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

{“questions”:{“n0cy0”:{“id”:”n0cy0″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Michael A. Evans, MD \u2013 Ann & Robert H. Lurie Children\u2019s Hospital of Chicago, Northwestern Feinberg School of Medicine\r\n\r\nA 5-year-old child with a history of Williams syndrome presents for a cardiac magnetic resonance imaging (MRI) under general anesthesia. During induction of anesthesia, the patient has a cardiac arrest. A code is called, and pediatric advanced life support (PALS) is initiated. To which MRI Zone should the patient be evacuated to facilitate assistance in resuscitation?\r\n”,”desc”:””,”hint”:””,”answers”:{“pjwe6”:{“id”:”pjwe6″,”image”:””,”imageId”:””,”title”:”A. Zone 1″},”wb3rw”:{“id”:”wb3rw”,”image”:””,”imageId”:””,”title”:”B. Zone 2″,”isCorrect”:”1″},”4ee8j”:{“id”:”4ee8j”,”image”:””,”imageId”:””,”title”:”C. Zone 3″},”8whcf”:{“id”:”8whcf”,”image”:””,”imageId”:””,”title”:”D. Zone 4″}}}},”results”:{“7hsof”:{“id”:”7hsof”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”The perioperative areas adjacent to the MRI scanner are divided into four zones: Zone 1, Zone 2, Zone 3, and Zone 4. \r\n\r\nZone 1 is open to unscreened patients and families. It typically consists of areas open to the general public that are outside of the MRI environment. Patients and families are not screened in Zone 1 and move freely and unsupervised. \r\n\r\nZone 2 is the interface between the publicly accessible and uncontrolled Zone 1 and the controlled Zones 3 and 4. Typically, preoperative evaluation, patient screening, and examination occur in Zone 2. \r\n\r\nMRI Zone 3 requires personnel be screened prior to entry. Thus, it is most appropriate to move this patient to MRI Zone 2 while continuing resuscitation. \r\n\r\nZone 3 is physically restricted from the general public and non-MR personnel. It is demarcated\/indicated as potentially hazardous, as there are static magnetic fields. The introduction of unscreened non-MR personnel or ferromagnetic materials\/equipment can result in serious injury or death. It is important to note that the nature of magnetic fields being three-dimensional means Zone 3 may extend between floors in a hospital. \r\n\r\nZone 4 consists of the room that contains the MRI scanner. It is clearly labeled as hazardous due to the existence of strong magnetic fields. \r\n\r\nBased on the American College of Radiology\u2019s manual on MR safety, controlled site-access restriction to Zones III and IV must be maintained during resuscitation and other emergent situations for the protection of all involved. This access restriction is enforced by Zone 2 MRI personnel during a code event to protect non-screened personnel from being harmed. \r\n\r\nThus, in the event of cardiac or respiratory arrest in Zone 4, a patient should be evacuated to Zone 2 (or other predetermined area) that is outside the confines of Zones 3 and 4 as quickly and safely as possible while undergoing resuscitative efforts. \r\n\r\nQuenching a superconductive magnet is not advised, as quenching the magnet to dissipate the magnetic field can take more than a minute. It could also introduce other hazards to Zone 4. \r\n\r\nReferences \r\n1. ACR Manual on MR Safety. https:\/\/www.acr.org\/-\/media\/ACR\/Files\/Radiology-Safety\/MR-Safety\/Manual-on-MR-Safety.pdf . Accessed August 2, 2021. ACR COMMITTEE ON MR SAFETY. AMERICAN COLLEGE OF RADIOLOGY. 1891 Preston White Drive, Reston, VA 20191 \r\n\r\n2. Sammet S. Magnetic resonance safety. Abdom Radiol<\/em>. 2016; 41(3): 444-451. \r\n\r\n3. Expert Panel on MR Safety, Kanal E, Barkovich AJ, et al. ACR guidance document on MR safe practices: 2013. J Magn Reson Imaging<\/em>. 2013; 37(3): 501-530. doi:10.1002\/jmri.24011\r\n\r\n”,”redirect_url”:””}}}

{“questions”:{“55tk6”:{“id”:”55tk6″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Jed Kinnick, MD and Destiny F. Chau MD \u2013 Arkansas Children\u2019s Hospital\/ University of Arkansas for Medical Sciences, Little Rock, AR.\r\n\r\nA 5-year-old boy who recently immigrated to the country presents for dental abscess drainage and dental rehabilitation under general anesthesia. The caregivers report that the child will often squat during play and that his color improves after squatting. Physical examination reveals clubbing of fingers and toes and an SpO2 of 88% while breathing room air. A transthoracic echocardiogram confirms a diagnosis of Tetralogy of Fallot. What is the MOST LIKELY<\/em> mechanism that causes an acute clinical improvement with a squatting posture in patients with Tetralogy of Fallot? \r\n”,”desc”:””,”hint”:””,”answers”:{“q8f41”:{“id”:”q8f41″,”image”:””,”imageId”:””,”title”:”A. Decrease in cardiac contractility “},”vkwsi”:{“id”:”vkwsi”,”image”:””,”imageId”:””,”title”:”B. Increase in systemic venous return “,”isCorrect”:”1″},”gvto5″:{“id”:”gvto5″,”image”:””,”imageId”:””,”title”:”C. Decrease in heart rate “},”nc5bv”:{“id”:”nc5bv”,”image”:””,”imageId”:””,”title”:”D. Decrease