Peripheral nerve injury in regional anesthesia: a narrative review

Peripheral nerve injury is defined as a condition diagnosed no earlier than 48 hours after regional block, manifesting as sensory and/or motor deficits in the innervation zone of the affected nerve, and confirmed by neurological examination. The incidence of transient neuropathy associated with peripheral nerve block is 2.2%, whereas persistent neurological deficit occurs in 2 to 4 cases per 10,000 blocks. Although postoperative nerve injury is rare, when such complications occur, they pose significant concerns for both the patient and the anesthesiologist. The aim of this work was to summarize data from contemporary scientific publications on the prevention and management of peripheral nerve injuries associated with regional anesthesia. A search was conducted for the period from 2014 to 2024 using keywords in Russian and English: периферический нерв (peripheral nerve), повреждение (injury), регионарная анестезия (regional anesthesia), неврологические осложнения (neurological complications), профилактика повреждений нерва (nerve injury prevention) in the PubMed, eLibrary, and CyberLeninka databases. A total of 433 publications were identified, of which 383 were excluded for not addressing nerve injuries related to regional anesthesia. The remaining 50 publications formed the basis of this review. The review discusses the anatomy of peripheral nerves and the classification of nerve injuries, and provides detailed descriptions of mechanical, intraneural, ischemic, and neurotoxic mechanisms of nerve injury. Preventive techniques are described. It has been shown that the combined use of neurostimulation to identify the target nerves, ultrasound guidance to visualize the nerve, and injection pressure monitoring to avoid nerve injury is the key to safe regional anesthesia. The diagnostic assessment of nerve injury includes both assessment of clinical presentation and computed tomography and electrophysiological evaluations. A monitoring algorithm is presented for patients with suspected nerve injury following regional anesthesia. Management strategies for peripheral nerve injury are described in detail, including physiotherapy, pharmacotherapy, low-frequency electrical stimulation, low-intensity ultrasound, and phototherapy. Intraoperative nerve injuries during regional block are rare and more often manifest as neurapraxia, which is transient and has a favorable prognosis. The combined use of neurostimulation, ultrasound navigation, and injection pressure monitoring ensures the safety and success of regional block. Treatment of nerve injuries requires a multidisciplinary approach. The development of Russian clinical guidelines for the prevention of nerve injuries during regional block will help anesthesiologists reduce the risk of complications.