Usg in Ra Anaesthesia 2010

8/9/2019 Usg in Ra Anaesthesia 2010

1/12

Ultrasound in regional anaesthesia

J. Griffin1

and B. Nicholls2

1 Specialist Registrar in Anaesthesia, South West School of Anaesthesia, Derriford Hospital, Plymouth, Devon, UK

2 Consultant in Anaesthesia and Pain Management, Taunton & Somerset NHS Foundation Trust, Musgrove Park

Hospital, Taunton, Somerset, UK

Summary

Ultrasound guidance is rapidly becoming the gold standard for regional anaesthesia. There is an

ever growing weight of evidence, matched with improving technology, to show that the use of

ultrasound has significant benefits over conventional techniques, such as nerve stimulation and loss

of resistance. The improved safety and efficacy that ultrasound brings to regional anaesthesia will

help promote its use and realise the benefits that regional anaesthesia has over general anaesthesia,

such as decreased morbidity and mortality, superior postoperative analgesia, cost-effectiveness,

decreased postoperative complications and an improved postoperative course. In this review we

consider the evidence behind the improved safety and efficacy of ultrasound-guided regional

anaesthesia, before discussing its use in pain medicine, paediatrics and in the facilitation of neuraxial

blockade. The Achilles heel of ultrasound-guided regional anaesthesia is that anaesthetists are far

more familiar with providing general anaesthesia, which in most cases requires skills that are

achieved faster and more reliably. To this ends we go on to provide practical advice on ultrasound-

guided techniques and the introduction of ultrasound into a department.

........................................................................................................

Correspondence to: Dr B. Nicholls

E-mail: [email protected]

The use of ultrasound imaging techniques in regional

anaesthesia is rapidly becoming an area of increasing

interest. It represents one of the largest changes that the

field of regional anaesthesia has seen. For the first time,

the operator is able to view an image of the target nerve

directly, guide the needle under real-time observation,

navigate away from sensitive anatomy, and monitor the

spread of local anaesthetic (LA). This comes at a time

when an ageing population presents with an increasing

range of comorbidities, thereby demanding a wider

choice of surgical and anaesthetic options to ensure

optimal clinical care and a decreased risk of complica-

tions. The key to successful regional anaesthesia isdeposition of LA accurately around the nerve structures.

In the past, electrical stimulation or paraesthesia, both of

which relied on surface landmark identification, was

used for this. However, landmark techniques have

limitations; variations in anatomy [1] and nerve

physiology [2], as well as equipment accuracy have

had an effect on success rates and complications. The

introduction of ultrasound may go some way to

changing this.

If the use of ultrasound is to become more widespread

amongst anaesthetists, then it must be shown to be

clinically effective, practical and cost-effective. The use of

ultrasound guidance in daily clinical practice requires a

degree of training and an understanding of the equipment

and technology. This article will address the benefits and

widespread uses of ultrasound in regional anaesthesia. It

will provide practical tips on how to achieve success in its

use. It will review the evidence that support its use and

provide advice on the introduction of ultrasound into a

department.

Background

Regional anaesthesia, when used alone or in combination

with general anaesthesia, offers several potential benefits

over general anaesthesia alone: a decrease in morbidity

and mortality [36]; superior postoperative analgesia [7

10]; cost-effectiveness [11]; a decrease in postoperative

complications [1214]; and an improved postoperative

course (decreased use of opioids and anti-emetics, faster

recovery and discharge, increased patient satisfaction)

Anaesthesia, 2010, 65 (Suppl. 1), pages 112 doi:10.1111/j.1365-2044.2009.06200.x.....................................................................................................................................................................................................................

2010 The Authors

Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland 1


2/12

[7, 15, 16]. Unfortunately, despite these clinical benefits,

regional anaesthesia remains less popular than general

anaesthesia. Its use is associated with a number of

shortcomings. Perhaps the greatest is that general anaes-

thesia is far more successful and reliable than regional

anaesthesia [17, 18]. Even in experienced hands and with

the use of nerve stimulation, there is an inherent failure

rate. Anaesthetists are more familiar with providing

general anaesthesia [19], which is generally achieved faster

and using skills that are easier to attain. However, regional

anaesthesia does not compete with general anaesthesia, in

much the same way as ultrasound-guided regional tech-

niques do not compete with nerve stimulation techniques.

What ultrasound can bring to regional anaesthesia is a

number of potential advantages that serve to redress some

of the shortcomings of the current techniques: direct

observation of nerves [21, 2428]; direct observation of

surrounding structures (vessels, muscles, tendons), facili-

tating the identification of nerves [2428]; direct observa-tion of LA deposition and spread [24, 25, 27, 29];

avoidance of painful evoked muscle contractions [25]; a

decrease in complications such as accidental intraneural or

intravascular injection [21, 24, 25, 27, 29, 31, 32]; faster

onset of block [24, 25, 27, 28, 30]; longer duration of

block [25]; improved block quality [24, 28, 30, 34, 35];

and decreased dose of LA [23, 30]. A number of recent

editorials [2022] have agreed that ultrasound guidance

will become the gold standard for regional anaesthesia, but

that this transition will take another 510 years.

Advantages

The single most important advantage that ultrasound

brings to regional anaesthesia is the ability to confirm the

exact placement and spread of LA; it is the LA that blocks

the nerve and not the needle. The needle can be

manipulated under real-time observation to the target

nerve, and LA placed directly around the nerve, resulting

in a faster onset, longer duration and improved quality

block using less LA. Hazardous structures such as blood

vessels, pleural and viscera can be avoided, and compli-

cations can thereby be minimised. Ultrasound frees the

operator from using the classically described landmarks.

Nerves can be targeted at any point along their coursewhere they can be seen. Blind techniques relying on

pops, clicks, twitches and the need for multiple trial and

error needle passes, with their lack of accuracy, reliability,

longer placement times, patient discomfort and injury,

can now, for many blocks, be dispensed with.

