The Nurse’s Guide to Peripheral Nerve Blocks

On mobile? Review peripheral nerve blocks in episode 387 from your favorite podcast player here.

What is a peripheral nerve block?

A peripheral nerve block (PNB) is a type of regional anesthesia that provides pain relief at specific areas of the body. As a cornerstone of surgical care, PNBs have a lot of advantages: 

• Reduced need for opioid medications both during and after surgery.
• Reduced need for sedation during surgery, which enables the anesthesiologist to utilize a type of anesthesia called MAC (monitored anesthesia care). In procedures utilizing MAC, the patient is able to breathe on their own and the patient does not have to be intubated, though a laryngeal mask airway (LMA) may be used to maintain airway patency. Note that MAC is not always used when a PNB is utilized, but the use of a peripheral nerve block means MAC is an option for anesthesia.
• Avoidance of general anesthesia in pregnant patients, those who are at high risk for respiratory depression (ex: OSA, pulmonary disease or advanced age), and in patients who have a fear of being anesthetized.
• Decreased incidence of post-operative nausea and vomiting, which is often related to opioid administration.
• Better pain management in individuals who wish to avoid systemic medications or who are less responsive to oral medications (such as those with malabsorption disorders).
• Decreased risk for post-operative sedation (since less opioid medication is utilized).
• Promotes early ambulation, improved recovery times, and faster discharge..

How do peripheral nerve blocks work?

Peripheral nerve blocks work by preventing pain stimuli at the location of injury from reaching the central nervous system. The medication is instilled near specific peripheral nerves or nerve plexuses. The block affects nerve fibers in the following order: sensory, then motor, then sympathetic. However, as the block is resolving, the motor function returns first, followed by sensory function, then sympathetic function. This is important to understand as it helps the patient know what to expect as they are recovering from surgery. 

When is a peripheral nerve block utilized?

Peripheral nerve blocks are utilized in a wide variety of situations. 

They are avoided or contraindicated in cases where there is infection at the site of injection, the patient has an existing neural deficit in the area where the block would be utilized, and in some cases of coagulopathy where a deep block is injected into a non-compressible anatomical location. 

Surgical procedures where a PNB may be utilized either during or after the procedure (or both) include surgeries of the periphery, such as:

• Femoral nerve block for knee surgeries (replacement, arthroscopy, meniscus repair, etc…). Note that because a femoral nerve block causes quadricep weakness, you may actually see a different type of block utilized called an adductor canal block. This is a type of interfascial plane block that doesn’t weaken the quadriceps as drastically so the patient can have earlier ambulation and faster discharge.
• Axillary block for surgeries of the wrist or hand such as carpal tunnel release or a fracture repair. 
• Popliteal block for foot or ankle surgery.
• Interscalen block or brachial plexus block for surgeries of the shoulder or arm.
• And many, many more!

How are peripheral nerve blocks administered?

Peripheral nerve blocks can be administered as single injections (often called a “single shot”) or as a continuous or intermittent infusion. When a continuous or intermittent infusion is utilized, the anesthesiologist inserts a catheter much like an IV catheter and the medication is instilled via a portable pump or pressurized system. 

One example of a portable pump is the Ambit pump. This battery-powered device can be programmed to deliver a continuous infusion, intermittent boluses, on-demand boluses, or combinations of these delivery modalities. In contrast, a pressure-based system does not use a battery-powered pump. Instead it involves the use of an elastomeric pump that essentially looks like a ball. Delivery modality depends on which specific elastomeric pump is chosen. Options include a steady flow of medication at a set rate, a steady flow of medication that can be adjusted based on pain level, and a combination of adjustable flow rate with on-demand boluses as needed.

What medications are used in peripheral nerve blocks?

Peripheral nerve blocks utilize local anesthetics, which block nerve impulses so that pain signals aren’t transmitted to the brain. The result is that the anesthetized area is numb and pain is controlled. A key way to know if a medication is a local anesthetic is that it ends in the suffix -caine. The most common local anesthetics utilized in PNBs are ropivacaine and bupivacaine, though you could see lidocaine utilized when a shorter duration of action is warranted. 

