35 y/o presents to the ED with the cc of "back pain, difficulty walking and worse since last night." He notes 10/10 bilateral low back pain x 3 days. Pain radiates to R buttock. He has a known hx of a bulging disc (from a worker's comp injury 12 yrs ago) and has intermittent back pain from that, but it has never caused 10/10 pain or difficulty walking until now. He denies recent injury, bladder dysfunction, motor and sensory loss. He was taken to a room via a wheelchair and seen by the PA. ROS was negative except for the mention of difficulty walking.
Gen: Alert. Distress appears due to pain and anxiety
V/s: normal. afebrile
HEENT: normal external inspection
Neck: normal inspection, nontender, painless ROM
CVS: heart sounds normal. Pulses normal
Respiratory: no resp distress. Lung sounds normal
Back: normal inspection
Skin: warm and dry
Neuro: oriented x 3. Mood/affect normal. Reflexes: R biceps 2+, L biceps 2+, R brachioradialis 2+, left brachioradialis 2+, R patellar 2+, left patellar 2+
ED course and MDM: After Norco and Ativan, he looked comfortable. Dx: Myofascial strain. Plan: Rx for pain meds and f/u with PCP in 3 days.
The patient returned 4 days later by ambulance complaining of worsening back pain, weakness and inability to walk. The physician chart notes he complains of 5/10 pain worse when he tries to walk and denies bowel/bladder dysfunction or motor/sensory loss. His PMH was noted to be negative except for chronic back pain. Nursing note states the pt complained of bilateral leg numbness and couldn’t sit up.
Gen: Alert. NAD
V/s: 02 sat 97% on RA. Interpreted as normal
Neck: Normal inspection
CVS: Normal heartrate and rhythm
Respiratory: No respiratory distress. Lung sounds normal
Abd: Normal inspection. Soft. Nontender
Back: Normal inspection. Soft tissue tenderness in lumbar area
Skin: warm and dry
Extremities: Normal ROM
Neuro: Oriented x 3. Normal mood/affect. No motor or sensory deficit
ED course and MDM: 35 y/o with sciatica. NV intact. No sign of cauda equina. Dx: Sciatica. Plan: D/c home with Rx for pain meds.
11 hours later he called 911 again. EMS took him to another ER where he complained of urinary retention, bowel incontinence, saddle anesthesia, and inability to move his legs. He stated the numbness and urinary retention started yesterday. MRI in the ED, dx with cauda equina, admitted and went to surgery.
Plaintiff sued for negligence stating the delay in dx led to permanent spinal cord damage resulting in chronic urinary retention, lack of bowel control, and difficulty walking. The physician on visit #2 settled out of court. The other defendants were dropped without indemnity payment.
1. ED Expert opinions were supportive but felt there would be challenges to the defense. The records from both visits were templated and therefore the expert felt their documents did not reflect the reality of the true physical exam. ED visit 1 does not document a motor and sensory exam. ED visit 2 also had a limited neuro exam. Neither chart had a good MDM. What else in the documentation was a problem for the defense?
2. Upwards of 90% of low back pain presentations in the ED are due to benign causes. However, there are several important life/limb threatening diagnoses we must consider in the low back pain patient, and some of these diagnoses are easy to miss. There are numerous red flags of back pain and we encourage you to refresh yourselves on them. What red flag should have triggered the physician on the second visit to consider imaging?
3. Anchoring bias is the term used to describe the mental error of maintaining one's initial impression despite evidence pointing to the contrary. (Wellerby C. Flaws in clinical reasoning: a common cause of diagnostic error. Am Fam Physician. 2011;84(9):1042-1048). In this case, the providers heard “worker’s comp injury”, “prior back pain”, “chronic pain” and anchored. They neglected to address this was different and associated with difficulty walking, weakness, and (on the 2nd visit) numbness. How do we combat anchoring bias?