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Post-Dental Cavernous Sinus Thrombosis — FRCA Final MCQ

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HardGeneral AnaesthesiaPost-Dental Cavernous Sinus ThrombosisFRCA Final

A 45-year-old man (ASA I) with no known medical conditions undergoes an uneventful wisdom tooth extraction under GA (propofol, sevoflurane, fentanyl). In recovery, he develops unilateral proptosis, chemosis, and ophthalmoplegia of the left eye. No external eye trauma or pressure was applied. What is the most likely diagnosis?

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Correct answer: D — Cavernous sinus thrombosis

Unilateral proptosis, chemosis, and ophthalmoplegia (affecting cranial nerves III, IV, VI) occurring post-operatively without direct orbital trauma or prone positioning suggests cavernous sinus thrombosis. This is rare but described post-dental extraction, with infection tracking from the maxillary/pterygoid venous plexus to the cavernous sinus. It is a medical emergency requiring urgent CT/MR venography, IV antibiotics, anticoagulation, and neurosurgical/ophthalmological input. Differential diagnosis includes orbital cellulitis and allergic reaction. Direct pressure on the eye during prone positioning causes orbital compartment syndrome but this patient was supine.

Reference: RCOA – 2023 – Perioperative eye complications; AAGBI – 2018 – Eye care during anaesthesia