The content of this article reflects the opinions of the authors and is not intended to, and does not, establish a standard of care.
By Mark Spiro, MD
Most low back pain presentations in the ED have benign causes. For that reason, among others, the low back pain presentations that have potential for serious health consequences can be missed. In this article, we identify (1) the spinal emergencies that most often have led to patient injury and resulting allegations of medical negligence; (2) common treatment issues; and (3) observations of The Mutual’s Claims Advisory Committee following review of the claims and lawsuits in which medical negligence was alleged as a consequence of the spinal pain presentation.
Low Back Pain Presentations
Spinal Epidural Abscess
Spinal epidural abscess is often missed on first ED visit. Fever is present in only 50% of patients, and neuro deficits can start subtly. Epidural abscess may be the cause of back pain (1) in a patient with back pain or neurologic deficits and fever, (2) in an immune-compromised patient or (3) in a patient who recently underwent a spinal procedure and has either of the above presentations.
Risk factors for spinal epidural abscess include diabetes, intravenous drug use, indwelling catheters, spinal interventions, infections elsewhere (especially skin), immune suppression (i.e. HIV), and “repeat ED visits.”
The classic triad of fever, back pain, and neurologic deficit is present early in only 15% of patients, depending on the stage of disease. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) results may be instructive, depending on the clinical suspicion for epidural abscess. If there is a high index of suspicion, an MRI may be indicated as the abscess is not infrequently significantly above the level of the back pain. When epidural abscess is suspected, the entire spine should be imaged by MRI. Spinal cord obstruction and paralysis can happen very quickly from epidural abscess, so there needs to be definitive imaging and surgical decompression as quickly as possible.
It warrants comment that a CT cannot rule out epidural abscess because it does not show the epidural space, spinal cord or spinal nerves adequately.
2. Cauda Equina Syndrome
Cauda equina syndrome (CES) usually is a surgical emergency. Patients who present with CES typically experience urinary retention, rectal dysfunction or sexual dysfunction (or all of the above), plus saddle or anal anesthesia and/or hypoesthesia.
Urinary retention is non-specific for CES, but sensitive. A post void residual >100mL should raise the suspicion for CES.
3. Spinal Epidural Hematoma
Spinal epidural hematoma may present after spinal procedures (epidural anesthesia), but can be spontaneous, especially in anti-coagulated patients. Neurologic findings depend on the extent of spinal cord compression— from isolated pain to flaccid paralysis. Patients with a history of trauma and neurologic findings who are coagulopathic fit the profile for spinal epidural hematoma.
4. Spinal Metastasis
In patients presenting with known cancer plus new back pain, it is reasonable to consider a diagnosis of spinal metastases until proven otherwise.
Spinal metastases are common causes of cord compression.
Diagnosis/Treatment may consist of the following:
- X-ray to identify compression, soft tissue changes, blastic/lytic lesions or pedicle erosion;
- Consider testing ESR and CRP, and calcium profile if signs are consistent with hypercalcemia;
- Consider ordering an urgent MRI if there are symptoms of cord compression and MRI within 24 hours if there are hard neurologic findings.
- Failure to timely diagnose the problem.
- Frequent visits with no or an inaccurate diagnosis (anchoring bias).
- Lack of 24-hour availability of MRIs.
- Patients too large for the MRI machine.
- On call neurosurgeon declines to come in.
- Delay in transfers to other facilities.
Observations from The Mutual’s Claims Advisory Committee
- Document the patient’s medical record to fully reflect your medical decision making, demonstrating your clinical thought process, including differential diagnoses and rule outs.
- Order appropriate MRI—entire spine, not just lumbar.
- If MRI is not immediately available, order a stat CT myelogram or transfer.
- If MRI is not available on nights or weekends, a protocol should be in place to address this.
- Seek neurosurgical consultation regardless of doubts that the on-call neurosurgeon will come in.
- Spinal mass and cauda equina are very time sensitive diagnoses; do not delay evaluation if suspected.
- If it is determined a test or procedure is not warranted (such as an MRI), explain your reasoning in MDM.
- Unscheduled repeat visits warrant an elevated workup, not the opposite; by the third unscheduled visit, there should be a good reason not to admit the patient.
- Cognitive Pause—Utilize prior to discharge especially when all findings do not agree or there are multiple clinical issues.