When anesthesiologists at Johns Hopkins University School of Medicine studied treatments for chronic lower back pain, they weren't surprised to find that epidural injections of steroids were much more effective than intramuscular injections of steroids, saline or local anesthetic.
They didn't expect to discover, however, that epidural injections of saline or analgesic were also 2 times as effective in relieving pain than intramuscular shots were.
"Just injecting liquid into the epidural space appears to work," says Steven P. Cohen, MD, a professor of anesthesiology and critical care medicine and the co-author of a study appearing in the October issue of the journal Anesthesiology. "This shows us that most of the relief may not be from the steroid, which everyone worries about" due to its potential for adverse effects.
After reviewing 43 published studies involving 3,641 patients up to October 2012, Dr. Cohen and his colleagues speculated that previous research may have tended to pit epidural steroids against control injections that were not actually placebos but other types of treatment.
While they don't recommend halting the administration of steroids in pain management injections, they suggest that further studies examine whether smaller doses might provide the same amount of benefit.