in pulmonary vascular resistance”}}}},”results”:{“0mfxo”:{“id”:”0mfxo”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease representing 10% of all congenital heart defects. It has been noted that a proportion of patients with TOF naturally resort to postural changes for symptomatic relief of acute desaturations from baseline. In ambulatory children and infants, postural changes include squatting and assuming a knee-to-chest position. TOF is characterized by a tetrad of heart abnormalities including the following: 1) ventricular septal defect (VSD), 2) right ventricular outflow tract obstruction (RVOT), 3) an overriding aorta, and 4) right ventricular hypertrophy. \r\n\r\nDue to this constellation of defects, systemic deoxygenated blood can preferentially cross the VSD and into the systemic circulation rather than the pulmonary circulation. Depending on the severity of the RVOTO, the patient\u2019s oxygen saturation may range from normal to extreme cyanosis. Acute hypercyanotic episodes or \u201ctet spells\u201d are characterized by severe oxygen desaturation, dyspnea, and even syncope. Common precipitating factors – such as physical exertion, crying, agitation or pain – result in increased sympathetic activity and spasm of the infundibular portion of the right ventricular outflow tract thereby leading to increased right to left intracardiac shunting. The infundibular spasm is caused by increased sympathetic tone and increased cardiac contractility. A decrease in ventricular afterload can also increase right to left intracardiac shunting, which may occur during a febrile illness, due to inhaled anesthetic agents, and with dehydration. Persistent hypoxemia may eventually lead to the development of metabolic acidosis, peripheral vasodilation, and further decreases in systemic vascular resistance. This may worsen the hypercyanotic episode and potentially result in syncope and cardiac arrest. \r\n\r\n\r\nThe modern therapeutic approach to TOF is surgical repair during infancy to avoid the pathophysiologic and anatomic changes related to worsening cyanosis and increasing RVOTO. Children with TOF in low- to middle-income countries may have limited access to health care and remain unrepaired for many years before gaining access to surgical care. \r\n\r\n\r\nTextbooks commonly cite that postural changes of knee-to-chest positioning or squatting lead to increased venous return and increased systemic vascular resistance (SVR), which in turn increases pulmonary blood flow and oxygen saturation. Several reports have studied the physiologic and hemodynamic changes resulting from squatting. Many investigative studies that utilized unrepaired, older TOF patients are decades old. More contemporary reports of squatting have been conducted in healthy volunteers or acyanotic patients. The following is a general overview of relevant studies. \r\n\r\n\r\nLurie, in a 1953 study, performed several tilt tests on subjects with unrepaired TOF and demonstrated that oxygen saturation dropped with increasing tilt from the supine towards the standing position. Elastic bandages were placed to compress the abdomen and the lower extremities in two subjects; the decrease in oxygen saturation was lessened when going from supine to standing as compared to those in patients without compression bandages. The authors concluded that the improvement in oxygen saturation was related to the increased venous return to the heart secondary to the postural changes. \r\n\r\n\r\nA 1957 study by Brotmacher et al. recruited nine subjects with unrepaired TOF who were routine squatters (experimental group), and ten subjects who had either acyanotic heart disease or non-cardiac conditions (control group). After oxygen desaturation from baseline was induced by exertion; subjects with TOF either squatted or remained standing. Those who squatted demonstrated an immediate rise in oxygen saturations with a faster return to baseline compared to the standing group. Those patients who remained standing after exertion demonstrated oxygen saturations that continued to drop after exertion was stopped and that took longer to increase and return to baseline. \r\n\r\n\r\nA 1962 study by O\u2019Donnell et al. recruited 14 subjects with unrepaired TOF and 14 acyanotic subjects. Overall, the results showed that going from standing to squatting, both groups demonstrated increased blood pressure and decreased heart rate (HR). The TOF group also showed increased saturations. Results from dye-dilution method on cardiac catheterization suggested that squatting led to a decrease in right to left intracardiac shunting. \r\n\r\n\r\nMore contemporary studies include those by Hanson (1995) and Murakami (2002). Hanson et al. analyzed the hemodynamic changes occurring in adult subjects when changing from a standing to a squatting position in nine normal and six heart transplant recipient subjects. Stroke volume was measured by thoracic impedance cardiography. The results showed that both groups