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

{“questions”:{“elmq8”:{“id”:”elmq8″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Vera Winograd-Gomez, MD \u2013 Cincinnati Children\u2019s Hospital and Medical Center, Cincinnati, OH AND\r\nDestiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 2-month-old infant with cor triatriatum sinister is to undergo surgical repair. Which of the following hemodynamic goals is MOST appropriate during the pre-bypass period? \r\n”,”desc”:”EXPLANATION \r\nCor triatriatum (\u201ctriatrial heart\u201d), a rare cardiac anomaly found in approximately 1 in 1000 patients with congenital heart disease, describes the anatomical finding of a membrane dividing the left atrium (sinister) or right atrium (dexter) into two chambers. Cor triatriatum sinister results from an inadequate merging of the common pulmonary vein with the left atrium during heart development. In this malformation, a fibromuscular membrane with one or more orifices separates the atrium into an upper chamber, with the pulmonary veins, and a lower chamber with the left atrial appendage and the mitral valve. The degree of obstruction to blood flow through the orifices in the membrane determines the severity of the patient\u2019s symptoms. Significant obstruction may result in severe left atrial hypertension, low cardiac output, and pulmonary venous hypertension. The symptoms and pathophysiology are similar to severe mitral stenosis. Most patients develop symptoms during the first year of life, or earlier if severe obstruction is present. There are also reports of completely asymptomatic adult patients with multiperforated membranes. Cor triatriatum sinister is usually associated with other congenital cardiac malformations including hypoplastic left heart syndrome, left superior vena cava, and anomalous pulmonary venous drainage.\r\n\r\nAnesthetic considerations and goals are similar to mitral stenosis, which include the following: 1) preservation of contractility and normal sinus rhythm; 2) low to low-normal heart rate to enhance left ventricular filling time in the presence of inflow obstruction; 3) maintenance of adequate preload (central venous pressure[CVP]) to minimize the functional obstruction to left ventricular (LV) filling; and 4) adequate afterload for maintenance of systemic and coronary artery perfusion. Maneuvers to decrease pulmonary vascular resistance (PVR) before relieving pulmonary venous obstruction can result in the worsening of pulmonary venous hypertension. Conversely, after repair, pulmonary arterial hypertension may indicate a need for inhaled nitric oxide during the postoperative period. \r\nIn this case scenario, during the pre-bypass period, the hemodynamic goals are normal sinus rhythm, low to low-normal heart rate, maintenance of adequate preload (CVP) and afterload (mean arterial pressure (MAP)), and avoidance of low PVR. Decreased afterload can result in coronary artery hypoperfusion in the setting of a reduced MAP pressure in a patient with impaired left ventricular filling\/stroke volume. Excessive preload or high central venous pressure (CVP) can exacerbate left atrial hypertension and pulmonary edema, whereas low preload and CVP can further reduce stroke volume (LV end-diastolic volume) and cardiac output. Left atrial hypertension and pulmonary venous hypertension with secondary pulmonary arterial hypertension may require initiation of inhaled nitrous oxide post-operatively. \r\n\r\n\r\n \r\nREFERENCES \r\n\r\nSpaeth J, Loepke A. Anesthesia for left-sided obstructive lesions. In: Andropoulos DB, Mossad EB, Gottlieb EA, eds. Anesthesia for Congenital Heart Disease<\/em>. 4th ed. Hoboken, NJ; Wiley-Blackwell. 2023: 513-514.\r\n\r\nStout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA\/ACC Guideline for the Management of Adults With Congenital Heart Disease: Executive Summary: A Report of the American College of Cardiology\/American Heart Association Task Force on Clinical Practice Guidelines [published correction appears in J Am Coll Cardiol. 2019 May 14;73(18):2361]. J Am Coll Cardiol. 2019;73(12):1494-1563. doi:10.1016\/j.jacc.2018.08.1028\r\n”,”hint”:””,”answers”:{“mlgrq”:{“id”:”mlgrq”,”image”:””,”imageId”:””,”title”:”A. Heart rate 100 to 140 bpm”,”isCorrect”:”1″},”1ih89″:{“id”:”1ih89″,”image”:””,”imageId”:””,”title”:”B. Mean arterial pressure 35 to 45 mmHg”},”zauyj”:{“id”:”zauyj”,”image”:””,”imageId”:””,”title”:”C. Central venous pressure 3-5 mmHg”}}}}}

