Peripheral nerve blocks of the pelvic limb

Otero & Portela

Editors

Pablo E. Otero, MV, PhD Professor Head of the Anesthesiology and Pain Management Department Facultad de Ciencias Veterinarias Universidad de Buenos Aires Buenos Aires, Argentina [email protected]

Diego A. Portela, MV, PhD, DACVAA Assistant Professor, Anesthesiology and Pain Management Department of Comparative, Diagnostic, and Population Medicine College of Veterinary Medicine University of Florida, Gainesville (FL), USA [email protected]

Associate Editors Santiago E. Fuensalida, MV Department of Anesthesiology and Pain Management Facultad de Ciencias Veterinarias, Universidad de Buenos Aires Buenos Aires, Argentina

Marta Romano, DVM, MSc, PhD, DACVAA Clinical Assistant Professor, Anesthesiology and Pain Management. Department of Comparative, Diagnostic and Population Medicine College of Veterinary Medicine University of Florida, Gainesville (FL), USA v

Regional Anesthesia

Contributors Annatasha Bartel, BScH, BVM&S, MRCVS, DACVAA Head of Anesthesia and Analgesia Toronto Veterinary Emergency and Referral Hospital Toronto, Canada Angela Briganti, DVM, PhD Assistant Professor, Anesthesia Department Chairman of the Emergency and Intensive Care Unit Veterinary Teaching Hospital “Mario Modenato” Veterinary Science Department, University of Pisa Pisa, Italy

Natali Verdier, Vet Department of Anesthesiology and Pain Management, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires. Buenos Aires, Argentina Klinische Abteilung für Anästhesiologie und perioperative Intensivmedizin, Department für Kleintiere und Pferde, Veterinärmedizinische Universität Wien. Vienna, Austria Jaime Viscasillas Monteagudo, Ldo Vet, DECVAA The Royal Veterinary College University of London, UK

Paulo R. Klaumann, MV, MS, PhD Chairman of the Anesthesia and Pain Management Department Clinivet Veterinary Hospital Curitiba, Paraná, Brazil

Andrea S. Zaccagnini, MV Department of Anesthesiology and Pain Management Facultad de Ciencias Veterinarias, Universidad de Buenos Aires Buenos Aires, Argentina

Robert A. Menzies, BVSc, DAVDC, DEVDC University of Veterinary Medicine, Vienna Veterinaerplatz 1. A-1210 Vienna. Austria

Maja Drozdzynska, DVM, MVetMed, Dip.ECVAA, MRCVS DWR Staff. Consultant, Anaesthesia and Analgesia

Scientific Committee Francisco Ginés Laredo Álvarez, Ldo Vet, PhD, Cert. VA, MRCVS University Professor in Veterinary Anesthesiology Department of Medicine and Animal Surgery Faculty of Veterinary Medicine, University of Murcia, Spain Luis Campoy, Ldo Vet, Cert. VA, DECVAA, MRCVS Department of Clinical Science, Faculty of Veterinary Medicine, Cornell University, Ithaca, New York, USA

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Fernando Garcia-Pereira DVM, MS, DACVAA Department of Clinical Science in Large Animals College of Veterinary Medicine, University of Florida, Gainesville, USA Fernando Martínez Taboada, Ldo Vet, CertVA, PGCert (Biostats), DECVAA, MRCVS Faculty of Veterinary Medicine, University of Sydney, Australia

Otero & Portela

Content Section 1 | Regional Anesthesia. General Considerations ....................1 Pablo E. Otero, Paulo R. Klaumann, Marta Romano, Annatasha Bartel and Diego A. Portela

Chapter 1 | Nerve blocks .................................................................................................................3 Chapter 2 | Nerve localization techniques .......................................................................................13 Chapter 3 | Needles for neuraxial and peripheral nerve blocks .........................................................37

Section 2 | Peripheral nerve blocks of the thoracic limb ..........................47 Pablo E. Otero, Santiago E. Fuensalida, Natali Verdier, Marta Romano and Diego A. Portela

