michael dubilet md senior attending anesthesiologist...

Michael Dubilet MD

Head of Acute Pain Service

Senior Attending Anesthesiologist

Department of Anesthesiology Critical Care and Pain Management

Soroka University Medical Center,

Ben Gurion University of the Negev,

Beer Sheva,

Israel

A fundamental principle of medicine

Primum non nocere …….

There are a few GOLDEN RULES , which should never be broken.

1. Always insert an intravenous line before commencing a block.

2. Always monitor (pulse oximetry, EGG, BP as indicated).

3. Always practice proper aseptic technique.

4. Always have resuscitation equipment at hand.

5. Always obtain the patients informed consent.

6. Always have an adequate knowledge of the correct technique and know how to handle complications.

These rules are sensible and obvious, but you ignore them at your peril.

Shortcuts and casual practice are the highway to hell for the unsuspecting inexperienced anaesthetist.

Upper Extremity Block AnatomyThe Brachial Plexus Blockades

Upper Extremity Block AnatomyThe Brachial Plexus

I believe that if anesthesiologists are to deliver comprehensive anesthesia care they should be familiar with brachial plexus blocks. Familiarity with these techniques demands an understanding of brachial plexus anatomy. One problem with “understanding” this anatomy is that the traditional wiring diagram for the brachial plexus is unnecessarily complex and intimidating.

The plexus is formed by the ventral rami of the fifth to eighth Cervical Nerves C4-C8 and the greater part of the ramus of the first Thoracic Nerve. Additionally, small contributions may be made by the fourth Cervical and second Thoracic nerves.

The intimidating part of this anatomy is what happens from the time these ventral rami emerge from between the Middle and Anterior scalene muscles until they end in the four terminal branches to the upper extremity: the Musculocutaneous, Median, Ulnar, and Radial nerves.

Most of what happens to the roots on their way to becoming peripheral nerves is not clinically essential information for an anesthesiologist. However, there are some broad concepts that may help clinicians understand Brachial Plexus anatomy; throughout, my goal is to simplify this anatomy.

UPPER EXTREMITY BLOCK ANATOMYThe Brachial Plexus Anatomy

After the roots pass between the scalene muscles, they

reorganize into trunks and continue toward the first rib…

• Superior trunk C5 - C6

• Middle trunk C 7• Inferior trunk C8 - T1

At the lateral edge of the first rib, these trunks undergo a

primary anatomic division, into ventral and dorsal

divisions.

This anatomic division is significant because nerves

destined to supply the originally ventral part of the upper

extremity.

• Superior and Middle trunks form the Lateral Cord;

• Three trunks unite to form the ;

• Inferior trunks form the Medial Cord.

UPPER EXTREMITY BLOCK ANATOMYThe Brachial Plexus Anatomy

Thus, the Radial Nerve supplies all the dorsal musculature

in the Upper Extremity below the shoulder.

The Musculocutaneous Nerve supplies muscular innervation

in the Arm while providing cutaneous innervation to the

forearm.

In contrast, the Median and Ulnar Nerves are nerves of

passage in the Arm, but in the Forearm and Hand they provide

the ventral musculature with motor innervation.

The Median Nerve innervates more heavily in the Forearm

The Ulnar Nerve innervates more heavily in the Hand.

Upper extremity peripheral nerve function mnemonic: “ PUSH, PULL, PINCH, PINCH. ”

THE RADIAL NERVE: motor innervation to the triceps muscle weak

elbow extension and extension of wrist and fingers PUSH

THE MUSCULOCUTANEUS NERVE: motor innervation to the biceps

muscle , weak elbow flexion and Bicep Curl PULL

THE MEDIAN NERVE : pronation of forearm and flexion of wrist

pinching the fingers in the distribution of median nerve -that is, at the base

of second digit PINCH

THE ULNAR NERVE: flexion of pinky finger and ulnar wrist

deviation pinching the fingers in the distribution of the ulnar - that is, at

the base of the fifth digit PINCH

Upper Extremity Nerve Anatomy

The Brachial Plexus Anatomy

▪ Median antebrachial cutaneous

▪ Musculocutaneous

▪ Radial

▪ Ulnar

▪ Median

▪ Axillary

▪ Intercostobrachial

▪ Supraclavicular

Radial Radial

Ulnar

MedianMedian

Supraclavicular Supraclavicular

AxillaryAxillary

Median antebrachial cutaneous

MusculocutaneousIntercostobrachial

Musculocutaneous

Lateral antebrachial cutaneous

Always aspirate during needle insertion )5 ml's (, before injection, during injection, and after injection to ensure that inadvertent intravascular injection has not occurred. If the aspiration for blood is negative, inject the Local Anesthetic.

