Abstract
RATIONALE: Kounis syndrome is a rare but life-threatening anaphylactic reaction that can lead to acute coronary syndrome and cardiac arrest, and requires prompt diagnosis. Adrenaline, which is used to treat anaphylaxis, may cause coronary vasoconstriction and worsen ischemia, whereas coronary vasodilators may dilate systemic vessels and exacerbate hypotension. Delayed diagnosis of Kounis syndrome and inadequate therapeutic intervention may thus lead to a poor outcome. PATIENT CONCERNS: A 59-year-old man was treated for sepsis due to a liver abscess. Following administration of daptomycin, the patient developed severe anaphylactic shock leading to refractory cardiac arrest. Because conventional cardiopulmonary resuscitation was ineffective, extracorporeal cardiopulmonary resuscitation was considered as an alternative approach. DIAGNOSES: On bedside monitoring during cardiopulmonary resuscitation, unexpected ST-segment elevation was found on lead II electrocardiogram. Accordingly, the patient was clinically diagnosed with Kounis syndrome. INTERVENTIONS: Nicorandil (6 mg/h), a coronary vasodilator with minimal blood pressure effects, was administered along with high doses of vasopressors, including adrenaline 0.2 µg/kg/min. OUTCOMES: After the initiation of nicorandil administration, the patient achieved return of spontaneous circulation and did not require extracorporeal cardiopulmonary resuscitation. Based on the elevated serum tryptase level, normal creatine kinase-MB range, and lack of stenosis on coronary angiography, the patient was definitively diagnosed with type I (coronary vasospasm) Kounis syndrome. He was subsequently transferred to the referring hospital without neurological sequelae. LESSONS: If anaphylaxis leads to refractory shock and cardiac arrest, ischemic changes on the electrocardiogram should be investigated to identify underlying Kounis syndrome. In addition to adrenaline, coronary dilators are the definitive treatment. Nicorandil may be a useful treatment option because of its minimal effect on blood pressure.