Medical Malpractice Insights – Warfarin is poison – and not just for rats

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Chuck Pilcher, MD, FACEP

Editor, Medical Malpractice Insights

Warfarin is poison – and not just for rats

Spinal epidural hematoma leaves patient paralyzed

Facts: A 68-year-old male presents to the ED at the end of the night shift complaining of a 2 day history of 8/10 neck pain radiating to his upper back and increasing with movement. He also has facial swelling which he attributes to a dental crown 2 months prior. ROS is positive for a subjective fever the day before, jaw pain, and a dry cough. He is on warfarin, but no medication reconciliation is done. On exam, he has limited flexion/extension of his neck and pain with motion, no tenderness to palpation, and minor swelling of the left side of the face and neck. Neurologic exam is limited to “Alert and oriented x3.” Differential diagnosis includes “abscess, cellulitis, viral syndrome, mass and dental infection.” There is no reference to the neck px. A CBC, Chem 7m and CT of the soft tissues of the neck are ordered by the departing ED doc whose clinical info for the radiologist is “facial swelling”. An INR is not done. The “day doc” gets the reports: CBC is normal and CT shows “cellulitic changes in the left cheek and left anterior lateral neck without organized fluid or abscess. Straightening of the normal cervical lordosis.” Without questioning the patient further, the “day doc” diagnoses the patient with facial cellulitis, prescribes Norco and Augmentin, and discharges him. Seven hours later he is unable to use his arms and legs, calls 911, and returns to the ED. On exam he is quadriplegic. His INR is now checked and is 13. An MRI shows an epidural hematoma compressing the spinal cord from C2-T1. He is treated with 4 factor PCC and taken to the OR. He remains quadriparetic after a rocky post-op course. An attorney is consulted and a lawsuit filed against the first two EP’s, the radiologist, and the hospital, claiming that the patient was negligently cared for during the first ED visit.

Plaintiff: My main complaint was neck and upper back pain, and you only addressed the facial swelling that I mentioned. My last INR was 1 month earlier, and I was due to have it done that day. You never asked about my blood thinner or checked my INR. When I was in your ED 6 months ago for gout, you checked it. Why not this time? You were too focused on my facial swelling and my comment about recent dental work. That, and a recent hip replacement, are risk factors for a spinal epidural abscess. You only told the radiologist I had “facial swelling.” So even if you weren’t suspecting an epidural hematoma, you should have ordered an MRI and given the radiologist more information. A CT scan – of the soft tissues no less – is insufficient. Despite that, with hindsight, your own radiologist agrees that my hematoma IS visible on my facial CT. A miss like this is below the standard of care.

Defense:

Emergency Physician: I had no reason to suspect any spinal problem. All you had was neck pain and facial swelling, and the latter was your main complaint.

Radiologist: You didn’t give me enough clinical information. A soft-tissue CT of the neck is adequate to find a spinal epidural hematoma. I saw none at the time. Your expert has the advantage of hindsight, and in retrospect so do I.

Hospital: The nurse drew a full “rainbow” set of blood tubes. The doctor didn’t order an INR or give the radiologist enough information. Our expert believes the CT scan is only positive in hindsight. The standard of care was met.

Result: Settlement for undisclosed amount described by attorney as “insufficient to care for the patient’s ongoing needs.” Apportionment among defendants not disclosed.

Takeaways:

• Re-check patients handed off to you at change of shift. Don’t depend on your colleagues to get it right all the time.
• Before discharge, ask patients if they have any remaining concerns or questions.
• A medication history is important. Warfarin (and DOAC’s) should always be addressed in a patient’s medical history. It’s on par with chemotherapy.
• Spontaneous spinal epidural hematoma is rare, even rarer than spinal epidural abscess. Thinking of either in this case would have avoided catastrophe.
• Drug-drug and drug-food interactions should be considered.
• The possibility that a new onset complaint is related to the anticoagulant should be addressed.
• The patient’s last INR should be documented, and one obtained if not recent.
• For patients on warfarin, documenting a reason for not checking an INR is a worthwhile practice.
• This is a classic case of “anchoring bias” (i.e., failure to assess the overall presentation and instead jumping to conclusions).

References:

1. Spontaneous Spinal Epidural Hematoma. Baek BS et al. J Korean Neurosurg Soc. 2008 Jul; 44(1): 40–42.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2588288/

2. The Significance of Drug—Drug and Drug—Food Interactions of Oral Anticoagulation. Vranckx P et al. Arrhythm Electrophysiol Rev. 2018 Mar; 7(1): 55–61. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5889806/

3. NOAC-Drug Interactions Linked to Increased Bleeding. Hughes S, Medscape eMedicine, October 06, 2017. https://www.medscape.com/viewarticle/886733

Learn from the mistakes of others. You’ll never live long enough to make them all yourself.