Chapter 4 | Introduction ...............................................................................................................49 Chapter 5 | Paravertebral block of the brachial plexus .....................................................................53 Chapter 6 | Subscalenic block of the brachial plexus .......................................................................71 Chapter 7 | Axillary approach to the brachial plexus .......................................................................77 Chapter 8 | Distal block of the brachial plexus (proximal RUMM block)..........................................90 Chapter 9 | Distal block of the brachial plexus (distal RUMM block) ............................................102 Chapter 10 | Distal block of the thoracic limb (proximal RUM block)............................................118 Chapter 11 | Block of the cutaneous branches of the intercostobrachial nerves II and III .................131

Section 3 | Peripheral nerve blocks of the pelvic limb............................135 Diego A. Portela, Santiago E. Fuensalida, Natali Verdier, Marta Romano and Pablo E. Otero

Chapter 12 | Introduction ...........................................................................................................137 Chapter 13 | Femoral nerve block: paravertebral approach.............................................................143 Chapter 14 | Femoral nerve block: lateral pre-iliac approach..........................................................148 Chapter 15 | Block of the femoral-saphenous nerve complex through an inguinal approach ..............157 Chapter 16 | Block of the saphenous and medial articular nerves: proximal and distal medial approach .......166 Chapter 17 | Lumbosacral trunk block: parasacral approach ..........................................................178 Chapter 18 | Sciatic nerve block ..................................................................................................187 Chapter 19 | Tibial and common fibular nerves block: distal approach in the popliteal fossa ............197 Chapter 20 | Obturator nerve block .............................................................................................204 Chapter 21 | Block of the lateral cutaneous femoral nerve ..............................................................209 Chapter 22 | Selective block of the caudal cutaneous femoral nerve .................................................213 Chapter 23 | Genitofemoral nerve block .......................................................................................216 ix

Regional Anesthesia

Section 4 | Peripheral nerve blocks of the thorax and abdomen ......219 Diego A. Portela, Santiago E. Fuensalida, Jaime Viscasillas, Natali Verdier and Pablo E. Otero

Chapter 24 | Peripheral nerve blocks of the thorax and abdomen....................................................221 Chapter 25 | Thoracic paravertebral block ....................................................................................224 Chapter 26 | Intercostal nerves block ............................................................................................236 Chapter 27 | Serratus plane block ...............................................................................................242 Chapter 28 | Erector spinae plane block ........................................................................................248 Chapter 29 | Transversus abdominis plane block ...........................................................................254 Chapter 30 | Quadratus lumborum block .....................................................................................262 Chapter 31 | Tumescent local anesthesia .......................................................................................269

Section 5 | Neuraxial blocks ............................................................273 Pablo E. Otero, Santiago E. Fuensalida, Annatasha Bartel and Diego A. Portela

Chapter 32 | Neuraxial blocks .....................................................................................................275 Chapter 33 | Approach to the epidural space ................................................................................279 Chapter 34 | Approach to the subarachnoid space ..........................................................................304

Section 6 | Perineural anesthesia of the head, eye and ear......................313 Paulo R. Klaumann, Robert A. Menzies, Angela Briganti, Diego A. Portela and Pablo E. Otero

Chapter 35 | Nerve blocks of the head ..........................................................................................315 Chapter 36 | Nerve blocks of the upper jaw ..................................................................................319 Chapter 37 | Block of the infraorbital nerve..................................................................................326 Chapter 38 | Nerve blocks of the lower jaw ...................................................................................331 Chapter 39 | Block of the trigeminal nerve via a temporal approach ...............................................338 Chapter 40 | Ophthalmic nerve blocks .........................................................................................342 Chapter 41 | Block of the ophthalmic nerve via a US-guided posterior extraconal approach .............348 Chapter 42 | Anesthesia of the eye: extraconal nerve block ..............................................................352 Chapter 43 | Anesthesia of the eye: intraconal nerve block ..............................................................359 Chapter 44 | Nerve blocks of the auricular region..........................................................................367

Section 7 | Atlas of regional blocks in cats and rabbits ..........................375 Santiago E. Fuensalida, Andrea S. Zaccagnini, Natali Verdier, Diego A. Portela and Pablo E. Otero

Chapter 45 | Regional anesthesia in the cat...................................................................................377 Chapter 46 | Regional anesthesia in the rabbit ..............................................................................407 x

SECTION 1 Regional Anesthesia General Considerations Pablo E. Otero, Paulo R. Klaumann, Marta Romano, Annatasha Bartel and Diego A. Portela

SECTION 1 | Regional Anesthesia

Regional Anesthesia | Otero & Portela

Figure 2-4: Nerve stimulator and the electrodes: anode (red) and cathode (black).