Adjuvant medications may also be administered to help the medication act more quickly or prolong the duration of pain control. Adjuvants utilized include:

• Epinephrine – Epinephrine is the most common vasoconstrictor utilized with a PNB. Its vasoconstricting properties help the local anesthetic remain close to the target nerves for a longer period of time, which extends the duration of the block. Another benefit of epinephrine is it helps prevent the local anesthetic from entering systemic circulation and reduces the risk of systemic toxicity.
• Dexamethasone – For some types of PNBs, the corticosteroid dexamethasone can extend the duration of the block. 
• Sodium bicarbonate – This medication is utilized to speed up the onset time of the PNB. 
• Clonidine – This alpha-2 agonist has been shown to prolong the duration of the block but it does cause adverse effects including sedation, hypotension, and bradycardia.

Peripheral nerve block complications

Serious adverse effects from the use of a PNB are uncommon, but can still occur. 

• Infection – Any invasive procedure can cause infection, and the risk is higher when an indwelling catheter is utilized (versus a single bolus injection). 
• Pneumothorax – This can occur in cases where the injection is near the lung such as in a supraclavicular block.
• Hoarse voice, drooping eyelid, vision changes, unequal pupils, facial drooping and mild shortness of breath – These adverse effects can occur when the injection is near the neck. Symptoms resolve once the block effects subside.
• Nerve damage – Permanent nerve damage is an uncommon complication, though some patients can experience prolonged numbness for up to one year following the procedure.
• Bleeding or hematoma – Vascular damage can lead to bleeding and hematoma formation. This is more likely in patients on anticoagulants and is most troublesome when the area is non-compressible such as with a deep block.
• Local anesthetic systemic toxicity (LAST) – This complication can occur when local anesthetics extend into the system at toxic levels. This is most typically due to the medication inadvertently being administered into the vascular space, but it can also be due to overdose of local anesthetic. Learn more about LAST here.

Nursing considerations for peripheral nerve blocks

Though PNBs are highly effective at managing pain and come with an impressive list of benefits over other pain modalities, they still require thorough nursing assessment and appropriate interventions to spot and avoid complications. 

Patient safety – When a limb is unable to feel sensation and/or unable to move, the patient is at higher risk for injury. When the arm is anesthetized ensure the patient wears an arm sling to protect the limb from inadvertent injury and support its position until the medication wears off. In patients who have received a PNB of a lower extremity, your biggest safety concern is a fall. Ensure the patient has adequate sensation and strength before attempting to get the patient out of bed.

Monitor for complications – As with any medication or invasive procedure, it’s important to monitor for complications such as those mentioned above. Early symptoms of LAST include confusion, tinnitus, a metallic taste in the mouth, and numbness/tingling around the mouth. Signs of pneumothorax include shortness of breath, tachypnea, decreased SpO2, and absent lung sounds on the affected side. Should you suspect any serious complication, alert the anesthesiologist immediately.

Monitor for nerve trauma – Sharp pain, especially while the anesthetic is being delivered, could indicate nerve trauma. Notify the anesthesiologist if this occurs.

Pain assessment – Assess your patient’s pain level and quality routinely throughout PNB therapy to ensure adequate coverage. In some cases, the anesthesiologist may be able to provide an additional bolus injection. Oftentimes you will need to supplement the PNB with another analgesic medication such as acetaminophen, ketorolac or an opioid.

Sensation testing – Another key component of PNB assessment is monitoring the patient for numbness and paresthesia (tingling) using light touch. 

Motor function assessment – Monitor for resolution of motor blockade by assessing the patient’s motor function. Remember, as the block is resolving, motor function returns before sensory function. This can give you a heads-up that additional pain management modalities may soon be needed. It’s also important to assess for muscle strength and mobility before assisting the patient out of bed when lower extremity blocks are used.

