Differential Diagnosis for Sudden Decrease in Saturation and Hematuria
Single Most Likely Diagnosis
- Bleeding due to anticoagulation (abixapan): The patient is on abixapan, an anticoagulant, for atrial fibrillation. A sudden decrease in saturation along with hematuria could indicate bleeding, which is a common complication of anticoagulant therapy. The presence of 50 ml of hematuria suggests a possible bleed that could be contributing to the decrease in saturation if it's part of a larger, unapparent hemorrhage.
Other Likely Diagnoses
- Pulmonary Embolism (PE): Although the patient is on anticoagulation, the therapy might not be fully effective, or there could be a new thromboembolic event. A PE could cause a sudden decrease in saturation and, if associated with renal vein thrombosis, could also explain hematuria.
- Cardiac Decompensation: In a patient with multiple comorbidities and atrial fibrillation, cardiac decompensation could lead to decreased saturation due to pulmonary congestion. Hematuria could be secondary to renal hypoperfusion or another cardiac-related issue.
- Sepsis: An infection could lead to both a decrease in saturation (due to pneumonia or ARDS) and hematuria (due to a urinary tract infection or sepsis-induced renal injury).
Do Not Miss Diagnoses
- Aortic Dissection: Although less likely, an aortic dissection could cause both a sudden decrease in saturation (if it involves the aortic root and affects coronary blood flow or leads to tamponade) and hematuria (if it involves the renal arteries). This diagnosis is critical to consider because of its high mortality rate if missed.
- Pulmonary Hemorrhage: This could be due to various causes, including anticoagulation, infection, or vasculitis. It would directly explain the decrease in saturation and could be associated with hematuria if there's a systemic cause.
Rare Diagnoses
- Thrombotic Thrombocytopenic Purpura (TTP): A rare condition characterized by thrombocytopenia, microangiopathic hemolytic anemia, renal failure, neurological symptoms, and fever. It could potentially explain both the hematuria and the decrease in saturation if there's significant renal and pulmonary involvement.
- Goodpasture Syndrome: An autoimmune disease that could cause both pulmonary hemorrhage and renal failure, explaining the decrease in saturation and hematuria. However, it's a rare condition and would be less likely without other supporting symptoms like coughing up blood or specific autoantibodies.