Figure 2-5: Insulated needle used for nerve stimulation. Note the Luer lock adapter used for attachment of the syringe and the cathode cable that connects to the NS.

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2 | Nerve localization techniques Aspirate before injection to verify extravascular placement of the tip of the needle Inject the calculated volume § Injection should be immediately stopped if resistance is detected and the needle should be slightly withdrawn before resuming the injection. A high resistance to injection may indicate intraneural needle placement, which can lead to iatrogenic neuropraxis. There are devices specifically designed to measure the pressure achieved during injection and that may contribute to avoiding intraneural injections (Fig. 2-8)

COMMENT Leaving an air bubble between the syringe plunger and the injectate solution may help assess the position of the tip of the needle. If the size of the air bubble is reduced ≥ 50% during the injection, this indicates that the injection pressure is excessive and that the tip of the needle may be inside the nerve. Administration of the injectate should be immediately discontinued and the tip of the needle repositioned slightly before administering the remainder of the solution (Fig. 2-9).

Figure 2-8: Injection pressure measurement device (BSmart, Concert Medical, USA).

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The elicited muscular response will abate as the local anesthetic is injected. The injected solution alters the electrical circuit thereby preventing depolarization of the nerve Slowly inject the calculated volume § The injection should not elicit a nociceptive response, i.e. increased heart rate, respiratory rate, and/or arterial blood pressure. If any of these sings are observed, stop injecting, withdraw the needle and reposition it before completing the injection Once the block has been performed, the patient should be monitored closely for early detection of any adverse effects

3 | Needles for neuraxial and peripheral nerve blocks

Figure 3-4: Tuohy needle’s bevel. The arrows indicate the edge of the bevel.

B


A

Figure 3-5: Weiss epidural needle (A) and Tuohy epidural needle (B). Note that both needles have their shaft marked in centimeters. The color coding of these needles is the same used for other needle types.

KEY CONCEPT The epidural needle should be at least 2G bigger than the catheter used.

Nerve stimulation needles Nerve stimulation needles are attached to a cable that is connected to the negative pole (cathode) of the NS and to an extension line that should be prefilled with the anesthetic injectate. The needle shaft has markings along its length and is covered by an insulating coating with the exception of the needle tip (Fig. 3-7). The aim of the insulation is to channel the electrical current towards the tip of the needle so that the nerve can only be depolarized by the 41

SECTION 2 Peripheral nerve blocks of the thoracic limb Pablo E. Otero, Santiago E. Fuensalida, Natali Verdier, Marta Romano and Diego A. Portela

7 | Axillary approach to the brachial plexus

Figure 7-9: Schematic view of the anatomical landmarks to perform a brachial plexus block using an axillary approach.

SECTION 2 | Peripheral nerve blocks of the thoracic limb

Figure 7-10: Nerve stimulator-assisted brachial plexus block using an axillary approach. The needle is inserted cranially to the acromion and advanced in a ventral and caudal direction, parallel to the longitudinal axis of the vertebral column. The angle of needle insertion should be 20-30º relative to the surface on which the animal is positioned. The needle is advanced through the belly of the brachiocephalicus muscle, medially to the subscapularis muscle, and parallel to the thoracic wall.

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SP

Superficial pectoral muscle

BB

Biceps brachii muscle

B BC

Brachiocephalicus muscle

TB(LO)

Triceps brachii muscle (long head)

TB(LA)

Triceps brachii muscle (lateral head)

TB(AC)

Triceps brachii muscle (accesory head)

TB(M) H


Brachial muscle

Triceps brachii muscle (medial head) Humerus

BA

Brachial artery

BV

Brachial vein

MC

Musculocutaneous nerve

R

Radial nerve

M

Median nerve

U

Ulnar nerve

Figure 9-3: Transverse view of the forelimb at the middle third of the brachium.