Efficacy and safety

Several studies have shown increased efficacy and safety

when using ultrasound to aid regional anaesthesia when

compared with the traditional landmark and nerve

stimulation techniques. Chan et al. [36] undertook a

randomised, controlled trial of 188 patients undergoing

axillary brachial plexus blocks, comparing ultrasound with

nerve stimulation techniques. Block success rate was

higher with ultrasound (82.8%, p = 0.01) and combined

ultrasound and nerve stimulation (80.7%, p = 0.03),

compared with nerve stimulation alone (62.9%). They

reported the additional benefits of less axillary pain and

bruising. None of the groups reported any major

complications. However, one must be mindful that this

ultrasound success rate, in the hands of experienced

operators using high-end ultrasound machines, was well

short of 100%. The authors commented that this was

most likely due to mistakes in nerve identification and

misinterpretation of circumferential spread of LA.

Orebaugh et al. [37], in a larger but non-randomised

study of 248 patients requiring any one of four different

peripheral nerve blocks (interscalene, axillary, femoral,popliteal), compared ultrasound plus nerve stimulation

with nerve stimulation alone. They found a significantly

shorter time was needed to perform the blocks with fewer

attempts (both p < 0.001) when ultrasound was used.

However, they failed to show a statistical difference in the

failure rate between the two groups: 2% (3 124) in the

ultrasound plus nerve stimulation group and 6% (8 124)

in the nerve stimulation group (p = 0.334). Pearlas et al.

[35], in a prospective, randomised trial, assigned 74

patients undergoing major elective foot or ankle surgery

to receive a sciatic block in the popliteal fossa. Half of the

blocks were guided by real-time ultrasound and half by

nerve stimulation. Sensory and motor function were

assessed by a blinded observer at predetermined intervals

for up to 1 h. Block success was identified as loss of

sensation to pinprick within 30 min in the distribution of

both tibial and common peroneal nerves. They found that

the ultrasound group had a significantly higher block

success rate compared with the nerve stimulation group

(89.2% vs 60.6% respectively, p = 0.005). Onset and

progression time for the block was faster in the ultrasound

group, without an increase in block procedure time or

complications.

Casati et al. [38] undertook a prospective, randomised,

blinded study to test the hypothesis that ultrasoundguidance can shorten the onset time of axillary brachial

plexus blocks compared with nerve stimulation when

using a multiple injection technique. Thirty patients were

randomised to each group. The average number of needle

passes was four in the ultrasound group and eight in the

nerve stimulation group. Mean (SD), sensory block onset

time was shorter in the ultrasound group (14 (6) vs 18 (6)

min respectively, p = 0.01). However, no difference was

seen in the onset time of the motor block or readiness for

J. Griffin and B. Nicholls Ultrasound in regional anaesthesia Anaesthesia, 2010, 65 (Suppl. 1), pages 112......................................................................................................................................................................................................................

2010 The Authors

2 Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland


3/12

surgery. An insufficient block was seen in one patient in

the ultrasound group and two in the nerve stimulation

group. However, procedure-related pain was seen in 14

patients (48%) in the nerve stimulation group compared

with only six patients (20%) in the ultrasound group

(p = 0.48). In conclusion, the group commented that

with multiple injection axillary blocks, ultrasound pro-

vided a similar success rate and had a comparable

incidence of complications when compared with nerve

stimulation. Marhofer et al. [30] conducted a prospective

randomised controlled trial comparing ultrasound with

nerve stimulation in 60 patients receiving femoral three-

in-one blocks for hip surgery following trauma. The

onset time of sensory block in each nerve was significantly

shorter with ultrasound guidance when compared with

nerve stimulation. The quality of the nerve block was also

significantly better in the ultrasound group (p < 0.01).

The femoral nerve could be viewed in 95% of the

ultrasound group in which there were no cases of vascularpuncture compared with 10% in the nerve stimulation

group. In a large retrospective study by Sandhu et al. [39],

1146 patients underwent ultrasound-guided infraclavicu-

lar blocks. These were carried out by 88 different junior

doctors who were supervised by 37 different anaesthetists,

and hence this represented a real world scenario.

Ninety-nine per cent of the blocks were successful

(1138 1146), arterial puncture occurred in < 1% of cases

and no patients had accidental intravascular injection,

local toxicity or symptoms of peripheral nerve injury.

Furthermore, the use of ultrasound has shed some light

on the failings of nerve stimulation. A study by Beach

et al. [40] showed that for adequately imaged nerves, a

positive motor response to nerve stimulation did not

improve the success of the block. In addition, they found

that a block could be successful without positive nerve

stimulation. Indeed, muscle stimulation and paraesthesia

may not occur even when ultrasound confirms the

correct needle position [2]. Other papers have shown that

the needle can be intraneural and there can still be failure

to provoke muscle contractions by the nerve stimulator

[41]. In diabetic patients, it has been demonstrated that

nerve stimulation and paraesthesia may be impossible to

elicit at currents < 2.4 mA [42]. Biegeleisen [43], in a

prospective study of US-guided axillary blocks, foundthat nerve puncture and intraneural injection of LA does

not always lead to nerve injury.

In the last year alone there has been a large number of

excellent studies published that provide more evidence

that ultrasound will soon become the main method of

guidance in regional anaesthesia. This has been sup-

ported by the recent publication of the UK National

Institute for Health and Clinical Excellence (NICE)

Interventional Procedure Guidance 285 on ultrasound-

guided regional nerve block, published in January 2009

[44].

Epidural and spinal anaesthesia

In January 2008 NICE published guidelines [45] that

suggested that ultrasound could be used in two different

ways to facilitate catheterisation of the epidural space.

One method is the use of real-time ultrasound imaging to

observe the passage of the needle towards the epidural

space. The second method (pre-puncture ultrasound) is

the use of ultrasound as a guide to the conventional

technique, using an initial scan of the patients lumbar

spine to identify the midline, interspinous spaces and

depth of the epidural space. The guidance relates to

children, neonates, pregnant women and patients with

scoliosis. Neuraxial imaging with ultrasound is particu-

larly challenging as the structures in which we are

interested (ligamentum flavum, epidural space and dura)are mostly encased in bone, through which ultrasound

will not pass. Visibility is via one or two acoustic

windows, the interspinous space and the intralaminar

space. These are best imaged when scanning transversely

in the midline and longitudinally in the paramedian area

respectively (Figs 1 and 2). To understand spinal ultra-

sound, a thorough knowledge of lumbar spine anatomy is

necessary, as certain bony landmarks can be easily

identified: sacrum, spinous processes, articular processes

(facet joints) and vertebral bodies. The epidural space is

hypo-echoic and often not seen clearly. The ligamentum

flavum and posterior dura are commonly seen as a single

AP

AD

VB

PD

SP

SC

Figure 1 Midline ultrasound view of the lumbar spine and theepidural space. The depth to the epidural space is marked (A).SP, spinous process; AP, articular process; AD, anterior dura ligamentum flavum complex; PD, posterior dura; SC, spinalcanal; VB, vertebral body.

