1 - Serviço de Anestesiologia, Centro Hospitalar Universitário de Lisboa Ocidental
2 - Serviço de Anestesiologia, Centro Hospitalar Universitário de Lisboa Ocidental
3 - Serviço de Anestesiologia, Centro Hospitalar Universitário de Lisboa Central
- reunião nacional (congresso “O Norte da Anestesia”)
Resumo:
Background: Congenital heart diseases (CHD) are one of the most common birth defects. Tetralogy of Fallot (TOF) is the most prevalent cyanotic CHD.1 A diagnosis of CHD increases the mortality risk for noncardiac surgery.2 Thus, the anesthetic approach of patients with unrepaired TOF is challenging. Hypercyanotic spells (HS) are episodes of shunt reversal with acute worsening of cyanosis that require immediate intervention. Here we present a report of intraoperative HS and its anesthetic management.
Case Report: A 10-month-old, 9kg male child presented for cleft lip repair. He was evaluated preoperatively, presenting an unrepaired TOF medicated with propanolol. The echocardiogram showed the four typical changes in TOF, with left-to-right shunt. Upon arrival at the operating room, pulse oximetry was 96-98% on room air. Inhalation induction was performed uneventfully and continuous propofol infusion was started for maintenance. A few minutes later, before the surgical procedure begins, severe desaturation occurs, with pulse oximetry values of 40-60%. After confirming the integrity of the airway and adequacy of the ventilation, the cyanosis was considered to be of cardiac origin. Ketamine 2mg/kg was administered, followed by a bolus of normal saline 10mL/kg, and anesthetic drugs were reversed. A progressive improvement of the condition was observed, with complete reversal of hypoxemia.
Discussion: HS are episodes of shunt reversal that may occur in children with intracardiac shunts, being more often associated with TOF. HS during anaesthesia is rare and is generally due to infundibular spasm and consequent increase in right-left shunt, but it may also occur when systemic vascular resistance (SVR) decreases and pulmonary vascular resistance increases due to anaesthetic drugs or increased airway pressures. Therapy includes increasing SVR, fluid optimization and decreasing outflow track obstruction.1
References: 1Athar M. A case of severe perioperative hypoxia in uncorrected tetralogy of fallot: Anesthetic management. Rev Esp Anestesiol Reanim 2016; 2Menghraj SJ. Anaesthetic considerations in children with congenital heart disease undergoing non-cardiac surgery. Indian J Anaesth. 2012.
Learning Points: The optimal management of these patients require a thorough understanding of the pathophysiology of the unrepaired TOF, which is essential for the successful outcome for non-cardiac surgery.
Palavras Chave: Tetralogia de Fallot, inversão de shunt, abordagem anestésica