had increases in stroke volume index and blood pressure. Heart rate decreased in the subjects with normal hearts but was unchanged in the heart transplant recipients. Interestingly, both groups had an initial decrease in systemic vascular resistance followed by a return to baseline after 20 seconds. \r\n\r\n\r\nMurakami enrolled 12 healthy adults with the goal to study the changes in ventricular afterload by evaluating the aortic pressure waveform when going from standing to squatting. The results showed that squatting increased aortic pressures, specifically the systolic component. The aortic waveform showed an increased augmentation index [(peak systolic pressure- inflection point pressure)\/ pulse pressure]. The author concluded that squatting increased the afterload to the left ventricle by enhancing the aortic wave reflection. \r\n\r\n\r\nThe above early research on postural behavior in patients with unrepaired TOF for acute symptomatic relief of oxygen desaturation provided important clinical insight. The management of acute oxygen desaturation in patients with unrepaired TOF focuses on decreasing the degree of right to left shunt across the VSD with the net effect of increasing the pulmonary blood flow. Decreasing sympathetic stimulation and\/or removing\/treating the stimulating trigger is a first step, ie administration of pain medication for painful experiences. Performing maneuvers to increase systemic vascular resistance and left ventricular afterload function to increase venous return, increase preload, maintain lower heart rate, and decrease right to left intracardiac shunting. Specific maneuvers to accomplish these goals include the assumption of a squatting posture or knee to chest position, administration of a fluid bolus, administration of phenylephrine and medications such as esmolol to reduce cardiac contractility and relieve infundibular muscle spasm. \r\n\r\n\r\nReferences \r\n\r\n1.\tSquatting in Fallot’s tetralogy. Br Med J<\/em>. 1968; 4(5629): 470. \r\n\r\n2.\tSchmitz M, Ullah S, Dasgupta R. Anesthesia for Right-sided Obstructive Lesions. In: Andropoulos D, Stayer S, Mossad E, Miller-Hance W, eds. Anesthesia for Congenital Heart Disease<\/em>. 3rd Edition. Hoboken, New Jersey: John Wiley & Sons, Inc.; 2015: 516-541.\r\n\r\n3.\tLurie PR. Postural effects in tetralogy of Fallot. Am J Med<\/em>. 1953; 15(3): 297-306. \r\n\r\n\r\n4.\tBrotmacher L. Haemodynamic effects of squatting during recovery from exertion. Br Heart J<\/em>. 1957; 19(4): 567-573. \r\n\r\n5.\tO’Donnell TV, McIlroy MB. The circulatory effects of squatting. Am Heart J<\/em>. 1962; 64: 347-356. \r\n\r\n\r\n6.\tGuntheroth W, Mortan B, Mullins G. Venous return with knee-chest position and squatting in tetralogy of Fallot. Am Heart J<\/em>. 1968; 75(3): 313-318.\r\n\r\n7.\tHanson P, Slane PR, Rueckert PA, Clark SV. Squatting revisited: comparison of haemodynamic responses in normal individuals and heart transplantation recipients. Br Heart J<\/em>. 1995; 74(2): 154-158. \r\n\r\n8.\tMurakami T. Squatting: the hemodynamic change is induced by enhanced aortic wave reflection. Am J Hypertens<\/em>. 2002; 15(11): 986-988. \r\n\r\n\r\n9.\tCarano N, Tchana B. An equivalent posture to squatting is seen in an unoperated adult with tetralogy of Fallot. Cardiol Young<\/em>. 2008; 18(6): 644.\r\n\r\n\r\n\r\n”,”redirect_url”:””}}}

{“questions”:{“h70we”:{“id”:”h70we”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Destiny F. Chau MD and Meera Gangadharan MD \u2013 Arkansas Children\u2019s Hospital\/ University of Arkansas for Medical Sciences, Little Rock, AR.\r\n\r\nA 10-year-old, otherwise healthy female is undergoing aortic coarctation repair via left posterolateral thoracotomy. In addition to coarctation of the aorta, a transthoracic echocardiogram demonstrated mild left ventricular hypertrophy, normal systolic function, mildly impaired relaxation, and a bicuspid aortic valve. The surgery proceeds uneventfully with an excellent result and the patient is extubated in the operating room with spontaneous movement of all extremities and has adequate postoperative pain control. The arterial blood pressure gradually increases to 128\/74. What is the MOST APPROPRIATE<\/em> therapy? “,”desc”:””,”hint”:””,”answers”:{“l6zon”:{“id”:”l6zon”,”image”:””,”imageId”:””,”title”:”A.\tNo specific action “},”4nch0”:{“id”:”4nch0″,”image”:””,”imageId”:””,”title”:”B.\tInitiate a sodium nitroprusside infusion “,”isCorrect”:”1″},”76t5f”:{“id”:”76t5f”,”image”:””,”imageId”:””,”title”:”C.\tAdminister morphine”},”b4tux”:{“id”:”b4tux”,”image”:””,”imageId”:””,”title”:”D.