5.1 Upper Limb Flashcards
Brachial plexus originates from
does it vary
type nerve
The brachial plexus originates from
the
anterior primary rami
of C5–T1
spinal nerves
supplies the upper limb.
There may be a contribution from
C4 or T2 occasionally,
resulting in a pre-fixed (C4–C8)
or post-fixed (C6–T2) brachial plexus.
What does it supply BP
except
The brachial plexus supplies the
entire upper limb
except the
trapezius muscle
(spinal accessory nerve)
and
the skin of axilla
(intercostobrachial nerves).
What is the BP comprised of
It is comprised of
roots (five),
trunks (three),
divisions (six)
and
cords (three).
There are five terminal branches
and
numerous collateral branches
that leave the plexus at various points.
Describe its divisions BP
The roots first converge to form
three vertical trunks
(upper, middle and lower),
which each divide into
anterior
and posterior divisions
(totalling six);
the divisions merge
variously to form
the three cords
(lateral, posterior and medial)
that finally give
the five terminal
branches.
The cords are described in
terms of their relation to the
axillary artery
Where does it travel (muscle)
The plexus travels between the
anterior and middle scalene muscles
(interscalene groove or the apex of scalene triangle)
in the neck,
over the first rib,
under the midpoint of the clavicle,
medial to the coracoid process to the axillary artery.
This line of Grossi
presents an anatomical perspective
to guide the localisation of the brachial plexus
Does it display anatomic variations
is it the same in each arm
do these variations make a reliable block mor challenging
The brachial plexus
displays marked anatomical variations,
and
29 different variations have been described,
mainly below the level of the clavicle.
Over 60% of individuals have different brachial plexus anatomy in each arm.
However, the high success rate of upper-limb blocks is because of the superficial and reliable landmarks for accessing blockade of nerves.
What are the roots
What is the division of the trunks
Then the
The five roots are the five anterior rami of the spinal nerves.
These roots merge to form three vertically arranged trunks:
‘superior’ or ‘upper’ (C5–C6)
‘middle’ (C7)
‘inferior’ or ‘lower’ (C8–T1).
Each trunk then splits into two, to form six divisions: anterior divisions of the upper, middle and lower trunks posterior divisions of the upper, middle and lower trunks
Supraclav branches of brachial plexus
Name
4
Dorsal scapular nerve
Long thoracic nerve
Nerve to the subclavius
Suprascapular nerve
Dorsal scapular nerve
exit @
supply by
supply to
Roots
C5
Rhomboid muscles and levator scapulae
Long thoracic nerve
Roots
C5, C6, C7
Serratus anterior
Nerve to the subclavius
Upper trunk
C5, C6
Subclavius muscle
Suprascapular nerve
Upper trunk
C4, C5, C6
Supraspinatus and infraspinatus
Where does the phrenic nerve come off the BP
Phrenic nerve is a branch of the
cervical plexus (C3–C5)
and
not brachial plexus,
although it receives a contribution from C5.
branches of the cords are:
Posterior cord branches
Posterior cord branches
(ULTRA): upper subscapular, lower subscapular, thoracodorsal, radial and axillary nerves
Lateral cord branches
Lateral cord branches (LML):
lateral pectoral,
musculocutaneous and
lateral root of the median nerve
Medial cord branches
Medial cord branches (M4U):
medial pectoral,
medial cutaneous nerve of arm,
medial cutaneous nerve of forearm,
medial root of the
median nerve
and
ulnar nerve.
Root value of terminal nerves
Musculocutaneous
Root value of terminal nerves:
Musculocutaneous: C5, C6, C7
Root value of terminal nerves
Median
Median: medial root, C5, C6, C7; lateral root: C8, T1
Root value of terminal nerves
Axillary
Axillary: C5, C6.
Root value of terminal nerves
Radial
Radial: C5–T1.
Root value of terminal nerves
Ulnar:
Ulnar: C8, T1
axillary nerve continues
axillary nerve continues as the
lateral cutaneous nerve of the arm
musculocutaneous nerve continues
musculocutaneous nerve continues
as the lateral cutaneous nerve
of the forearm
radial nerve continues
radial nerve continues as the
posterior cutaneous nerve of the forearm.
What provides cutaneous supply to the hand.