SP

Superficial pectoral muscle

BB

Biceps brachii muscle

B BC

Brachial muscle Brachiocephalicus muscle

TB(LO)

Triceps brachii muscle (long head)

TB(LA)

Triceps brachii muscle (lateral head)

TB(AC)

Triceps brachii muscle (accesory head)

TB(M) H

Triceps brachii muscle (medial head) Humerus

BA

Brachial artery

BV

Brachial vein

MC

Musculocutaneous nerve

R

Radial nerve

M

Median nerve

U

Ulnar nerve

Figure 9-4: Schematic representation of the structures observed in Figure 9-3.

Indications Surgical procedures of the: § Antebrachium § Carpus § Pes 104



Figure 9-6: Dog positioned for the block of the radial nerve on the lateral aspect of the brachium.

Figure 9-7: Dog positioned for the block of the musculocutaneous, median, and ulnar nerves on the medial aspect of the brachium.

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SECTION 3 Peripheral nerve blocks of the pelvic limb Diego A. Portela, Santiago E. Fuensalida, Natali Verdier, Marta Romano and Pablo E. Otero


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SECTION 3 | Peripheral nerve blocks of the pelvic limb

Femoral nerve block: lateral pre-iliac approach The lateral pre-iliac approach aims to block the femoral nerve in the abdominal portion of the psoas compartment. Once injected in this location, the local anesthetic solution can spread cranially and caudally, which may affect the rest of the branches forming the lumbar plexus. If a large enough volume is injected, the obturator nerve, which innervates the hip and the stifle joints, may also be blocked.

COMMENT To desensitize the craniolateral aspect of the thigh and knee, the femoral cutaneous nerve should also be blocked (see Chapter 21). KEY CONCEPT Depending on the duration of the local anesthetic chosen, this technique may cause profound motor block. Flexion of the hip and extension of the stifle will be impaired following this block. In large dogs, the lack of proprioception and muscle weakness may result in complications and injury, therefore, special care including potential sedation, protective bandaging, and sling-walking should be undertaken until normal motor function is regained.

Review of the anatomy The ventral branches of the lumbar spinal nerves join together in the psoas muscle and form the lumbar plexus (Figs. 14-1 and 14-2). The femoral nerve runs in a ventrolateral direction within the intraabdominal portion of the psoas compartment, sometimes alongside the obturator nerve.

COMMENT Due to the lack of a fascia between the muscles and the nerves at this site, it is very likely that the injected local anesthetic will reach the perineural space. For this reason, this block is usually very effective.

Indications The block of the femoral nerve with this approach is indicated for surgical procedures involving: Hip joint Femur Thigh Stifle Pelvic limb amputations 148

14 | Femoral nerve block: lateral pre-iliac approach

SONOANATOMY

Sonoanatomy of the psoas compartment The external iliac artery is an important and easily identifiable landmark. It appears as an anechoic, circular, and pulsatile structure located in the ventromedial quadrant of the image screen. The iliac fascia is identified as a hyperechoic line that lies dorsal to the external iliac artery and ventrally to the psoas major muscle, with the latter being located ventrally to the vertebral body. The vertebral body is seen as a hyperechoic line producing an acoustic shadow. The quadratus lumborum muscle can be identified in the dorsolateral quadrant. The femoral nerve is located within the belly of the psoas major muscle and it appears as a round, hypoechoic structure surrounded by a hyperechoic rim (Figs. 14-10 and 14-11). The position of the femoral nerve within the psoas compartment varies depending on the position of the transducer. The more cranial the transducer is positioned, the more dorsal the femoral nerve will be visualized. As the transducer is moved caudally, the nerve is identified in the caudoventral quadrant of the iliopsoas muscle (Fig. 14-2). The abdominal wall and the iliac fascia can also be identified; the deep abdominal fascia, peritoneum, retroperitoneal space, and the iliac vessels are located between them.

F EIA

Femoral nerve External iliac artery

Figure 14-10: Ultrasound image of the sublumbar region at the level of L7 and at a depth of 2.7 cm, obtained with a 13 MHz linear transducer placed on the abdominal wall, oriented perpendicularly to the long axis of the spine. The compass indicates the transducer orientation (L: lateral; M: medial; Cr: cranial; Cd: caudal).

