Perineural medication is medication that is administered around nerves, often to block sensation in specific areas of the body. This technique has evolved significantly, enhancing pain management in surgical procedures and chronic pain conditions. The growing utilization of perineural medication highlights its effectiveness in providing targeted anesthesia, reducing systemic side effects, and improving patient outcomes.
Perineural medication entails the injection of drugs near peripheral nerves. In the context of anesthesia, the primary goal is to achieve a nerve block, which interrupts pain signals traveling to the brain. This method contrasts with systemic administration, where drugs are delivered through oral or intravenous routes, affecting the entire body. By focusing on specific nerves, perineural anesthesia offers precise control over pain relief 1,2.
Local anesthetics like lidocaine, bupivacaine, and ropivacaine are commonly used in perineural injections for anesthesia. These agents work by inhibiting sodium channels in nerve membranes, preventing the propagation of nerve impulses. The choice of anesthetic depends on the required duration and intensity of the nerve block. For instance, lidocaine provides rapid onset but shorter duration, while bupivacaine offers prolonged action 3,4.
Adjuvants such as epinephrine, clonidine, and dexamethasone are often added to enhance the effects of local anesthetics. Epinephrine, for example, prolongs the duration of anesthesia by causing vasoconstriction, which slows the absorption of the anesthetic. Clonidine and dexamethasone can provide additional analgesic effects and prolong the nerve block 5,6.
Various techniques exist for delivering perineural medication. The simplest method is a single-shot injection, where the drug is administered in one go. Continuous nerve blocks, in contrast, involve placing a catheter near the nerve, allowing for prolonged infusion of anesthetics. Ultrasound guidance has revolutionized the accuracy and safety of these procedures, enabling real-time visualization of nerve structures and needle placement 7.
Perineural medication is widely used in orthopedic, thoracic, and abdominal surgeries to provide anesthesia. Beyond surgical applications, perineural medication plays a vital role in managing chronic pain conditions such as complex regional pain syndrome and neuropathic pain—by targeting specific nerves involved in the pain pathway, clinicians can offer significant relief to patients who have not responded well to conventional treatments 1,8,9.
The benefits of perineural medication in anesthesia are manifold. By providing targeted pain relief, it minimizes the risk of systemic toxicity and side effects associated with oral or intravenous analgesics. This approach also facilitates faster recovery and rehabilitation, as patients experience better pain control and reduced opioid consumption. Challenges remain too, however. Precise needle placement is critical to avoid complications such as nerve injury or intravascular injection. The use of adjuvants, while beneficial, requires careful consideration to prevent adverse effects. In addition, the duration of the nerve block must be managed to ensure it covers the entire postoperative period without leading to prolonged numbness or motor impairment 1,10.
References
1. Continuous Perineural Anesthesia. Available at: https://www.bcm.edu/healthcare/specialties/anesthesia/continuous-perineural-anesthesia.
2. Perineural Drug Administration – an overview | ScienceDirect Topics. Available at: https://www.sciencedirect.com/topics/medicine-and-dentistry/perineural-drug-administration.
3. Eng, H. C., Meela Ghosh, S. & Chin, K. J. Practical use of local anesthetics in regional anesthesia. doi:10.1097/ACO.0000000000000091
4. Knight, B., Walker, J. & Nair, L. S. Perineural local anesthetic treatments for osteoarthritic pain. Regen. Eng. Transl. Med. 7, 262 (2021). doi: 10.1007/s40883-021-00223-0
5. Desai, N., Albrecht, E. & El-Boghdadly, K. Perineural adjuncts for peripheral nerve block. BJA Education (2019). doi:10.1016/j.bjae.2019.05.001
6. Brummett, C. M. & Williams, B. A. Additives to local anesthetics for peripheral nerve blockade. in International Anesthesiology Clinics (2011). doi:10.1097/AIA.0b013e31820e4a49
7. Continuous Peripheral Nerve Blocks. Available at: https://www.asra.com/news-publications/asra-updates/blog-landing/legacy-b-blog-posts/2019/08/07/continuous-peripheral-nerve-blocks.
8. Capdevila, X. et al. Effect of patient-controlled perineural analgesia on rehabilitation and pain after ambulatory orthopedic surgery: A multicenter randomized trial. Anesthesiology (2006). doi:10.1097/00000542-200609000-00022
9. Kim, H., Kim, H. J., Jung, Y.-H., Do, W. & Kim, E.-J. The effect of perineural injection therapy on neuropathic pain: a retrospective study. J. Dent. Anesth. Pain Med. (2024). doi:10.17245/jdapm.2024.24.1.47
10. Williams, B. A. et al. Neurotoxicity of adjuvants used in perineural anesthesia and analgesia in comparison with ropivacaine. Reg. Anesth. Pain Med. (2011). doi:10.1097/AAP.0b013e3182176f70