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Ultrasound-guided Greater Auricular Nerve Block for Emergency Department Ear Laceration and Ear Abscess Drainage
The Journal of Emergency Medicine, Vol. -, No. -, pp. 1–5, 2015 Copyright Ó 2015 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2015.10.003
Ultrasound in Emergency Medicine
ULTRASOUND-GUIDED GREATER AURICULAR NERVE BLOCK FOR EMERGENCY DEPARTMENT EAR LACERATION AND EAR ABSCESS DRAINAGE Stefan Flores, MD* and Andrew A. Herring, MD*† *Department of Emergency Medicine, Highland Hospital–Alameda Health System, Oakland, California and †Department of Emergency Medicine, University of California, San Francisco, San Francisco, California Corresponding Address: Andrew A. Herring, MD, Department of Emergency Medicine, Highland Hospital—Alameda Heath System, 1411 East 31st Street, Oakland, CA 94602-1018
, Abstract—Background: Adequate emergency department (ED) anesthesia for painful ear conditions, such as ear lacerations or ear abscesses, can be challenging. Much of the sensory innervation of the ear is supplied from the anterior and posterior branches of the greater auricular nerve (GAN). The GAN is a branch of the superficial cervical plexus, which arises from the C2/C3 spinal roots. The GAN innervation includes most of the helix, antihelix, the lobule, and the skin over the mastoid process and parotid gland. Anesthesia of the GAN is commonly performed in emergency medicine as part of a landmark-based ear ‘‘ring’’ block. Recently, a selective ultrasound-guided GAN block has been described. Case Report: We report the first cases of ultrasound-guided greater auricular nerve block (UGANB) successfully performed in the ED as the sole procedural anesthesia for both an ear laceration and abscess drainage. In addition, we review the relevant anatomy and technical details of the procedure. Why Should an Emergency Physician Be Aware of This?: Our cases suggest that UGANB is a potentially effective nerve block for ED management of acute ear pain related to procedures involving the tail of the helix and the lobule, such as ear lacerations or ear abscess incision and drainage. Advantages include real-time visualization of the GAN that may increase block success and the decreased volume of local anesthetic required for a block. Ó 2015 Elsevier Inc.
INTRODUCTION Painful ear conditions, such as ear lacerations and ear abscesses, are common in the emergency department (ED). Ultrasound-guided applications have become more widespread in the ED for regional anesthesia, joint aspirations, and vascular access (1–5). Ultrasound-guided regional nerve blocks allow for increased analgesic success, fewer needle stick attempts, and lower anesthetic volumes vs. landmark-based techniques (1,3–6). Our cases demonstrate a novel approach to ear procedural anesthesia management in the ED using the ultrasoundguided greater auricular nerve block (UGANB). CASE REPORTS Case 1 A 32-year-old man presented to the ED with an auricular laceration that extended from the antihelix to the lobule of the ear (Figure 1A). Case 2
, Keywords—acute pain; analgesia; ear abscess; ear laceration; emergency medicine; nerve block
A 28-year-old man presented to the ED with a right ear lobe abscess (Figure 2A). For pain reduction and procedural analgesia, an UGANB was performed in both cases. Patients were
Reprints are not available from the authors.
RECEIVED: 30 March 2015; FINAL SUBMISSION RECEIVED: 1 September 2015; ACCEPTED: 5 October 2015 1
2
S. Flores and A. A. Herring
Figure 1. (A) A 32 year-old man with a right ear laceration approximately 3 cm in length, involving the outer helix and ear lobe. (B) Probe positioning for the ultrasound-guided greater auricular nerve block (UGANB), using an in-plane posterior approach. (C) Laceration repair of the right ear after placement of the UGANB. (D) Ear laceration repaired after placement of the UGANB.
placed on continuous cardiac monitoring in the left lateral decubitus position with the ultrasound system contralateral to the provider. A high-frequency linear transducer (13-6 MHz; SonoSite M-Turbo, Bothell, WA) was positioned in the transverse plane at the superior pole of the thyroid cartilage (C4 level), at the posterolateral border of the sternocleidomastoid muscle (SCM), midway from mastoid to the clavicle (Figure 1B). By sliding superiorly and inferiorly along the border of the SCM, the GAN is identified as a small hypoechoic structure that wraps around the lateral border of the SCM to join the superficial cervical plexus (Figures 3 and 4A). The skin was cleaned with chlorehexidine. Using a 25-g, 1.5-inch standard hypodermic needle with an in-plane posterior approach, 4 mL of 0.5% bupivacaine was then injected
around the nerve. Aspiration and visualization of accumulation anechoic anesthetic was done to prevent intravenous injection (Figure 4B). Local anesthetic flow was visualized to spread circumferentially around the GAN (Figure 4C). Fifteen minutes after block placement, both patients reported complete reduction of pain. In case 1, the ear was sutured (Figures 1C and 1D). In case 2, the ear was incised and 5 mL of pus was drained (Figures 2B and 2C). Both patients had no complications and tolerated the procedures well. DISCUSSION The primary innervation of the ear derives from the cervical nerve C3 with an irregular contribution from C2.
