Congenital Cardiac Anesthesia Society
A Section of the the Society for Pediatric Anesthesia

{“questions”:{“ixq5l”:{“id”:”ixq5l”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:”https:\/\/ccasociety.org\/wp-content\/uploads\/2025\/06\/CCAS-QOW-Pic-6-4-2025.jpg”,”imageId”:”8741″,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Kaitlin M. Flannery, MD, MPH – Stanford University \r\nA 2-day-old, 3.1kg, term neonate has required non-invasive positive pressure ventilation and oxygen administration since delivery due to increased work of breathing and low oxygen saturation. A transthoracic echocardiogram was performed and subsequently a CT scan of the chest with contrast. An image from the CT is displayed. What is the diagnosis? “,”desc”:”EXPLANATION \r\nVascular rings are congenital malformations that result from abnormal embryologic development and regression of the ventral and dorsal aortae and the six paired pharyngeal arches. The malformation results in an encircling and possible compression of the trachea and esophagus. Some present with severe symptoms at birth while others are incidentally found.^{1<\/sup> \r\n\r\nThe Society of Thoracic Surgeons (STS) utilizes the Backer and Mavroudis classifications system. This system divides vascular rings into four categories. These categories account for about 95% of pathology seen. The categories with incidence are:2<\/sup>\r\n\r\n1.\tDouble Aortic Arch (0.53%) \u2013 presence of both left and right-sided aortic arches encircling the trachea and esophagus \r\n2.\tRight aortic arch with left ligamentum (0.05%) \u2013 presence of aberrant right-sided aortic arch with left ligamentum arteriosum attached to left subclavian artery or descending aorta, encircling the trachea and esophagus \r\n3.\tInnominate artery compression syndrome (0.004%) \u2013 not a true vascular ring; occurs mostly when innominate artery origin is more distal or posterior, thus passing across the front of the trachea \r\n4.\tPulmonary artery sling (0.006%) \u2013 not a true vascular ring; aberrant origin of one pulmonary artery arising from the other; passes between the trachea and esophagus at a level close to the carina4<\/sup> \r\n\r\nThe CT shows the left pulmonary artery arising from the right pulmonary artery and coursing between the trachea and esophagus thereby creating a pulmonary artery sling (PAS). Patients with PAS typically present after a few months of life with significant respiratory symptoms as the disease is associated with tracheal stenosis from complete tracheal rings.1<\/sup> The severity of symptoms and management depend on the degree and length of tracheobronchial narrowing. The largest case series on surgical management of PAS was published in 2012.3<\/sup> The series reports the outcomes of 34 patients repaired on CPB from 1985-2012. The surgical approach to tracheal repair changed over the years with slide tracheoplasty utilized since 2002. Slide tracheoplasty is mostly used in cases of long-segment stenosis, and consists in transection and oblique division of the proximal and distal trachea, with subsequent anastomosis of each end, thereby increasing lumen size. Short segment stenosis may be managed with excision of diseased segment and end-to-end anastomosis. The aberrant pulmonary artery is often reimplanted during the same surgery. In this series, 79% of patients had tracheal stenosis from complete tracheal rings. There were no early deaths in this series. The mean percent of LPA blood flow was 41% with only one patient requiring reintervention for stenosis. There were four late deaths in this series, two were unrelated PAS, and two were due to complications from older surgical techniques for complete tracheal rings that resulted in dehiscence during follow-up bronchoscopy.3<\/sup>\r\n\r\n\r\n \r\nREFERENCES \r\n1.