Taking anti-inflammatory drugs after surgery may hinder recovery, as blocking inflammation during this critical time could delay healing and extend pain.
This is according to a new study by researchers at Michigan State University.
In the study, they report that allowing inflammation to run its course led to a quicker cessation of pain and a faster overall recovery after surgery or injury.
Geoffroy Laumet, the study’s senior author and associate professor in the Department of Physiology and the Neuroscience Program at MSU, said: ‘The idea was that blocking inflammation would reduce pain overall. Instead, blocking inflammation increased pain in the long run. It was an unexpected result.’
The team used a mouse model to study postoperative pain, with and without TNF-α (tumour necrosis factor alpha) activity.
To compare, they inhibited TNF-α, which promotes inflammation, and mimicked surgery with a small incision. They expected that blocking TNF-α would reduce pain, but the opposite occurred: the mice remained in pain for much longer.
Laumet initially thought the result was a glitch. However, after the experiment was repeated by multiple lab members using three different methods to inhibit TNF-α – including Etanercept, an FDA-approved drug used in humans – the findings were clear.
Across all types of surgery, from a tooth extraction to a hip replacement, pain resolves in 90% of patients. But the remaining 10% develop chronic pain, Laumet said. That persistent pain is very hard to treat; it’s highly resistant to medication and can last for years.
More than 40 million Americans undergo surgery each year, meaning an estimated four million develop chronic postsurgical pain annually.
Laumet’s work suggests that the body’s ability to produce TNF-α in response to injury caused by the surgical incision could be a critical factor in whether a person’s pain resolves.
Although this study suggests that blocking TNF-α after surgery is likely unwise, there are other scenarios in which it may still be sensible, such as improving mobility by reducing joint inflammation in autoimmune diseases such as rheumatoid arthritis.
Laumet said: ‘Inflammation is not necessarily a bad thing. Yes, it hurts, but it’s also working on the inside to promote the resolution of that pain. The idea in the medical field that when you have an injury, you should absolutely block the inflammation right away might not always be the best strategy.’
The study was published in the Journal of Pain Research.