Anaesthesia, 2010, 65 (Suppl. 1), pages 112 J. Griffin and B. Nicholls Ultrasound in regional anaesthesia......................................................................................................................................................................................................................

2010 The Authors



4/12

bright hyperechoic line. Anterior and deep to these

structures, the anterior dura and posterior longitudinal

ligament can often be seen as being distinct from the

vertebral body; the spinal canal lies between these

superficial and deeper structures. In neonates and children

under six months, the internal architecture of the spinal

cord can be clearly seen; this is not so in older children

and adults.

Efficacy and safety

In a randomised controlled trial of 64 children, Willschke

et al. [46] compared real-time ultrasound with pre-

puncture ultrasound. Catheter placement was successful

in all children but was quicker to perform in the real-time

ultrasound group: a mean of 162 s compared with 234 s

(p < 0.01). None of the children in the real-time ultra-

sound group required supplementary intra-operative or

postoperative analgesia, compared with 6% (2 34) in the

pre-puncture group. Furthermore, in a case series of 35

neonates, he demonstrated that the tip of the needle and

spread of LA could be clearly seen in all cases.

Grau et al. [31, 47] conducted two randomised,

controlled studies of a total of 372 pregnant women

receiving obstetric epidurals. They compared the use ofpre-puncture ultrasound with no ultrasound. The mean

numbers of puncture attempts were 1.3 and 1.5,

compared with 2.2 and 2.6 respectively (p < 0.013 and

p < 0.001). In the larger of these studies (n = 300), they

showed a faster onset time for the block (4.6 min vs

5.3 min, p < 0.027) and a lower incidence of severe

headaches (2.7% vs 10.0%, p < 0.011) in the ultrasound

group. However, preparation time was increased at 6 min

compared with 4 min (p < 0.001). There was no signif-

icant difference in aspiration of blood, backache or

sensory problems. Dural puncture was seen in 0.7% of the

ultrasound group and 1.3% of the control group. Patient

satisfaction was higher in the ultrasound group.

On the premise that epidural anaesthesia may be

difficult in pregnancy, Grau et al. [48] went on to evaluate

the teaching possibilities of ultrasonography as a diagnos-

tic approach to the epidural region. Two groups of

residents performed their first 60 obstetric epidurals under

supervision. The control group used a conventional loss

of resistance technique while the ultrasound group

proceeded in the same way but were supported by

pre-puncture ultrasound imaging, giving them informa-

tion about optimum puncture point, depth and angle.

Success was defined as using fewer than three attempts,

not changing space or anaesthetic technique, and achiev-

ing adequate epidural anaesthesia. In the control group,

the success rate for the first 10 epidurals was 60%,

increasing to 84% over the next 50 epidurals. In theultrasound group, success rate started at 86% and

increased to 94%. The authors concluded that the study

showed the possible value of ultrasound imaging for

teaching and learning obstetric regional anaesthesia.

Arzola et al. [49] imaged 61 pregnant women undergoing

epidural analgesia with a midline, transverse ultrasound

approach. They found a good level of success in the

ultrasound determined insertion point (91.8%) and in the

measured and actual depth to the epidural space. The

mean (SD) ultrasound determined depth of the space was

4.66 (0.68) cm; the actual depth of the space as measured

by the epidural needle was 4.65 (0.72) cm.

It is unsurprising that NICE have targeted the use of

ultrasound in these groups. In children, the quality of

image is superior because of the lesser depths involved,

the relatively larger acoustic windows and the reduced

ossification of the surrounding bony structures [50].

While in pregnancy it has been shown [51] that the

optimum puncture site available on the skin for lumbar

epidural space cannulation is smaller, the soft-tissue

channel between the spinal processes is narrower, and

the skinepidural space distance is greater than in the

non-pregnant patient. Furthermore, the visibility of the

ligamentum flavum, dura mater and epidural space is

decreased during pregnancy. An increased incidence ofobesity and oedema obscures anatomical landmarks (the

spinous processes and the midline), and hormonal changes

result in softer ligaments, making the loss of resistance

technique less reliable.

Ultrasound can be used to pre-scan the lumbar spine in

difficult cases, confirming both the midline and the depth

to the ligamentum flavum and epidural space, decreasing

the failure rate and the incidence of complications. Real-

time epidural guidance is not routinely used; both

PD

AD

SC

AP

Figure 2 Paramedian ultrasound view of the lumbar spine andepidural space. The depth of the epidural space is marked (A).AP, articular process; AD, anterior dura ligamentum flavumcomplex; PD, posterior dura; SC, spinal canal.


2010 The Authors



5/12

visibility of the needle and the practicalities of holding the

probe and manipulating a loss of resistance technique

means that a minimum of three hands are necessary. The

development of probe supports and needle guidance

devices may see this as a realistic possibility in the future,

but as for now, real-time guidance is reserved for experts.

Experience with spinal anaesthesia reflects that found with

epidurals, being used to assess the vertebral level [52] and

to identify normal spaces in difficult cases [53], but

ultrasound is still not routinely used to guide the needle.

Pain medicine

The use of ultrasound in pain medicine has lagged

behind its use in regional anaesthesia, and initial studies

were primarily concerned with identifying anatomy

sonographically and the feasibility of performing estab-

lished techniques using ultrasound. More recently,

comparative studies comparing fluoroscopic and com-puterised tomography-guided techniques with ultra-

sound have begun to appear and these are now

contesting the gold standard for pain interventions.

Although X-ray gives better definition for bony struc-

tures than ultrasound, it lacks the ability to demonstrate

musculoskeletal and peripheral nerve structures.

Although limited by bony shadowing and decreased

resolution at depth, ultrasound for spinal injections has

included cervical and lumbar facet joint injections,

lumbar medial branch blocks, peri-radicular injections,

caudal and sacro-iliac joint injections.