{“questions”:{“74dah”:{“id”:”74dah”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: David Fitzgerald, MD and Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 1-month-old boy who is born with multiple intracavitary left ventricular tumors presents for follow-up cardiac evaluation. A transthoracic echocardiogram demonstrates multiple masses of homogeneous appearance without inflow or outflow obstruction that are reduced in size from previous imaging. Delta waves are noted on the electrocardiogram. Which of the following cardiac tumors is the MOST likely diagnosis?”,”desc”:”EXPLANATION \r\nPrimary cardiac tumors in children are rare with a reported incidence of up to 0.4%, excluding inflammatory masses, thrombi, and vegetations. Although most congenital cardiac tumors are benign (90%), the degree of involvement with or invasion into surrounding cardiac structures can lead to detrimental physiologic consequences. \r\n\r\nThe most common type of cardiac tumor in children is rhabdomyoma, accounting for over 60% of cases. Morphologically, these tumors are well circumscribed, multiple, and often located in the ventricles, either in an intramural or intracavitary position. On echocardiographic images, rhabdomyomas appear echogenic and homogenous. As many of these tumors regress spontaneously, an initial conservative, observational approach to management is appropriate unless the tumors cause hemodynamically significant sequelae. Both atrial and ventricular arrhythmias can occur in 40% of cases. Specifically, the incidence of Wolff-Parkinson-White syndrome is ten-fold that of the general population. Rhabdomyomas are known to be associated with tuberous sclerosis, an autosomal dominant multi-systemic disease affecting the brain, kidney, liver, and lungs. The drugs sirolimus and everolimus have been shown to reduce tumor size in the heart and brain, thus offering a potential alternative to surgical resection.\r\n\r\n\r\nThe second most common type of cardiac tumor in children is fibroma, accounting for 10-25% of cases. Unlike rhabdomyomas, fibromas are solitary tumors that typically do not regress. They tend to grow slowly, typically reaching maximal size in late gestation and early infancy. They are usually located in the interventricular septum or on the ventricular free wall. Fibromas are echogenic, well circumscribed, and often have areas of calcification or cystic degeneration. Fibromas often grow into the conduction system and may cause ventricular tachycardia or sudden death. \r\n\r\nMyxomas are rare in neonates but account for approximately 10% of cardiac tumors in older children. They are the most common cardiac tumor in adults. They are most commonly located in the left atrium arising from the fossa ovalis. Morphologically they appear sessile or pedunculated and lobular with frond like projections. Myxomas do not recede but rather require resection. The morphological appearance, typical location in the left atrium and later presentation in life tend to make these lesions easily identifiable. Clinically significant, intermittent obstruction of left ventricular inflow across the mitral valve can occur, as can embolization. \r\n\r\nIn the stem, the patient has multiple tumors with a characteristic echocardiographic appearance and history of regression over time that is most consistent with a cardiac rhabdomyoma. Fibromas may have a cystic appearance, are solitary and do not regress. Myxomas are usually present in older children, are typically located in the left atrium, and do not recede.\r\n\r\n\r\n \r\nREFERENCES \r\nUzun O, Wilson DG, Vujanic GM, Parsons JM, De Giovanni JV. Cardiac tumours in children. Orphanet J Rare Dis<\/em>. 2007;2:11. \r\n\r\nMarx G, Moran A. Cardiac tumors. In: Shaddy R, Penny D, Feltes T, Cetta F, Mital S, eds. Moss & Adams\u2019 Heart Disease in Infants, Children, and Adolescents: Including the Fetus and Young Adult<\/em>. 10th ed. Philadelphia: Lippincott Williams and Wilkins; 2022:1639-1644\r\n\r\nMcKenzie I, Markakis Zestos M, Stayer S, Kamiski E, Davies P, Andropoulos D. In: Andropoulos D, Mossad E, Gottlieb E, eds. Anesthesia for miscellaneous lesions. Anesthesia for Congenital Heart Disease<\/em>. 4th ed. New Jersey: John Wiley & Sons, Inc.; 2023: 816-820.\r\n\r\n\r\n”,”hint”:””,”answers”:{“f9oqu”:{“id”:”f9oqu”,”image”:””,”imageId”:””,”title”:”A.\tFibroma”},”ldlpv”:{“id”:”ldlpv”,”image”:””,”imageId”:””,”title”:”B.\tRhabdomyoma”,”isCorrect”:”1″},”urfik”:{“id”:”urfik”,”image”:””,”imageId”:””,”title”:”C.\tMyxoma\r\n\r\n”}}}}}