\tAdminister furosemide”}}}},”results”:{“j7lxm”:{“id”:”j7lxm”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Postoperative paradoxical hypertension after coarctation of the aorta repair is a common occurrence. It is immediately apparent in greater than 50% of patients following coarctation repair. This phenomenon can have an early or delayed postoperative presentation. Early presentation often is limited to the first 24 hours postoperatively. A delayed presentation typically manifests after three to five postoperative days and may be associated with abdominal pain, mesenteric arteritis, and possible bowel ischemia. \r\n\r\nThe etiology of postoperative paradoxical hypertension is likely multifactorial in origin although the exact mechanism is still uncertain. Disproportionate increases in epinephrine, norepinephrine, renin and angiotensin levels have been found following surgical repair of aortic coarctation. Proposed theories for postoperative hypertension include the following: \r\n\r\n\u2022\tThe carotid and aortic arch baroreceptor set points adapt to a higher blood pressure in patients with an aortic coarctation in order to perfuse distal organs such as the kidney. This is the most likely mechanism for the immediate hypertensive response following repair. \r\n\r\n\r\n\u2022\tThe release of stretch\/pressure on the carotid and aortic arch baroreceptors after coarctation resection results in sympathetic nervous system activation with release of norepinephrine and hypertension. \r\n\r\n\r\n\u2022\tActivation of the renin\u2013angiotensin\u2013aldosterone system with a resultant increase in renin production is proposed to contribute to delayed hypertension. \r\n\r\n\r\nDiligent and immediate antihypertensive therapy is necessary for adequate blood pressure control in order to minimize bleeding, prevent anastomotic leaks, and to counteract the clinical sequelae of delayed postoperative paradoxical hypertension. \r\n\r\nPharmacotherapy of postoperative paradoxical hypertension varies from institution to institution. An international survey demonstrated that the most commonly utilized first-line agents include sodium nitroprusside, esmolol, labetalol, angiotensin-converting enzyme inhibitors, and nicardipine. The selection of a particular therapeutic drug may be influenced by regional availability and cost. Some patients require several antihypertensive agents for satisfactory blood pressure control. In addition to the aforementioned drugs, dexmedetomidine may reduce the need for multiple antihypertensive agents to control blood pressure in behaviorally challenging patients. Adequate pain management is also important to minimize the hypertensive response. In this case scenario, the patient appeared comfortable, thus administering an opioid would not be the most appropriate therapeutic choice. In a retrospective study comparing patients who developed hypertension to those who did not develop hypertension in the immediate postoperative period after coarctation repair, the authors concluded that a net positive fluid balance (caused either by higher intraoperative fluid volumes or decreased urine output) contributed to an increased incidence of postoperative hypertension and longer intensive care unit stays. Despite this conclusion, survey research suggests that most institutions do not use diuretics such as furosemide in the management of hypertension in this patient population, which explains why choice D is incorrect. \r\n\r\nReferences: \r\n\r\nFox S, Pierce WS, Waldhausen JA. Pathogenesis of paradoxical hypertension after coarctation repair. Ann Thorac Surg<\/em>. 1980; 29(2): 135-141. \r\n\r\n\r\nRocchini AP, Rosenthal A, Barger AC, Castaneda AR, Nadas AS. Pathogenesis of paradoxical hypertension after coarctation resection. Circulation<\/em>. 1976; 54(3): 382-387. \r\n\r\n\r\nRoeleveld PP, Zwijsen EG. Treatment strategies for paradoxical hypertension following surgical correction of coarctation of the aorta in children. World J Pediatr Congenit Heart Surg<\/em>. 2017; 8(3): 321-331. \r\n\r\n\r\nMoffett BS, Penny DJ. Variability in treatment of post-coarctectomy hypertension: a multicenter study. Pediatr Cardiol<\/em>. 2016; 37(4): 772-777. \r\n\r\n\r\nSchroeder VA, DiSessa TG, Douglas WI. Postoperative fluid balance influences the need for antihypertensive therapy following coarctation repair. Pediatr Crit Care Med<\/em>. 2004; 5(6): 539-541. \r\n\r\n\r\nSahu MK, Manikala VK, Singh SP, Bisoi AK, Chowdhury UK. Use of dexmedetomidine as an adjunct in the treatment of paradoxical hypertension after surgical repair of coarctation of the aorta in infants. Ann Card Anaesth<\/em>. 2015; 18(3): 437-440. \r\n\r\n\r\nSoliman R, Saad D. Assessment the effect of dexmedetomidine on incidence of paradoxical hypertension after surgical repair of aortic coarctation in pediatric patients. Ann Card Anaesth<\/em>. 2018; 21(1): 26-33. \r\n”,”redirect_url”:””}}}