Greher et al. [54] first described the feasibility of

ultrasound-guided facet joint injections and Galiano

et al. [55], in a prospective, randomised clinical trial,

showed that the ultrasound approach to lumbar facet

joints is clinically feasible, and results in a significant

decrease in procedure duration and radiation dose

compared with computerised tomography. However,

formal comparison with fluoroscopy is still awaited.

Nerve root injections are difficult with ultrasound, and

the trans-foraminal approach is limited by poor visibility;

reliable needle placement within the foramina is

unachievable with present equipment and approaches.

Sympathetic blocks are one of the mainstays of pain

medicine, and the use of ultrasound for stellate ganglionblocks was initially describe by Kapral et al. in 1995

[56]. A recent case report [57] suggests improved safety

with the use of ultrasound: less risk of damage to the

thyroid gland and vessels, vertebral artery and oesoph-

agus. The ability to monitor the spread of the LA sub-

fascially along the longus coli muscle may help to

decrease the incidence of complications such as recur-

rent laryngeal nerve palsy, and intrathecal and epidural

spread [58].

Peripheral nerve injections using ultrasound include the

occipital nerve, suprascapular nerve, intercostal nerve,

ilio-inguinal and ilio-hypogastric nerve, pudendal nerve

and lateral cutaneous nerve of thigh. Eichenberger et al.

[59] were able to locate the occipital nerve with

ultrasound and reliably block it. This compares well with

the recommended three-needle fluoroscopy technique

that is used to accommodate the variable anatomy of the

nerve. More recent studies comparing ultrasound and

fluoroscopy for piriformis injections [60] (for piriformis

syndrome) and glenohumeral joint injections [61] have

shown improved accuracy with ultrasound.

Ultrasound has the potential to influence the diagnosis

and treatment of many pain conditions, not only with the

increased accuracy of injection techniques but also with

the potential to diagnose common musculoskeletal prob-

lems. Further outcome studies to confirm the benefits of

ultrasound in comparison to fluoroscopy are eagerly

awaited.

Paediatrics

Regional anaesthesia is usually performed under general

anaesthesia in children. Absolute distances are smaller and

the nerves lie closer to the skin. Ultrasound would

therefore seem an obvious choice in this area, improving

block efficacy and safety even though the incidence of

peripheral nerve block-related complications is already

exceptional low (1:10 000) in paediatric practice [62].

Where ultrasound offers benefits over established tech-

niques is in fascial plane blocks such as rectus sheath, ilio-

inguinal and transversus abdominis blocks, in which the

endpoint relies on clicks and pops. Ultrasound decreases

the risk of intramuscular and intraperitoneal injection,

bringing science to an imperfect art. Local anaesthetic

volume reduction studies as described below enhance the

safety of regional anaesthetic techniques in children.

Willschke et al. [32] conducted a randomised con-

trolled trial of 100 children with a mean age of

41 months. They showed that LA could be placed

around 100% of ilio-inguinal and iliohypogastric nerves

using ultrasound, but only 50% when a fascial click

technique was used, as detected by ultrasound after

injection (p < 0.0001). Heart rate increase on incisionwas 6% and 22% in the two groups respectively

(p < 0.0001). Additional analgesia was necessary in 4%

and 26% respectively (p = 0.004). The mean volume of

LA required to produce an effective block was signifi-

cantly lower at 0.19 ml.kg)1 compared with 0.3 ml.kg)1

(p < 0.0001). Furthermore, a smaller proportion of

patients required postoperative rectal analgesia: 6% com-

pared with 40% (p < 0.0001). No complications were

reported in either group.


2010 The Authors



6/12

Cost analysis

The initial cost of a modern portable ultrasound system is

often used as an argument against ultrasound and its

introduction into a department. A typical machine costing

in the range of 15 00020 000 and with a conserva-

tive average life span of five years, at 1000 procedures per

year, equates to a cost of 3.004.00 per patient event.

Sandhu et al. [33] compared the costs of administering

infraclavicular nerve blocks by either nerve stimulator or

ultrasound. The per case cost of the ultrasound machine

($17 000), spread over 5000 blocks, was $3.40. Time

saving in block onset and placement came to 21 min.

Theatre time at $8.00 per min meant a $168.00 saving per

nerve block. Over 5000 blocks, this is a saving of

$84 000. We know that ultrasound-guided blocks are also

safer, more efficacious and with fewer complications

(potential reduction in litigation costs); less LA is used and

the incidence of conversion to general anaesthesia islower. Further cost savings would be expected in day

surgery patients as they are able to bypass recovery and are

discharged sooner with a decreased incidence of postop-

erative nausea and vomiting. In addition, the ultrasound

machine can also be used for central line and arterial line

placement, and in the intensive care unit for assisting in

procedures such as drainage of pleural effusions or ascitic

fluid.

Practical tips for ultrasound-guided regional

anaesthesia

The premise of ultrasound-guided regional anaesthesia is

the visual location of the nerve, guidance of the needle to

the nerve and the spread of LA around the nerve and, in a

perfect world, if all these criteria are met, then a 100%

success rate should be achievable. Attention to detail and

the development of good practical skills can go along way

towards achieving this goal.

Visual location of the nerve

To optimise demonstration of nerves and surrounding

structures, it is important to understand the equipment

and its limitations, and to have a good, sound anatomical

knowledge of the structures being viewed. The probe

used should match the procedure being performed

(Table 1). Choosing the wrong probe can make identi-

fication of the anatomy difficult (Figs 3 and 4). It is

important to use the highest frequency probe available for

the depth of image being scanned.

Needle guidance

The holy grail in ultrasound-guided regional anaesthesia

is to find a needle that defies the laws of physics and can

be seen at any depth and at any angle. To this end, needles

have been coated and scored, the tips multifaceted and

needle guides designed [63], all to increase their reflec-

tivity and ease of use. At present, there is no single needle

that is significantly more echogenic than another. Facet-

tipped needles appear to have more feel and may

decrease the chances of intraneural needle placement.

