Can a nerve block during surgery prevent pain months later?
Yes. In a review of 158 trials, patients who got regional anaesthesia, meaning nerve blocks and similar techniques, had about a 27 percent lower risk of developing chronic postsurgical pain, and the benefit lasted up to 12 months. The risk ratio was 0.73, which means the chance of long-term pain dropped to roughly three-quarters of what it was without a block.
Chronic postsurgical pain is pain that starts after an operation and sticks around for more than three months. For some people it never fully goes away. Preventing it is one of the biggest goals in surgery research right now, and this study offers some of the strongest evidence yet that the type of anaesthesia used during surgery can make a real difference.
What is regional anaesthesia?
Regional anaesthesia numbs one part of the body instead of putting you fully to sleep. A nerve block, for example, delivers numbing medicine near the nerves that carry pain signals from the surgical area. This can be done as a single injection or through a small catheter that keeps delivering medicine over time. The idea is that if you block those pain signals early, before and during surgery, the nervous system is less likely to get stuck in a lasting pain pattern afterward.
What the data show
Researchers pooled 158 randomized controlled trials covering 18,794 adults having surgery. Overall, regional anaesthesia lowered the risk of chronic postsurgical pain compared with no block, with a risk ratio of 0.73 and a 95 percent confidence interval of 0.67 to 0.80. That protection held up as far out as 12 months after the operation.
The benefit was clearest for some of the most pain-prone surgeries. After mastectomy, the risk ratio was 0.69. After thoracotomy, a type of open chest surgery, it was 0.72. For video-assisted chest surgery it was 0.73, and for knee replacement it was 0.71. In plain terms, across these procedures the risk of lasting pain fell by roughly 28 to 31 percent.
One thing regional anaesthesia did not clearly change was long-term opioid use. The risk ratio there was 0.88, but the range ran from 0.61 to 1.28, which crosses 1.0 and means the result could easily be down to chance. So the main win here is preventing persistent pain, not reducing how many people end up relying on opioids.
Dr. Kumar’s Take
As a neurosurgeon, I find this really encouraging. We have known for years that the way the nervous system processes pain during and right after surgery can set the stage for chronic pain later. This study puts hard numbers behind that idea across a huge pool of patients. A 27 percent drop in the risk of lasting pain is meaningful, especially for surgeries like mastectomy and chest operations where chronic pain is common and hard to treat.
I want to be clear about the limits though. The authors rated the certainty of the pain evidence as low, and the opioid evidence as very low. That does not mean the finding is wrong, it means we should hold it with appropriate humility. The direction and consistency across 158 trials is what gives me confidence, even if the exact numbers may shift as more research comes in.
How the studies were done
This was a network meta-analysis, which is a step beyond a standard review. It lets researchers compare many different techniques against each other, even when they were not tested head to head in the same trial. The team followed PRISMA reporting standards and searched medical databases through October 2025. They also used GRADE and CINeMA, two formal systems for rating how trustworthy the evidence is.
The network analysis found that not all nerve blocks work equally well. For chest surgeries, neuraxial techniques, meaning blocks placed near the spinal cord like epidurals, worked better than peripheral blocks placed out near the limbs or chest wall. After thoracotomy, neuraxial blocks had a risk ratio of 0.64 versus 0.84 for peripheral blocks. The pattern was similar for video-assisted chest surgery.
Where the evidence is strongest and weakest
Interestingly, the type of surgery, the patient’s sex, and their baseline risk of pain did not significantly change how well regional anaesthesia worked. What mattered most was the specific technique chosen. That is a useful signal for surgical teams, because it suggests the tool itself, rather than the patient, drives much of the benefit.
The weak spots are worth naming. The overall certainty was low, and the network comparisons ranged from low to very low certainty. The best timing and delivery method also varied by surgery type, so there is no single recipe that fits every operation. More large, well-run trials would help pin down exactly which block works best for which surgery.
Practical Takeaways
- If you are scheduling surgery known for lasting pain, such as a mastectomy, chest operation, or knee replacement, ask your surgical team whether a nerve block or regional anaesthesia is an option for you.
- For chest surgeries specifically, ask whether a neuraxial technique like an epidural is appropriate, since it outperformed peripheral blocks in this analysis.
- Do not expect a nerve block to reduce your need for opioids later, since the study found no clear benefit there, and plan pain management with your care team accordingly.
- Bring up your personal history of chronic pain with your anesthesiologist before surgery, as pain prevention works best when it is planned in advance rather than treated after the fact.
Related Studies and Research
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FAQs
How long does chronic postsurgical pain usually last?
By definition, chronic postsurgical pain is pain that continues for more than three months after an operation. For some people it fades over the following year, but for others it becomes a long-term problem that can last for years. This study measured pain outcomes up to 12 months after surgery, which is why the researchers could say the protective effect of nerve blocks held steady for a full year. The lasting nature of this pain is exactly why prevention matters so much more than treatment after the fact.
Is a nerve block safe compared with general anaesthesia?
Regional anaesthesia is widely used and generally considered safe, and it is often combined with general anaesthesia rather than replacing it entirely. Nerve blocks can actually reduce the amount of general anaesthetic and opioid medicine needed during the operation itself. That said, every procedure carries some risk, and the right choice depends on your health, the surgery, and your anesthesiologist’s judgment. This particular study focused on preventing chronic pain, not on comparing overall safety, so those decisions should still be made with your care team.
Why did nerve blocks not reduce long-term opioid use?
This is one of the more surprising findings. Even though regional anaesthesia lowered the risk of lasting pain, it did not clearly reduce how many people were still using opioids long after surgery. The result had a wide range of uncertainty and could have been due to chance. One possible reason is that long-term opioid use is driven by many factors beyond surgical pain, including prior use, mental health, and prescribing habits. The evidence on opioids was also rated very low certainty, so this question needs more study before we draw firm conclusions.
Bottom Line
This large review of 158 trials and nearly 19,000 patients found that regional anaesthesia lowers the risk of chronic postsurgical pain by about 27 percent, with the benefit lasting up to a year. The protection was strongest for mastectomy, chest surgery, and knee replacement, and neuraxial techniques worked especially well for chest operations. It did not clearly reduce long-term opioid use, so the real payoff is in preventing persistent pain. The evidence is not airtight, but it is consistent enough that anyone facing a high-pain surgery should ask their team about a nerve block.