Key patient education

Patient education regarding a PNB is especially important due to the safety factors involved and the fact that many times patients go home with an infusion pump for prolonged therapy. Key things to include are: 

Duration – How long a nerve block lasts depends on the medication used and the type of block performed. In the case of a single-shot injection, pain control can last up to 12 to 24 hours. Of course, with an infusion pump, pain medication is delivered either continuously or intermittently for a period of two to three days. If you are unsure, it is always helpful to ask the anesthesiologist how long they expect the pain block to last. If pain sensation returns sooner than expected, this is a sign the block has not been fully effective and additional intervention may be warranted. Conversely, ensure the patient understands to contact their physician if the effects of the block last longer than expected.

Administration – Teach the patient that administering the injection or catheter placement takes about 5 to 10 minutes and it is done under ultrasound guidance to ensure the most accurate placement possible. 

Onset – Teach the patient that the local anesthetic should start to have its full effect in 15 to 20 minutes.

Safety – Ensure the patient understands how to avoid injury while the area is under the effects of the block. For example, they should wear an arm sling until they recover full sensation and movement of the affected arm. They should also be especially careful with hot or cold temperatures since they won’t be able to feel either and tissue damage can occur.

Avoid pressure injury – Teach the patient to periodically reposition the affected extremity to avoid pressure injury. Sleeping in a recliner with the arm supported on pillows is also helpful to avoid accidental entrapment and injury.

Infusion pump – Teach the patient to keep their infusion pump in its bag to prevent tangling and kinking of the tubing or accidentally dropping it which can cause the catheter to become dislodged or the tubing to become disconnected. Also teach the patient to notify their physician or call the support phone number provided at discharge if they experience any complications with the pump including leaking or signs of infection.

What to expect – Teach the patient that feelings of numbness, heaviness, tingling, weakness, and inability to move the extremity are normal effects of the block. 

Expected side effects – Teach the patient that some side effects are expected and should not be cause for alarm. For example, with interscalene and supraclavicular blocks the patient can experience hoarseness, unequal pupils, blurred vision, and drooping on one side of the face. These symptoms should resolve once the block wears off. 

When to call the physician – Ensure the patient understands when to call their physician with their concerns. This includes prolonged block effects, significant or prolonged shortness of breath, pain that is not controlled by the block or pain medication, and any other sign of a potential complication such as infection or hematoma.

Tl;DR

Peripheral nerve blocks (PNBs) are regional anesthesia techniques that provide targeted pain relief for various surgeries by injecting local anesthetics near specific nerves or plexuses. Local anesthetics used include ropivacaine and bupivacaine, while adjuvants such as dexamethasone and epinephrine enhance efficacy. Nursing priorities include monitoring for complications, assessing pain, ensuring patient safety, and evaluating both sensory and motor function. Two key benefits of PNBs are that they reduce systemic analgesic use and shorten recovery times.

_____________________________________

The information, including but not limited to, audio, video, text, and graphics contained on this website are for educational purposes only. No content on this website is intended to guide nursing practice and does not supersede any individual healthcare provider’s scope of practice or any nursing school curriculum. Additionally, no content on this website is intended to be a substitute for professional medical advice, diagnosis or treatment.

References:

Avanos Pain Management. (n.d.-a). ambIT Electronic Pain Control System. Avanos Pain Management. https://avanospainmanagement.com/solutions/acute-pain/ambit-pain-control-system/

Avanos Pain Management. (n.d.-b). ON-Q* Pain Relief System. Avanos Pain Management. https://avanospainmanagement.com/solutions/acute-pain/on-q-pain-relief-system/

Chan, E.-Y., Fransen, M., Parker, D., Assam, P., & Chua, N. (2014). Femoral nerve blocks for acute postoperative pain after knee replacement surgery – PMC. The Cochrane Database of Systematic Reviews, 5. https://pmc.ncbi.nlm.nih.gov/articles/PMC7173746/

Chang, A., Dua, A., Singh, K., & White, B. A. (2024). Peripheral Nerve Blocks. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK459210/

Department of Anesthesiology. (n.d.). Common Patient Questions about Nerve Blocks. Washington University School of Medicine in St. Louis. https://anesthesiology.wustl.edu/patient-care/for-patients/common-patient-questions-about-nerve-blocks/