3
web 4C/FPO
US-guided Greater Auricular Nerve Block
Figure 2. (A) A 28 year-old man with a right ear lobe abscess undergoing dynamic injection with an ultrasound-guided block of the greater auricular nerve. (B) Drainage of ear abscess with notable pus drainage during the procedure. (C) Postincision and drainage of the right ear abscess, with small loop drain placed.
The course of the GAN runs deep to the SCM, winding around the posterior border of the SCM to reach the lateral surface of the muscle. It then ascends toward the auricle to divide into anterior and posterior branches (Figure 5B). The UGANB was recently described for surgical procedures involving the outer ear, mastoid, and mandibular angle (6–11). Here we present the first use of an UGANB in the ED. The UGANB performed was technically uncomplicated and successful in producing adequate anesthesia of the ear lobule and antihelix. The UGANB may increase success rates by directly targeting the nerve in comparison to large volume, landmark-based techniques (7,9).
Figure 3. Survey ultrasound scan of the greater auricular nerve (small hypoechoic structure to the left of the screen) when scanned caudally to cephalad. The levator scapulae muscle (LSM) and sternocleidomastoid muscle (SCM) are labeled for identification.
Thallaj et al. recently described a UGANB in an observational study that used small anesthetic volumes (<1 mL) (11). In their study, the GAN was identified on ultrasound in all 27 volunteers, with successful blockade of the tail of the helix, the antitragus, lobule, and mandibular angle in all cases. Selekler et al. described GAN blockade without ultrasound for red ear syndrome, leading to complete pain reduction for a rare ear condition (10). There are no described major complications from an UGANB; however, sensory blockade distribution patterns have been variably reported and should be considered when the UGANB is used in clinical practice (6,8,11,12). This can be prevented by appropriate patient selection, with use restricted to conditions involving the tail of the helix and lobule (Figure 5A).
4
S. Flores and A. A. Herring
Figure 4. (A) Preinjection identification of the greater auricular nerve (GAN) on ultrasound survey scan. The levator scapulae muscle (LSM) and sternocleidomastoid muscle (SCM) are labeled for identification. (B) Dynamic injection of the GAN with anesthetic and needle tip identification. (C) Postinjection ultrasound image showing the GAN surrounded by local anesthetic.
US-guided Greater Auricular Nerve Block
5
and drainage. Advantages include real-time visualization of the GAN that may increases block success and decreased volume of local anesthetic required for a block. Prospective study of the UGANB is warranted to better determine the utility of this technique for ED management of acute ear pain and procedural anesthesia of the ear. REFERENCES
Figure 5. (A) Relevant anatomy and sensory distribution of the ear: (1) area blocked with the ultrasound-guided greater auricular nerve block, including the lobule and tail of the helix. Other areas less consistently blocked: (2) spine of helix, (3) concha, (4) antihelix, (5) anti-tragus, (6) and tragus. (B) (1) Course of the greater auricular nerve as it exits around the posterolateral border of the sternocleidomastoid muscle (SCM) and runs superficial to the SCM to innervate the inferior portion of the ear (2, shaded). (3) SCM insertion on the clavicle, (4) the sternal notch, and (5) superior pole of the thyroid cartilage (C4 level).
