Anaphylaxis and cardiac surgery for hypertrophic obstructive cardiomyopathy: a case report and review of anaesthetic management

BACKGROUND: The aim of this paper is to describe clinical management in a situation where patient has experienced anaphylaxis while undergoing surgical septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM). CASE REPORT: A 40-yr-old female was scheduled to undergo surgical septal myectomy for the treatment of HOCM. After induction, the patient developed refractory hypotension that did not respond to escalating doses of vasopressors and volume therapy. Although a clinical examination led to the diagnosis of anaphylaxis, epinephrine, which is the usual treatment of choice, failed to improve the patient's haemodynamics. A transesophageal echocardiography revealed a worsening of left ventricular outflow tract obstruction (LVOTO) after epinephrine administration. In the end, the rapid institution of a cardiopulmonary bypass was required as a rescue therapy instead of to save a patient. CONCLUSION: The anaesthetic goals in a patient in HOCM are to maintain preload and afterload and to avoid stimulation of inotropy and chronotropy to leading to left ventricular outflow obstruction. In a patient with anaphylaxis, maintaining these haemodynamic goals becomes much more difficult since the pathophysiology and usual treatment of choice will worsen LVOTO. Special consideration for the need to have extracorporeal life support to treat refractory hypotension in surgical patients with HOCM may be warranted.