The median, ulnar and radial nerves provide cutaneous supply to the hand.
The medial cutaneous nerve of the arm
and the medial cutaneous nerve of the forearm originate
The medial cord.
Dermatomal supply of the
upper limb can be summarised as:
C4 – shoulder tip
C5 – radial side of upper arm, lateral epicondyle
C6 – radial side of forearm, thumb
C7 – middle three fingers
C8 – little finger, ulnar side of forearm
T1 – medial epicondyle, ulnar side of upper arm
T2 – skin of axilla.
Root values of common reflexes
Root values of common reflexes:
Biceps reflex (C5, C6)
Brachioradialis reflex (C5, C6)
Triceps reflex (C7, C8)
Finger reflex (C8, T1)
Patellar reflex or knee-jerk reflex (L3, L4)
Ankle-jerk reflex (Achilles reflex) (S1, S2)
Plantar reflex or Babinski reflex (L5, S1, S2).
Axillary
Roots
Muscles
Cutaneous
C5, C6
Deltoid
Teres minor
Lateral shoulder
Musculocutaneous
Roots
Muscles
Cutaneous
Musculocutaneous
– C5, C6, C7
Biceps brachii
Brachioradialis
Coracobrachialis
Lateral forearm
Radial –
Roots
Muscles
Cutaneous
Radial –
C5–T1
BEAST
Brachioradialis
Brachialis
Extensors of forearm and hand
(abductor pollicis longus)
Anconeus
Supinator
Triceps
Posterior lower arm and forearm
Dorsum of hand
(lateral three and a half
fingers except terminal phalynx
Ulnar
Roots
Muscles
Cutaneous
Ulnar –
C8, T1
Forearm:
flexor carpi ulnaris
flexor digitorum profundus (medial part)
Hand: hypothenar muscles interossei lumbricals (third and fourth) adductor pollicis
Both surfaces of medial one and a half finger
Median
Roots
Muscles
Cutaneous
Median –
C5–T1
Forearm: pronator teres flexor carpi radialis flexor digitorum sperficialis flexor digitorum profundus (lateral part)
Hand: LOAF Lumbricals (first and second) Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis
Palm of hand (lateral three and a half
fingers)
Levels of brachial plexus block
Root
Block Nearby bony structures Nearby artery
Root
Interscalene
Verterbral transverse processes
Vertebral artery
Levels of brachial plexus block
Trunks
Block Nearby bony structures Nearby artery
Trunks
Supraclavicular
Above first rib
Subclavian artery
Levels of brachial plexus block
Divisions
Block Nearby bony structures Nearby artery
Divisions
None
Under clavicle
N/A
no block is possible under the clavicle, and hence none involves the
divisions. Occasionally, divisions may be present above clavicle, hence
supraclavicular block may be at the level of trunks (mostly) or divisions
(infrequently).
Levels of brachial plexus block
Cords
Block Nearby bony structures Nearby artery
Cords
Infraclavicular
Medial to coracoid process
Second part of axillary artery
Levels of brachial plexus block
Terminal nerves
Block Nearby bony structures Nearby artery
Terminal nerves
Axillary
N/A
Third part of axillary artery
Appropriate blocks for surgeries are:
Clavicle
superficial and deep cervical plexus block
Appropriate blocks for surgeries are:
Shoulder
Shoulder:
interscalene
Appropriate blocks for surgeries are:
Upper humerus
Upper humerus:
interscalene + supraclavicular
Appropriate blocks for surgeries are:
Elbow
Elbow: infraclavicular
Appropriate blocks for surgeries are:
Hand
Hand: axillary.
brachial plexus ‘sheath’
Derived from
Described by
how did he suggest blocking
derived from the
invagination of prevertebral fascia.
The concept of the brachial plexus sheath
was put forth by Winnie.
He supported the concept of single-injection
blocks for brachial plexus anaesthesia
resulting from widespread
distribution of local anaesthetic solution.
Is the Sheath theory accepted
concept has been challenged by others, and recent
cryomicrotome evidence suggests that below the clavicle, this sheath is
less robust, actually being a multicompartment space. This is
supported clinically, since infraclavicular and axillary blocks have a
higher success rate when a multistimulation technique is used rather
than a single injection
Landmarks needed to identify
the interscalene groove and perform
the interscalene block are:
1
sternal head of sternocleidomastoid
2
clavicular head of sternocleidomastoid
3
upper border of cricoids cartilage
(C6 – Chassaignac’s tubercle)
4
clavicle
interscalene block tips
1st rib?