{“questions”:{“r4mpy”:{“id”:”r4mpy”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”This Question of the Week was written by Drs. Sanabria and Campo from Madrid, Spain. English translation by Destiny F Chau, MD. \r\nLa incidencia de complicaciones neurol\u00f3gicas en ni\u00f1os sometidos a reparaci\u00f3n quir\u00fargica de su cardiopat\u00eda es elevada. Los mecanismos de lesi\u00f3n son multifactoriales asociados a diversos factores de riesgo y otras condiciones predisponentes. La monitorizaci\u00f3n cerebral ha demostrado ser una herramienta eficaz para identificar y tratar precozmente los mecanismos fisiopatol\u00f3gicos involucrados en la lesi\u00f3n neurol\u00f3gica. Se\u00f1ale cu\u00e1l de las siguientes estrategias de monitorizaci\u00f3n cerebral intraoperatoria ha demostrado mayor eficacia para identificar los mecanismos de lesi\u00f3n involucrados: \r\n\r\nChildren undergoing surgical repair of congenital heart disease have a high incidence of neurological complications. The mechanisms of injury are multifactorial and are associated with various risk factors and predisposing conditions. Brain monitoring has proven to be an effective tool for the early identification and treatment of pathophysiological mechanisms involved in the neurological injury. What is the MOST EFFECTIVE intraoperative brain monitoring strategy used to identify the mechanism of neurological injury? \r\n”,”desc”:””,”hint”:””,”answers”:{“3akba”:{“id”:”3akba”,”image”:””,”imageId”:””,”title”:”A.\tLa Espectroscopia Cercana al Infrarrojo (NIRS) bifrontal \/ Bifrontal Near Infrared Spectroscopy (NIRS)”},”wn4iy”:{“id”:”wn4iy”,”image”:””,”imageId”:””,”title”:”B.\tLa Electroencefalograf\u00eda (EEG) \/ Electroencephalography (EEG)”},”5xere”:{“id”:”5xere”,”image”:””,”imageId”:””,”title”:”C.\tNeuromonitorizaci\u00f3n multimodal con EEG, Doppler Transcraneal y NIRS \/ Multimodal neuromonitoring with EEG, Transcranial Doppler and NIRS”,”isCorrect”:”1″},”84qm8″:{“id”:”84qm8″,”image”:””,”imageId”:””,”title”:”D.\tLa Ecograf\u00eda Transfontanelar con ultrasonidos \/ Transfontanelle Ultrasonography”}}}},”results”:{“7kygj”:{“id”:”7kygj”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Explicaci\u00f3n: \r\n\r\n\r\nLa incidencia de da\u00f1o neurol\u00f3gico en pacientes pedi\u00e1tricos sometidos a cirug\u00eda card\u00edaca con bypass cardiopulmonar (BCP) se ha descrito en un 25% de los pacientes intervenidos, principalmente cuando la correcci\u00f3n quir\u00fargica se realiza en el per\u00edodo neonatal, provocando aumento de morbimortalidad perioperatoria y diversos grados de d\u00e9ficit neurol\u00f3gico, aunque en ocasiones la repercusi\u00f3n neurocognitiva no se manifiestan hasta a\u00f1os despu\u00e9s, generando un gran impacto social (1-4). \r\nLa incidencia y gravedad de la lesi\u00f3n neurol\u00f3gica se relaciona directamente con la severidad de la cardiopat\u00eda, cuando la correcci\u00f3n se realiza en periodo neonatal y cuando est\u00e1 asociada a s\u00edndromes y\/o malformaciones que afectan al neurodesarrollo (5). El mecanismo de lesi\u00f3n est\u00e1 relacionado con episodios hip\u00f3xico-isqu\u00e9micos que ocurren durante el per\u00edodo perioperatorio, y son de origen multifactorial debidos a hipoxemia, hipocapnia, hipoperfusi\u00f3n, bajo gasto card\u00edaco, disfunci\u00f3n en canulaci\u00f3n arterial y venosa durante el BCP, hemodiluci\u00f3n excesiva, hemorragia intracraneal, microembolias, respuesta inflamatoria, producci\u00f3n de radicales libres (6,7), parada circulatoria con hipotermia profunda y exposici\u00f3n a agentes anest\u00e9sicos durante horas o incluso d\u00edas (8). Sin embargo datos recientes extra\u00eddos de imagenolog\u00eda cerebral neonatal, se ha hecho evidente que existen anomal\u00edas cerebrales, incluso antes de la reparaci\u00f3n quir\u00fargica, secundario a alteraciones del neurodesarrollo en periodo fetal relacionadas con la cardiopat\u00eda, afectando predominantemente a la sustancia blanca, aunque tambi\u00e9n se observan en la sustancia gris cortical y subcortical. Esta inmadurez cerebral puede aumentar la susceptibilidad al riesgo neurol\u00f3gico sobrea\u00f1adido durante la etapa perioperatoria por mecanismos multifactoriales y sin\u00e9rgicos (9), siendo recomendable la neuromonitorizaci\u00f3n, exploraci\u00f3n cl\u00ednica neurol\u00f3gica y pruebas de imagen como la resonancia magn\u00e9tica (RM) (4,10). \r\n\r\nLa monitorizaci\u00f3n neurol\u00f3gica de rutina durante la cirug\u00eda card\u00edaca puede proporcionar informaci\u00f3n que podr\u00eda conducir a mejoras y disminuir el potencial de da\u00f1o neurol\u00f3gico. La oximetr\u00eda transcraneal mediante espectroscopia pr\u00f3xima al infrarrojo (NIRS) permite la medici\u00f3n continua, no invasiva y no puls\u00e1til de la saturaci\u00f3n de ox\u00edgeno cerebral regional (rSO2), lo que permite detectar la hipoxia-isquemia cerebral. Dicha monitorizaci\u00f3n est\u00e1 influenciada por el equilibrio entre el suministro y el consumo de ox\u00edgeno cerebral. Los valores registrados se ven afectados por la oxigenaci\u00f3n, el gasto card\u00edaco y la perfusi\u00f3n, la hipo\/hipercapnia, el hematocrito, la temperatura y la profundidad de la anestesia. Valores bajos de NIRS pueden estar asociados con da\u00f1o neurol\u00f3gico, y ha demostrado utilidad para mantener oxigenaci\u00f3n y perfusi\u00f3n cerebral adecuados en pacientes anestesiados, evitando episodios de desaturaci\u00f3n