Differential Diagnosis for Unilateral Cyanosis Post Sepsis and UTI
Single Most Likely Diagnosis
- Cavernous sinus thrombosis: This condition is highly suggested by the presence of gas in the cavernous sinus at the time of presentation for sepsis. The unilateral cyanosis could be due to the obstruction of venous return from the face, which is a common presentation of cavernous sinus thrombosis.
Other Likely Diagnoses
- Septic pulmonary embolism: Given the history of sepsis and UTI, it's possible that the patient developed septic emboli that lodged in the pulmonary arteries, potentially causing unilateral cyanosis if the embolism is large enough to affect blood flow significantly.
- Paradoxical embolism: Although less common without a known right-to-left shunt, the presence of sepsis and potential for venous thromboembolism could lead to a paradoxical embolism, where a clot crosses from the venous to the arterial system, potentially causing unilateral cyanosis.
Do Not Miss Diagnoses
- Pulmonary embolism with pulmonary infarction: While the patient is not on vasopressors, a large pulmonary embolism could still cause significant hypoxia and potentially unilateral cyanosis if it leads to infarction of a significant portion of the lung.
- Aortic dissection: Although less directly related to the initial presentation, an aortic dissection could potentially cause unilateral cyanosis by compromising blood flow to one of the subclavian arteries or by causing a right-to-left shunt through a dissection flap.
Rare Diagnoses
- Chronic thromboembolic pulmonary hypertension (CTEPH): This is a rare condition that could potentially cause unilateral cyanosis if the thromboembolic disease is asymmetric, but it would be less directly related to the acute presentation of sepsis and UTI.
- Arteriovenous malformation (AVM): An AVM could potentially cause unilateral cyanosis due to right-to-left shunting, but this would be an unusual presentation in the context of sepsis and UTI without prior known history of such a malformation.