\tRagalie WS, Mitchell ME. Chapter 44: Vascular rings and pulmonary artery slings. In: Ungerleider RM, Meliones JN, McMillan KN, Cooper DS, Jacobs JP, eds. Critical Heart Disease in Infants and Children. 3rd ed<\/em>. Elsevier; 2019: 544-50. \r\n2.\tWadle M, Joffe D, Backer C, Ross F. Perioperative and anesthetic considerations in vascular rings and slings. Semin Cardiothorac Vasc Anesth<\/em>. 2024 Sep;28(3):152-64. \r\n3.\tBacker CL, Russel HM, Kaushal S, et al<\/em>. Pulmonary artery sling: current results with cardiopulmonary bypass. J Thorac Cardiovasc Surg<\/em>. 2012 Jan;143(1):144-51. \r\n4.\t McKenzie I, Zestos MM, Stayer SA, Kaminski E, Davies P, Andropoulos DB. Anesthesia for miscellaneous cardiac lesions. In: Andropoulos DB, Mossad EB, Gottlieb EA. Eds. Anesthesia for Congenital Heart Disease. 4th Ed<\/em>. Wiley Blackwell; 2023:781-831. \r\n”,”hint”:””,”answers”:{“lbw7e”:{“id”:”lbw7e”,”image”:””,”imageId”:””,”title”:”A.\tDouble aortic arch”},”70r1i”:{“id”:”70r1i”,”image”:””,”imageId”:””,”title”:”B.\tInnominate artery compression”},”6afqo”:{“id”:”6afqo”,”image”:””,”imageId”:””,”title”:”C.\tPulmonary artery sling “,”isCorrect”:”1″}}}}}}

{“questions”:{“11v76”:{“id”:”11v76″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Omar El Masri, MD, MA – Stanford University AND Kaitlin M. Flannery, MD, MPH – Stanford University \r\nA 5-day-old, 3.2kg, term neonate with severe aortic coarctation and hypoplastic transverse arch (Z-score = -4) is currently managed on a PGE_{1<\/sub> infusion with low lactate and good lower extremity pulses. According to the 2024 Society of Thoracic Surgeons (STS) Clinical Practice Guidelines on the management of neonates and infants with coarctation which is the MOST appropriate next step in management?\r\n\r\n”,”desc”:”EXPLANATION \r\nCoarctation of the aorta accounts for 4-5% of congenital heart disease (CHD). It is the second most common CHD requiring neonatal intervention after patent ductus arteriosus (PDA). In the current era, mortality following surgical repair is low at 0.98%. However, important short and long-term morbidity requiring repeat intervention persists, including re-coarctation and hypertension.^{1, 2<\/sup>\r\n\r\n\r\nDespite the frequency of coarctation, management plans remain heterogenous among institutions and surgeons. In 2024, the STS published practice guidelines for the management of neonates and infants with coarctation of the aorta. Experts in the field reviewed the available literature and using a modified Delphi method established guidelines with classification of the recommendations and level of evidence.1<\/sup> \r\n\r\n\r\nThe following are the practice guidelines for neonates and infants with isolated coarctation1<\/sup>:\r\n\r\n\r\n1.\tSurgical intervention is recommended in the absence of obvious contraindications. (Class I) \r\n2.\tIn patients with prematurity, low weight, or other risk factors for surgical intervention, medical optimization before intervention or primary operation is reasonable. (Class IIa) \r\n3.\tIn patients without associated arch hypoplasia, repair through a thoracotomy is indicated. (Class I) \r\n4.\tIn patients with associated arch hypoplasia that cannot be adequately addressed through a thoracotomy, repair through a sternotomy is preferable. (Class IIa) \r\n5.\tIn patients with bovine arch anatomy, repair through a sternotomy may be reasonable given the potential increased risk of re-coarctation with bovine arch anatomy repaired through a thoracotomy. (Class IIb) \r\n6.\tIn patients undergoing repair through a sternotomy, antegrade cerebral perfusions or limited duration deep hypothermic circulatory arrest may be reasonable. (Class IIb) \r\n7.