Conditions like auricular hematomas are not appropriate for the UGANB without additional anesthesia. Large anesthetic volumes may cause deeper spread, potentially leading to complications similar to other regional neck blocks, such as Horner’s syndrome (4,13,14). WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS? Our case suggests that the UGANB is a potentially effective nerve block for ED management of acute ear pain related to procedures involving the tail of the helix and the lobule, such as ear lacerations or ear abscess incision
1. Flores S, Herring AA. Ultrasound-guided dorsal penile nerve block for ED paraphimosis reduction. Am J Emerg Med 2015;33: 863.e3–5. 2. Freeman K, Dewitz A, Baker WE. Ultrasound-guided hip arthrocentesis in the ED. Am J Emerg Med 2007;25:80–6. 3. Herring AA, Stone MB, Fischer J, et al. Ultrasound-guided distal popliteal sciatic nerve block for ED anesthesia. Am J Emerg Med 2011;29:697.e3–5. 4. Herring AA, Stone MB, Frenkel O, Chipman A, Nagdev AD. The ultrasound-guided superficial cervical plexus block for anesthesia and analgesia in emergency care settings. Am J Emerg Med 2012; 30:1263–77. 5. Herring AA, Stone MB, Nagdev A. Ultrasound-guided suprascapular nerve block for shoulder reduction and adhesive capsulitis in the ED. Am J Emerg Med 2011;29:963.e1–3. 6. Thallaj A. Ultrasound guidance of uncommon nerve blocks. Saudi J Anaesth 2011;5:392–4. 7. Burtles R. Analgesia for ‘bat ear’ surgery. Ann Royal Coll Surg Engl 1989;71:332. 8. Christ S, Kaviani R, Rindfleisch F, Friederich P. Brief report: identification of the great auricular nerve by ultrasound imaging and transcutaneous nerve stimulation. Anesth Analg 2012;114: 1128–30. 9. Cregg N, Conway F, Casey W. Analgesia after otoplasty: regional nerve blockade vs local anaesthetic infiltration of the ear. Can J Anaesth 1996;43:141–7. 10. Selekler M, Kutlu A, Uc¸ar S, Almac A. Immediate response to greater auricular nerve blockade in red ear syndrome. Cephalalgia 2009;29:478–9. 11. Thallaj A, Marhofer P, Moriggl B, Delvi BM, Kettner SC, Almajed M. Great auricular nerve blockade using high resolution ultrasound: a volunteer study. Anaesthesia 2010;65:836–40. 12. Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat 2002;15:35–7. 13. Alzahrani T, Alnajjar M, Algarni AD, Al-Ahaideb A. Delayed Horner’s syndrome following ultrasound- guided interscalene brachial plexus block. Saudi J Anaesth 2014;8:121–3. 14. Mantuani D, Nagdev A. Sonographic evaluation of a paralyzed hemidiaphragm from ultrasound-guided interscalene brachial plexus nerve block. Am J Emerg Med 2012;30:2099.e5–7.
http://dx.doi.org/10.1016/j.jemermed.2015.10.003
Ultrasound in Emergency Medicine
ULTRASOUND-GUIDED GREATER AURICULAR NERVE BLOCK FOR EMERGENCY DEPARTMENT EAR LACERATION AND EAR ABSCESS DRAINAGE Stefan Flores, MD* and Andrew A. Herring, MD*† *Department of Emergency Medicine, Highland Hospital–Alameda Health System, Oakland, California and †Department of Emergency Medicine, University of California, San Francisco, San Francisco, California Corresponding Address: Andrew A. Herring, MD, Department of Emergency Medicine, Highland Hospital—Alameda Heath System, 1411 East 31st Street, Oakland, CA 94602-1018
, Abstract—Background: Adequate emergency department (ED) anesthesia for painful ear conditions, such as ear lacerations or ear abscesses, can be challenging. Much of the sensory innervation of the ear is supplied from the anterior and posterior branches of the greater auricular nerve (GAN). The GAN is a branch of the superficial cervical plexus, which arises from the C2/C3 spinal roots. The GAN innervation includes most of the helix, antihelix, the lobule, and the skin over the mastoid process and parotid gland. Anesthesia of the GAN is commonly performed in emergency medicine as part of a landmark-based ear ‘‘ring’’ block. Recently, a selective ultrasound-guided GAN block has been described. Case Report: We report the first cases of ultrasound-guided greater auricular nerve block (UGANB) successfully performed in the ED as the sole procedural anesthesia for both an ear laceration and abscess drainage. In addition, we review the relevant anatomy and technical details of the procedure. Why Should an Emergency Physician Be Aware of This?: Our cases suggest that UGANB is a potentially effective nerve block for ED management of acute ear pain related to procedures involving the tail of the helix and the lobule, such as ear lacerations or ear abscess incision and drainage. Advantages include real-time visualization of the GAN that may increase block success and the decreased volume of local anesthetic required for a block. Ó 2015 Elsevier Inc.
