The number of patients reaching adulthood after undergoing Fontan palliation for the repair of a congenital heart defect continues to increase. In this case report, we present the anesthetic management of a patient with a history of tricuspid atresia treated with palliative Fontan repair who had developed clinical evidence of Fontan failure. He presented with septic shock secondary to streptococcal toxic shock syndrome complicated by a loculated pleural effusion. He underwent open thoracic decortication under 1-lung ventilation. Discussion focuses on the management of volume status and pulmonary vascular resistance as well as surgical implications of Fontan physiology in thoracic surgery.