Cardiac arrest due to anaphylactic shock after cardiac surgery with massive bleeding and cardiac tamponade following cardiopulmonary resuscitation: case report

Abstract

Introduction: Anaphylaxis is a severe and life-threatening systemic hypersensitivity reaction. Perioperative anaphylaxis is reported in up to 1/13.000 anaesthetic procedures. Hypotension related to anaesthetic agents, inability of the anaesthetised patient to communicate early symptoms and that the patient is covered can contribute to delayed diagnosis with terrible consequences. Case report: We report a case of a 76-year old man admitted to ICU after elective valvular heart surgery. Immediate postoperative follow-up was complicated by hemodynamic instability due to a major bleeding requiring surgical revision. After re-admission to ICU, the patient stayed hemodynamically stable with low doses of vasoactive and inotropic drugs with no evidence of bleeding or myocardial dysfunction. Unexpectedly, the patient developed refractory hypotension and subsequent cardiac arrest (asystole). Cardiopulmonary resuscitation (CPR) was started. When we uncovered the chest of the patient to perform urgent transthoracic echocardiography generalised flushing and hives were noticed. At that point fresh frozen plasma (FFP) was being transfused to optimise coagulation, as well as metamizol. Immediate management of anaphylaxis (epinephrine, aggressive fluid therapy, corticosteroids and antihistamines) was started stopping all the suspected triggers (FFP, metamizol). During external cardiac massage, massive bleeding appeared through the thoracic drainage tubes and plasmafree management according to our institutional protocol was started. Emergency resternotomy was performed in the ICU due to cardiac tamponade and ineffective CPR. A bleeding point in the aorta was repaired successfully. A total of 10 red packed blood cells, 4g of fibrinogen concentrate, 1200 IU of prothombin complex concentrate and 2 pools of platelets were transfused, achieving patient stabilisation after 40 min of CPR. Once again, the patient was transferred to the operating room for surgical revision. The levels of plasma total tryptase after the reaction were not elevated, neither histamine, latex or complement factors. Patient was discharged from hospital two months later, after overcoming multiple postoperative complications. At the moment, the delayed immunological study is still outstanding. Discussion: Serious allergic events occurring during anaesthesia and the peri-operative period are rare, but can rapidly evolve into life-threatening situations if not recognised and managed promptly. In the postoperative period after cardiac surgery the immediate diagnosis of anaphylaxis can be difficult, particularly as sudden cardiovascular collapse is also observed in situations of cardiogenic shock, major bleeding, cardiac tamponade, vasoplegia or severe arrhythmias. Nevertheless anesthesiologists should not forget about the rare diagnosis of anaphylaxis. While transthoracic echocardiography is performed, the patient's body should be uncovered to check for cutaneous manifestations. With a high level of clinical suspicion early and specific management of anaphylaxis should be started. In this case it is possible that high levels of triptase were not detected because of total replacement of circulating blood volume due to massive transfusion.