cerebral cr\u00edtica (2,11). Otras estrategias de neuromonitorizaci\u00f3n como electroencefalograma (EEG), el Doppler transcraneal (DTC) y ultrasonidos transfontanelar han demostrado su utilidad para obtener informaci\u00f3n sobre mecanismos de lesi\u00f3n neurol\u00f3gica que se producen en el pre, intra y postoperatorio. El EEG estandar, EEG procesados como EEG integrado por amplitud (EEGa) o Bispectral Index (BIS) y potenciales evocados somatosensoriales (SEPs) han demostrado utilidad para la determinaci\u00f3n de la profundidad anest\u00e9sica, prevenir despertar intraoperatorio, evitar sobredosis de anest\u00e9sicos y detecci\u00f3n de episodios de isquemia, hipoglucemia y presencia de convulsiones subcl\u00ednicas, brindando oportunidades para su detecci\u00f3n y manejo precoz (12,13). La ecograf\u00eda Doppler transcraneal (DTC) sobre la arteria cerebral media tambi\u00e9n es una herramienta valiosa para identificar flujo cerebral inadecuado durante el BCP. Los ultrasonidos utilizados por ventana transfontanelar son adecuados para uso a pie de cama y detectar complicaciones como la hemorragia intraventricular, sin embargo, no proporciona la resoluci\u00f3n necesaria para detectar la mayor\u00eda de alteraciones estructurales sutiles, s\u00f3lo detectables mediante RM, pero esta \u00faltima presenta limitaciones para desplazar al paciente cr\u00edtico o utilizarla en el intraoperatorio (14). \r\n\r\nLa etiolog\u00eda multifactorial de la lesi\u00f3n neurol\u00f3gica hace que sea menos probable que una \u00fanica modalidad de monitorizaci\u00f3n intraoperatoria sea eficaz para captar todas las posibles amenazas. Sin embargo, la neuromonitorizaci\u00f3n multimodal combina varios aspectos de vigilancia sobre la oxigenaci\u00f3n, hemodin\u00e1mica y electrofisiolog\u00eda cerebrales asociando NIRS, DTC y EEG, permite una aplicaci\u00f3n cl\u00ednica de rutina, reduce las limitaciones de la monitorizaci\u00f3n \u00fanica, ligadas a la variabilidad individual (NIRS, DTC) o a la interacci\u00f3n con las drogas anest\u00e9sicas (EEG) y se obtiene mayor sensibilidad y especificidad en la detecci\u00f3n de los mecanismos de lesi\u00f3n neurol\u00f3gica (15), reduciendo incidencia de complicaciones neurol\u00f3gicas y proporcionando m\u00e1s seguridad al paciente durante la cirug\u00eda (16,17,18,19). \r\n\r\nExplanation: \r\n\r\n\r\nThe incidence of neurological damage in pediatric patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) has been described in about 25% of the operated patients, mainly when surgical correction is performed during the neonatal period, leading to increased perioperative morbidity and mortality and varying degrees of neurological deficit. In some patients, the neurocognitive repercussions may not appear until years later generating associated great social consequences (1-4). \r\n\r\n\r\nThe incidence and severity of the neurological injury is directly correlated to the severity of the heart disease, the timing of correction in the neonatal period, its association with syndromes and \/ or malformations that affect neurodevelopment (5). The mechanism of injury is related to hypoxic-ischemic episodes that occur during the perioperative period which are of multifactorial origin due to hypoxemia, hypocapnia, hypoperfusion, low cardiac output, inadequate arterial and venous cannulation during CPB, excessive hemodilution, intracranial hemorrhage, microembolisms, inflammatory response, production of free radicals (6,7), circulatory arrest with profound hypothermia, and exposure to anesthetic agents for hours or even days (8). However, recent data from neonatal brain imaging have shown evidence that brain abnormalities are present even before surgical repair. The abnormalities are thought to arise from neurodevelopmental alterations in the fetal period related to the heart lesion. They predominantly affect the white matter, although they are also observed in the cortical and subcortical gray matter. \r\n\r\n \r\nThis brain immaturity increases the susceptibility to added neurological risk during the perioperative stage through multifactorial and synergistic mechanisms (9). Thus, it is recommended to perform neuromonitoring, neurological clinical examinations and imaging tests such as magnetic resonance imaging (MRI) (4,10). \r\n\r\n\r\nRoutine neurological monitoring during cardiac surgery can provide information that could lead to improvements and decrease the potential for neurological damage. Transcranial oximetry using near infrared spectroscopy (NIRS) allows continuous, non-invasive and non-pulsatile measurement of regional cerebral oxygen saturation (rSO2), which allows the detection of cerebral hypoxia-ischemia. This monitoring modality is influenced by the balance between brain oxygen supply and consumption. The NIRS values are affected by oxygenation, cardiac output and perfusion, hypo \/ hypercapnia, hematocrit, temperature, and depth of anesthesia. Low NIRS values may be associated with