INTRODUCTION Painful ear conditions, such as ear lacerations and ear abscesses, are common in the emergency department (ED). Ultrasound-guided applications have become more widespread in the ED for regional anesthesia, joint aspirations, and vascular access (1–5). Ultrasound-guided regional nerve blocks allow for increased analgesic success, fewer needle stick attempts, and lower anesthetic volumes vs. landmark-based techniques (1,3–6). Our cases demonstrate a novel approach to ear procedural anesthesia management in the ED using the ultrasoundguided greater auricular nerve block (UGANB). CASE REPORTS Case 1 A 32-year-old man presented to the ED with an auricular laceration that extended from the antihelix to the lobule of the ear (Figure 1A). Case 2
, Keywords—acute pain; analgesia; ear abscess; ear laceration; emergency medicine; nerve block
A 28-year-old man presented to the ED with a right ear lobe abscess (Figure 2A). For pain reduction and procedural analgesia, an UGANB was performed in both cases. Patients were
Reprints are not available from the authors.
RECEIVED: 30 March 2015; FINAL SUBMISSION RECEIVED: 1 September 2015; ACCEPTED: 5 October 2015 1
2
S. Flores and A. A. Herring
Figure 1. (A) A 32 year-old man with a right ear laceration approximately 3 cm in length, involving the outer helix and ear lobe. (B) Probe positioning for the ultrasound-guided greater auricular nerve block (UGANB), using an in-plane posterior approach. (C) Laceration repair of the right ear after placement of the UGANB. (D) Ear laceration repaired after placement of the UGANB.
placed on continuous cardiac monitoring in the left lateral decubitus position with the ultrasound system contralateral to the provider. A high-frequency linear transducer (13-6 MHz; SonoSite M-Turbo, Bothell, WA) was positioned in the transverse plane at the superior pole of the thyroid cartilage (C4 level), at the posterolateral border of the sternocleidomastoid muscle (SCM), midway from mastoid to the clavicle (Figure 1B). By sliding superiorly and inferiorly along the border of the SCM, the GAN is identified as a small hypoechoic structure that wraps around the lateral border of the SCM to join the superficial cervical plexus (Figures 3 and 4A). The skin was cleaned with chlorehexidine. Using a 25-g, 1.5-inch standard hypodermic needle with an in-plane posterior approach, 4 mL of 0.5% bupivacaine was then injected
around the nerve. Aspiration and visualization of accumulation anechoic anesthetic was done to prevent intravenous injection (Figure 4B). Local anesthetic flow was visualized to spread circumferentially around the GAN (Figure 4C). Fifteen minutes after block placement, both patients reported complete reduction of pain. In case 1, the ear was sutured (Figures 1C and 1D). In case 2, the ear was incised and 5 mL of pus was drained (Figures 2B and 2C). Both patients had no complications and tolerated the procedures well. DISCUSSION The primary innervation of the ear derives from the cervical nerve C3 with an irregular contribution from C2.
3
web 4C/FPO
US-guided Greater Auricular Nerve Block
Figure 2. (A) A 28 year-old man with a right ear lobe abscess undergoing dynamic injection with an ultrasound-guided block of the greater auricular nerve. (B) Drainage of ear abscess with notable pus drainage during the procedure. (C) Postincision and drainage of the right ear abscess, with small loop drain placed.
The course of the GAN runs deep to the SCM, winding around the posterior border of the SCM to reach the lateral surface of the muscle. It then ascends toward the auricle to divide into anterior and posterior branches (Figure 5B). The UGANB was recently described for surgical procedures involving the outer ear, mastoid, and mandibular angle (6–11). Here we present the first use of an UGANB in the ED. The UGANB performed was technically uncomplicated and successful in producing adequate anesthesia of the ear lobule and antihelix. The UGANB may increase success rates by directly targeting the nerve in comparison to large volume, landmark-based techniques (7,9).
Figure 3. Survey ultrasound scan of the greater auricular nerve (small hypoechoic structure to the left of the screen) when scanned caudally to cephalad. The levator scapulae muscle (LSM) and sternocleidomastoid muscle (SCM) are labeled for identification.
Thallaj et al. recently described a UGANB in an observational study that used small anesthetic volumes (<1 mL) (11). In their study, the GAN was identified on ultrasound in all 27 volunteers, with successful blockade of the tail of the helix, the antitragus, lobule, and mandibular angle in all cases. Selekler et al. described GAN blockade without ultrasound for red ear syndrome, leading to complete pain reduction for a rare ear condition (10). There are no described major complications from an UGANB; however, sensory blockade distribution patterns have been variably reported and should be considered when the UGANB is used in clinical practice (6,8,11,12). This can be prevented by appropriate patient selection, with use restricted to conditions involving the tail of the helix and lobule (Figure 5A).
