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

{“questions”:{“ek71w”:{“id”:”ek71w”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Amy Babb, MD – Vanderbilt University Medical Center AND\r\nKaitlin Flannery, MD – Stanford University \r\n\r\nAn infant with Tetralogy of Fallot, pulmonary atresia and major aortopulmonary collateral arteries (TOF\/PA\/MAPCAs) presents for unifocalization. An intraoperative pulmonary artery flow study is requested by the surgeon. Which hemodynamic value obtained during the flow study is MOST likely to predict a successful repair with VSD closure and RV-PA conduit after unifocalization?\r\n”,”desc”:”EXPLANATION \r\nTOF\/PA\/MAPCAs describes a heterogeneous type of congenital heart disease with an outlet ventricular septal defect (VSD), pulmonary atresia (PA) and variable sources of pulmonary blood flow via collateral vessels. Standard surgical repair involves unifocalization of MAPCAs to form a reconstructed pulmonary artery tree using both native and homograft tissue. After the pulmonary arteries have been unifocalized, the next step consists of closure of the VSD and addition of an RV-PA conduit. Some patients will undergo unifocalization with complete intracardiac repair in one procedure, while others will require a staged approach.\r\n\r\nIt remains difficult to predict if a newly reconstructed pulmonary artery bed will be adequate to accommodate a full cardiac output after VSD closure. An insufficient pulmonary bed will result in elevated right ventricular systolic pressure (RVSP) and RV failure. Methods of predicting successful intracardiac repair based on anatomic metrics, such as neopulmonary artery index and pulmonary segment artery ratio, have been tried. In 2009, a study by Honjo et al concluded that a mean pulmonary artery pressure (mPAP) less than 30 mmHg at a cardiac index of 2.5 L\/min\/m^{2<\/sup> could predict a reasonable RV pressure after unifocalization with VSD closure better than anatomic characteristics.1<\/sup> In 2016, Zhu et al demonstrated that VSD closure with mPAP greater than 25 mmHg on flow study is a predictor of mortality following unifocalization.2<\/sup>\r\n\r\nIntraoperative pulmonary artery flow study is performed after PA unifocalization. The surgeon will place an aortic-sized cannula into the newly reconstructed PAs for flow from the cardiopulmonary bypass circuit.3<\/sup> A small needle is placed into the PAs and attached to pressure tubing with a transducer to monitor PA pressures. The anesthesiologist will ventilate the lungs while the perfusionist ramps up flows into the pulmonary arteries with the goal of achieving a cardiac index of 2.5 \u2013 3.0 L\/min\/m2<\/sup>. Ventilation with tidal volumes of 2-5 mL\/kg with respiratory rate of 30-35 breaths\/min will simulate normal cardiopulmonary interactions.4<\/sup> If mPAPs are higher than 25-30 mmHg at the target cardiac index, the right ventricle will likely struggle with VSD closure. Significant bleeding from the reconstructed PAs should be ruled out for an accurate interpretation. Flow studies have been shown to have reasonable correlation with post-operative RVSP, and be a better predictor than simple anatomic assessments.1<\/sup> Alternative strategies to VSD closure after failed flow study include central shunt placement or VSD closure with fenestration. \r\n\r\n\r\n \r\nREFERENCES \r\n\r\n1.\tHonjo O, Al-Radi O, MacDonald C, Tran K. et al. The Functional Intraoperative Pulmonary Blood Flow Study is a More Sensitive Predictor than Preoperative Anatomy for Right Ventricular Pressure and Physiologic Tolerance of Ventricular Septal Defect Closure after Complete Unifocalization in Patients with Pulmonary Atresia, Ventricular Septal Defect, and Major Aortopulmonary Collaterals. Circulation<\/em>. 2009; 120(11) supp 1: s46-s52. \r\n2.\tZhu J, Meza J, Kato A, et al. Pulmonary flow study predicts survival in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. J Thorac Cardiovasc Surg<\/em>. 2016; 152(6):1494-1503.e1. doi:10.1016\/j.jtcvs.2016.07.082 \r\n3.\tMargetson TD, Sleasman J, Kollmann S, McCarthy PJ, et al. Perfusion Methods and Modifications to the Cardiopulmonary Bypass Circuit for Midline Unifocalization Procedures. J Extra Corpor Technol<\/em>. 2019; 51(3):147-152. \r\n4.\tQuinonez ZA, Laura D, Abbasi RK, et al. Anesthetic management during surgery for tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries. World J Pediatr Congenit Heart Surg<\/em>. 2018; 9(2): 236-41.\r\n”,”hint”:””,”answers”:{“ojlgz”:{“id”:”ojlgz”,”image”:””,”imageId”:””,”title”:”A.\tmPAP less than 15 mmHg at 1.5 L\/min\/m2″},”iiqbf”:{“id”:”iiqbf”,”image”:””,”imageId”:””,”title”:”B.\tmPAP greater than 30 mmHg at 2.5 L\/min\/m2″},”8vfaa”:{“id”:”8vfaa”,”image”:””,”imageId”:””,”title”:”C.\tmPAP less than 25 mmHg at 3.0 L\/min\/m2\r\n\r\n”,”isCorrect”:”1″}}}}}}

