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992 www.pccmjournal.org October 2019 • Volume 20 • Number 10 Infants with congenital heart disease (CHD) requiring surgical intervention on cardiopulmonary bypass (CPB) are at high risk for developing a low cardiac output state (LCOS) and, of relevance to this critique, cardiac surgery associated acute kidney injury (CS-AKI) during the early postoperative period. The vast majority of pediatric cardiac surgical cases are planned, which makes this an appealing population in whom to prospectively study the potential role of pharmacologic agents in reducing the occurrence rate of LCOS or associated organ dysfunction. Levosimendan is a calcium-sensitizing inodilator that has been widely available in Europe for nearly 2 decades, but not approved by the Food and Drug Administration for use in the United States (1). Levosimendan increases force of myocardial contraction by stabilizing calcium binding to troponin C and separately enhances peripheral and coronary vasodilation by direct effect on adenosine triphosphate–sensitive potassium channels in vascular smooth muscle (2). These mechanisms of action without increased myocardial oxygen demand have made levosimendan an attractive target for study in populations at high risk for marginal systemic oxygen delivery associated with low cardiac output, including patients after surgery for CHD. In several small randomized controlled trials (RCTs) in postoperative CHD populations, levosimendan was associated with improved cardiac output, improved cerebral near-infrared spectroscopy, and reduced myocardial oxygen demand, and pulmonary artery pressure compared with either milrinone or dobutamine (3–6). Despite these promising findings, a meta-analysis of the studies did not find levosimendan to be superior to standard inotropic agents in preventing postoperative LCOS or mortality, or improving postoperative intensive care or hospital length of stay in children with either biventricular or palliated 3. Harris KC, Holowachuk S, Pitfield S, et al: Should early extubation be the goal for children after congenital cardiac surgery? J Thorac Cardiovasc Surg 2014; 148:2642–2647 4. Hamilton BC, Honjo O, Alghamdi AA, et al: Efficacy of evolving earlyextubation strategy on early postoperative functional recovery in pediatric open-heart surgery: A matched case-control study. Semin Cardiothorac Vasc Anesth 2014; 18:290–296 5. Ferreira FV, Sugo EK, Aragon DC, et al: Spontaneous Breathing Trial for Prediction of Extubation Success in Pediatric Patients Following Congenital Heart Surgery: A Randomized Controlled Trial. Pediatr Crit Care Med 2019; 20:940–946 6. Randolph AG, Wypij D, Venkataraman ST, et al: Effect of mechanical ventilator weaning protocols on respiratory outcomes in infants and children: A randomized controlled trial. JAMA 2002; 288:2561–2568 7. Farias JA, Retta A, Alía I, et al: A comparison of two methods to perform a breathing trial before extubation in pediatric intensive care patients. Intensive Care Med 2001; 27:1649–1654 8. Willis BC, Graham AS, Yoon E, et al: Pressure-rate products and phase angles in children on minimal support ventilation and after extubation. Intensive Care Med 2005; 31:1700–1705 9. Khemani RG, Hotz J, Morzov R, et al: Pediatric extubation readiness tests should not use pressure support. Intensive Care Med 2016; 42:1214–1222 10. Farias JA, Alía I, Retta A, et al: An evaluation of extubation failure predictors in mechanically ventilated infants and children. Intensive Care Med 2002; 28:752–757 11. Laudato N, Gupta P, Walters HL 3rd, et al: Risk factors for extubation failure following neonatal cardiac surgery. Pediatr Crit Care Med 2015; 16:859–867 12. Gupta P, Rettiganti M, Gossett JM, et al: Risk factors for mechanical ventilation and reintubation after pediatric heart surgery. J Thorac Cardiovasc Surg 2016; 151:451–458.e3 13. Gaies M, Tabbutt S, Schwartz SM, et al: Clinical epidemiology of extubation failure in the pediatric cardiac ICU: A report from the Pediatric Cardiac Critical Care Consortium. Pediatr Crit Care Med 2015; 16:837–845 14. Mastropietro CW, Cashen K, Grimaldi LM, et al: Extubation failure after neonatal cardiac surgery: A multicenter analysis. J Pediatr 2017; 182:190–196.e4 15. Venkataraman ST: Weaning and extubation in infants and children: Religion, art, or science. Pediatr Crit Care Med 2002; 3:203–205