These landmarks can be accentuated by
asking the patient to lift their head
or take a deep sniff.
The first rib cannot be palpated in
all but the thinnest of
individuals.
The brachial plexus passes over the
first rib, hence walking over
the first rib helps with
doing the supraclavicular block.
Contraindications to upper-limb blocks
Absolute
Patient refusal
Local infection at the site of block
Allergy to local anaesthetics
Active bleeding in anticoagulated patient
A vital capacity < 1 L Incapacity to endure a decrease of 25% of vital capacity
Contraindications to upper-limb blocks
Relative
Pre-existing neurological deficit
Chronic obstructive pulmonary disease
Pre-existing contralateral lung disease
Contralateral phrenic or recurrent laryngeal nerve paresis
Incapacity to endure a decrease of 25% of vital capacity
Interscalene
Use
Problem
Interscalene block is most suitable
for shoulder surgery,
as it blocks the upper trunk (C5–C6);
however, ulnar sparing makes it
unsuitable for forearm or hand surgery.
Interscalene
preferred / accepted twitch response
Although
deltoid twitch is the preferred
response to neurostimulation,
bicep, pectoral or triceps muscle response offers a
similar success rate.
Interscalene
Problem freq encountered
Because of the
proximity of the phrenic nerve
to the interscalene groove,
blocks at this level
(especially if performed at a high level in
the neck) nearly always lead to its paresis
Shoulder innervation
exclusively brachial plexus?
(detailed)
Shoulder innervation
is through both cervical and brachial plexus.
Cutaneous innervation:
Clavicle and shoulder tip: supraclavicular nerve (C2–C4)
Anterior and lateral deltoid:
upper lateral cutaneous branch of the axillary
nerve (C5, C6)
Posterior deltoid: axillary nerve
Medial side of the arm:
medial cutaneous nerve of the arm (C8–T1)
Axilla: intercostobrachial nerve (T2).
Joint innervation:
Acromioclavicular joint: suprascapular nerve
Glenohumeral joint: suprascapular nerve (superior), axillary nerve (inferior),
subscaplular nerve and musculocuatneous nerve (minor).
Can posterior port shoulder approach be performed with Interscalene
why
No
The anterior and lateral port
insertion is usually painless,
as these areas are well
anaesthetised by an
interscalene block.
However, an axillary port placement
requires the blockade of the
intercostobrachial nerves.
Posterior arthroscopic port insertion
is often painful in an awake
patient,
as this area is supplied by the suprascapular nerve
(which leaves the plexus early at the
level of trunk and is spared by an
interscalene block).
Infiltrating the posterior port insertion site with
local anaesthetic anaesthetises the posterior part of joint capsule.
Various approaches to interscalene block
Winnie’s
Approach Level Direction of needle Advantages Disadvantages
Winnie’s (classic) Cricoid cartilage (CC) at C6 Perpendicular in all planes (50° caudal and posterior)
Reliable with both
paraesthesia
and peripheral nervous system
High risk of complications
from medial direction
(vertebral artery/spinal
cord injections); difficult catheter insertion
Various approaches to interscalene block
Approach Level Direction of needle Advantages Disadvantages
Meire’s
Meire’s
(modified lateral)
2–3 cm above CC or
superior thyroid notch
30° caudal and posterior
towards middle or lateral third
of clavicle
Reduced complications
and allows catheter
placement
Needs peripheral nervous
system to guide placement
Various approaches to interscalene block
Approach Level Direction of needle Advantages Disadvantages
Borgeat’s
Borgeat’s (modified
lateral)
0.5 cm below CC
30° caudal and posterior
towards middle or lateral third
of clavicle
Reduced complications
and allows catheter placement
N/A
Various approaches to interscalene block
Approach Level Direction of needle Advantages Disadvantages
Pippa’s
Posterior approach
Pippa’s
(cervical paravertebral approach)
Between C6 and C7
3 cm lateral to midline,
directed 5°–10° anterolaterally towards
posterior edge of the
sternocleidomastoid muscle at the level of CC
Lateral angulation is
intended to reduce some
neurological adverse effects
Painful, therefore needs
local anaesthetic
infiltration
Boezaart approach
Boezaart cervical paravertebral approach
is a modification of Pippa’s posterior approach,
and involves the insertion of a
stimulating Tuohy needle
at C6 level
at the apex of ‘V’ formed
by levator scapulae and trapezius,
directed anteromedially
(instead of anterolateral)
and 30° caudad (aiming
for the suprasternal notch).