{“questions”:{“yl7ni”:{“id”:”yl7ni”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Amy Babb, MD AND Amanpreet Kalsi, MBBS, FRCA – Vanderbilt University Medical Center – Monroe Carell Jr. Children’s Hospital at Vanderbilt \r\n\r\nA teenage boy with history of dilated cardiomyopathy supported with a continuous flow left ventricular assist device (LVAD) presents for heart transplant. After separation from cardiopulmonary bypass (CPB), he is hypotensive despite adequate biventricular function, normal central venous pressure, and epinephrine, vasopressin, and norepinephrine infusions. Which of the following factors is MOST likely associated with vasoplegia in this patient?\r\n\r\n”,”desc”:”EXPLANATION \r\nVasoplegia presents as severe hypotension secondary to vasodilation with low systemic vascular resistance (SVR) despite normal or elevated cardiac index. Vasoplegia after cardiac surgery is a known entity associated with significant morbidity and mortality in adults^{1<\/sup>. In addition, vasoplegia immediately post cardiac surgery may be difficult to diagnose when balancing the other potential causes of shock such as myocardial failure or hemorrhage. \r\n\r\nPatients undergoing procedures with CPB are at risk of vasoplegia secondary to multiple proinflammatory insults, including surgical trauma, transfusion, and exposure to foreign materials from the circuit. Patients preoperatively supported with continuous-flow ventricular assist devices (CF-VADs) are at even higher risk for vasoplegia post-transplant2<\/sup>. Proposed mechanisms for this include a unique proinflammatory profile and dysregulation of vasomotor tone thought secondary to continuous flow physiology.\r\n\r\nA study by Sacks et al. in 2019 describes a small cohort of pediatric patients supported preoperatively with either pulsatile or continuous flow ventricular assist devices who met criteria for vasoplegia after orthotopic heart transplant3<\/sup>. One third of all patients were diagnosed with vasoplegia, 79% of which had been supported with a CF-VAD prior to transplant. This article also proposed a definition of pediatric vasoplegia using the typical monitors and parameters seen in pediatric patients. The definition of pediatric vasoplegia published in their study consisted of:3<\/sup>\r\n\r\n1.\tUse of any of the following medications: \r\na.\tNorepinephrine, vasopressin, high dose epinephrine (>0.08 mcg\/kg\/min), or high dose dopamine (>8 mcg\/kg\/min) \r\n2.\tDiastolic blood pressure below the 10th percentile \r\n3.\tSystolic ejection fraction greater than 60% on echocardiogram \r\n4.\tRight atrial or central venous pressure greater than 5 mmHg \r\n5.\tAbsence of positive blood or urine cultures\r\n\r\nThis small study concluded that preoperative continuous-flow ventricular assist devices are a likely risk factor for post-operative vasoplegia after heart transplant in the pediatric population. Because there is no strong consensus on the definition of vasoplegia in either adults or pediatrics4<\/sup>, understanding the risk factors may help with early identification of vasoplegia and prevent delay in treatment. Both dilated cardiomyopathy and pulmonary hypertension may occur concomitantly with vasoplegia, especially in the setting of prolonged CPB, but are not recognized independent risk factors. \r\nREFERENCES \r\n \r\n\r\n1.\tAsleh R, Alnsasra H, Daly RC, et al. Predictors and Clinical Outcomes of Vasoplegia in Patients Bridged to Heart Transplantation With Continuous-Flow Left Ventricular Assist Devices. J Am Heart Assoc<\/em>. 2019;8(22):e013108. doi:10.1161\/JAHA.119.013108 \r\n2.