\tIn patients undergoing repair through a sternotomy, extended end-to-end, arch advancement, and patch augmentation are all reasonable techniques. (Class IIa) \r\n\r\nThe patient presented above has no contraindications to surgical intervention and should undergo surgical repair before onset of complications. Given the patient\u2019s significant transverse arch hypoplasia with a Z-score of -4, a sternotomy with repair on CPB is preferable as the risk of re-coarctation would be high with thoracotomy and repair that did not address the hypoplastic transverse arch. \r\n\r\nThe decision to perform arch repair on CPB with antegrade cerebral perfusion versus coarctation repair via thoracotomy without CPB significantly changes the anesthetic management and postoperative course. However, the literature review to produce these clinical practice guidelines found no significant difference in mortality, global neurologic outcomes, recurrent laryngeal nerve injury, or incidence of chylothorax between the two approaches.1,3<\/sup> \r\n\r\n\r\n \r\nREFERENCES \r\n1.\tStephens EH, Feins EN, Karamlou T, et al<\/em>. The Society of Thoracic Surgeons Clinical Practice Guidelines on the Management of Neonates and Infants with Coarctation.Ann Thorac Surg<\/em>. 2024 Sep;118(3):527-44.\r\n2.\tSpaeth JP, Loepke AW. Chapter 22: Anesthesia for left-sided obstructive lesions. In: Andropoulos DB, Stayer S, Mossad EB, Miller-Hance WC, eds. Anesthesia for Congenital Heart Disease<\/em>. 3rd ed. Wiley Blackwell; 2015: 506-9. \r\n3.\tWaldman JC, Ing RJ, Stone ML. Current Practice Management Guidelines in Neonates and Infants with Isolated Coarctation of the aorta. J Cardiothorac Vasc Anesth<\/em>. 2025 Mar;39(3):573-5.\r\n\r\n”,”hint”:””,”answers”:{“2mnn1”:{“id”:”2mnn1″,”image”:””,”imageId”:””,”title”:”A.\tContinue medical management”},”okp13″:{“id”:”okp13″,”image”:””,”imageId”:””,”title”:”B.\tSurgical repair via sternotomy and cardiopulmonary bypass”,”isCorrect”:”1″},”7ipgr”:{“id”:”7ipgr”,”image”:””,”imageId”:””,”title”:”C.\tSurgical repair via thoracotomy”}}}}}}}

{“questions”:{“vwpuk”:{“id”:”vwpuk”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Sonya V. Gupta, AM, MS1 – Stanford University AND Kaitlin M. Flannery, MD, MPH – Stanford University \r\n\r\nA 2-year-old, 10kg female with DiGeorge syndrome, reactive airway disease, and history of Tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals (MAPCAS), who has undergone unifocalization and complete intracardiac repair with RV-PA conduit, presents to the cardiac catheterization lab for conduit and pulmonary artery dilation. The procedure is complicated by pulmonary hemorrhage, requiring urgent intervention and ICU admission. According to PREDIC^{3<\/sup>T (Procedural Risk in Congenital Cardiac Catheterization), which of the following factors MOST increased the risk of the high-severity adverse event (HSAE) that occurred?\r\n”,”desc”:”EXPLANATION \r\nCatheterization laboratory-based procedures have expanded considerably in recent years, as has the complexity of patients and interventions. To update catheterization lab risk stratification with some of these novel procedures, the PREDIC3<\/sup>T (Procedural Risk in Congenital Cardiac Catheterization) study was published in 2022. The risk stratification system was created looking at the incidence of adverse events in over 23,000 catheterizations at 13 different institutions from January 2014 – December 2017. Importantly, this period included transcatheter pulmonary valve replacement (TPVR), which is missing from older risk stratification systems \r\n\r\nAdverse events were categorized as level 1-5, with 3-5 being high-severity adverse events (HSAE). Level 1 was a near-miss, such as an equipment malfunction with no