neurological damage, and it has been shown to be useful for maintaining adequate cerebral oxygenation and perfusion in anesthetized patients, avoiding episodes of critical brain desaturation (2,11). Other neuromonitoring strategies such as electroencephalogram (EEG), transcranial Doppler (TCD) and transfontanellar ultrasound have demonstrated their usefulness to obtain information on mechanisms of neurological injury that occur in the pre, intra, and postoperative period. Standard EEG, processed EEG such as amplitude-integrated EEG (EEGa) or Bispectral Index (BIS), and somatosensory evoked potentials (SEPs) have proven useful for determining anesthetic depth, preventing intraoperative awareness, avoiding anesthetic overdose and detection of events of ischemia, hypoglycemia and subclinical seizures, providing opportunities for their early detection and management (12,13). Transcranial Doppler ultrasound (TCD) over the middle cerebral artery is also a valuable tool to identify inadequate cerebral flow during CPB. Transfontanelle ultrasonography is suitable for bedside use to detect complications such as intraventricular hemorrhage; however, it does not provide the necessary resolution to detect most subtle structural alterations which are only detectable by MRI. MRI requires transporting the critically ill patient to the MRI site thus limiting its intraoperative utility (14). \r\n\r\n\r\nThe multifactorial etiology of neurologic injury makes it less likely that a single intraoperative monitoring modality will be effective in capturing all potential threats. However, multimodal neuromonitoring such as NIRS, TCD and EEG combines several monitoring aspects of brain oxygenation, hemodynamics and electrophysiology. Its routine clinical application reduces the limitations associated to a single monitor, due to its inherent variability (NIRS, TCD) or interactions with anesthetic drugs (EEG). It allows greater sensitivity and specificity in the detection of neurological injury mechanisms (15), reducing the incidence of neurological complications and providing increased safety to the patient during surgery (16,17, 18,19). \r\nReferences \r\n\r\n1.\tGalli KK, Zimmerman RA, Jarvik GP, et al. Periventricular leukomalacia is common after neonatal cardiac surgery. J Thorac Cardiovasc Surg. 2004; 127: 692-704. \r\n2.\tVretzakis G, Georgopoulou S, Stamoulis K, et al. Cerebral oximetry in cardiac anesthesia. J Thorac Dis. 2014; 6(S1): S60-S69. doi: 10.3978\/j.issn.2072-1439.2013.10.22 \r\n3.\tMenache CC, du Plessis AJ, Wessel DL, Jonas RA, Newburger JW. Current incidence of acute neurologic complications after open heart operations in children. Ann Thorac Surg. 2002; 73: 1752-1758. \r\n4.\tMiller S, McQuillen P, Hamrick S, et al. Abnormal Brain Development in Newborns with Congenital Heart Disease. N Engl J Med. 2007; 357: 1928-1938. \r\n5.\tWernovsky G. Current insights regarding neurological and developmental abnormalities in children and young adults with complex congenital cardiac disease. Cardiol Young. 2006; 16 (suppl1): 92\u2013104. doi: 10.1017\/ S1047951105002398. \r\n6.\tDominguez TE, Wernovsky G, Gaynor W. Cause and prevention of central nervous system injury in neonates undergoing cardiac surgery. Semin Thorac Cardiovasc Surg. 2007; 19: 269-277. \r\n7.\tAlbers EL, Bichell DP, McLaughlin B. New approaches to neuroprotection in infant heart surgery. Pediatr Res. 2010; 68: 1-9. \r\n8.\tChar D, Ramamoorthy C, Wise-Faberowski L. Cognitive dysfunction in children with heart disease: the role of anesthesia and sedation. Congenit Heart Dis. 2016; 11: 221-229. \r\n9.\tMorton P, Ishibashi N, Jonas R. Neurodevelopmental abnormalities and congenital heart disease insights into altered brain maturation. Circ Res. 2017; 120: 960-977. DOI: 10.1161\/CIRCRESAHA.116.309048. \r\n10.\tPeyvandi S, Latal B, Miller S, McQuillen P. The neonatal brain in critical congenital heart disease: Insights and future directions. Neuroimage. 2018. https:\/\/doi.org\/10.1016\/j.neuroimage.2018.05.045 \r\n11.\tWeber F, Scoones G. A practical approach to cerebral near-infrared spectroscopy (NIRS) directed hemodynamic management in non cardiac pediatric anesthesia. Pediatric Anesthesia. 2019; 29: 993-1001. \r\n12.\tSury M. Brain Monitoring in Children. Anesthesiology Clin. 2014; 32: 115\u2013132. \r\n13.\tBarry A, Chaney M, London M. Anesthetic Management During Cardiopulmonary Bypass: A Systematic Review. Anesth Analg. 2015; 120: 749\u2013769. \r\n14.\tMorton P, Ishibashi N, Jonas R. Neurodevelopmental abnormalities and congenital heart disease Insights Into altered brain maturation. Circ Res. 2017; 120: 960-977. DOI: 10.1161\/CIRCRESAHA.116.309048 \r\n15.\tZanatta P, Benvenuti S, Bosco E, Baldanzi F, Palomba D, Valfr\u00e8 C. Multimodal brain monitoring reduces major neurologic complications in cardiac surgery. Journal of Cardiothoracic and Vascular Anesthesia. 2011; 25: 1076-1085. \r\n16.\tAndropoulos DB, Stayer SA, Diaz LK, Ramamoorthy C. Neurological monitoring for congenital heart surgery. Anesth Analg. 2004; 99: 1365\u20111375. \r\n17.\tThudium M, Heinze I, Ellerkmann R, Hilbert T. Cerebral function and perfusion during cardiopulmonary bypass: A plea for a multimodal monitoring approach. The Heart Surgery Forum. 2018; 21(1): 1894. \r\n18.\tMittnacht A, Rodriguez\u2011Diaz C. Multimodal neuromonitoring in pediatric cardiac anesthesia. Annals of Cardiac Anaesthesia. 2014; 17: 25-32. \r\n19.\tFinucane E, Jooste E, Machovec K. Neuromonitoring Modalities in Pediatric Cardiac Anesthesia: A Review of the Literature. Journal of Cardiothoracic and Vascular Anesthesia. 2020; 34: 3420-3428. \r\n”,”redirect_url”:””}}}

