A case report of a patient with undiagnosed systemic mastocytosis (SM) who experienced unexpected complications during heart surgery has been recently published in Cardiothoracic and Vascular Anesthesia.
SM is a disease characterized by excessive mast cell activity and proliferation. Mast cells produce substances such as histamine and heparin that, under normal conditions, help promote an inflammatory response towards infection. In patients with SM, mast cells release substances even without an infection.
The excessive release of mast cell granules can generate excessive unregulated immune responses, including anaphylaxis. During anaphylactic crises, patients can experience dangerously low blood pressure (hypotension), an accelerated heart rate and difficulty breathing. Without proper treatment, anaphylaxis can be deadly.
“As a result, SM can have profound consequences for patients during cardiac surgery.” the authors wrote. ”Despite this, there is insufficient evidence documenting the management of Cardiopulmonary Bypass (CPB) for SM patients,”
The case involved a 72-year-old man scheduled to undergo cardiac surgery for aortic and mitral valve replacement and tricuspid valve repair, which required the patient to be put under a coronary bypass (CBP).
As the patient was put on CBP, he experienced severe hypotension that persisted despite the administration of fluids and adrenaline. The physicians thought the patient was in anaphylaxis due to one of the drugs administered during the surgery, but the symptoms persisted despite treatment with corticosteroids and antihistamines.
Due to the lack of improvement, the patient was taken off CPB. The patient improved significantly after CPB cessation. After stabilization, CPB was started again and stopped due to a blood clot. After the third attempt, the physicians were able to carry out the surgery successfully.
After discharge, the patient underwent extensive allergy testing, which was negative. Further testing revealed a significantly elevated tryptase level associated with SM. The patient was then referred to the hematology department, where a bone marrow biopsy confirmed the SM diagnosis.
“Therefore, a cautious approach should be taken where SM, even without formal diagnosis, is indicated in a patient requiring CPB,” the authors concluded.