consequence. Level 2 was a minor event that was not life-threatening, such as a groin hematoma or a self-resolving hemodynamically stable arrhythmia. Level 3 was a moderate event, which could be life-threatening if not treated, such as an unstable arrhythmia or vascular injury that requires treatment. Level 4 is a major event that is life-threatening and requires CPR, surgical treatment, major interventional procedure, or ECMO to treat. Level 5 is a catastrophic event resulting in death. Adverse events occurred in 10.9% of cases, including HSAEs in 5.2% of cases. A total of 17 deaths occurred for a rate of 0.07%.1<\/sup> Of note, case complexity is also increased if multiple procedures are being performed together.1-2<\/sup>\r\n\r\nThe following patient factors were found to be significantly associated with HSAEs1<\/sup>: \r\n\u25cf\tAge < 30 days \r\n\u25cf\tSingle ventricle physiology \r\n\u25cf\tCardiac surgery in the past 90 days \r\n\u25cf\tLow systemic oxygen saturation (<95% for biventricular physiology, <78% for single ventricle) \r\n\u25cf\tLow mixed venous saturation (<60% for biventricular physiology, <50% for single ventricle) \r\n\u25cf\tHigh pulmonary artery pressure (PASP > 45 mmHg for biventricular physiology, mPAP > 17 mmHg for single ventricle) \r\n\u25cf\tSystemic ventricle end-diastolic pressure \u226518 mmHg \r\n\u25cf\tQp:Qs > 1.5:1 \r\n\u25cf\tPVR > 3 iWU \r\n\r\nThe following patient factors were not found to be significantly associated with HSAEs1<\/sup>: \r\n\u25cf\tGenetic syndromes \r\n\u25cf\tNoncardiac problems (ex: chronic lung disease, coagulation disorder) \r\n \r\nThe case types were divided into six risk categories (Table 1). The frequency of HSAE in risk category 0 was 1.1% and 7.7%, 10.8%, and 13.9% for categories 3, 4, and 5, respectively.1<\/sup> \r\n\r\nTable 1. PREDIC3<\/sup>T Case-Type Risk Categories \r\n\r\n \r\nTable from: Quinn BP, Yeh M, Gauvreau K, et al<\/em>. Procedural Risk in Congenital Cardiac Catheterization (PREDIC3<\/sup>T). J Am Heart Assoc<\/em>. 2022;11(1):e022832. Used under Creative Commons License. \r\n\r\nThe patient in the question stem is presenting for a case that falls in risk category 5 due to intervention on \u2265 2 pulmonary arteries and RV-PA conduit intervention. The other answer choices, her genetic syndrome and noncardiac condition, are not associated with increased risk of HSAE in the PREDIC3<\/sup>T study. \r\n\r\n \r\nREFERENCES \r\n1.\tQuinn BP, Yeh M, Gauvreau K, et al. Procedural Risk in Congenital Cardiac Catheterization (PREDIC3T). J Am Heart Assoc<\/em>. 2022;11(1):e022832. doi:10.1161\/JAHA.121.022832\r\n2.\tKobayashi D, Amin EK, Morgan GJ, et al. Usefulness of PREDIC3T Case Type Risk Category in the CRISP Registry. Am J Cardiol<\/em>. 2024;212:73-79. doi:10.1016\/j.amjcard.2023.11.056\r\n”,”hint”:””,”answers”:{“f58rg”:{“id”:”f58rg”,”image”:””,”imageId”:””,”title”:”A. Reactive Airway Disease”},”vxqpo”:{“id”:”vxqpo”,”image”:””,”imageId”:””,”title”:”B. Genetic Syndrome”},”8ugnp”:{“id”:”8ugnp”,”image”:””,”imageId”:””,”title”:”C. Interventional dilation of RV-PA conduit and branch pulmonary arteries”,”isCorrect”:”1″}}}}}}

{“questions”:{“redml”:{“id”:”redml”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Sonya V. Gupta, AM, MS1 – Stanford University AND Kaitlin M. Flannery, MD, MPH – Stanford University\r\n\r\nA 5-year-old, 15kg male with a history of Tetralogy of Fallot, pulmonary atresia and major aortopulmonary collaterals (MAPCAs) who has undergone unifocalization and complete intracardiac repair with RV-PA conduit, presents for a conduit exchange. Additional past medical history includes tracheobronchomalacia, frequent respiratory infections, and hypocalcemia requiring oral calcium supplementation. Which of the following syndromes does this patient MOST likely have?