4
S. Flores and A. A. Herring
Figure 4. (A) Preinjection identification of the greater auricular nerve (GAN) on ultrasound survey scan. The levator scapulae muscle (LSM) and sternocleidomastoid muscle (SCM) are labeled for identification. (B) Dynamic injection of the GAN with anesthetic and needle tip identification. (C) Postinjection ultrasound image showing the GAN surrounded by local anesthetic.
US-guided Greater Auricular Nerve Block
5
and drainage. Advantages include real-time visualization of the GAN that may increases block success and decreased volume of local anesthetic required for a block. Prospective study of the UGANB is warranted to better determine the utility of this technique for ED management of acute ear pain and procedural anesthesia of the ear. REFERENCES
Figure 5. (A) Relevant anatomy and sensory distribution of the ear: (1) area blocked with the ultrasound-guided greater auricular nerve block, including the lobule and tail of the helix. Other areas less consistently blocked: (2) spine of helix, (3) concha, (4) antihelix, (5) anti-tragus, (6) and tragus. (B) (1) Course of the greater auricular nerve as it exits around the posterolateral border of the sternocleidomastoid muscle (SCM) and runs superficial to the SCM to innervate the inferior portion of the ear (2, shaded). (3) SCM insertion on the clavicle, (4) the sternal notch, and (5) superior pole of the thyroid cartilage (C4 level).
Conditions like auricular hematomas are not appropriate for the UGANB without additional anesthesia. Large anesthetic volumes may cause deeper spread, potentially leading to complications similar to other regional neck blocks, such as Horner’s syndrome (4,13,14). WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS? Our case suggests that the UGANB is a potentially effective nerve block for ED management of acute ear pain related to procedures involving the tail of the helix and the lobule, such as ear lacerations or ear abscess incision
1. Flores S, Herring AA. Ultrasound-guided dorsal penile nerve block for ED paraphimosis reduction. Am J Emerg Med 2015;33: 863.e3–5. 2. Freeman K, Dewitz A, Baker WE. Ultrasound-guided hip arthrocentesis in the ED. Am J Emerg Med 2007;25:80–6. 3. Herring AA, Stone MB, Fischer J, et al. Ultrasound-guided distal popliteal sciatic nerve block for ED anesthesia. Am J Emerg Med 2011;29:697.e3–5. 4. Herring AA, Stone MB, Frenkel O, Chipman A, Nagdev AD. The ultrasound-guided superficial cervical plexus block for anesthesia and analgesia in emergency care settings. Am J Emerg Med 2012; 30:1263–77. 5. Herring AA, Stone MB, Nagdev A. Ultrasound-guided suprascapular nerve block for shoulder reduction and adhesive capsulitis in the ED. Am J Emerg Med 2011;29:963.e1–3. 6. Thallaj A. Ultrasound guidance of uncommon nerve blocks. Saudi J Anaesth 2011;5:392–4. 7. Burtles R. Analgesia for ‘bat ear’ surgery. Ann Royal Coll Surg Engl 1989;71:332. 8. Christ S, Kaviani R, Rindfleisch F, Friederich P. Brief report: identification of the great auricular nerve by ultrasound imaging and transcutaneous nerve stimulation. Anesth Analg 2012;114: 1128–30. 9. Cregg N, Conway F, Casey W. Analgesia after otoplasty: regional nerve blockade vs local anaesthetic infiltration of the ear. Can J Anaesth 1996;43:141–7. 10. Selekler M, Kutlu A, Uc¸ar S, Almac A. Immediate response to greater auricular nerve blockade in red ear syndrome. Cephalalgia 2009;29:478–9. 11. Thallaj A, Marhofer P, Moriggl B, Delvi BM, Kettner SC, Almajed M. Great auricular nerve blockade using high resolution ultrasound: a volunteer study. Anaesthesia 2010;65:836–40. 12. Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat 2002;15:35–7. 13. Alzahrani T, Alnajjar M, Algarni AD, Al-Ahaideb A. Delayed Horner’s syndrome following ultrasound- guided interscalene brachial plexus block. Saudi J Anaesth 2014;8:121–3. 14. Mantuani D, Nagdev A. Sonographic evaluation of a paralyzed hemidiaphragm from ultrasound-guided interscalene brachial plexus nerve block. Am J Emerg Med 2012;30:2099.e5–7.