\tPatarroyo M, Simbaqueba C, Shrestha K, et al. Pre-operative risk factors and clinical outcomes associated with vasoplegia in recipients of orthotopic heart transplantation in the contemporary era. J Heart Lung Transplant<\/em>. 2012; 31(3): 282-287. \r\n3.\tSacks L, Hollander S, Zhang Y, et al. Vasoplegia After Pediatric Cardiac Transplantation in Patients Supported with Continuous Flow Ventricular Assist Devices. The Journal of Thoracic and Cardiovascular Surgery<\/em>. 2019; 157(6): 2433 \u2013 2440. \r\n4.\tOrtoleva J, Cobey F. A Systematic Approach to the Treatment of Vasoplegia Based on Recent Advances in Pharmacotherapy. Journal of Cardiothoracic and Vascular Anesthesia<\/em>. 2019; 33(5): 1310 \u2013 1314.\r\n\r\n”,”hint”:””,”answers”:{“6alp6”:{“id”:”6alp6″,”image”:””,”imageId”:””,”title”:”A.\tPreoperative continuous flow LVAD support”,”isCorrect”:”1″},”k7ybv”:{“id”:”k7ybv”,”image”:””,”imageId”:””,”title”:”B.\tHistory of dilated cardiomyopathy”},”0ufj3″:{“id”:”0ufj3″,”image”:””,”imageId”:””,”title”:”C.\tPost-operative pulmonary hypertension”}}}}}}

{“questions”:{“r7qk2”:{“id”:”r7qk2″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Amy Babb, MD, AND Amanpreet Kalsi, MBBS, FRCA – Vanderbilt University Medical Center -\r\nMonroe Carell Jr. Children’s Hospital at Vanderbilt \r\nA 16-year-old female with a history of truncus arteriosus presents for RV-PA conduit change via sternotomy and cardiopulmonary bypass. She recently underwent a cardiac catheterization procedure for attempted percutaneous pulmonary valve placement and had severe post operative nausea and vomiting despite ondansetron and dexamethasone. Aprepitant is chosen for PONV prophylaxis after this surgery. What class of medication does aprepitant belong to? “,”desc”:”EXPLANATION \r\nAprepitant is a neurokinin 1 receptor antagonist used to decrease the risk of nausea and vomiting in adults and children with chemotherapy-induced and post-operative nausea and vomiting (PONV). These drugs target receptors in both central and peripheral nervous systems. In the central nervous system, aprepitant crosses the blood brain barrier inihibiting g-protein coupled signals at the NK1 receptor. Inhibition at the NK1 receptors prevents substance P formation at multiple sites in the brain known to induce nausea and vomiting. In addition, NK1 receptors present in the peripheral nervous system and gut are inihibited by aprepitant leading to an overall deceased vomiting signal to the central nervous system. \r\n\r\nAprepitant can be given orally (tab or liquid) or intravenously. Fosaprepitant is a prodrug of aprepitant that is only available as an IV formulation. Dosing in pediatric patients is limited to the available prescribing information for chemotherapy-induced nausea and vomiting, with few studies describing pediatric patients receiving aprepitant for PONV. Consensus guidelines for PONV published in 2020 by Gan et al recommend a dose of aprepitant 40 mg PO given within 3 hours of anesthesia induction for adults and dosing of aprepitant 3 mg\/kg up to 125 mg for PONV prophylaxis in children^{1<\/sup>.\r\n\r\nA 2019 study evaluating noncardiac pediatric surgical patients from birth to 17 years demonstrated efficacy and safety for PONV with doses of 10 mg, 40 mg and 125 mg2<\/sup>. In 2023, Belk J, et al. described a single-center experience with preoperative aprepitant administration for pediatric cardiac surgical and catheterization patients with a history of severe PONV. This small subset of patients were older, with a mean age of 16 years, and received either 80 mg PO (if over 50 kg) and 40 mg PO (if less than 50 kg)3<\/sup>. \r\n\r\nDescribed risks of aprepitant include decreased INR in patients taking warfarin as well as reduced efficacy of hormonal contraceptives for up to 28 days after administration4<\/sup>. As a general precaution, aprepitant is a weak inhibitor and inducer of CYP3A44. NK1 receptor antagonists have no effect on the QT interval, providing a potential advantage to its use in pediatric cardiac patients with risk factors for PONV. Multimodal management of PONV after pediatric cardiac surgery is an important aspect to any enhanced recovery protocol and NK1 receptor inhibitors may prove to be a useful addition. \r\n\r\n\r\n \r\nREFERENCES \r\n1.