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SECTION 3 | Peripheral nerve blocks of the pelvic limb

Figure 14-9: Ultrasound-guided femoral nerve block through a lateral pre-iliac approach. The needle is introduced in-plane in a medial direction. The box shows the ultrasound visualization of the femoral nerve as the needle is advanced through the sublumbar muscles.

SECTION 4 Peripheral nerve blocks of the thorax and abdomen Diego A. Portela, Santiago E. Fuensalida, Jaime Viscasillas, Natali Verdier and Pablo E. Otero

25 | Thoracic paravertebral block Once a clear image of the paravertebral space and its components is obtained, rotate the transducer slightly at an oblique angle until the caudal border of the transducer lies over the caudal rib of the target space, facilitating introduction of the needle (Fig. 25-6) Introduce the needle in-plane from the caudal border of the transducer with a caudodorsal to cranioventral orientation The needle is advanced through the epaxial muscle, the levatores costorum, the external intercostal muscle, and finally the internal intercostal membrane § The needle runs between two consecutive transverse processes (parasagittal approach) or between a rib and a transverse process (oblique approach) Stop needle advancement immediately after puncturing the internal intercostal membrane § A subtle ‘pop’ may be felt when the needle pierces this membrane (Fig. 25-9) Confirm that the tip of the needle is not intravascular or intrathoracic Slowly inject the local anesthetic into the space between the parietal pleura and the internal intercostal membrane (Fig. 25-10) Repeat this technique for every paravertebral space to be blocked

COMMENT

KEY CONCEPT The injection of local anesthetic in the thoracic paravertebral space produces ventral displacement of the parietal pleura, which is used as a confirmation sign of an accurate injection.

Figure 25-6: Ultrasound-guided thoracic paravertebral block. The probe is placed in an oblique parasagittal plane to visualize the transverse process cranially and the rib caudally. Note the transducer orientation and the direction of the needle.

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SECTION 4 | Peripheral nerve blocks of the thorax and abdomen

The authors recommend blocking the spinal nerve corresponding to the target paravertebral space and that of one to two spaces cranial and caudal to the area of interest.

26 | Intercostal nerves block Landmarks and injection site Landmarks (Fig. 26-4) § Caudal border of the rib § Target intercostal space(s) Injection site § Intercostal space corresponding to the target nerve. Injection can occur at any level between the proximal and middle thirds of the rib.

Ultrasound transducer positioning and block technique Apply the sterile cover to the transducer and adjust the reading depth to 1.5 – 3 cm depending on the size of the animal Adjust the ultrasound gain and apply sterile gel or alcohol to enhance acoustic coupling Identify the target intercostal spaces § Identify the desired intercostal space by counting from the last rib either manually or using the ultrasound probe The ultrasound scan should be performed over the proximal third of the rib, ideally close to the angle of the rib Center the target intercostal space in the middle of the ultrasound screen Introduce the needle in-plane at the caudal border of the transducer and advance it through the intercostal muscles in a cranial direction until the tip is located just above the parietal pleura (Fig. 26-5) Confirm that the tip of the needle is not in an intravascular or intrathoracic location Slowly inject the local anesthetic in the space between the parietal pleura and the internal intercostal muscle Repeat this technique for every intercostal space to be blocked 239

SECTION 4 | Peripheral nerve blocks of the thorax and abdomen

Figure 26-4: Ultrasound-guided intercostal nerve block. The transducer is positioned transversally to the ribs. The needle is introduced from the caudal aspect of the transducer and advanced towards the target nerve, which is located between the parietal pleura and the internal intercostal muscle.

SECTION 5 Neuraxial blocks Pablo E. Otero, Santiago E. Fuensalida, Annatasha Bartel and Diego A. Portela

33 | Approach to the epidural space

Figure 33-12: Transverse ultrasound image of the spine at the lumbosacral level obtained by submerging a skeleton in a bucket of water.