In general, large needles are more readily visible on

ultrasound and the visibility of all needles becomes less as

distance from the probe increases. Identification of theneedle can be improved by: rotating the needle, as

ultrasound reflecting from the bevel can improve visibil-

ity; gentle in-and-out movements (jiggling); or injection

of small volumes of fluidhydrolocalisation [64]. The

needle can be introduced using either an in-plane

approach in which the needle is passed along the long

axis of the probe, parallel to the probe face, or an out-of-

plane approach in which the needle passes at right angles

to the long axis of the probe. Use of the in-plane

technique means that the entire needle can be seen

(Fig. 5), that there is excellent visibility of the needle-

nerve interface, and that a technique such as that

described as the walk-down can be used [65]. However,

it can be difficult to keep the whole needle within the

narrow (often < 1 mm) beam, and the method often

requires unfamiliar needle approaches to blocks and may

demand the use of a longer needle with increased passage

through muscle and other tissues, causing additional pain.

Use of the out-of-plane technique can mimic established

techniques, allows more needle movement in a larger

field of vision and provides a shorter distance for the

needle to travel between the skin and the nerve.

However, the tip of the needle may be difficult to see

(Fig. 6) and there is poorer demonstration of the nerve-

needle interface.

Table 1 Different types of probe andtheir uses.

Probe

Crystal

Array Frequency

Field

depth Resolution Blocks

Linear Linear 613 MHz 1.86 cm 0.5 mm axial

1 mm lateral

Brachial plexus, abdominal wall,

femoral and distal sciatic,

peripheral nerves

Curvilinear Curved

face

25 MHz 5 16 cm 2 mm axia l

3 mm lateral

Neuraxial,lumbar plexus

and proximal sciatic


2010 The Authors



7/12

Local anaesthetic injection

Using ultrasound, the volume of LA needed is reduced,

and general consensus appears to suggest that at least a

50% decrease in volume is common; volumes as low as

5 ml have been used with good clinical effect ininterscalene blocks used for postoperative analgesia [66].

The ideal pattern of spread and minimum volume for

individual nerve blocks has still to be determined, but

circumferential spread appears to be the ideal (Figs. 7 and

8). The incidence of complications and neurological

sequelae can be decreased by not deliberately contacting

the nerve and with attention to detail as described below:

Injection should be painless.

There should be no resistance to injection.

The LA should be clearly seen during injection. If it is

not, consider intravascular injection. Look for smoke

in the vessels (the microbubbles in the injectate will

SMSA

BPR

Figure 3 View with correct linear array probe of interscalenearea. SA, anterior scalene muscle; SM, middle scalene muscle;BPR, brachial plexus roots.

Figure 5 Block needle seen in in-plane view.

Needle

Figure 6 Block needle seen in out-of-plane view.

Needle

LA

UN

Figure 7 Acceptable local anaesthetic (LA) spread. UN, ulnarnerve in the forearm.

SASM BPR

Figure 4 View with incorrect curvilinear array probe of in-terscalene area. SA, anterior scalene muscle; SM, middle scalenemuscle; BPR, brachial plexus roots.


2010 The Authors



8/12

appear as white hyperechoic artefacts within the

vessels). If this is seen, stop injection immediately and

reposition the needle.

If the needle tip is not within the ultrasound beam,

move the probe to demonstrate the needle tip before

injecting.

The nerve often appears brighter and more easily

identified after injection of LA around the nerve.

If the nerve swells during the injection, stop immedi-

ately as the injection may be intraneural.

Introduction of ultrasound into a department

The success of the introduction of any new technique

into a department is dependant upon the availability of

the equipment and the training of the individuals using

that equipment. The purchase of an ultrasound machine

by a department has been made easier with NICE

guidance No. 285 [44, 45]. Most purchases are made on

the premise of increased success, decreased complications,

improved patient care and, importantly, cost-effective-

ness. The evidence supporting the use of ultrasound in

regional anaesthesia is growing all the time and the

majority of anaesthetic departments in the UK now haveaccess (although often limited) to some form of ultra-

sound machine capable of imaging nerves. The choice of

ultrasound machine is individual, often dictated by

resources and personal preferences, but they should

ideally have the following capabilities:

Ease of use, to accommodate multiple users of varying

levels of experience.

Portability, to allow multiple areas of use; can be cart

based or truly portable.

A selection of probes: linear, curvilinear and phased

array.

Doppler facilities: colour flow and power to identify

vessels and flow.

Harmonic imaging, beam steering or compound

imaging to provide improved image quality and

resolution.

Image and video capture functionality for training,

audit and clinical governance reasons.

A long warranty of three to five years and a long

predicted clinical life.

The successful use of ultrasound is highly operator-

dependent and as such has a distinct learning curve.

Practitioners using ultrasound without training have been

shown to have more complications and lower success

rates. For this reason, the introduction of ultrasound into

a department should be structured, and predicated on

training and supervision. Recommendations for training

and a proposed curriculum have been published by theRoyal College of Radiologists [67]. The proposed

training should be modular and it is recommended that

training should be specific to the requirements of the

trainees and to the department. It is also understood that

different specialties require different levels of training and

these can broadly be divided in levels 1, 2 and 3 [68]:

Level 1 (basic) is training that can be achieved within

recognised postgraduate training programmes.

Level 2 (intermediate) requires specific sub-speciality

training.

Level 3 (advanced).

Within anaesthesia, most trainees are only likely to

achieve some of the competencies included in Level-1

training. Guidelines for ultrasound-guided regional anaes-

thesia have recently been published [69]. These propose

sensible recommendations both for training and the

competencies needed to practice the technique. In general,

all recommendations agree on the need to develop basic

ultrasound skills including: understanding the equipment

used; image acquisition and optimisation; image interpre-

tation; and needling techniques. These skills can be

achieved by a mixture of theoretical and practical training,

and should follow the suggested outline:

Knowledge of ultrasound and equipment:

o Basic physics of ultrasound.o Machine characteristic and use.

o Optimisation and storage of the image (resolution,

gain, focus etc.).

o Patient care, safety and infection control.

Knowledge of anatomy relevant to commonly used

techniques:

o Brachial plexus anatomy interscalene, supracla-

vicular, infraclavicular, axillary and terminal

peripheral nerve regional anaesthetic techniques.

FP

Needle

UN

LA

Figure 8 Unacceptable, subfascial local anaesthetic (LA)spread. UN, ulnar nerve in the forearm; FP, fascial plane.


2010 The Authors



9/12

o Lumbar plexus anatomy femoral, saphenous,

obturator, sciatic, popliteal and tibial.

o Abdominal wall anatomy rectus sheath, ilio-

inguinal, transversus abdominus plane.

o Spinal anatomy paravertebral, intercostal, epidu-

ral, caudal and psoas compartment.