The needle is advanced until
a deltoid twitch is stimulated,
and then a catheter may be inserted.
Troubleshooting for interscalene block muscle responses
Diaphragm
Twitch Interpretation Action
(redirect needle)
Diaphragm
Phrenic nerve stimulation
(anterior to anterior scalene)
Posterolateral redirection
Troubleshooting for interscalene block muscle response
Trapezius
Trapezius
Accessory spinal nerve stimulation
(posterior to interscalene groove)
Redirect anteriorly
Troubleshooting for interscalene block muscle responses
Scapular
Scapular
Dorsal scapular nerve (posterior)
Thoracodorsal nerve (posterior)
Long thoracic nerve (posterior
Redirect anteriorly
Troubleshooting for interscalene block muscle responses
Biceps, deltoid, triceps,
pectoral
Biceps, deltoid, triceps,
pectoral
All part of brachial plexus Alright to inject at
this point
Complications of interscalene block are
- Vascular
a. IV injection
- last
b. Bezold - Jarisch Reflex
2. Neurologic:
Other: haematoma, bruising, infection, bronchospasm (due to
sympathetic blockade) and rare pneumothorax.
Complications of interscalene block are
- IV injection
- last
intravascular injection into
vertebral or carotid artery can result in
rapid-onset seizures (local anaesthetic toxicity)
hence the doses
should always be fractionated
and only injected after gentle negative
aspiration
Bezold–Jarisch reflex
Bezold–Jarisch reflex –
sudden bradycardia and hypotension (15%– 30%) favoured by sitting position, awake patient and hypovolaemia; it is treated by atropine and ephedrine.
Neurologic: x6 interscalene complication
phrenic nerve –
paresis results almost always causing
hemi diaphragmatic paresis
recurrent laryngeal nerve palsy –
hoarseness of voice (20%)
epidural injection
intrathecal injection (rachianaesthesia)
spinal cord injection
nerve damage: temporary or permanent.
sympathetic chain block
sympathetic chain block – Claude Bernard-Horner’s syndrome or oculosympathetic palsy (40%–60%); it is characterised by ptosis, enophthalmos, miosis and anhidrosis
Pourfour du Petit’s
sympathetic chain irritation – Pourfour du Petit’s syndrome: exophthalmia, mydriasis and inability to close the ipsilateral eye rarely occurs
Neurological injuries possible with interscalene
a phrenic nerve
b recurrent laryngeal nerve palsy
c sympathetic chain block
d sympathetic chain irritation
e epidural injection
f intrathecal injection (rachianaesthesia)
g spinal cord injection
h nerve damage: temporary or permanent.
Ultrasound-guided interscalene block
Probe type
High frequency (6–13 MHz) probe is preferred (poor penetration), as brachial plexus at interscalene groove is at 1–2 cm depth.
Ultrasound-guided interscalene block
level - how does it appear
between what
At this level, the C5–C7 nerve roots
are seen as ‘traffic signal lights’
appearance,
sandwiched between the
anterior scalene muscle medially
and the middle scalene laterally.
Problems going below C6
interscalene block
Below C6, the vertebral artery is not protected by the vertebral transverse process and is exposed to being punctured or injected into if a low approach is used.
How can BP be identified Ultrasound-guided interscalene block
Medial-to-lateral search:
The plexus may be identified in two ways:
Medial-to-lateral search:
the probe is initially placed in the midline
of the neck and moved laterally, identifying trachea, carotid artery,
internal jugular vein,
tail of sternocleidomastoid and eventually the
nerve roots lying between the two scalene muscles.
How can BP be identified Ultrasound-guided interscalene block
Inferior-to-superior search
Inferior-to-superior search:
the probe is placed first in the
supraclavicular area to identify the subclavian artery, with the brachial
plexus anterolateral to it.
As the plexus is traced proximally, the
interscalene groove is seen and the roots are identified.
