Study Finds Nerve Blocks Risky

Sedating a patient before a nerve block increases the cost and raises the risk of unnecessary surgeries, while doing nothing to control long-term pain, according to a new study by a Johns Hopkins researcher.

“Sedation doesn’t help, but it does add expense and risk,” says study leader Steven P. Cohen, MD, a professor of anesthesiology at the Johns Hopkins University School of Medicine. “In some places, every patient is being sedated. Our research shows it should be used very sparingly.”

Results of the study, reported online in the journal Pain Medicine, show that sedation before a nerve block significantly increases false-positive results, which means patients are more likely to be sent in for surgeries and other procedures that won’t cure the underlying pain.


Nerve blocks are often performed by injecting steroids or analgesics such as Lidocaine into a pain patient prior to a diagnostic procedure used to find the nerve that’s causing their pain. If the injection works, that nerve may then be chosen for an epidural steroid injection or some other treatment.

Researchers at Johns Hopkins and several other medical centers in the U.S. recruited 73 patients with back or limb pain who were scheduled to receive multiple nerve blocks. Half of the patients received the first injection with sedation and the second without. The remaining patients received their injections in the opposite order.

Patients were given pain diaries to determine whether the injections brought pain relief. They were also seen a month later and asked to rate their pain and function after the treatment.

Although the sedated patients reported less pain immediately after the nerve block injection, on every other measure — from 30-day pain assessments to overall patient satisfaction — the results were the same whether or not they were sedated.

“A lot of cost for very little benefit,” Cohen says.

If patients believe that the nerve block eased their underlying pain, physicians will often conclude that they have found the source and will move ahead with treatment, which may include spinal fusion or radiofrequency ablation of nerves for arthritis.  But Cohen says many patients wind up back at square one — still in pain, but having suffered through a potentially unnecessary operation.

Cohen says that while many physicians use sedation to make diagnostic procedures less traumatic for patients, there is also a financial incentive to use it.

“Unfortunately, medicine in many places has become a business. The fact is, you get paid more money to do the procedure with sedation,” he says. “The costs of anesthesia can be more than the fee for the procedure itself. And patients are getting harmed.”

“Nerve blocks are yet another band aid approach that leads to more imaging and damaging procedures,” says Dawn Gonzalez, whose spine was damaged by an epidural during child birth. She now suffers from arachnoiditis and is an advocate for Arachnoiditis Society for Awareness and Prevention (ASAP).

“If steroids are used, it causes the same tissue, bone, and muscle degradation issues and risks of fracture and osteoporosis as steroid injections. The risks are too many and too large for temporary relief. This has been a common treatment for Reflex Sympathetic Dystrophy (also known as Complex Regional Pain Syndrome) until recently, but has been proven to be ineffective and risky. It can cause worsening rather than relief.”

Epidural steroid injections are increasingly being used to treat back pain of all kinds, with nearly 9 million spinal injections in the U.S. in 2011. Several previous studies have found that steroid injections increase the risk of spinal fracture and do little to relieve back pain.

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