20-25 ml

• If the patient experiences pain or paresthesia with injection withdraw the needle slightly. Continue with injection as long as there is no pain or paresthesia.

Add Epinephrine 2,5mcg/ml

Add Dexamethasone 8 mg

Ropivacaine 0,2%

THE INTERSCALENE BRACHIAL PLEXUS BLOCKANATOMY LANDMARK

INDICATIONS:

not reliably blocked the hand

Tuberculum caroticum/Chassaignac

The Interscalene Block is performed at the level

of the C6 vertebral body (Chassaignac’s tubercle)

These are the primary Landmarks for performing this block:

1. The clavicle

2. Posterior border of the clavicular head of the SternoCleidoMastoid muscle

3. External jugular vein (usually crosses the interscalene groove at the level of the trunks)

• The needle must never be oriented cephalad !!!

In plane needle ( IP ) insertion approach (lateral to medial) Out of Plane ( OOP ) insertion approach

Out of Plane

Any position that allows comfortable placement of the Ultrasound transducer and needle advancement is appropriate.

The block is typically performed with the patient in Supine, Semisitting, or Semilateral decubitus position, with the patient's

head facing away from the side to be blocked.

The Latter position may prove ergonomically more convenient, especially during an in-plane approach from the lateral side,

in which the needle is entering the skin at the posterolateral aspect of the neck. A slight elevation of the head of the bed is

often more comfortable for the patient, and it allows for better drainage and less prominence of the neck veins

THE INTERSCALENE BRACHIAL PLEXUS BLOCKAnatomy and Ultrasound landmark

CA

THE INTERSCALENE BRACHIAL PLEXUS BLOCKAnatomy and Ultrasound landmark

Always aspirate during needle insertion )5 ml's (, before injection, during injection, and after injection to ensure that inadvertent intravascular injection has not occurred. If the aspiration for blood is negative, inject the Local Anesthetic.

10-15 ml

• If the patient experiences pain or paresthesia with injection withdraw the needle slightly. Continue with injection as long as there is no pain or paresthesia.

Add Epinephrine 2,5mcg/ml

Add Dexamethasone 8 mg

Ropivacaine 0,2%

Upper Trunk

Middle Trunk

Lower Trunk

• This block without visual guidance is generally not recommended for outpatients.

Although pneumothorax is an infrequent complication of the block, such an event often becomes apparent only after a delay of several hours, when an outpatient may already be at home

The Brachial Plexus is located lateral and Posterior to the Subclavian Artery.

The Subclavian Vein and Anterior Scalene Muscle are found medial to the Subclavian Artery.

The pleura is usually found within 1-2 cm from the brachial plexus.

With the classic approach, the needle insertion site is approximately 1 cm superior to the clavicle at the clavicular midpoint.

The needle should be a 22-gauge, 5-cm needle that typically contacts the rib at a depth of 2 to 3 cm

Clavicular midpoint

Clavicular midpoint

Clavicle

Always aspirate during needle insertion )5 ml's (, before injection, during injection, and after injection to ensure that inadvertent intravascular injection has not occurred. If the aspiration for blood is negative, inject the Local Anesthetic.

15-20 ml

• If the patient experiences pain or paresthesia with injection withdraw the needle slightly. Continue with injection as long as there is no pain or paresthesia.

Add Epinephrine 2,5mcg/ml

Add Dexamethasone 8 mg

Ropivacaine 0,2%

The brachial plexus divisions become cords as they enter the axilla.

The Posterior divisions of all three trunks unite to form the Posterior Cord;

The Anterior divisions of the superior and middle trunks form the Lateral Cord;

The Anterior division of the Inferior trunk form the Medial cord.