Practice on models and phantoms.

Simulation of techniques models, animals or cadavers.

Supervised performance of techniques.

Independent practice.

At present all assessments during training are optional

and there is no consensus on whether ultrasound-guided

regional anaesthesia should be certificated and accredited.

Table 2 outlines the advantages and disadvantages of

training models. Table 3 divides blocks into levels of

difficulty.

Table 2 Training models for ultra-sound-guided regional anaesthesia. Training model Advantages Disadvantages

Live models

(anywhere)

Readily accessible

Usually compliant

Nerve structures seen

Large numbers present

good for anatomical

variations

Variable anatomy and echogenicity

Not able to needle

Purely for scanning

Phantoms

(anywhere)

Cheap and mobile-use

anywhere, reusable

Home made (gelatine,

olives, pasta)

Commercial expensive

Poor realism, no nerves

Agar gelatine preps tracking of

needle path

Needling techniques only

Limited life span

Animals

(Europe, North

America,

Australasia

not UK)

Demonstration of nerves

Use of nerve stimulator

Vascular landmarks present

Needling techniques, single

injection and catheter

techniques

Animal anatomy

Unfamiliar approaches

Ethical and cultural objections

Expensive

Cadaveric

preparations

(anatomy

departments UK,

Europe andworldwide)

As close to real as possible

Observe all nerves easily

Good needling technique

Injection of saline, catheter

techniquesMimics normal techniques

and ergonomics

Visibility often poorer than living

Limited access to some areas

No pulsations or Doppler signal loss

of landmarks

Acquisition of preparations (cost)

Table 3 Level of difficulty for eachblock with recommendations on choiceof probe and needling technique.

Techniques

Recommended

probe

Needling

techniques

Level of

difficulty

Superficial cervical plexus,

interscalene

HFL IP OOP Basic

Axillary, terminal branches

(ulnar, median, radial)

HFL IP OOP Basic

Femoral, saphenous, ankle HFL IP OOP Basic

Rectus sheath, ilio-inguinal,

iliohypogastric

HFL IP OOP Basic

Supraclavicular HFL IP only Intermediate

Infraclavicular HFL (depth < 5 cm)

LFC (depth > 5 cm)

IP OOP Intermediate

Obturator, sciatic- (all

approaches including popliteal)

HFL (depth < 5 cm)

LFC (depth > 5 cm)

IP OOP Intermediate

Intercostal HFL IP recommended Intermediate

Lumbar plexus thoracic

paravertebral lumbar epidural

HFL (upper thoracic

paravertebral) LFC

IP OOP Advanced

HFL, High frequency linear > 10 MHz; LFC, Low frequency curvilinear 25 MHz; IP, in-plane; OOP,

out-of-plane.


2010 The Authors



10/12

Conclusions

Since the first papers on ultrasound in regional anaesthesia

were published in 1994, there is now an overwhelming

weight of evidence (> 1500 papers) supporting its use.

We are now at a point at which worldwide opinion is

shifting behind the use of ultrasound as the main method

for needle guidance in regional anaesthesia. Indeed, direct

ultrasound observation improves the outcome in most

peripheral nerve techniques in adults and children.

Anaesthetists can now directly see relevant nerve struc-

tures in both the upper and lower limb at all levels.

For neuraxial techniques, further studies are needed to

establish whether ultrasonography can lead to improve-

ment in performance. However, there have been prom-

ising results in children, neonates and in pregnancy. In

pain medicine, ultrasound guidance is still a technique in

evolution. However, for an increasing number of blocks,

evidence is now appearing with regard to feasibility andimproved outcome. Safety and efficacy aside, for ultra-

sound to be truly embraced there are still mental obstacles

to overcome, financial resources to provide and training

to be delivered. It is when these are achieved that the full

list of potential advantages that ultrasound brings to

regional anaesthesia will be seen.

Conflicts of interest

Dr Nicholls has received honoraria and equipment loans

from Sonosite, B Braun and GE. Dr Griffin declares no

conflicts of interest.

References

1 Wedel DJ. Ultrasonographic findings of the axillary part of

the brachial plexus. Regional Anesthesia and Pain Medicine

2001; 92: 12715.

2 Perlas A, Niazi A, McCartney C, Chan V, Xu D, Abbas

S. The sensitivity of motor response to nerve stimulation

and paresthesia for nerve localization as evaluated by

ultrasound. Regional Anesthesia and Pain Medicine 2006; 31:

44550.

3 Urwin SC, Parker MJ, Griffiths R. General versus

regional anaesthesia for hip fracture surgery: a meta-

analysis of randomized trials. British Journal of Anaesthesia2000; 84: 4505.

4 Rodgers A, Walker N, Schug S, et al. Reduction of post-

operative mortality and morbidity with epidural or spinal

anaesthesia: results from overview of randomized trials.

British Medical Journal 2000; 321: 1493.

5 Ballantyne JC, Carr DB, deFerranti S. The comparative

effects of postoperative analgesic therapies on pulmonary

outcome: cumulative meta-analyses of randomized, con-

trolled trials. Anesthesia & Analgesia 1998; 86: 598612.

6 Beattie WS, Badner NH, Choi P. Epidural analgesia reduces

postoperative myocardial infarction: a meta-analysis.

Anesthesia & Analgesia 2001; 93: 8538.

7 Hadzic A, Karaca PE, Hobeika P, et al. Peripheral nerve

blocks result in superior recovery profile compared with

general anesthesia in outpatient knee arthroscopy. Anesthesia

& Analgesia 2005; 100: 97681.8 Hadzic A, Arliss J, Kerimoglu B, et al. A comparison of

infraclavicular nerve block versus general anesthesia for hand

and wrist day-case surgeries. Anesthesiology 2004; 101: 127

32.

9 Chelly JE, David B, Williams BA, Kentor ML. Anesthesia

and postoperative analgesia: outcomes following orthopedic

surgery. Orthopedics 2003; 26: 86571.

10 Buist RJ. A survey of the practice of regional anesthesia.

Journal of the Royal Society of Medicine 1990; 83: 70912.

11 Chan VW, Peng PW, Kaszas Z, et al. A comparative study

of general anesthesia, intravenous regional anesthesia, and

axillary block for outpatient hand surgery: clinical outcome

and cost analysis. Anesthesia & Analgesia 2001; 93: 11814.