{“questions”:{“di61c”:{“id”:”di61c”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Amy Babb, MD – Vanderbilt University and Kaitlin M. Flannery, MD, MPH – Stanford University \r\nA 16-year-old girl with a history of orthotopic heart transplantation is admitted with one week of nausea, vomiting, and fatigue. She is scheduled for an urgent endomyocardial biopsy due to suspected rejection. Past medical history includes stage 3 chronic kidney disease and type 2 diabetes, and current medications are aspirin, atorvastatin, carvedilol and empagliflozin. Which of the following laboratory values is MOST likely to be associated with euglycemic diabetic ketoacidosis associated with empagliflozin?\r\n”,”desc”:”EXPLANATION \r\nEmpagliflozin, dapagliflozin, canagliflozin, and ertugliflozin are sodium-glucose cotransporter-2 (SGLT2) inhibitors used for managing type 2 diabetes, chronic kidney disease, and heart failure. SGLT2 inhibitors work by blocking reabsorption of glucose and sodium in the proximal renal tubules leading to glucosuria, natriuresis, and diuresis. Adult studies and limited pediatric studies have shown SGLT2 inhibitors can decrease HbA1c, proteinuria, brain natriuretic peptide (BNP), and blood pressure, and modestly improve ejection fraction in heart failure. Adverse effects include urinary tract infection and fungal genital infections (due to glucosuria), headache, diarrhea, vomiting, and euglycemic diabetic ketoacidosis (eDKA). \r\n\r\nThe mechanism of SGLT2-associated eDKA is not completely understood. However, diagnostic criteria of eDKA are similar to classic DKA. The most notable difference is the absence of hyperglycemia in eDKA that is typically seen in classic DKA. DKA occurs during a relative or absolute state of insulin deficiency with increased counter-regulatory hormones, including glucagon, corticosteroids and catecholamines. The imbalance of hormones leads to ketone formation and anion-gap metabolic acidosis. In the presence of SGLT2 inhibitors, glucosuria and diuretic effect lowers the serum glucose and decreases the overall insulin requirement. During periods of stress, such as illness, nausea, vomiting, fasting and surgery, the low insulin\/high glucagon environment can lead to eDKA (see Figure 1 below). \r\n\r\n \r\n \r\n \r\nFigure 1. Proposed role of sodium-glucose cotransporter 2 (SGLT2) inhibition in euglycemic diabetic ketoacidosis (eDKA). Classic DKA results from insulin deficiency (absolute or relative) and concurrent increase in counter-regulatory hormones leading to ketosis, hyperglycemia, and osmotic diuresis. In contrast, SGLT2 inhibitor therapy in a well-compensated individual at baseline causes glucosuria, mild volume depletion, and lower serum glucose levels, associated with decreased insulin secretion. During times of intercurrent illness and\/or metabolic stress, such as surgery or gastrointestinal illness, decreased carbohydrate intake coupled with lower serum glucose levels can further depress insulin secretion. This can ultimately lead to eDKA (red box). \u2217Possible pathways of carbohydrate deficiency and causes of insulinopenia. Abbreviations: BP, blood pressure; PO, oral. (From: Wang KM and Isom RT. SGLT2 inhibitor-induced euglycemic diabetic ketoacidosis: A case report. Kidney Med. 2020;2:218-221. Used under Creative Commons License.) \r\n\r\nA diagnosis of eDKA requires the following: \r\n1.\tBlood glucose < 200 mg\/dL\r\n2.\tKetonemia (serum beta-hydroxybutyrate greater than 3 mmol\/L) \r\n3.\tAnion gap metabolic acidosis: \r\na.\tArterial pH < 7.3 \r\nb.\tSerum bicarbonate < 18 mEq\/L \r\nc.