Benefit of Ultrasound-guided interscalene block
what does it not do
Ultrasound can help improve success rate, reduce time to onset of block and reduce the volume of local anaesthetic needed;
however, it
cannot eliminate intraneural injections completely, since this is limited
operator skill and image resolution.
Describe path of phrenic nerve
what block is this relevant to
The phrenic nerve is
derived from the cervical plexus (C3–C5)
and passes over the
anterior surface of anterior scalene muscle.
An interscalene block is performed
in the groove between the
anterior and
middle
scalene muscles.
How often does the classic PNS guided block lead to diaphragm paresis
How
How is this risk
The classic peripheral nervous system
(PNS)-guided interscalene block
results in 100%
incidence of hemi diaphragmatic paresis.
How does the classic PNS guided block lead to diaphragm paresis
This is said to occur by spread upwards to C3–C4 level or by spilling over anterior scalene to involve the phrenic nerve.
How is the risk higher risk of phrenic
nerve paresis with the classic PNS guided block
The risk of phrenic
nerve paresis is increased by
medially directed injections,
high-volume injections (30–40 mL),
injections at C6 (vs C7) level
or PNS-guided
blocks.
How is the risk of phrenic nerve block reduced
At C6, the phrenic nerve
and brachial plexus are close together
(at the apex of interscalene groove);
however, subsequently (i.e. at C7 and C8) the phrenic nerve moves medially while the brachial plexus moves laterally toward midpoint of the clavicle.
As this distance increases, the risk of injectate spilling over the belly of anterior scalene and affecting the phrenic nerve reduces.
- Hence low-volume
injections (5–10 mL), - injections at C7 (vs C6) and
- ultrasound-guided
blocks may have a phrenic sparing effect
the brachial plexus anatomy at
the supraclavicular
What is the division group
how does it appear
trunks
in the supraclavicular area
in a compact bundle within a sheath
high success if injection is
made at this site
cluster of
grapes’
the brachial plexus anatomy at
the supraclavicular
relations
Subclavian Vessels
First rib
Clavicle
Pleural dome
subclavian vessels lying medial to the plexus,
the first rib inferiorly
and the clavicle lies superiorly.
The pleural dome lies far medially
Is phrenic blocked as much with supraclav vs interscalene
Phrenic nerve paresis is less common than interscalene blocks
Infraclavicular block
where relation to ax a
whats the boundary
Infraclavicular block involves blocking the brachial plexus at the level of cords that lie around the second part of the axillary artery.
Infraclavicular block
whats the boundary
At this level, the plexus is bounded by the
clavicle above,
the ribcage medially and
the coracoid process laterally.
Infraclavicular block
covered by (muscle)
whats cord relation to AA at this level
It is covered by both
pectoralis major and
pectoral minor.
Medial to the coracoid process,
the lateral cord of the plexus
lies superolaterally,
the posterior cord lies posteriorly
and the medial cord
lies posteromedially with respect to the axillary artery.
Infraclav
Modified Raj’s
(modification of classic Raj’s approach)
3 cm below the midpoint of line
joining jugular notch
and acromioclavicular joint
(midclavicular point)
100-mm needle,
directed 45°–60° laterally toward
axillary artery
As needle is directed laterally, no
danger of pneumothorax
Long intramuscular
trajectory is
painful
Infraclav
Klaastad ultrasound guidance
Klaastad ultrasound guidance approach
Intersection between
clavicle and coracoid process
80-mm needle inserted at a 30° angle in the
sagittal plane
Appropriate for ultrasound guidance
N/A
Following muscle responses
Performing PNS-guided infraclavicular block
Infraclavicular block is made at
the level of cords.
at the cords, pinkie (fifth digit) towards’.