{“questions”:{“ow9nc”:{“id”:”ow9nc”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Jessica Yeh, MBBS and Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR\r\n\r\nA 6-month-old infant with a normal karyotype is undergoing repair of a complete atrioventricular canal defect. Compared to an infant with Trisomy 21, what is the MOST LIKELY complication after a full operative repair in a patient with a normal karyotype?\r\n”,”desc”:””,”hint”:””,”answers”:{“2pfwt”:{“id”:”2pfwt”,”image”:””,”imageId”:””,”title”:”A. Left atrioventricular valve regurgitation”,”isCorrect”:”1″},”wna9d”:{“id”:”wna9d”,”image”:””,”imageId”:””,”title”:”B. Complete heart block “},”z0uht”:{“id”:”z0uht”,”image”:””,”imageId”:””,”title”:”C. Junctional ectopic tachycardia”},”ad8hb”:{“id”:”ad8hb”,”image”:””,”imageId”:””,”title”:”D. Right ventricular hypertrophy “}}}},”results”:{“11vkd”:{“id”:”11vkd”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Atrioventricular (AV) septal or canal defects are strongly associated with Trisomy 21. There is a 40-50% risk of Trisomy 21 in fetuses with a prenatal diagnosis of AV canal defect and approximately 40% of fetuses with Trisomy 21 also have an associated AV canal defect. \r\n\r\nTimely surgical repair of AV canal defects can reduce the risk of developing pulmonary vascular disease and subsequent pulmonary hypertension and heart failure. After surgical repair, hemodynamically significant residual defects may necessitate surgical re-intervention. Several studies have demonstrated that the presence of Trisomy 21 is not a risk factor for re-operation. Patients with a normal karyotype have an increased rate of re-operation after primary AV canal defect repair. A common indication for re-operation is residual left atrioventricular valve regurgitation, presumably due to a higher prevalence of left atrioventricular valve abnormalities such as valve dysplasia. An additional indication for re-operation is significant subaortic stenosis or left ventricular outflow tract obstruction, which is also more prevalent in patients with a normal karyotype. \r\n\r\nTrisomy 21 is a risk factor for the development of pulmonary hypertension even after repair of an AV canal defect. The etiology is multifactorial including a genetic contribution to endothelial cell dysfunction or abnormal lung development as well as the presence of other comorbidities such as obstructive sleep apnea, gastric aspiration, or tracheobronchomalacia. Right ventricular hypertrophy typically develops over time due to increased pulmonary arterial pressure. \r\n\r\n\r\nArrhythmias in the immediate postoperative period after AV canal defect repair occur in approximately 10-15% of patients with 3-4% of patients requiring subsequent implantation of a permanent pacemaker for complete heart block. However, there is no difference in the proportion of patients with heart block relative to the presence of Trisomy 21. \r\n\r\nNeurodevelopmental outcomes after cardiac surgery vary depending on the extent of the congenital cardiac lesion. A child with a normal karyotype and complete atrioventricular canal defect has an increased risk of neurodevelopmental impairment compared to their healthy peers, but the presence of Trisomy 21 increases this risk even further. \r\n\r\n\r\nReferences: \r\n1.\tSt Louis JD, Jodhka U, Jacobs JP, et al. Contemporary outcomes of complete atrioventricular septal defect repair: Analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database. J Thorac Cardiovasc Surg<\/em>. 2014; 148: 2526-2531. \r\n2.\tXie O, Brizard CP, d\u2019Udekem Y, et al. Outcomes of repair of complete atrioventricular septal defect in the current era. Eur J Cardiothorasc Surg<\/em>. 2014; 45(4): 610-617. \r\n3.\tFormigari R, Di Donato RM, Gargiulo G, et al. Better surgical prognosis for patients with complete atrioventricular septal defect and Down’s syndrome. Ann Thorac Surg<\/em>. 2004; 78(2): 666-672. \r\n4.\tLange R, Guenther T, Busch R, et al. The presence of Down syndrome is not a risk factor in complete atrioventricular septal defect repair. J Thorac Cardiovasc Surg<\/em>. 2007; 134(2): 304-310. \r\n5.\tMussatto KA, Hoffmann RG, Hoffman GM, et al. Risk and prevalence of developmental delay in young children with congenital heart disease. Pediatrics<\/em>. 2014; 133(3): e570-e577. \r\n”,”redirect_url”:””}}}