\tAnion gap > 10 mmol\/L \r\n\r\n\r\nTreatment of eDKA includes initiation of IV insulin infusion and dextrose solution, as well as IV fluid repletion and electrolyte management. The goal of therapy in eDKA is not to lower the serum glucose, but to replenish the insulin stores necessary to reduce ketone production. Monitoring of urine glucose can help determine residual SGLT2 inhibitor activity, and urine\/serum ketones can guide efficacy of treatment. \r\n\r\nDue to the frequency of reported perioperative eDKA events, the FDA updated its safety labeling in 2020 to recommend that empagliflozin, dapagliflozin, and canagliflozin be held for THREE days and ertugliflozin for FOUR days prior to elective procedures. In addition, a recent study from Massachusetts General Hospital has shown that anion gap metabolic acidosis develops in all patients when SGLT2 inhibitors were not held appropriately. \r\n\r\nWhen patients on SGLT2 inhibitors present for urgent\/emergent procedures, they must be monitored closely for the development of eDKA. Signs and symptoms of eDKA are non-specific and include nausea, vomiting, abdominal pain, fatigue, tachycardia, and tachypnea. Unfortunately, these are also signs of orthotopic heart transplant rejection and heart failure. \r\n\r\nDue to increased evidence in the literature, candidacy and indications for SGLT2 inhibitor use are being expanded to include children ages ten years and older, non-diabetic patients with heart failure and congenital heart disease patients. This trend will increase the likelihood of pediatric cardiac anesthesiologists and pediatric anesthesiologists managing patients treated with SGLT2 inhibitors in the perioperative setting.\r\n\r\nThe correct answer is B. EDKA is characterized by the finding of increased serum and urine ketones, such as serum beta-hydroxybutyrate 5, in the presence of an increased anion-gap metabolic acidosis and relatively normal serum glucose levels. \r\n\r\n \r\nREFERENCES \r\nGrube PM, Beckett RD. Clinical studies of dapagliflozin in pediatric patients: a rapid review. Ann Pediatr Endocrinol Metab<\/em>. 2022;27:265-72.\r\n\r\nSteinhorn B, Wiener-Kronish J. Dose-dependent relationship between SGLT2 inhibitor hold time and risk from postoperative anion gap acidosis: a single-centre retrospective analysis. Br J Anaesth<\/em>. 2023 Oct;131(4):682-6.\r\n\r\nChow E, Clement S, Garg R. Euglycemic diabetic ketoacidosis in the era of SGLT-2 inhibitors. BMJ Open Diab Res Care<\/em>. 2023;11:e003666.\r\n\r\nFDA revises labels of SGLT2 inhibitors for diabetes to include warnings about too much acid in the blood and serious urinary tract infections (fda.gov). 2022. Available at: https:\/\/www.fda.gov\/drugs\/drug-safety-and-availability\/fda-revises-labels-sglt2-inhibitors-diabetes-include-warnings-about-too-much-acid-blood-and-serious. Accessed 7\/17\/2023.\r\n\r\n”,”hint”:””,”answers”:{“qqk3f”:{“id”:”qqk3f”,”image”:””,”imageId”:””,”title”:”A.\tArterial pH 7.35″},”un9x4″:{“id”:”un9x4″,”image”:””,”imageId”:””,”title”:”B.\tSerum beta-hydroxybutyrate 5 mmol\/L “,”isCorrect”:”1″},”gxnjc”:{“id”:”gxnjc”,”image”:””,”imageId”:””,”title”:”C.\tBlood Glucose 350 mg\/dL”}}}}}

{“questions”:{“nalqn”:{“id”:”nalqn”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Nicholas Houska, DO – University of Colorado, Children\u2019s Hospital Colorado \r\n\r\nA 14-year-old girl with a past medical history of obesity and family history of Factor V Leiden presents with chest pain, dyspnea, tachycardia and hypotension. Computed tomography pulmonary angiography demonstrates a pulmonary embolism in the main pulmonary artery with extension into bilateral branch pulmonary arteries. Transthoracic echocardiography reveals interventricular septal flattening, severe tricuspid regurgitation, and severely diminished right ventricular function. Which of the following medication regimens is the MOST appropriate treatment for severe high-risk pulmonary embolism?”,”desc”:”EXPLANATION \r\nThough less common in children than adults, pulmonary embolism (PE) is associated with significant morbidity and mortality. Guidelines for management of acute pulmonary embolism in children are based on those created for adults, due to the more established literature in this population. In most guidelines, risk stratification of pulmonary embolism is the initial step in the diagnostic and treatment algorithm. High risk (massive) pulmonary embolism is typically defined as having signs of severe cardiopulmonary dysfunction