A Case of Clinically Suspected Kounis Syndrome Associated with Platelet Transfusion during Thoracoscopic Right Lower Lobectomy.

INTRODUCTION: Kounis syndrome is an acute coronary syndrome associated with allergic or hypersensitivity reactions and is characterized by the concurrent occurrence of allergic manifestations and coronary artery spasm or myocardial ischemia. Transfusion-related cases, particularly those associated with platelet transfusion, are extremely rare. We report a case of clinically suspected intraoperative Kounis syndrome associated with platelet transfusion during thoracoscopic right lower lobectomy.

CASE PRESENTATION: A 70-year-old man with chronic hepatitis C-associated thrombocytopenia underwent thoracoscopic right lower lobectomy for primary lung cancer. Prophylactic antibiotic administration was uneventful. Irradiated platelet concentrate was transfused intraoperatively as planned. Three minutes after completion of the platelet concentrate transfusion, the heart rate increased and hypotension developed, accompanied by flushing of the face and upper extremities. Phenylephrine and ephedrine were administered without improvement, and anaphylactic shock associated with platelet transfusion was suspected. Adrenaline, antihistamines, and methylprednisolone were administered. Shortly after a continuous intravenous adrenaline infusion was started, ST-segment depression in lead II was noted on the intraoperative electrocardiogram (ECG) monitor, and review of the ECG record confirmed that this change had been present since the onset of the hemodynamic deterioration. Cardiac biomarkers, including troponin T, showed no elevation. Because hemodynamics stabilized under continuous intravenous adrenaline infusion and oxygenation and ventilation remained stable, the surgery was continued and completed thoracoscopically. Postoperative 12-lead electrocardiography showed ST-segment depression in leads II, III, and augmented vector foot, which was resolved by POD 1, without echocardiographic wall motion abnormalities. The postoperative course was uneventful.

CONCLUSIONS: The clinical course and electrocardiographic findings were clinically suggestive of Type I Kounis syndrome. However, because direct coronary assessment, such as coronary angiography, was not performed, a definitive diagnosis could not be established. Under general anesthesia, subjective symptoms cannot be reliably assessed, and hemodynamic instability or ECG abnormalities may be the only clues. Therefore, when allergic reactions and ischemic ECG changes occur intraoperatively, Kounis syndrome should be considered in the differential diagnosis. Platelet transfusion may be associated with intraoperative clinically suspected Kounis syndrome. Prompt recognition, hemodynamic stabilization, and close collaboration between anesthesiologists and surgeons, with strict hemodynamic and electrocardiographic monitoring, are essential for appropriate perioperative management.