Ultrasound-Guided Peripheral Nerve Blocks

The opioid epidemic has led ED providers to investigate effective opioid-sparing pain management strategies.

The provision of ultrasound-guided nerve blocks (UGNBs) is endorsed by the American College of Emergency Physicians

(ACEP) as a core skill for emergency physicians and a core component of a multimodal pain pathway.1

Current literature supports the use of UGNBs as part of "pre-procedural pain management for orthopedic

reductions/splinting, complex laceration repair, abscess incision and drainage, or acute on chronic pain conditions".1

Ultrasound guidance has been shown to reduce time to nerve block onset and improve the quality of peripheral nerve

blocks when compared to other techniques.2

UGNBs have been associated with improved post-surgical functional outcomes, decreased delirium, and decreased

length of stay. 2

General Contraindications for Peripheral Nerve Blocks3

Infection at site of injection

Non-responsive/non-verbal patient

Hardware at or near planned injection site

Pre-existing nerve injury or peripheral neuropathy

Concern for development of compartment syndrome at the site of injury

Allergies to local anesthetics

Crush injury at or near the site of injection

Potential Complications of Peripheral Nerve Blocks3

Local anesthetic toxicity

Nerve injury

Ecchymosis

Hematomas

MOA

Anesthetics bind to sodium channels on nerve cells and prevent subsequent depolarization and further

nerve impulse conduction until the anesthetic is displaced from the neuronal membrane

Agents

Lidocaine

Lidocaine w/ epi

Bupivacaine

Ropivacaine

Mepivacaine

Max Dose (NTE)

7 mg/kg (500 mg)

2 mg/kg (175 mg)

3 mg/kg (300 mg)

4 mg/kg (300 mg)

*Dose will vary with block location due to differences in vascularity, size of the nerve, and the duration of anesthesia required

Onset

4-7 min

4-7 min

~20 min

~15 min

~10 min

Duration of

Analgesia

~2 hours

~3-4 hours

~6-8 hours

~6-8 hours

~2-3 hours

Admin

Risks

hemodynamic collapse, widened PR interval, QRS prolongation, VT, VF, hypotension, asystole

Britany Byrkit & [email protected]

Author,

year

Design & Sample

Size

Patient Population

Intervention & Comparison

Outcome

Beaudoin

et al.,

20135

Randomized

controlled trial

(N=36)

Adults >=55 yrs w/

confirmed hip

fractures AND pain

score >=5

femoral nerve block w/

25 mL bupivacaine 0.5% +

morphine

morphine

min and at 4 hours vs SC group (4 [0-

10] vs 8 [6 -10])

opioids than the SC group (0 mg [0-6

mg] vs 5 mg [0-21 mg])

Bhoi et al.,

20126

Prospective

observational

feasibility study

(N=50)

Patients >=5 yrs

requiring

analgesia for

acute limb

emergencies

Brachial plexus block: 3-5

mg/kg lidocaine 2%

UGNBs have the potential to improve pain control, reduce opioid use, and improve patient outcomes.

The choice of local anesthetic should be based on the site of the block and the desired duration of analgesia.

There is currently inconclusive evidence for or against the benefits and risks of combining vasoconstrictors with local

anesthetics to alter onset and duration of analgesia.

Self-Test Questions

Which of the following are potential complications of a fascia iliaca block?

a.

Hematoma formation

b.

Intravascular injection

c.

Nerve injury

d.

Local anesthetic systemic toxicity (LAST)

e.

All of the above

American College of Emergency Physicians. Ultrasound-Guided Nerve Blocks.; 2021. doi:10.1111/j.1553

Liu SS. Evidence Basis for Ultrasound-Guided Block Characteristics Onset, Quality, and Duration. Reg Anesth Pain Med. 2016;41:205-220.

doi:10.1097/AAP.0000000000000141

Amini R, Kartchner JZ, Nagdev A, Adhikari S. Ultrasound-guided nerve blocks in emergency medicine practice. J Ultrasound Med.

2016;35(4):731-736. doi:10.7863/ultra.15.05095

Lexicomp Online, Ohio: UpToDate, Inc.; 2013; May 12, 2021.

Beaudoin FL, Haran JP, Liebmann O. A comparison of ultrasound-guided three-in-one femoral nerve block versus parenteral opioids alone

for analgesia in emergency department patients with hip fractures: A randomized controlled trial. Acad Emerg Med. 2013;20(6):584-591.

doi:10.1111/acem.12154

Bhoi S, Sinha TP, Rodha M, Bhasin A, Ramchandani R, Galwankar S. Feasibility and safety of ultrasound-guided nerve block for

management of limb injuries by emergency care physicians. J Emergencies, Trauma Shock. 2012;5(1):28-32. doi:10.4103/0974-2700.93107

Mori T, Nomura O, Ihara T. Ultrasound-guided peripheral forearm nerve block for digit fractures in a pediatric emergency department ☆.

Am J Emerg Med. 2019;37:489-493. doi:10.1016/j.ajem.2018.11.033

Cisewski DH, Alerhand S. "SCALD-ED" BLOCK: SUPERFICIAL CUTANEOUS ANESTHESIA IN A LATERAL LEG DISTRIBUTION WITHIN THE EMERGENCY

DEPARTMENT-A CASE SERIES. J Emerg Med. 2019;56(3):282-287. doi:10.1016/j.jemermed.2018.12.005

Barton DJ, Marino RT, Pizon AF. Multimodal analgesia in crotalid snakebite envenomation: A novel use of femoral nerve block. Am J Emerg

Med. 2018;36:2340.e1-2340.e2. doi:10.1016/j.ajem.2018.09.020

Blaivas M, Adhikari S, Lander L. A prospective comparison of procedural sedation and ultrasound-guided interscalene nerve block for

shoulder reduction in the emergency department. Acad Emerg Med. 2011;18(9):922-927. doi:10.1111/j.1553-2712.2011.01140.x

Answer Key

E

C

D

B

C