or obstructive shock, such as tachycardia, hypotension, and altered mental status. Intermediate risk (sub massive) PE typically lacks signs of obstructive shock but retains the signs of right ventricular (RV) strain as evidenced by echocardiography and electrocardiogram, or elevated cardiac enzymes. \r\n\r\n\r\nSigns and symptoms of PE in children may differ from those in adults. Children often have a delayed presentation due to an increased ability to physiologically compensate as compared to adults, non-specific symptoms, and difficulty in symptom communication. These signs and symptoms include chest pain, dyspnea, hypoxemia, cough, hemoptysis, or more severely, hypotension, tachycardia, and cardiac arrest. There should be a high index of suspicion in children with risk factors for PE, which include use of oral contraceptives, hypercoagulable state, presence of an indwelling central venous catheter, obesity, malignancy, sickle cell anemia, and sepsis. \r\n\r\n\r\nSevere pulmonary embolism causes an acute increase in pulmonary artery pressure based on the degree of obstruction. Acute RV dysfunction or failure can lead to RV dilation, tricuspid regurgitation, left ventricular (LV) dysfunction, and cardiac arrest. The combination of systemic hypotension and increased RV pressure leads to a decrease in myocardial oxygen supply with increased demand that results in a downward spiral of myocardial ischemia followed by further mismatch in myocardial oxygen supply and demand. Useful laboratory values include d-dimer, coagulation studies, and cardiac enzymes. The electrocardiogram will often show signs of right ventricular strain. Echocardiography may demonstrate the pulmonary embolism and indirect signs of acute pulmonary hypertension with tricuspid regurgitation, RV dilation, and RV systolic dysfunction. When risk factors, clinical signs and symptoms, and laboratory values suggest a high probability of PE, computed tomography pulmonary angiography (CTPA) is considered the diagnostic test of choice. \r\n\r\n\r\nIn patients with severe high-risk pulmonary embolism, systemic thrombolysis with thrombolytic agents such as tissue plasminogen activator (tPA) has been shown to improve outcomes. This is reflected in guidelines recommending this treatment, with the greatest benefit being initiation within 24 hours of symptom onset. Surgical embolectomy (SE) or catheter-based embolectomy (with or without catheter directed thrombolytic treatment) may also be considered in severe cases, though evidence on outcomes is less robust. In patients with intermediate risk PE, systemic thrombolysis may be associated with less progression of symptoms but is associated with increased risk for severe intracranial bleeding. Retrospective studies in adults have found equivalent short- and long-term mortality between patients receiving systemic thrombolysis versus surgical embolectomy. These studies have found that the thrombolysis patients experienced more stroke, reintervention, and recurrence, as compared to the SE group, which experienced a higher rate of major bleeding. A small retrospective study in children showed similar mortality rate between thrombolysis and SE but higher rates of non-fatal major hemorrhage in patients undergoing SE. Other practical considerations in choosing management are the timing and availability of a surgical team versus catheterization team, how distal the embolus resides, and if the patient has contraindications to systemic thrombolysis. \r\n\r\n\r\nGiven the severity of the signs and symptoms in this patient consistent with a high-risk massive PE with hemodynamic compromise, thrombolytic intervention with tissue plasminogen activator would be indicated to prevent further decompensation. Unfractionated heparin alone would not be sufficient for a high-risk PE but may appropriate for intermediate risk PE. Warfarin alone would not be an appropriate treatment in a patient with high-risk PE because it requires administration for 5 to 7 days to achieve a therapeutic level and has a transient procoagulant effect during initial administration requiring coadministration with either unfractionated heparin or low molecular-weight heparin. \r\n\r\n\r\n \r\nREFERENCES \r\n\r\nRoss C, Kumar R, Pelland-Marcotte MC et al. Acute Management of High-Risk and Intermediate-Risk Pulmonary Embolism in Children: A Review. Chest<\/em>. 