\tGan TJ, Belani KG, Bergese S, et al. Fourth Consensus Guidelines for the Management of Postoperative Nausea and Vomiting Anesth Analg<\/em>. 2020;131(2):411-448. doi:10.1213\/ANE.0000000000004833 \r\n2.\tSalman FT, DiCristina C, Chain A, et al. Pharmacokinetics and pharmacodynamics of aprepitant for the prevention of postoperative nausea and vomiting in pediatric subjects. Journal of Pediatric Surgery<\/em>. 2019; 54(7): 1384-1390. https:\/\/doi.org\/10.1016\/j.jpedsurg.2018.09.006. \r\n3.\tBelk JW, Twite MD, Klockau KS, Silveira LJ and Clopton RG (2023) Effects of aprepitant on post-operative nausea and vomiting in patients with congenital heart disease undergoing cardiac surgery or catheterization procedures: a retrospective study with subjects as their own historical control. Front. Anesthesiol<\/em>. 2023; 2:1190383. doi: 10.3389\/fanes.2023.1190383 \r\n4.\tMerck & Co. Emend (Aprepitant). US Food and Drug Administration website. Issued July 2009. https:\/\/www.accessdata.fda.gov\/drugsatfda_docs\/label\/2007\/021549s012lbl.pdf\r\n”,”hint”:””,”answers”:{“qufqz”:{“id”:”qufqz”,”image”:””,”imageId”:””,”title”:”A.\tNeurokinin 1 receptor antagonist”,”isCorrect”:”1″},”fnlzu”:{“id”:”fnlzu”,”image”:””,”imageId”:””,”title”:”B.\t5-HT3 receptor antagonist”},”chtq9″:{“id”:”chtq9″,”image”:””,”imageId”:””,”title”:”C.\tNeurokinin 1 receptor agonist”}}}}}}

{“questions”:{“yfux1”:{“id”:”yfux1″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Manal Mirreh, MD, Jennifer M. Lynch, MD, PhD, Lea C. Matthews, MD \u2013 Children\u2019s Hospital of Philadelphia, Philadelphia, PA \r\n\r\nA 4-day-old, 3 kg neonate with HLHS is undergoing a Norwood procedure under hypothermic cardiopulmonary bypass. A few minutes after initiation of antegrade cerebral perfusion (ACP) through the innominate artery, a decrease in bilateral cerebral NIRS values is observed. Which of the following is the MOST LIKELY explanation for the observed drop?\r\n\r\n”,”desc”:”EXPLANATION \r\nNear-infrared spectroscopy (NIRS) offers continuous, non-invasive monitoring of regional tissue oxygen saturation (rSO_{2<\/sub>), reflecting the balance between oxygen delivery and consumption at the tissue level. The NIRS value represents the relative ratio of hemoglobin that remains oxygenated after traversing the local tissue bed. Trending NIRS values can help detect fluctuations in oxygen delivery and\/or utilization. \r\n\r\nNIRS is based on the modified Beer-Lambert Law, which describes how light travels through a scattering medium. NIRS emits near-infrared light through tissues and measures the amount of light at different wavelengths absorbed by oxygenated and deoxygenated hemoglobin. From this information, regional oxygen saturation (rSO2<\/sub>) can be calculated.^{1<\/sup>\r\n\r\nTissue oxygenation is related to oxygen delivery to the tissue (i.e., arterial oxygen content and blood flow) and oxygen consumption by the tissue. Thus, rSO2<\/sub> fluctuates as these parameters change. \r\n\r\nClinically used conventional continuous-wave near-infrared spectroscopy (NIRS) has several limitations that should be considered when interpreting its readings. First, its spatial coverage is limited, as it primarily monitors the superficial anterior brain regions where the sensors are placed\u2014typically the frontal cortex\u2014potentially missing injuries in deeper or posterior areas such as the parieto-occipital regions. Additionally, NIRS provides relative rather than absolute values, which makes clinical guidelines based on absolute rSO2<\/sub> values hard to establish. Furthermore, its accuracy as even a relative trend monitor can be limited depending on factors such as hemoglobin concentration and temperature changes2<\/sup>, which is a crucial point, particularly in this patient population, due to the widespread use of hypothermic cardiopulmonary bypass.3<\/sup>\r\n\r\nBelow is a suggested decision tree guiding management when decreasing cerebral rSO2<\/sub> on CPB is encountered:\r\n\r\n \r\n\r\nA Circle of Willis (cerebral circulation) abnormality (Answer A) would result in an asymmetric drop in rSO2<\/sub> during antegrade cerebral perfusion due to inadequate blood flow to the contralateral brain. It would not result in bilateral drops in cerebral rSO2<\/sub>, assuming adequate flow rate and unimpinged cerebral venous return.