space is more concentric with the laminae and dura with a distance varying from 3-4 mm at the mid-sagittal point. This interval can be increased to about 5-6 mm with forward neck flexion.

-Epidural puncture in the cervical region is therefore technically simpler than THORACIC ENTRY because of the prominence of the 6th and 7th spinous processes and the amount of widening that occurs in the interlaminal spaces with flexion as opposed to the interlaminal spaces in the thoracic region where there is practically no increase in size with anteroposterior movement.

Cervical Epidural Anaesthesia...-Because of the increased negative pressure in the thoracic region, cephalad movement of any injected fluid will be impeded by the natural tendency for it to move towards the area of greater negativity. Placing the patient in a steep Trendelenburg position will facilitate cephalad movement of the local anesthetic.

-The subatmospheric pressure in the cervical epidural space is exaggerated by forward flexion, particularly when the patient is sitting.

-Either a median or a paramedian approach may be used. Advantages of the paramedian approach over the midline approach are -much greater ease with which it is possible to insert an epidural catheter, and -the lowered risk of accidental dural puncture.

Cervical Epidural Anaesthesia...Choice of Anesthetic Agent

The choice of anesthetic will depend on the duration required. In cervical regions, duration of epidural anesthesia is approximately 15 % shorter than expected from an equivalent dose in the lumbar region.

The volume of local anesthetic required to block all the cervical and upper 4-5 dermatomes is 8-12 ml. An initial dose of 8 ml is recommended. If this is inadequate, then an additional 12 ml should be administered after waiting 30 minutes.

The concentration of local anesthetic will depend on whether a full motor block, sensory analgesia or sympathetic block is required.

Cervical Epidural Anaesthesia...

Complications

-Because of the size of needle, accidental dural puncture will almost invariably result in a severe spinal headache. - Accidental puncture of an epidural vein will be revealed by a test dose containing 1:200,000 (5 mcg/ml) of adrenaline.- Neural injury from either catheter or needle is possible. - Epidural hematoma, although extremely rare, is always a possibility and while it is known to occur spontaneously.-Epidural abscess may be associated with an in-dwelling epidural catheter but can occur after installation of steroid. -Although frequently anticipated, diaphragmatic paralysis is rarely seen with cervical epidural anesthesia. It does seem however that the phrenic nerves are more resistant than other segmental nerves to the Cm of local anesthetic agents.

Cervical Epidural Anaesthesia...Physiological effects block Above T4

The cardiovascular effects of a block above T4 are the result of a high sympathetic block. The cardiac sympathetic fibers arise from T1 to T4, and when blocked, profound hypotension and bradycardia can occur.

In addition to the cardiac effects, a high level of sympathetic blockade causes: Increased central venous pressure without an increase in stroke volume Vasoconstriction in the head, neck, and upper limbs Splanchnic nerve blockade with blockade of medullary secretion of catecholamines Blockade of vasoconstrictive effect on the capacitance vessels of the lower limbs

Cervical Epidural Anaesthesia...-When a sympathetic block occurs at such a high level, the cardiovascular system may be left without its mechanisms for responding to low cardiac output states. This can be detrimental to a patient with limited cardiac reserve because profound hypotension with bradycardia and decreased contractility can result.

The anesthesiologist must be prepared to take over the control of the circulatory system until the block subsides and the patient stabilizes.

- Rarely, respiratory arrest during high epidural blockade has been reported. The reported causes of rare instances of respiratory arrest is from the sympathetic block, leading to decreased cardiac output with subsequent reduced blood flow to the brain.