Following muscle responses
Performing PNS-guided infraclavicular block
Lateral
cord
Lateral cord
Median (lateral root)
Pronation,
elbow flexion, finger flexion,
thumb opposition
Pinkie -
Laterally (due to pronation)
Following muscle responses
Performing PNS-guided infraclavicular block
Posterior
cord
Posterior cord
Radial and axillary
Finger and wrist extension,
abduction of thumb
Posteriorly
(due to wrist
extension)
Following muscle responses
Performing PNS-guided infraclavicular block
Medial
Medial cord
Ulnar
Medial finger flexion,
ulnar deviation of wrist
Medial (due to ulnar
deviation of wrist)
Inappropriate muscle responses
during neurostimulation of
cords of brachial plexus
Biceps twitch
Due to musculocutaneous nerve stimulation;
needle too superior,
as the musculocutaneous nerve leaves the plexus superiorly
Redirect inferiorly
Deltoid
Due to axillary nerve stimulation;
needle is inferior, as the axillary nerve
originates lower down
Redirect
superiorly
Pectoral
Direct muscle stimulation
Redirect
deeper
Salient features of infraclavicular block are as follows.
cords stimulation
lat
med
post
biceps twitch appropriate?
lateral cord is the first to be stimulated
medial cord is usually situated between the axillary artery and
the axillary vein.
Posterior cord stimulation is met with the best success rate and most
widespread block.
musculocutaneous nerve leaves the lateral cord more proximally,
hence biceps twitch is not an appropriate response
What position of arm
infraclavicular
Classic infraclavicular block can be made with the arm by the side.
However, recent analysis has revealed that arm abduction to 90° will
stretch the brachial plexus and make it taut. This will bring the three
cords closer together and will enhance nerve visualisation under
ultrasound.
infraclavicular
catheter?
the best block for catheter placement (since muscle bulk holds
catheter well).
What is the best block for elbow surgery
Infraclav
the best block for elbow surgery
Can bilateral infraclav be pefromed
performed bilaterally, since it does not cause
hemidiaphragmatic paresis.
infraclav probe
type
plane
A low-frequency
(higher penetration) probe is
best suited for an
ultrasound approach.
Usually a short-axis view of the anechoic
pulsatile axillary artery is used with in-plane needle advancement in a
postero-caudal direction.
infraclav probe
A low-frequency
(higher penetration) probe is
best suited for an
ultrasound approach.
Usually a short-axis view of the anechoic
pulsatile axillary artery is used with in-plane needle advancement in a
postero-caudal direction.
What technique infraclav offers better succes
High or low volume block
A multistimulation technique takes longer, but offers a higher success
rate.
Infraclavicular blocks are large-volume blocks (40 mL) and a lower
success rate is reported with lower volumes
anatomy of terminal nerves in the axillary area
Median and musculocutaneous nerves
lie above the axillary artery,
while the ulnar and radial nerves lie below it.
The musculocutaneous nerve
actually lies away
from the artery under the
coracobrachialis muscle.
Each of these four terminal nerves must be blocked for effective anaesthesia.
Abduction of the arm at 90° facilitates access to the axilla
Appropriate muscle responses during neurostimulation of branches of brachial plexus in
the axillary area
Musculocutaneous Elbow flexion
Median Pronation, finger flexion, thumb opposition
Radial Finger and wrist extension, abduction of thumb
Ulnar Medial finger flexion, ulnar deviation of wrist
PNS axillary approaches
de Jong)
Single injection (de Jong):
PNS- or paraesthesia-guided insertion of
needle above or
below the artery depending on
the surgical site
(e.g. above the artery for median territory
and below the artery for
radial/ulnar territory).
The entire drug is injected now; however, the
disadvantage is that sparing is quite frequent.
Multi-injection axillary
Multi-injection: two, three or four injections have been advocated.
First, the median nerve is sought above the artery followed by
injection of 5–10 mL of local anaesthetic.
Subsequently, the needle is
redirected obliquely into coracobrachialis muscle to stimulate
musculocutaneous (elbow flexion), and 5 mL is deposited here. The
needle is then inserted below the artery, stimulating the ulnar and then
the radial nerves with 5–10 mL injectate at each location. Total volume
used is 20–40 mL.
Transarterial
Transarterial (Urquhart):
half injection made posterior to the artery
(after puncturing it) and half superficial to it.
Transarterial axillary
Transarterial (Urquhart):
half injection made posterior to the artery
(after puncturing it) and half superficial to it.
Perivascular infiltration axillary
Perivascular infiltration: 10–20 mL infiltrated above the artery and
10–20 ml below it in a fan-wise manner.
Axillary US guided
Ultrasound guided:
high-frequency probe used to guide injections.