\r\n\r\nChanges in temperature do affect rSO2<\/sub> values as cerebral metabolic rate changes. However, periods of antegrade cerebral perfusion typically occur during deep hypothermia, which aims to reduce cerebral metabolic rate. Thus, an increase in cerebral demand due to hypothermia (Answer C) is incorrect.\r\n\r\nThere are many reasons that bilateral cerebral NIRS values may drop during the course of cardiopulmonary bypass, including low hematocrit, arterial cannula malposition, or obstruction to venous drainage. However, of the choices presented, only inadequate flow (Answer B) represents a possible explanation in this case.\r\n\r\n\r\n \r\nREFERENCES \r\n1. Owen-Reece H, Smith M, Elwell CE, Goldstone JC. Near infrared spectroscopy. Br J Anaesth<\/em>. 1999;82(3):418-426. doi:10.1093\/bja\/82.3.418 \r\n2. Kleiser S, Ostojic D, Andresen B, et al. Comparison of tissue oximeters on a liquid phantom with adjustable optical properties: an extension. Biomed Opt Express<\/em>. 2017;9(1):86-101. Published 2017 Dec 5. doi:10.1364\/BOE.9.000086 \r\n3. Lynch JM, Mavroudis CD, Ko TS, et al. Association of Ongoing Cerebral Oxygen Extraction During Deep Hypothermic Circulatory Arrest With Postoperative Brain Injury. Semin Thorac Cardiovasc Surg<\/em>. 2022;34(4):1275-1284. doi:10.1053\/j.semtcvs.2021.08.026\r\n”,”hint”:””,”answers”:{“6k6gr”:{“id”:”6k6gr”,”image”:””,”imageId”:””,”title”:”A.\tCircle of Willis abnormality\r\n”},”auc22″:{“id”:”auc22″,”image”:””,”imageId”:””,”title”:”B.\tInadequate flow during ACP”,”isCorrect”:”1″},”itw5n”:{“id”:”itw5n”,”image”:””,”imageId”:””,”title”:”C.\tIncreased cerebral metabolic demand “}}}}}}}

{“questions”:{“99moa”:{“id”:”99moa”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Manal Mirreh, MD, Lindsey Weidmann, MD, and Lea Matthews, MD \u2013 Children\u2019s Hospital of Philadelphia, Philadelphia, PA \r\n\r\nA 14-year-old female with a history of ANCA-associated vasculitis, end-stage renal disease requiring dialysis, and severe left ventricular dilation is undergoing left ventricular assist device (LVAD) implantation. Cardiopulmonary bypass (CPB) is initiated uneventfully, and the patient is maintained normothermic with no use of aortic cross-clamp or cardioplegia. During CPB, her serum potassium level is noted to rise to 6.5 mEq\/L. Given the risk of worsening hyperkalemia following transfusion of red blood cells, which of the following intraoperative ultrafiltration strategies is most appropriate to manage her electrolytes prior to separation from CPB?”,”desc”:”EXPLANATION \r\nHyperkalemia is defined as a serum potassium higher than the upper limit of normal, commonly considered to be 5.5 mEq\/L. Homeostatic mechanisms regulate potassium balance to maintain high intracellular levels required for cellular functions (eg, metabolism and growth) and low extracellular concentration to preserve the steep concentration gradient across the cell membrane needed for nerve excitation and muscle contraction.^{1<\/sup>\r\n\r\nPreoperative chronic kidney disease and the administration of potassium-rich cardioplegic solutions are common causes of hyperkalemia during CPB. Additional sources of exogenous potassium include the transfusion of older units of packed red blood cells or irradiated blood products, due to red cell membrane injury, which increases extracellular potassium.2<\/sup>\r\n\r\nCardiopulmonary bypass during pediatric cardiac surgery is linked to a robust inflammatory response, fluid overload, and end-organ dysfunction, all of which contribute to postoperative morbidity and mortality. To address these complications, a range of intraoperative ultrafiltration strategies\u2014including conventional ultrafiltration, modified ultrafiltration (MUF), zero-balance ultrafiltration (ZBUF), and hybrid approaches such as ZBUF-MUF\u2014have been employed over the years to reduce these adverse effects and enhance postoperative recovery. However, no clear consensus exists on which ultrafiltration technique provides the greatest benefit for infants and children undergoing open-heart surgery.