Ultrasound images of the spine at the lumbosacral level obtained with the transducer positioned in a transverse orientation (Fig. 33-13)

SECTION 5 | Neuraxial blocks

Figure 33-13: Transverse ultrasound image of the spine at the lumbosacral level obtained with a linear transducer. The compass indicates orientation of the transducer (D: dorsal; V: ventral; R: right; L: left). The box shows an anatomic dissection of the same structures.

Ultrasound images of the lumbar region at the level of L6-7, transverse view (Figs. 33-14 and 33-15)

Figure 33-14: Transverse ultrasound image of the spine at the lumbosacral level obtained with a linear transducer. The compass indicates the orientation of the transducer (D: dorsal; V: ventral; R: right; L: left).

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SECTION 6 Perineural anesthesia of the head, eye and ear Paulo R. Klaumann, Robert A. Menzies, Angela Briganti, Diego A. Portela and Pablo E. Otero


SECTION 6 | Perineural anesthesia of the head, eye and ear

Approaches to the nerve blocks of the head, eye and ear canal The subsequent chapters will describe the following nerve blocks (Fig. 35-2): Nerve blocks of the upper jaw § Nerve blocks of the maxillary branch of the trigeminal nerve (cranial nerve V) w Subzygomatic (lateral) approach guided by anatomic references w Ultrasound-guided subzygomatic approach w Infraorbital canal catheterization approach w Intraoral approach § Nerve blocks of the infraorbital nerve w Nerve block guided by anatomic references w Ultrasound-guided nerve block Nerve blocks of the lower jaw § Nerve blocks of the inferior alveolar nerve, a continuation of the mandibular branch of the trigeminal nerve (cranial nerve V) w Intraoral nerve block guided by anatomic references w Extraoral nerve block guided by anatomic references w Nerve stimulation-guided retromandibular approach § Nerve block of the mental nerve, guided by anatomic references Nerve blocks of the eye § Nerve block of the ophthalmic branch of the trigeminal nerve § Ultrasound-guided extraconal nerve block (periconal or peribulbar) § Ultrasound-guided intraconal nerve block Blockade of the trigeminal nerve § Ultrasound-guided temporal approach Nerve block of the ear canal and external ear § Ultrasound-guided auriculotemporal and caudal auricular nerve blocks § Ultrasound-guided greater auricular nerve block

Figure 35-2: Nerve blocks of the head, eye and ear canal in the dog.

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SECTION 7 Atlas of regional anesthesia in cats and rabbits Santiago E. Fuensalida, Andrea S. Zaccagnini, Natali Verdier, Diego A. Portela and Pablo E. Otero

45 | Regional anesthesia in the cat

Figure 45-12: Ultrasound scan of the brachial plexus (lateral view) performed with the transducer placed at the level of the proximal epiphysis of the humerus. Color Doppler mode allows to identify the brachial artery (BA) and vein (BV).

SECTION 7 | Atlas of regional anesthesia in cats and rabbits

Block of the nerves of the thorax Thoracic paravertebral block 1

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2 Figure 45-13: Nerve stimulation-guided thoracic paraverterbal block. The cat is placed in sternal recumbency. 1) The needle is introduced perpendicular to the skin and advanced until it contacts the transverse process. 2) The needle is withdrawn until its tip is in the subcutaneous tissue and the distance from skin to transverse process is measured. 3) The needle is angled cranially towards the intertransverse space and advanced until contraction of the intercostal muscles is elicited.

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46 | Regional anesthesia in the rabbit Block of the ischiatic nerve through a proximal lateral approach

Figure 46-45: Nerve stimulation-guided ischiatic nerve block through a proximal lateral approach. The rabbit is positioned in lateral recumbency. Reference points: IT: Ischiatic tuberosity; GT: Greater trochanter of femur. The needle is introduced perpendicular to the skin and caudal to the greater trochanter of the femur.

SECTION 7 | Atlas of regional anesthesia in cats and rabbits

Block of the ischiatic nerve through a medium lateral approach

Figure 46-46: Ultrasound-guided ischiatic nerve block through a medium lateral approach. The transducer is placed on the lateral aspect of the thigh, at the level of its proximal third. The needle is introduced ‘in-plane’ and advanced in a cranial direction through the belly of the semitendinosus muscle. In the box, the acoustic window to see the nerve complex and the needle in close proximity to the common epineural sheath.

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