A Diagnosis of Exclusion?
CRPS is sometimes difficult to diagnose in clinical practice, especially for physicians not familiar with the condition, says Salim Hayek, MD, a professor of anesthesiology from Case Western Reserve University School of Medicine in Cleveland, Ohio.
“The problem with CRPS is that we don’t have a biomarker for it, no blood test or imaging study that we could order and confirm that a particular patient has the diagnosis,” Dr Hayek told Clinical Pain Advisor, noting that the symptoms can often mimic other conditions and the diagnosis is often one of exclusion.
According to Andreas Goebel, MD, a senior lecturer in pain medicine from the University of Liverpool’s Institute of Translational Medicine and chair of the development panel for UK CRPS guidelines, the study highlights an important aspect of CRPS in clinical practice.
“Non-specific pain is always a difficult situation for a surgeon, whose training is to look for a structural cause of the pain,” Dr. Goebel told Clinical Pain Advisor. “Many people come to surgeons with unexplained pain. They have limb pain and the surgeon, if they haven’t seen [CRPS] often enough, come with their general ideas of how to address that pain — and arthroscopy is one of those ways.”
“Typically, there may be something that looks a bit abnormal on imaging, so the surgeon is inclined to shave a bit of bone off. If this is a situation where CRPS is present, then it can get quite a bit worse,” Dr Goebel noted.
Epidural Catheters: Limited by Infection Risk
Pain specialists have been trying to find ways to manage pain in patients with CRPS, as well prevent its occurrence in patients undergoing surgery. In many cases, a peripheral nerve or tunneled epidural catheter is placed preoperatively to maintain pain control in the postoperative period.
In a retrospective study published in the Clinical Journal of Pain,3 Dr Hayek and colleagues examined the effectiveness of tunneled epidural catheters to control pain and facilitate rehabilitation in patients with regional pain syndromes. They found that tunneled epidural catheters were often effective for achieving good analgesia and allowing rehabilitation, but were associated with a high risk for infection.
“Placement of externalized tunneled epidural catheter with continuous infusion of bupivacaine and fentanyl in patients with neuropathic pain (particularly CRPS) carries a significantly higher risk of infection than placement in patients with somatic pain,” the authors concluded.