Peripheral nerve blocks are an important anesthetic technique used to provide local pain relief by interrupting the transmission of nerve impulses. Their applications vary significantly across pediatric, adult, and geriatric populations due to physiological and anatomical differences, as well as varying risks and benefits. The approach to peripheral nerve blocks should be tailored to the unique characteristics of each age group.
In the pediatric age group, the use of peripheral nerve blocks requires careful consideration due to their unique anatomy and physiology. For example, the smaller size of nerves and surrounding tissues requires precision in needle placement and drug dosage (1). In addition, children’s faster metabolic rates affect the pharmacokinetics of local anesthetics, potentially increasing the risk of toxicity if doses are not adjusted appropriately. The psychological aspects of treatment are also critical; children may experience significant anxiety and require a calm and reassuring environment to facilitate cooperation. Techniques such as ultrasound guidance may enhance safety and efficacy in this population by improving visualization of anatomical structures and reducing the likelihood of complications such as inadvertent vascular puncture (2).
In the adult age group, peripheral nerve blocks are commonly used for perioperative pain management, particularly for orthopedic and other surgical procedures. Adults typically have more stable anatomical and physiological parameters compared to pediatric or geriatric patients, making the administration of nerve blocks relatively straightforward. However, individual variability, such as differences in body mass index (BMI) or the presence of comorbidities such as diabetes, can affect the outcomes and complications associated with nerve blocks. For example, adults with obesity may present challenges in locating nerves due to deeper anatomical structures, requiring advanced imaging techniques for accurate placement. Pain management strategies in adults often emphasize multimodal approaches, combining nerve blocks with systemic analgesics to achieve optimal outcomes while minimizing side effects (3).
Geriatric patients present unique challenges to the use of peripheral nerve blocks. Aging is associated with changes in nerve anatomy, such as increased connective tissue and decreased nerve conduction velocity, which can affect the efficacy of the block (4). In addition, age-related declines in renal and hepatic function may impair the metabolism and elimination of local anesthetics, increasing the risk of toxicity. Geriatric patients often have multiple comorbidities and take multiple medications, such as anticoagulants, which can complicate the procedure. For example, anticoagulated patients are at increased risk for hematoma formation, requiring careful risk assessment and timing of nerve block administration relative to anticoagulant dosing (3). In addition, cognitive decline in some elderly patients may impair communication and complicate assessment of pain relief or adverse effects.
Across all age groups, the use of advanced imaging technologies, such as ultrasound, has significantly improved the safety and precision of peripheral nerve blocks. This modality allows real-time visualization of nerve structures, surrounding tissues, and local anesthetic spread,
thereby reducing the risk of complications such as intraneural injection or systemic local anesthetic toxicity (2). Nevertheless, the choice of local anesthetic, its concentration, and volume must be carefully tailored to the patient’s age, weight, and comorbidities to maximize efficacy while minimizing adverse effects.
Peripheral nerve blocks are a versatile and effective tool for pain management in various age groups. However, their application requires a nuanced approach that considers the unique anatomical, physiological, and pharmacological characteristics of pediatric, adult, and geriatric patients. Advances in imaging and a growing understanding of patient-specific factors continue to refine the use of this technique, making it safer and more effective for different populations.
References
1. Cartwright MS, Mayans DR, Gillson NA, Griffin LP, Walker FO. Nerve cross-sectional area in extremes of age. Muscle Nerve. 2013;47(6):890-893. doi:10.1002/mus.23718
2. Bosenberg AT. Innovative peripheral nerve blocks facilitated by ultrasound guidance. Paediatr Anaesth. 2018;28(8):684-685. doi:10.1111/pan.13424
3. Guay J, Kopp S. Peripheral nerve blocks for hip fractures in adults. Cochrane Database Syst Rev. 2020;11(11):CD001159. Published 2020 Nov 25. doi:10.1002/14651858.CD001159.pub3
4. Taams NE, Drenthen J, Hanewinckel R, Ikram MA, van Doorn PA. Age-Related Changes in Neurologic Examination and Sensory Nerve Amplitude in the General Population: Aging of the Peripheral Nervous System. Neurology. 2023;101(13):e1351-e1358. doi:10.1212/WNL.0000000000207665