These cords are named according to their relation to the second part of the axillary artery

The patient is placed supine, with the arm to be

blocked abducted at the shoulder to a 90-degree

angle if possible, but if pain prevents this

positioning, the arm can be left at the patient’s

side, and adjustments can be made with skin

markings.

The anesthesiologist can stand on the

ipsilateral or the contralateral side of the

patient, depending on his or her preference and

the patient’s body habitus.

My personal preference is to stand on the

ipsilateral side of the patient.

THE INFRACLAVICULAR BRACHIAL PLEXUS BLOCKAnatomy and Ultrasound landmark

THE INFRACLAVICULAR BRACHIAL PLEXUS BLOCKNeurostimulation Technique

Lateral Cord

Posterior Cord

Medial Cord

THE INFRACLAVICULAR BRACHIAL PLEXUS BLOCKAnatomy and Ultrasound landmark

THE INFRACLAVICULAR BRACHIAL PLEXUS BLOCKAnatomy and Ultrasound landmark

Labeled ultrasound image of the Brachial Plexus (BP) in the infraclavicular fossa.

LC, lateral cord; PC, posterior cord; MC, medial cord.

Note that the Brachial Plexus and the axillary artery (AA) are located below the fascia (red line) of the pectoralis Minor

Muscle (PMiM) and (PMaM), Pectoralis Major Muscle.

PMiM

Always aspirate during needle insertion )5 ml's (, before injection, during injection, and after injection to ensure that inadvertent intravascular injection has not occurred. If the aspiration for blood is negative, inject the Local Anesthetic.

20-25 ml

• If the patient experiences pain or paresthesia with injection withdraw the needle slightly. Continue with injection as long as there is no pain or paresthesia.

Add Epinephrine 2,5mcg/ml

Add Dexamethasone 8 mg

Ropivacaine 0,2%

THE AXILLARY BLOCK

MEDIAN, ULNAR, RADIAL MUSCULOCUTANEOUS NERVES

Musculocutaneous Nerve Musculocutaneous Nerve

• The MEDIAN, ULNAR and RADIAL NERVES

Radial Nerve

An image demonstrating the ideal distribution patterns of Local Anesthetic spread after three separate injections to

surround the axillary artery with Local Anesthetic and block the Radial Nerve, Median Nerve , and Ulnar Nerve .

Musculocutaneous Nerve (MCN) is blocked with a separate injection because it is often outside the axillary

neurovascular tissue sheath. AA, axillary artery.

Anatomy and Ultrasound landmark

Both in-plane (IP) and Out-Of-Plane (OOP) techniques are commonly used.

Out-Of-Plane OOP has the advantage of having a shorter path to the nerve, making it less painful for the patient.

IP has the advantage of better needle visualization and needle accuracy.

When performing IP it is preferable to approach from the lateral side of the artery - this avoids needling through veins which

usually lie medial to the artery and provides an easier shorter needle path to block the McN.

Out-Of-Plane

In-Plane

An image demonstrating the ideal distribution patterns of Local Anesthetic spread after three separate injections (1-3) to

surround the axillary artery with Local Anesthetic and block the Radial Nerve (RN), Median Nerve (MN), and

Ulnar Nerve (UN). Musculocutaneous Nerve (MCN) is blocked with a separate injection (4) because it is often outside

the axillary neurovascular tissue sheath. AA, axillary artery.

Musculocutaneous nerve (MCN) is seen approximately 3 cm from the axillary neurovascular bundle (around AA).

MCN in this image is positioned between the Biceps and Coracobrachialis Muscles (CBM). MCN must be blocked

with a separate injection of Local Anesthetic for a complete axillary brachial plexus block.

CBM

Always aspirate during needle insertion )5 ml's (, before injection, during injection, and after injection to ensure that inadvertent intravascular injection has not occurred. If the aspiration for blood is negative, inject the Local Anesthetic.

10-15 ml + 10 ml

• If the patient experiences pain or paresthesia with injection withdraw the needle slightly. Continue with injection as long as there is no pain or paresthesia.

Add Epinephrine 2,5mcg/ml

Add Dexamethasone 8 mg

Ropivacaine 0,2%