The median nerve lies at the 11 o’clock position,
the ulnar at the 3 o’clock (separated from the median by the axillary vein),
while the radial nerve is at the 6 o’clock position
above the conjoint tendon.
The musculocutaneous nerve can be blocked easily within the coracobrachialis muscle.
Salient features of axillary block are as follows.
Most common and easiest upper-limb block.
Best block for ambulatory surgery.
Best suited for hand surgery
Best given as high in axilla as possible, as this allows proximal
anaesthetic spread and less sparing
Axillary + catheter?
+ multistim?
Not well suited for catheter because of frequent dislodgement
Multistimulation technique has higher success rate and shorter onset
time.
What’s most commonly spared with single injection
how can blocks be suplement
Musculocutaneous sparing is the most common inadequacy of singleinjection technique.
Inadequate blocks can be supplemented by relevant blocks at lower
(elbow or forearm) levels.
Arm position axillary
Excessive arm abduction (> 90°) is not advocated, as this obscures
the axillary pulse and limits proximal spread of anaesthetic.
tourniquet pain? axillar
Tourniquet use needs blocking of the medial cutaneous nerve of arm
and intercostobrachial by subcutaneous infiltration of local anaesthetic
at axillary floor
The correct way to assess adequacy of brachial plexus block is
The correct way to assess adequacy of brachial plexus block is ‘ push pull- pinch- pinch’ method.
push
pull-
pinch-
pinch’
It involves checking adequacy of four terminal
nerve actions as follows.
Push:
inability to push by elbow extension
against resistance
(indicates radial block – lack of elbow extension).
Pull:
inability to pull the forearm by flexing
it against resistance
(indicates musculocutaneous nerve block – lack of elbow flexion).
Pinch:
anaesthesia to pinch at palmar base of index finger (median block).
Pinch: anaesthesia to pinch at palmar surface of little finger (ulnar block).
Tourniquet pain
Rough onset
Tourniquet pain in non-anaesthetised volunteers occurs around
30 minutes.
General anaesthesia has little effect on this,
but under regional anaesthesia this may be delayed up to 60–90 minutes.
Tourniquet pain
Mediated by
It has been said that the pain may be
mediated by local metabolite accumulation
(due to ischaemia)
and
is transmitted by C fibres.
Tourniquet pain
Strategies to reduce
gabapentine premedication
intravenous ketamine to reduce intraoperative hypertensive response;
epidural clonidine (with bupivacaine)
systemic opioids
PNS technique:
Radial nerve:
PNS technique:
Radial nerve:
blocked 1–2 cm above the brachial crease,
between tendon of biceps and brachioradialis;
5–7 mL of local anaesthetic
injected here after stimulating a radial nerve response (wrist/finger extension).
PNS technique:
Median nerve:
Median nerve:
blocked medial to brachial artery 2 cm
above the brachial crease;
5–7 mL local anaesthetic is injected after stimulating a
median nerve response
(pronation, thumb opposition, finger flexion).
PNS technique:
Ulnar nerve
Ulnar nerve:
elbow is flexed to 30° and the ulnar nerve
is blocked just above the groove
between medial epicondyle and olecranon
(excessive flexion may cause nerve to slip out of the groove).
Local anaesthetic (5 mL) is injected, avoiding excessive pressure of injectate
(this can
injure the nerve, which rests against the bone here).
Ultrasound techniques
Radial nerve
(using high-frequency probe): nerves can be blocked at
the elbow, as shown in Figure 5.15, or as follows.
Radial nerve:
blocked at the spiral groove where the nerve is seen
above humerus, but below triceps.
As it proceeds distally, it divides
into a superficial and deep branch,
tracking anteriorly towards the
cubital fossa and appears to be ‘jumping off the cliff’.
It is ideally
blocked away from the humerus to avoid any nerve damage.
Ultrasound techniques
Ulnar nerve:
Ulnar nerve:
ulnar artery is identified at the wrist,
and tracked proximally until the
ulnar nerve is seen separating from the artery near
the mid-forearm.
It can be blocked here. At this level, the ulnar nerve
lies lateral to the ulnar artery.
Ultrasound techniques
Median nerve:
Median nerve:
at the same level (mid-forearm),
the ultrasound probe
is moved laterally to identify the median nerve
Wrist block is performed
Radial nerve:
just proximal to wrist crease (see Figure 5.16
on p. 159). It may be performed using a landmark technique, PNS or USG
technique as follows.