\r\n”,”desc”:”EXPLANATION \r\nThe patient\u2019s clinical presentation is most consistent with DiGeorge syndrome, a multisystem disorder associated with defective development of the pharyngeal pouch system and includes congenital heart disease, especially conotruncal defects including Tetralogy of Fallot, craniofacial anomalies, airway anomalies, and disorders of the endocrine, immune, and hematologic systems. It is most often caused by deletion of chromosome 22q11 (del22q11), though some patients may present with the phenotype without said mutation. While it can be inherited in an autosomal dominant pattern, most cases result from de novo mutations.^{1<\/sup>\r\n\r\nDiGeorge syndrome is the second most common genetic syndrome resulting in congenital heart disease, following Down syndrome. The incidence is 1 in 4000 live births with 70% of patients having CHD. Most data regarding anesthetic and cardiac surgical outcomes are limited to case series and case reports. A larger single-center retrospective study, from the Mayo Clinic, published in 2012, allows examination of outcomes.2<\/sup> The study included 62 unique patients undergoing 136 cardiac surgical procedures from 1976-2012. Despite craniofacial and airway anomalies, 95% of patients were intubated on the first attempt. The 3 patients who were not intubated on the first attempt, were easy to mask ventilate, and were intubated using direct laryngoscopy on attempt 2 or 3. The craniofacial and airway anomalies played a larger role postoperatively as 12% of patients required reintubation and 5% require tracheostomy. Postoperative infections occurred in 22% of cases including 6 sternal wound infections. There were no in-hospital deaths or 30-day mortality. This study did not include a control group. Therefore, it is unclear if the rates of reintubation, tracheostomy, or infection are higher in patients with DiGeorge syndrome.2<\/sup> \r\n\r\nPatients with DiGeorge syndrome may have complex CHD not amenable for corrective surgery and require heart transplantation. Management of immunosuppression may be impacted by the underlying immune deficiencies. A retrospective study published in 2019, utilizing data from all pediatric heart transplants in the United States since 1986, found 17 heart transplants performed in patients with DiGeorge syndrome. Of these patients, 47% underwent transplant as an infant. Pretransplant characteristics were not significantly different from patients without a genetic syndrome. Median survival after transplant was 5.4 years in patients with DiGeorge syndrome versus >15 years in patients without DiGeorge syndrome. However, when patients were matched by age and gender, the difference in post-transplant survival did not exist. There was no significant difference in hospitalization for infection or rejection in patients with or without DiGeorge syndrome. Based on these results, the authors of this study advocate that DiGeorge syndrome should not be an absolute contraindication to heart transplantation.3<\/sup> \r\n\r\nAnesthetic considerations for patients with DiGeorge syndrome involve management of the underlying cardiac lesions as well as extra-cardiac manifestations. Airway anomalies and velopharyngeal dysfunction with resulting risk of aspiration must be carefully considered. These patients are also prone to hypocalcemia from parathyroid hypoplasia and often require calcium supplementation in the perioperative period. Immune impairment from thymic hypoplasia and T-cell dysfunction makes these children at risk of infections as well as transfusion-associated graft-versus-host disease (TA-GVHD) and they should receive irradiated blood products until confirmation of normal immune function.4<\/sup> \r\n\r\nThe patient described in the vignette above has DiGeorge syndrome, based on the presence of conotruncal and airway anomalies, immune dysfunction and hypocalcemia. Down syndrome also presents with characteristic cardiac and craniofacial anomalies, thyroid dysfunction but without hypocalcemia. Goldenhar syndrome patients typically show asymmetrical midface anomalies without endocrine or cardiac manifestations. \r\n\r\n \r\nREFERENCES \r\n1.