2022 161(3):791-802. doi: 10.1016\/j.chest.2021.09.019. \r\n\r\n\r\nZaidi AU, Hutchins KK, Rajpurkar M. Pulmonary Embolism in Children. Front Pediatr<\/em>. 2017;5:170. doi: 10.3389\/fped.2017.00170. \r\n\r\n\r\nOrtel TL, Neumann I, Ageno W, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism. Blood Advances<\/em>. 2020;4(19):4693-4738.\r\n\r\n\r\nKonstantinides SV, Meyer G, Becattini C, et al. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (Ers). Eur Heart J<\/em>. 2020;41(4):543-603.\r\n\r\n\r\nNavanandan N, Stein J, Mistry RD. Pulmonary Embolism in Children. Pediatr Emerg Care<\/em>. 2019:35(2): 143-151.\r\n”,”hint”:””,”answers”:{“yw3nb”:{“id”:”yw3nb”,”image”:””,”imageId”:””,”title”:”A. Unfractionated heparin “},”zgmzc”:{“id”:”zgmzc”,”image”:””,”imageId”:””,”title”:”B. Tissue plasminogen activator”,”isCorrect”:”1″},”rs8ml”:{“id”:”rs8ml”,”image”:””,”imageId”:””,”title”:”C. Warfarin\r\n\r\n”}}}}}

{“questions”:{“5jebq”:{“id”:”5jebq”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Nicholas Houska, DO – University of Colorado, Children\u2019s Hospital Colorado \r\nA 2-day-old boy born at 31 weeks of gestation with a congenital diaphragmatic hernia develops severe hypoxemia despite utilization of high-frequency oscillatory ventilation. The patient is deemed NOT to be a candidate for extracorporeal membrane oxygenation according to institutional policy. Which of the following adverse outcomes is the MOST likely reason why this patient is not a candidate for extracorporeal membrane oxygenation?\r\n\r\n”,”desc”:”EXPLANATION \r\nThe Extracorporeal Life Support Organization (ELSO) Guidelines for Neonatal Respiratory Failure provide evidence-based guidelines on patient selection, modes of support, and technical considerations for extracorporeal membrane oxygenation (ECMO) in neonates. These 2020 guidelines state that postmenstrual age <34 weeks and weight <2 kg are relative contraindications for ECMO, where postmenstrual age is defined as the sum of gestational age and chronologic age. The reason for this is the historically high rate of intracranial hemorrhage (ICH) (36%) and mortality (62%) in neonates <35 weeks gestational age (GA) versus 12% rate of ICH and 49% mortality in those over 35 weeks gestation.\r\n\r\nWith improvements in mortality trends and the rates of ICH in neonates <34 weeks GA, there is increasing utilization of ECMO in this population. Survival in patients <34 weeks GA who are offered ECMO has increased from 21% to between 48-76%. As survival outcomes continue to improve, certain centers are considering younger and smaller patients as candidates for ECMO. In a 2023 article, Burgos et al suggest that ECMO should be considered for patients at 32 to 33 weeks GA when restricted to high-volume neonatal ECMO centers with close reporting to ELSO, targeted oxygen delivery, and continuous technology development. Despite this, prematurity and extremely low birth weight remain high risk factors for morbidity and mortality with ECMO.\r\n\r\nThe correct answer is B. The risk of intracranial bleeding is the major reason to avoid ECMO in the patient described in the stem. While thromboembolism and infection are both causes of morbidity and mortality in premature infants on ECMO, it is the risk of intracranial hemorrhage due to anticoagulation that is the basis for a relative contraindication to ECMO in patients < 34 weeks postmenstrual age. \r\n\r\n \r\nREFERENCES \r\nWild KT, Rintoul N, Kattan J, Gray B. Extracorporeal Life Support Organization (ELSO): Guidelines for Neonatal Respiratory Failure. ASAIO J<\/em>. 2020;66(5):463-470. \r\n\r\nUpp JR Jr, Bush PE, Zwischenberger JB. Complications of neonatal extracorporeal membrane oxygenation. Perfusion<\/em>. 1994;9(4):241-56.\r\n\r\nBurgos CM, Rintoul N, Broman LM. ECMO for premature neonates- Are we there yet? Seminars in Pediatric Surgery<\/em>. 2023;32(4):151335\r\n\r\n”,”hint”:””,”answers”:{“gczo3”:{“id”:”gczo3″,”image”:””,”imageId”:””,”title”:”A. Thromboembolism “},”2ie8t”:{“id”:”2ie8t”,”image”:””,”imageId”:””,”title”:”B. Intracranial hemorrhage “,”isCorrect”:”1″},”l00qy”:{“id”:”l00qy”,”image”:””,”imageId”:””,”title”:”C. Infection\r\n”}}}}}