Peripheral nerve injury arising in anaesthesia practice

Abstract

SummaryIn this article, we will discuss the pathophysiology of peripheral nerve injury in anaesthetic practice, including factors which increase the susceptibility of nerves to damage. We will describe a practical and evidence-based approach to the management of suspected peripheral nerve injury and will go on to discuss major nerve injury patterns relating to intra-operative positioning and to peripheral nerve blockade. We will review the evidence surrounding particular strategies to reduce the incidence of peripheral nerve injury during nerve blockade, including nerve localisation methods, timing of blocks, needle techniques and design, injection pressure-monitoring and local anaesthetic and adjunct choice. Pathophysiology of peripheral nerve injuryPeripheral nerve injury during the peri-operative period can occur when a nerve is subjected to stretch, compression, hypoperfusion, direct trauma, exposure to neurotoxic material or a combination of these factors [1,2].In many cases, no clear aetiology for nerve injury is apparent [3,4]. The shared pathophysiological precipitant of these injuries is often nerve hypoperfusion and consequent ischaemia due to physical disruption of the vasa nervorum, intraneural haemorrhage and/or endoneural oedema [5]. These result in a spectrum of histological neural abnormalities ranging from impaired axoplasmic transport, axonal degeneration, Schwann cell damage, myelin destruction, segmental demyelination and complete Wallerian degeneration [6][7][8]. Depending on the severity and duration of the ischaemic insult, either temporary or permanent disruption to nerve impulse transmission can result. There is a loose relationship between the severity of the original pathophysiological mechanism, degree of nerve ischaemia and subsequent clinical presentation, although in an animal model of compression injury, the degree of histological nerve damage has been correlated with the degree and duration of compression [8].Established peripheral neuropathy, pre-existing (but subclinical) peripheral neuropathy, profound hypothermia, hypovolaemia, hypotension, hypoxaemia, electrolyte disorders, malnutrition, small or large body mass index (BMI), tobacco use and anatomical variants (such as the presence of cervical ribs) may increase the susceptibility of peripheral nerves to peri-

The effect of rate of injection on injection pressure profiles measured using in‐line and needle‐tip sensors: an in‐vitro study

“…Alongside direct surgical complications, regional anaesthesia is one of the main reasons for postoperative neural dysfunction . Examination of the causal factors resulting in nerve damage secondary to regional blockade suggests it is the ischaemic insult to the nerve fibres that occurs during intraneural injection which plays an important role .…”

Analgesic benefits and clinical role of the posterior suprascapular nerve block in shoulder surgery: a systematic review, meta‐analysis and trial sequential analysis

“…Studies examining the addition of axillary nerve block to SSNB seem to substantiate this trend; while providing a more extensive sensory block of the joint itself [36], the combination similarly failed to demonstrate additional analgesic benefits for shoulder surgery [1,8]. Consequently, by being confined to partial pain control of limited clinical importance, the clinical role of posterior SSNB (with or without axillary nerve block) may be limited to cases where other alternatives are not feasible, or cases associated with a concern about brachial plexus injury [39]. That said, unlike ISB, SSNB did not appear to be associated with rebound pain [34] within the first 24 h.…”

Peri‐operative brachial plexus injury following self‐positioning for stereotactic radiofrequency ablation

“…Other structures at risk of positioning‐related injuries are the skin, joints, ligaments, vessels and the eyes . Different patient risk factors have been described such as hypertension and diabetes, pre‐existing peripheral neuropathy, tobacco use, vascular disease, extremes in weight, male sex and higher age . The severity of nerve damage depends on multiple factors and has implications with respect to nerve function and potential recovery .…”