Anaphylaxis is a life-threatening hypersensitivity reaction that can quickly progress to circulatory collapse, even in the presence of timely epinephrine administration. This report describes a case of rocuronium anaphylaxis which progressed to circulatory arrest despite intravenous epinephrine and crystalloid resuscitation. Transesophageal echocardiography performed during cardiopulmonary resuscitation enabled rapid identification of the cause of shock and redirected management to prioritize further fluid administration, leading to return of spontaneous circulation with a good outcome. The etiology of shock in anaphylaxis can be variable, and transesophageal echocardiography can rapidly identify the likely mechanism and guide treatment without interrupting ongoing resuscitative efforts.