SAN FRANCISCO -- A careful history and physical exam, without the need for lab tests or radiography, can help identify any red flags in patients presenting with low back pain, Dr. David Borenstein said at the annual meeting of the American College of Physicians.
The history can distinguish mechanical from systemic disorders, and the physical exam can distinguish neurologic from nonneurologic conditions, said Dr. Borenstein of George Washington University, Washington.
"Laboratory tests are notably inconsequential," he said. "When you're taking your history and you don't think they have one of these systemic illnesses, you really don't have to do laboratory tests on these individuals."
Laboratory tests can be useful in distinguishing inflammatory from noninflammatory disorders, and radiologic tests can confirm a diagnosis derived from other means. But testing can just as easily confuse the issue.
It's critical to quickly identify the 5% or so of patients with cauda equina compression, often associated with an expanding aneurism or a herniated disc because they require emergency surgery. Typically these patients will have urinary retention, incontinence, or saddle anesthesia. In those cases, Dr. Borenstein recommended getting an MRI on an emergent basis.
Results of one recent study showed that patients with cauda equina compression do much better if they get surgery within 48 hours of the start of acute symptoms. Patients whose surgery was delayed often experienced severe and persistent motor deficits, persistent sciatica, and sexual dysfunction (Spine 2000;25:348-51).
In taking a history of a patient with low back pain, five areas of questioning can identify many red flags. If the answers to these constitutional symptom questions are all negative, "you can treat an individual with back pain conservatively without doing an x-ray, without doing lab tests, in fact by telling them they're going to get better--and being right most of the time," Dr. Borenstein said.
Weight loss and/or fever can signal either vertebral osteomyelitis or a vertebral neoplasm. Radiography--either a plain x-ray, a CT scan, an MRI, or a bone scan--can be helpful here. …