\r\n\r\nUltrafiltration is the process of running blood through a device with a semipermeable membrane to remove \u201cfree water\u201d (water, electrolytes and substances with a molecular size smaller than the membrane pore size). It can be performed before, during, and\/or after CPB. The goals of ultrafiltration during cardiopulmonary bypass include the removal of excess crystalloid volume, hemoconcentration to increase hematocrit, and the clearance of electrolytes and inflammatory mediators.2<\/sup> \r\n\r\nUltrafiltration performed during cardiopulmonary bypass, known as conventional ultrafiltration (CUF), is primarily used to remove excess fluid that accumulates from various sources, including pre-bypass fluid administration, cardioplegia solutions, valve testing saline, and crystalloid added to the venous reservoir during periods of reduced venous return.3<\/sup>\r\n\r\nZero-balance ultrafiltration (ZBUF), also referred to as dilutional ultrafiltration (DUF), was initially introduced during the rewarming phase in pediatric patients. With ZBUF, ultrafiltrate is continuously removed and simultaneously replaced with an equivalent volume of crystalloid to maintain a net-zero fluid balance. The primary goal is to continuously clear electrolytes such as potassium and lactate, as well as inflammatory mediators, thereby producing a circulating volume with a composition closer to that of the replacement solution. Several crystalloids are utilized for ZBUF, including lactated ringers, Plasma-Lyte, and normal saline. In patients with chronic kidney disease, normal saline is preferred due to lack of potassium in the solution. However, use of normal saline is not ideal due to its high chloride content and may also exacerbate hyperkalemia due to potential for hyperchloremic acidosis. Case reports have described the use of Dialysate solution, in an attempt to avoid this occurrence, as it contains a lower potassium content than lactated ringers or Plasma-Lyte.4<\/sup>\r\n\r\nModified ultrafiltration (MUF) is performed after cardiopulmonary bypass to remove free water and concentrate the blood, resulting in increased hematocrit. It also allows recovery of whole blood from the bypass circuit, unlike cell salvage systems that return only red blood cells. While proposed benefits such as reduced edema, lower inotropic needs, and improved pulmonary function remain debated, MUF is widely accepted for its efficiency in raising hematocrit and reducing transfusion requirements.5<\/sup> In conclusion, among the available ultrafiltration techniques, zero-balance ultrafiltration (ZBUF) is the most appropriate choice in this setting, as it effectively reduces serum potassium levels and is particularly beneficial for managing hyperkalemia during cardiopulmonary bypass. \r\n\r\n \r\nREFERENCES \r\n1.\tKremen, J, Matoo TK, Somers, M. Hyperkalemia in children: Causes, clinical manifestations, diagnosis, and evaluation. In: UpToDate, Post TW (Ed). UpToDate. [Accessed May 10th, 2025]. Available from: https:\/\/www.uptodate.com \r\n2.\tOzdemir D, Chan R. The Challenges of Hyperkalemia on Cardiopulmonary Bypass. The Academy Newsletter. Summer 2012;(Summer):6\u20119 \r\n3.\tAndersen ND, Meza JM, Turek JW, Mavroudis C, Backer CL. Management of pediatric cardiopulmonary bypass. In: Mavroudis C, Backer CL, eds. Pediatric Cardiac Surgery<\/em>. 5th ed. John Wiley & Sons Ltd; 2023:161-189. doi:10.1002\/9781119282327.ch \r\n4.\tHeath M, Raghunathan K, Welsby I, Maxwell C. Using Zero Balance Ultrafiltration with Dialysate as a Replacement Fluid for Hyperkalemia during Cardiopulmonary Bypass. J Extra Corpor Technol<\/em>. 2014;46(3):262-266 \r\n5.\tMatte GS. The Bypass Plan. In: Perfusion for Congenital Heart Surgery: Notes on Cardiopulmonary Bypass for a Complex Patient Population<\/em>. Wiley Blackwell; 2015:55-59\r\n\r\n”,”hint”:””,”answers”:{“doo1j”:{“id”:”doo1j”,”image”:””,”imageId”:””,”title”:”A. Zero-balance ultrafiltration (ZBUF) “,”isCorrect”:”1″},”wbiwj”:{“id”:”wbiwj”,”image”:””,”imageId”:””,”title”:”B. Modified ultrafiltration (MUF) “},”ob7t8”:{“id”:”ob7t8″,”image”:””,”imageId”:””,”title”:”C. Conventional ultrafiltration (CUF)”}}}}}}