\tBassett AS, McDonald-McGinn DM, Devriendt K, et al. Practical guidelines for managing patients with 22q11.2 deletion syndrome. J Pediatr<\/em>. 2011;159(2):332-339.e1. doi:10.1016\/j.jpeds.2011.02.039 \r\n2.\tYeng Yeoh T, Scavonetto F, Hamlin RJ, Burkhart HM, Sprung J, Weingarten TN. Perioperative Management of Patients With DiGeorge Syndrome Undergoing Cardiac Surgery. J Cardiothorac Vasc Anesth<\/em>. 2014;28(4):983-989. doi:10.1053\/j.jvca.2013.10.025 \r\n3.\tWoolman P, Bearl DW, Soslow JH. Characteristics and outcomes of heart transplantation in DiGeorge syndrome. Pediatr Cardiol<\/em>. 2019 Feb 7;40(4):768-75. doi: 10.1007\/s00246-019-02063-w \r\n4.\tMcDonald-McGinn DM, Hain HS, Emanuel BS, Zackai EH. 22Q11.2 deletion syndrome. GeneReviews\u00ae<\/em> – NCBI Bookshelf. Published May 9, 2024. https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK1523\/\r\n\r\n\r\n”,”hint”:””,”answers”:{“utm0k”:{“id”:”utm0k”,”image”:””,”imageId”:””,”title”:”A. Down syndrome”},”wbjj8″:{“id”:”wbjj8″,”image”:””,”imageId”:””,”title”:”B. DiGeorge syndrome”,”isCorrect”:”1″},”idvgy”:{“id”:”idvgy”,”image”:””,”imageId”:””,”title”:”C. Goldenhar syndrome”}}}}}}

{“questions”:{“uy0gm”:{“id”:”uy0gm”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Anila B Elliott, MD – University of Michigan – C.S. Mott Children\u2019s Hospital \r\n\r\nA 2-month-old, 3.5kg boy with hypoplastic left heart syndrome (HLHS) palliated with ductal stenting and pulmonary artery banding whose postoperative course was complicated by deep vein thrombosis (DVT) now presents for a Norwood operation. An initial dose of 600 units\/kg heparin was administered with a subsequent activated clotting time (ACT) of 300 seconds. An additional dose of heparin was administered, and the ACT remained 305 seconds. What is the MOST effective course of action to increase the ACT to a level appropriate for cardiopulmonary bypass?”,”desc”:”EXPLANATION \r\nHeparin is currently the gold standard for anticoagulation to prevent thrombosis during cardiopulmonary bypass (CPB) due to its efficacy, cost-effectiveness, and ability to be reversed.^{1<\/sup> Unfractionated heparin (UFH) works by binding to antithrombin (AT), thereby enhancing its activity to inhibit thrombin (factor IIa), factor Xa and other clothing factors.2<\/sup> However, the anticoagulant effect of UFH can vary significantly among different patient populations and age ranges.\r\n\r\nActivated clotting time (ACT) has been in use since the 1960s to monitor the anticoagulant effects of heparin.3<\/sup> Due to the pharmacokinetics of heparin, higher doses result in an increase in intensity and duration of the anticoagulant effect with renal elimination playing a role in clearance. Most institutions require an ACT level of 400-480 seconds to safely initiate CPB. \r\n\r\nSince heparin requires AT to work effectively, a patient with AT deficiency will have a reduction in heparin effect.4<\/sup> In the congenital cardiac patient population, particularly infants, lower concentrations of AT increase the risk of heparin resistance. Congenital heart disease is also associated with coagulation abnormalities.5<\/sup> Cyanotic lesions can lead to chronic hypoxemia, stimulating erythropoiesis, which may suppress platelet production. Increased fibrinolysis