Incidence of peri‐operative peripheral nerve injuries associated with general and regional anaesthesia

We read with interest the study by Luo et al. examining peri-operative peripheral nerve injuries associated with anaesthesia 1. A fundamental challenge when interpreting administrative datasets is a lack of clinical detail. Coding categories combine injuries of varying severity and prognostic significance, yet many peri-operative nerve injuries resolve without long-term deficit 2. Without this differentiation, estimating the true burden of a clinically significant peri-operative peripheral nerve injury remains difficult. Equally important is attribution of causality because peri-operative peripheral nerve injuries are often multifactorial 3. The dataset cannot determine timing or mechanism of injury reliably and may capture events occurring before, during or after surgery. Thus, associations between anaesthetic modality and nerve injury may reflect overall peri-operative risk rather than causal effects of regional anaesthesia. Luo et al. report a greater incidence of peri-operative peripheral nerve injuries in patients receiving combined general and regional anaesthesia compared with general anaesthesia alone 1. However, this needs to be interpreted with caution. Combined techniques are more likely used in higher risk procedures, and general anaesthesia may be added in patients with significant comorbidity who may not lie flat/still for the procedure. This raises the possibility of confounding by indication. Therefore, the association should be interpreted as correlative rather than causal. Relative risk comparisons, such as reporting a doubling of risk, may obscure the clinical picture unless absolute risk is emphasised. Although combined general and regional anaesthesia (20.22/100,000) showed the highest incidence, the general anaesthesia-only group (13.8/100,000) had a substantially higher incidence than the regional anaesthesia-only group (4.42/100,000) 1. The occurrence of peri-operative peripheral nerve injuries in the general anaesthesia-only cohort highlights background risk attributable to surgical and patient factors. Against this background, regional anaesthesia alone appears to be associated with a lower incidence. While confounding factors exist and regional anaesthesia is not suitable for all procedures, this comparative framework better reflects the clinical implications. This approach supports shared decision-making by allowing patients to understand the baseline risk of peri-operative peripheral nerve injuries and the potential risk reduction associated with regional anaesthesia, using absolute rather than purely relative risk estimates. The inability of the dataset to distinguish timing of block placement relative to inducing general anaesthesia is a further limitation. Blocks performed awake allow early detection of nerve irritation by patient feedback, whereas blocks placed during general anaesthesia do not. It remains unclear how many combined cases involved pre- vs. post-induction blocks and whether this influences risk. The safety of regional anaesthesia during general anaesthesia has been shown in children 4 but there is as yet no consensus in adults. There has been a decline in peri-operative peripheral nerve injury incidence over time 1. While practice changes may contribute, it would be informative to know whether this trend was uniform across anaesthetic groups. If reductions were mainly in general anaesthesia-only cases, this may reflect broader peri-operative improvements. Consistent reductions across regional anaesthesia groups could indicate safer practice.