Radial nerve: since the radial nerve divides into many branches above
the radial styloid, two or more separate injections in a fan-wise
manner above the styloid process are needed to block it. Henceessentially it is a field block.
Median nerve
Median nerve: blocked between the tendons of palmaris longus and
flexor carpi radialis.
Ulnar nerve
should be blocked medial to flexor carpi ulnaris.
Spared nerves should be blocked by supplemental injection distally (digital
blocks). Epinephrine should not be added to these blocks, as they may cause
ischaemia in these terminal digits.
Suprascapular nerve arises
Suprascapular nerve arises
from the upper trunk of brachial plexus
C4, C5 and C6
Suprascapular nerve supplies:
supplies:
1. cutaneous supply to posterior shoulder joint capsule and scapular surface
2.
innervation of acromioclavicular joint and glenohumeral (shoulder) joint
3.
infraspinatus and supraspinatus (external rotation).
Suprascapular nerve block
It is blocked 1–2 cm lateral to
midpoint of spine of scapula,
at a depth of 4– 5 cm at the
suprascapular notch.
The nerve may be identified and blocked
with ultrasound.
Recently, shoulder arthroscopy has been performed under suprascapular and axillary block alone without an interscalene block.
The cervical plexus is formed by
The cervical plexus is formed
by the anterior primary rami
of the C1–C4.
The main components of the cervical plexus are:
The cervical plexus lies
It lies deep to the internal jugular vein
and the sternocleidomastoid muscle
and
superficial to scalenus medius and levator scapulae.
The main components of the cervical plexus are
1. cutaneous branches – lesser occipital, greater auricular (largest), transverse cervical, and supraclavicular nerves
2
ansa cervicalis –
innervates infrahyoid and geniohyoid
3
phrenic nerve innervates the diaphragm
4
contributions to the accessory nerve (CNXI) – innervates the sternocleidomastoid and trapezius muscles
5
muscular branches – supply prevertebral neck muscles.
cervical plexus cutaneous branches are derived
C2–C4
(as C1 gives only
motor fibres to suboccipital muscles
and has no sensory component)
superficial cervical plexus block emerges @
Can be perfomed
This plexus emerges at the
midpoint of the lateral border of
sternocleidomastoid and
can be blocked here by
superficial infiltration of 10 mL of
1%–2% lignocaine
along the middle third of the lateral border of sternocleidomastoid.
Superficial plexus block vs deep
A superficial cervical plexus block
constitutes injection superficial to
investing fascia of the neck,
while the deep cervical plexus block is
given deep to the deep cervical fascia.
An injection between the two
layers is called the intermediate block
Superficial plexus block Indications
Indications: analgesia for tracheostomy, thyroidectomy, anterior neck surgery, mastoid surgery, parietal craniotomy and clavicular surgery.
Carotid surgery and cervical plexus block
Carotid surgery may be
performed under cervical plexus block,
which offers benefits such as better
cardiovascular stability,
shorter critical care stay
and financial savings when compared to general anaesthesia.
deep cervical plexus block
How can it be done
deep cervical plexus block
(anterior cervical paraverterbral block)
is given under the deep cervical fascial
This can be accomplished by
joining the tips of Chassaignac’s tubercle
(C6) and mastoid process
where can each tubercle be located cervical plexus block
describe the moore technique
C2
tubercle is located 1.5 cm caudal to mastoid process, C3 tubercle 1.5
cm caudal to C2, and C4 tubercle 1.5 cm caudal to C3 tubercle. A 50-
mm 22-G needle is inserted at C4, and directed caudally towards the
tubercle; on contact with bone, it is ‘walked off’ and 3–5 mL of 1%
lignocaine is injected at each level from C2 to C4 (Moore
technique).
What is winnie technqieu
technique).
A single injection (Winnie technique) of 6–8 mL at a single level has
also been described.
Carotid surgery additional blocks
The carotid sheath needs to be infiltrated by the surgeon during
carotid surgery, as it is supplied by cranial nerves (CN IX, X, XI and
XII). Trigeminal nerve block may be required to allow surgical
retraction near the submandibular area
What type of block is perfomred by injection at c6
Injections at C6 are made for stellate ganglion blockade