has also been reported in cyanotic patients. Poor cardiac output, hypoxemia and chronic passive congestion of the liver can also result in underproduction of clotting factors, specifically those that are vitamin K-dependent (II, VII, IX, X). Patients with HLHS are particularly impacted by factor deficiencies with deficiencies reported in factors II, VII, IX, X, V, VII and protein C and S, which can be most pronounced prior to first-stage palliation. \r\n\r\nHeparin resistance is defined as failure of appropriate weight-based doses of heparin to achieve a target ACT.2<\/sup> Inadequate therapeutic effect of heparin can lead to thrombosis of the CPB circuit, a catastrophic event. Sub-therapeutic heparin levels can also trigger low levels of coagulation cascade activation, resulting in consumptive coagulopathy and excessive bleeding after heparin neutralization. It has been reported that heparin levels can decrease by 40-60% within 80 minutes, with recommendations to re-dose with 1\/3 to \u00bd the original heparin dose, which is often done while on CPB.2<\/sup> \r\n\r\nTreatment options for heparin resistance include additional heparin, fresh frozen plasma (FFP), and AT concentrates.1<\/sup> FFP contains approximately 1 IU of antithrombin per 1mL, but studies have shown that even two units of FFP may be insufficient to improve heparin responsiveness in adults. AT concentrates are an off-label alternative that have been shown to be more effective clinically. Given the paucity of data available in pediatric patients, dosing ranges are variable, with the most clinically efficacious studies showing 50units\/kg to be clinically effective, depending on ACT after initial dose of heparin and goal ACT.3<\/sup> \r\n\r\nThis patient likely has low levels of AT given their age, but also faces the risk of acquired AT deficiency from anticoagulant use. In this 3.5kg infant, approximately 175mL of FFP (more than half the patient\u2019s blood volume) would be needed to provide the equivalent amount of AT in a 50units\/kg dose of concentrate.4<\/sup> Therefore, although institutional practices may vary, the most EFFECTIVE treatment to increase ACT would be to administer AT concentrate, which is answer C. \r\n\r\n\r\n \r\nREFERENCES \r\n1.\tAvidan, MS., Levy, JH., Scholz, J. et al. A phase III, double-blind, placebo-controlled, multicenter study on the efficacy of recombinant human antithrombin in heparin-resistant patients scheduled to undergo cardiac surgery necessitating cardiopulmonary bypass. Anesthesiology<\/em>. 2005; 102: 276-284 \r\n2.\tFinley, A., Greenberg, C. Heparin Sensitivity and Resistance Management During Cardiopulmonary Bypass. Anesth Analg<\/em> 2013; 111(6): 1210-1222. DOI: 10.1213\/ANE.0b013e31827e4e62 \r\n3.\tHarnish, J., Beyer, K., Collins, J. Anticoagulation strategies in pediatric cardiopulmonary bypass, weight-based vs concentration-based approaches. J Extra Corpor Technol<\/em> 2022; 54(2): 153-160 \r\n4.\tJones, AJ., O\u2019Mara, KL., Kelly, BJ., et al. The impact of antithrombin III use in achieving anticoagulant goals in pediatric patients. J Pediatr Pharmacol Ther<\/em> 2017; 22(5): 320-325 \r\n5.\tStockton, WM., Padilla-Tolentino, E., Ragsdale, CE. Antithrombin III doses rounded to available vial sizes in critically ill pediatric patients. J Pediatr Pharmacol Ther <\/em>2017; 22(1): 15-21\r\n”,”hint”:””,”answers”:{“s4vvg”:{“id”:”s4vvg”,”image”:””,”imageId”:””,”title”:”A.\tAdminister 5mL\/kg fresh frozen plasma”},”6lcjd”:{“id”:”6lcjd”,”image”:””,”imageId”:””,”title”:”B.\tInitiate cardiopulmonary bypass and administer additional heparin via the circuit”},”qcnp3″:{“id”:”qcnp3″,”image”:””,”imageId”:””,”title”:”C.\tAdminister 50 units\/kg antithrombin concentrate”,”isCorrect”:”1″}}}}}}