Red Flags

Low back pain is very common. It is the most common medical reason for people in America to miss work. It is so common that when people ask me why they have back pain I feel like answering, “Because you are a human.”

Being such a common condition, back pain is also a common reason for people to come to the emergency department. We see everything from people with strains caused by lifting something heavy to people who have low back pain every waking minute of their miserable lives.

There is not much we can do in the emergency department for most people who have low back pain: Provide temporary relief of the pain. Give reassurance. Write prescriptions. Give advice for further care at home.

Mixed in with all of this regular back pain, there are people who have something really bad happening. This is a great example of what makes my job so challenging and interesting: I have to recognize the rare “bad” back pain among all those “regular” back pains.

To identify low back pain that might be caused by something serious, we look for what we call the Red Flags of Low Back Pain. Basically, the red flags are clues there is some pathology in the spinal column that puts the spinal cord at risk of injury. For example, decreased blood supply can cause a “stroke” of the spinal cord. Other injuries are caused by pressure against the spinal cord from things like cancer, an abscess or a herniated disc.

Patients with these red flags need further investigation that is not warranted in the vast majority of patients with low back pain. What raises a red flag for me? Cancer patients with new back pain, old age, fever, loss of tone in or numbness around the anus, problems emptying the bladder, among others.

One night, a 47 year-old lady came in with a four-day history of low back pain with pain and numbness down her left leg. She said she had never had anything like this and had never before seen a doctor for back pain. She was miserable. She leaned to the left when she walked and was unable to walk at all without holding onto something. She said she had no control of her urine and stool. As part of my exam, I stuck my finger in her anus. She had no tone and was unable to pinch down on my finger.

I hope I did a good enough job of explaining the red flags to help you see why I was seriously concerned this patient had something bad causing injury to her spinal cord. I needed to make arrangements for her to be admitted to the hospital, be seen by a neurosurgeon and have an MRI done to identify the badness causing her problems.

I paged the neurosurgeon on call and told him my patient’s story. He surprised me by calling her by name. He said he had recently admitted her to another local hospital. All the tests done there were normal and, after being in the hospital for a couple of days, the patient miraculously got better and walked out.

I went back to the patient and told her of my conversation with the neurosurgeon. I explained we would give her no more opiates for pain and that there was no reason for her to be admitted to our hospital that night. On hearing this, she leapt out bed, flipped me off and briskly walked out, swearing at me as she went.

There is no way for me to know how this lady ended up with red flag symptoms. How did she know all the bad things to lie about? How did she learn to fake having no anal tone? Was she faking to get opiate pain medications? Did she have Munchausen Syndrome?* I really don’t know and your guess is as good as mine.

* https://en.wikipedia.org/wiki/Munchausen_syndrome