Healthwise Staff. (2023, June 24). Peripheral Nerve Blocks: Care Instructions. Myhealth.Alberta.Ca. https://myhealth.alberta.ca:443/Health/aftercareinformation/pages/conditions.aspx?hwid=acm8395

Hunter, O. O., Kim, T. E., Mariano, E. R., & Harrison, T. K. (2019). Care of the Patient With a Peripheral Nerve Block. Journal of PeriAnesthesia Nursing, 34(1), 16–26. https://doi.org/10.1016/j.jopan.2018.01.006

Jeng, C. L., & Rosenblatt, M. A. (2024). Overview of peripheral nerve blocks. UpToDate. https://www.uptodate.com/contents/overview-of-peripheral-nerve-blocks?search=peripheral%20nerve%20blocks&source=search_result&selectedTitle=1%7E150&usage_type=default&display_rank=1

Jeng, C. L., Torrillo, T. M., & Rosenblatt, M. A. (2010a). Complications of peripheral nerve blocks. British Journal of Anaesthesia, 105, i97–i107. https://doi.org/10.1093/bja/aeq273

Jeng, C. L., Torrillo, T. M., & Rosenblatt, M. A. (2010b). Complications of peripheral nerve blocks. British Journal of Anaesthesia, 105 Suppl 1, i97-107. https://doi.org/10.1093/bja/aeq273

Koscielniak-Nielsen, Z., & Golebiewski, M. (n.d.). Axillary Brachial Plexus Block – Landmarks and Nerve Stimulator Technique – NYSORA. Nysora. https://www.nysora.com/techniques/upper-extremity/axillary-brachial-plexus-block/

Lin, E., Choi, J., & Hadzic, A. (2013). Peripheral nerve blocks for outpatient surgery: evidence-based indications. Current Opinion in Anaesthesiology, 26(4), 467–474. https://doi.org/10.1097/ACO.0b013e328362baa4

McIsaac, D. I., McCartney, C. J. L., & Walraven, C. van. (2017). Peripheral Nerve Blockade for Primary Total Knee Arthroplasty: A Population-based Cohort Study of Outcomes and Resource Utilization. Anesthesiology, 126(2), 312–320. https://doi.org/10.1097/ALN.0000000000001455

Nabhan, A., Ishak, B., Al-Khayat, J., & Steudel, W.-I. (2008). Endoscopic Carpal Tunnel Release using a modified application technique of local anesthesia: safety and effectiveness. Journal of Brachial Plexus and Peripheral Nerve Injury, 3, 11. https://doi.org/10.1186/1749-7221-3-11

Novus Spine & Pain Center. (n.d.). Interscalene Block. Novus Spine & Pain Center. https://novusspinecenter.com/pain-treatments/interscalene-block

Royal College of Anaesthetists. (2020). Nerve blocks for surgery on the shoulder, arm or hand. Royal College of Anaesthetists. https://kingstonhospital.nhs.uk/wp-content/uploads/2020/11/10-NerveBlocks2020web_0.pdf

Saint Luke’s Health System. (n.d.). Understanding Peripheral Nerve Blocks (PNBs). Saint Luke’s Health System. https://www.saintlukeskc.org/health-library/understanding-peripheral-nerve-blocks-pnbs

Salinas, F. V., & Joseph, R. S. (2014). Peripheral nerve blocks for ambulatory surgery. Anesthesiology Clinics, 32(2), 341–355. https://doi.org/10.1016/j.anclin.2014.02.005

Sort, R., Brorson, S., Gögenur, I., Hald, L. L., Nielsen, J. K., Salling, N., Hougaard, S., Foss, N. B., Tengberg, P. T., Klausen, T. W., & Møller, A. M. (2021). Peripheral nerve block anaesthesia and postoperative pain in acute ankle fracture surgery: the AnAnkle randomised trial. British Journal of Anaesthesia, 126(4), 881–888. https://doi.org/10.1016/j.bja.2020.12.037

Last Updated on February 1, 2025 by Maureen Osuna, MSN, RN