12 Moen V, Dahlgren N, Irestedt L. Severe neurologicalcomplications after central neuraxial blockades in Sweden

19901999. Anesthesiology 2004; 101: 9509.

13 Borgeat A, Ekatodramis G, Kalberer F, Benz C. Acute and

nonacute complications associated with interscalene block

and shoulder surgery: a prospective study. Anesthesiology

2001; 95: 87580.

14 Auroy Y, Narchi P, Messiah A, Litt L, Rouvier B, Samii K.

Serious complications related to regional anesthesia: results

of a prospective survey in France. Anesthesiology 1997; 87:

47986.

15 McCartney CJ, Brull R, Chan VW, et al. Early but no long-

term benefit of regional compared with general anesthesia

for ambulatory hand surgery. Anesthesiology 2004; 101: 4617.

16 Hadzic A, Williams BA, Karaca PE, et al. For outpatient

rotator cuff surgery, nerve block anesthesia provides superior

same-day recovery over general anesthesia. Anesthesiology

2005; 102: 10017.

17 Nielsen KC, Steele SM. Outcome after regional anesthesia

in the ambulatory settingis it really worth it? Best Practice

and Research Clinical Anaesthesiology 2002; 16: 14557.

18 Grau T, Fatehi S, Motsch J, Bartusseck E. Survey of current

practice of regional anaesthesia in Germany, Austria and

Switzerland. Part 2 Use Success rates and techniques, part 2.

Anaesthesist2004; 53: 84755.

19 Smith P, Sprung J, Zura A, Mascha E, Tetzlaff JE. A survey

of exposure to regional anesthesia techniques in Americananesthesia residency training programs. Regional Anesthesia

and Pain Medicine 1999; 24: 1116.

20 Hopkins PM. Ultrasound guidance as a gold standard in

regional anaesthesia. British Journal of Anaesthesia 2007; 98:

299301.

21 GreherM, Retzl G, Niel P, Kamholz L, Marhofer P, KapralS.

Ultrasonographic assessment of topographic anatomy in vol-

unteers suggest a modification of the infraclavicular vertical

brachial block. British Journal of Anaesthesia 2002; 88: 6326.


2010 The Authors



11/12

22 Peterson MK. Ultrasound-guided nerve blocks. British

Journal of Anaesthesia 2002; 88: 6214.

23 Eichenberger U, Stockli S, Marhofer P, et al. Minimal local

anesthetic volume for peripheral nerve block: a new ultra-

sound-guided nerve dimension based method. Regional

Anesthesia and Pain Medicine2009; 34: 2426.

24 Marhofer P, Schrogendorfer K, Koinig H, Kapral S,Weinstabl C, Mayer N. Ultrasonographic guidance im-

proves sensory block and onset time of three-in-one blocks.


25 Marhofer P, Greher M, Sitzwohl C, Kapral S. Ultrasono-

graphic guidance for infraclavicular plexus anaesthesia in

children. Anaesthesia 2004; 59: 6426.

26 Retzl G, Kapral S, Greher M, Mauritz W. Ultrasonographic

findings of the axillary part of the brachial plexus. Anesthesia

& Analgesia 2001; 92: 12715.

27 Sandhu NS, Capal LM. Ultrasound-guided infraclavicular

brachial plexus block. British Journal of Anaesthesia 2002; 89:

2549.

28 Williams SR, Chovinard P, Arcand G, et al. Ultrasound

guidance speeds execution and improves the quality of supr-aclavicular block. Anesthesia & Analgesia 2003; 97: 151823.

29 Marhofer P, Schrogendorfer K, Andel H, et al. Combined

sciatic nerve 3 in 1 block in high risk patient. Anaesthesiologie,

Intensivmedizin, Notfallmedizin, Schmerzthesapie 1998; 33:

399401.

30 Marhofer P, Schrogendorfer K, Wallner T, Koinig H,

Mayer N, Kapral S. Ultrasonographic guidance reduces the

amount of local anesthetic for 3-in-1 blocks. Regional


31 Grau T, Leipold RW, Conradi R, Martin E, Motsch J.

Efficacy of ultrasound imaging in obstetric epidural anes-

thesia. Journal of Clinical Anesthesia 2002; 14: 16975.

32 Willschke H, Marhofer P, Bosenberg A, et al. Ultrasonog-raphy for ilioinguinal iliohypogastric nerve blocks in chil-

dren. British Journal of Anaesthesia 2005; 95: 22630.

33 Sandhu NS, Sidhu DS, Levon LM. The cost comparison

of infraclavicular brachial plexus block by nerve stimulator

and ultrasound guidance. Anesthesia & Analgesia 2004; 98:

2678.

34 Kapral S, Greher M, Huber G, et al. Ultrasonographic

guidance improves the success rate of interscalene brachial

plexus blockade. Regional Anesthesia and Pain Medicine2008;

33: 1958.

35 Perlas A, Brull R, Chan VW, CMcCartney CJ, Nuica A,

Abbas S. Ultrasound guidance improves the success of sciatic

nerve block at the popliteal fossa. Regional Anesthesia and Pain

Medicine 2008; 33: 25965.36 Chan VW, Perlas A, McCartney CJ, et al. Ultrasound

guidance improves success rates of axillary brachial plexus

block. Canadian Journal of Anesthesia 2007; 54: 17682.

37 Orebaugh SL, Williams BA, Kentor ML. Ultrasound guid-

ance with nerve stimulation reduces the time necessary for

resident peripheral nerve blockade. Regional Anesthesia and

Pain Medicine 2007; 32: 44854.

38 Casati A, Danelli G, Baciarello M, et al. A prospective,

randomised, comparison between ultrasound and nerve

stimulation guidance for multiple injection axillary brachial

plexus block. Aaesthesiology 2007; 106: 9926.

39 Sandhu NS, Manne JS, Medabalmi PK, Capan LM. Sono-

graphically guided infraclavicular brachial plexus block in

adults; a retrospective analysis of 1146 cases. Journal of

Ultrasound in Medicine 2007; 25: 155561.

40 Beach ML, Sites BD, Gallagher JD. The use of a nervestimulator does not improve the efficacy of ultrasound

guided supraclavicular nerve blocks. Journal of Clinical

Anesthesia 2006; 18: 5804.

41 Sinh SK, Abrams JH, Weller RS. Ultrasound-guided in-

terscalene needle placement produces successful anesthesia

regardless of motor stimulation above or below 0.5 mA.


42 Sites BD, Gallagher J, Sparks M. Ultrasound guided popliteal

block demonstrates an atypical motor response to nerve

stimulation in 2 patients with diabeties mellitus. Regional


43 Biegeleisen PE. Nerve puncture and apparent intraneural

injection during ultrasound guided axillary block does not

invariably result in neurologic injury. Anesthesiology 2006;105: 77983.

44 National Institute for Health and Clinical Excellence.

http://www.nice.org.uk/Guidance/IPG285 (accessed

01 02 2009).

45 National Institute for Health and Clinical Excellence.

http://www.nice.org.uk/Guidance/IPG249 (accessed

01 02 2009).

46 Willschke H, Marhofer P, Bosenberg A, et al. Epidural

catheter placement in children: comparing a novel approach

using ultrasound guidance and a standard loss-of-resistance

technique. British Journal of Anaesthesia 2006; 97: 2007.

47 Grau T, Leipold RW, Conradi R, et al. Ultrasound control

for presumed difficult epidural puncture. Acta Anaesthesio-logica Scandinavica 2001; 45: 76671.

48 Grau T, Bartusseck E, Conradi R, Martin E, Motsch J.

Ultrasound imaging improves learning curves in obstetric

epidural anesthesia: a preliminary study. Canadian Journal of

Anesthesia 2003; 50: 104750.

49 Arzola C, Davies S, Rofaeel A, Carvalho JCA. Ultrasound

using the transverse approach to the lumbar spine provides

reliable landmarks for labor epidurals. Anesthesia & Analgesia

2007; 104: 118892.

50 Rapp HJ, Grau T. Ultrasound imaging in pediatric regional

anesthesia. Canadian Journal of Anesthesia 2004; 51: 2778.

51 Grau T, Leipold RW, Horter J, Conradi R, Martin E,

Motsch J. The lumbar epidural space in pregnancy: visuali-

zation by ultrasonography. British Journal of Anaesthesia 2001;86: 798804.

52 Furness G, Reilly MP, Kuchi S. An evaluation of ultrasound

imaging for identification of lumbar intervertebral level.

Anaesthesia 2002; 57: 27780.

53 Prasad GA, Tumber PS, Lupu CM. Ultrasound guided

spinal anesthesia. Canadian Journal of Anesthsia 2008; 55: 277

80.

54 Greher M, Scharbert G, Kamolz LP, et al. Ultrasound-

guided lumbar facet nerve block: a sonoanatomic study of a


2010 The Authors



12/12

new methodologic approach. Anesthesiology 2004; 100:

12428.

55 Galiano K, Obwegeser A, Walch C, Schatzer R, Ploner F,

Gruber H. Ultrasound-guided versus computed tomogra-

phy-controlled facet joint injections in the lumbar spine: a

prospective randomized clinical trial. Regional Anesthesia and

Pain Medicine 2007; 32: 31722.56 Kapral S, Krafft P, Gosch M, Fleischmann D, Weinstabl C.

Ultrasound imaging for stellate ganglion block: direct visu-

alization of puncture site and local anesthetic spread. A pilot

study. Regional Anesthesia and Pain Medicine 1995; 20: 3238.

57 Shibata Y, Fujiwara Y, Komatsu T. A new approach of

ultrasound-guided stellate ganglion block. Anesthesia &

Analgesia 2007; 105: 5501.

58 Christie JM, Martinez CR. Computerized axial tomography

to define the distribution of solution after stellate ganglion

nerve block. Journal of Clinical Anesthesia 1995; 7: 30611.

59 Eichenberger U, Greher M, Kapral S, et al. Sonographic

visualization and ultrasound-guided block of the third

occipital nerve. Anesthesiology 2006; 104: 3038.

60 Finnoff JT, Hurdle MFB, Smith J. Accuracy of ultrasound-guided versus fluoroscopic guided contrast-controlled piri-

formis injection: a cadaveric study. Journal of Ultrasound

Medicine 2008; 27: 115763.

61 Rutten MJ, Collins JM, Maresch BJ, et al. Glenohumeral

joint injection a comparative study of ultrasound and fluo-

roscopically guided techniques before MR arthrography.

European Journal of Radiology 2009; 19: 72230.

62 Giaufre E, Dalens B, Gombert A. Epidemiology and mor-

bidity of regional anesthesia in children: a one year pro-

spective survey of the French language society of paediatric

anaesthesiologists. Anesthesia & Analgesia 1996; 83: 90412.

63 Tsui BC. Facilitated needle alignment. In plane to the

ultrasound beam using a portable laser unit. Regional


64 Bloc S, Escoffey C, Dhonneur G. Controlled needle tip

progression during ultrasound guided regional anaesthesiausing hydrolocaization technique. Regional Anesthesia and

Pain Medicine 2004; 33: 3823.

65 Tsui BC. Needle puncture site and a walk down approach

for short axis alignment during ultrasound guided blocks.

Regional Anesthesia and Pain Medicine 2006; 31: 5867.

66 Riazi S, Carmichael N, Awad I, Holt RM, McCartney CJ.

Effect of local anaesthetic volume (20 vs 5 ml) on the

efficacy and respiratory consequences of ultrasound-guided

interscalene brachial plexus block. British Journal of

Anaesthesia 2008; 101: 54956.

67 The Royal College of Radiologists. http://www.rcr.ac.

uk/docs/radiology/pdf/ultrasound.pdf (accessed

01 02 2009).

68 European Federation of Societies for Ultrasound in Medi-cine and Biology. http://www.efsumb.org/uploads/

mintraining-feb2006.pdf (accessed 01 02 2009).

69 Sites BD, Chan VW, Neal J, et al. The American Society

of Regional Anesthesia and Pain Medicine and the

European Society of Regional Anaesthesia and Pain

Therapy Joint Committee Recommendations for Educa-

tion and Training in Ultrasound-Guided Regional

Anesthesia. Regional Anesthesia and Pain Medicine 2009; 34:

406.


2010 The Authors


Date post:	29-May-2018
Category:	Documents
Upload:	ivette-m-carroll-d
View:	215 times
Download:	0 times

Usg in Ra Anaesthesia 2010

Documents