Читать книгу Surgical Critical Care and Emergency Surgery - Группа авторов - Страница 10

Mauer Biscotti III, MD1, Matthew A. Goldshore, MD, PhD, MPH2, and Jeremy W. Cannon, MD, SM3,4

1 Division of General Surgery, Department of Surgery, San Antonio Military Medical Center, San Antonio, TX, USA

2 Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA

3 Division of Traumatology, Surgical Critical Care & Emergency Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA

4 Department of Surgery, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA

1 A 45‐year‐old previously healthy man was a pedestrian struck by a motor vehicle resulting in multiple injuries including traumatic brain injury with a subarachnoid hemorrhage (SAH), multiple rib fractures, pulmonary contusion, hemothorax, splenic laceration, and a pelvic fracture. On postinjury day 5, he developed severe hypoxemic respiratory failure (PaO2:FiO2 ratio of 70 on FiO2 of 1) and was diagnosed with an MRSA pneumonia. Workup for other causes of respiratory failure or sepsis was negative, and there was no evidence of SAH progression or torso hemorrhage on his most recent imaging. Which of the following should be performed before considering this patient for extracorporeal membrane oxygenation (ECMO)?High‐frequency oscillatory ventilationAirway pressure release ventilationProne positioningRib fracture stabilizationDecompressive laparotomyThis patient is potentially a good candidate for venovenous extracorporeal membrane oxygenation (ECMO) for hypoxemic respiratory failure. The basic principles for determining a patient’s candidacy for ECMO include lack of response to conventional ventilator management and rescue interventions for severe hypoxemic or hypercarbic respiratory failure, an underlying process that is potentially reversible, and no contraindications to ECMO. The ventilator should be optimized for acute respiratory distress syndrome (ARDS) management, and proning can be employed as a rescue intervention to optimize gas exchange. Chemical paralysis can also be used along with deep sedation, particularly in the setting of ventilator dyssynchrony. If the patient’s oxygenation does not improve, ECMO is reasonable so long as his traumatic brain injury is not severe, his intracranial bleeding has stabilized, and there is no ongoing torso hemorrhage. The RESP score calculator can be used to quantify the patient’s projected outcome on ECMO (https://www.elso.org/Resources/ECMOOutcomePredictionScores.aspx).High‐frequency oscillatory ventilation requires special expertise and does not offer any clear survival benefit for this patient. Airway pressure release ventilation (APRV) is better suited to awake patients with moderate respiratory failure and ventilator synchrony problems. Rib fracture stabilization should be performed earlier in the hospital course. The patient would not likely benefit from this procedure and also would be unlikely to significantly improve with this intervention. In the absence of abdominal compartment syndrome or refractory intracranial pressure elevation, decompressive laparotomy has no role in the management of this patient.Answer: CBrodie D, Bacchetta M . Extracorporeal membrane oxygenation for ARDS in adults. N Engl J Med. 2011; 365(20):1905–14. doi: https://doi.org/10.1056/NEJMct1103720. PMID: 22087681.Brodie D, Slutsky AS, Combes A . Extracorporeal life support for adults with respiratory failure and related indications: a review. JAMA. 2019; 322(6):557–568. doi: https://doi.org/10.1001/jama.2019.9302. PMID: 31408142.Bullen EC, Teijeiro‐Paradis R, Fan E . How i select which patients with ARDS should be treated with venovenous extracorporeal membrane oxygenation. Chest. 2020; 158(3):1036–1045. doi: https://doi.org/10.1016/j.chest.2020.04.016. Epub 2020 Apr 21. PMID: 32330459.Cannon JW, Gutsche JT, Brodie D . Optimal strategies for severe acute respiratory distress syndrome. Crit Care Clin. 2017; 33(2):259–275. doi: https://doi.org/10.1016/j.ccc.2016.12.010. PMID: 28284294.ELSO Guidelines for Adult Respiratory Failure (2017). Extracorporeal Life Support Organization, Version 1. https://www.elso.org/Portals/0/ELSO%20Guidelines%20For%20Adult%20Respiratory%20Failure%201_4.pdf (accessed 4 August 2017).Schmidt M, Bailey M, Sheldrake J, et al. Predicting survival after extracorporeal membrane oxygenation for severe acute respiratory failure. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score. Am J Respir Crit Care Med. 2014; 189(11):1374–82. doi: https://doi.org/10.1164/rccm.201311‐2023OC. PMID: 24693864.

2 A 62‐year‐old man with a history of alcoholic cirrhosis (MELD 18), active alcohol abuse, mild aortic valve insufficiency, type II diabetes, and obesity (BMI = 35) presents to the emergency department with an ST‐elevation MI. He is immediately taken to the cardiac catheterization lab for percutaneous coronary intervention; a left anterior descending artery culprit lesion is successfully stented. However, postprocedure, he remains in profound shock on very high doses of intravenous epinephrine, norepinephrine, and vasopressin. Arterial blood pressure is 85/40 mm Hg. A bedside echocardiogram indicates significant left ventricular dysfunction with an ejection fraction of 25%. The cardiologist is requesting veno‐arterial (VA) ECMO given the patient’s shock state. Which of the following patient characteristics is the strongest contraindication for providing ECMO support?Age of 62Morbid obesity (BMI 35)Mild aortic valve insufficiencyAlcoholic cirrhosisImmediately post‐MI with LV dysfunctionThis patient is a poor candidate for several reasons; however, cirrhosis is the strongest contraindication to this therapy as it portends a poor overall outcome. Chronic end‐organ dysfunction with no exit strategy (such as transplant for which this patient is not a candidate given his active alcohol abuse) is an absolute contraindication to ECMO.Advanced age is a relative contraindication to ECMO, with age of 65 often used as a cutoff in older literature. However, VA ECMO in patients up to 75 years of age has proven safe and effective. Obesity is no longer a contraindication to ECMO, and in select patients it may even be protective. Severe aortic valve insufficiency is a relative contraindication to VA ECMO. Mild aortic valve insufficiency may require venting of the left ventricle with a microaxial pump, atrial septostomy, or LV drainage cannula, but it is not in itself a contraindication to VA ECMO. Cardiogenic shock after myocardial infarction is a reasonable indication for VA ECMO. It may also be considered in other forms of cardiogenic shock, including myocarditis, pulmonary embolism, and postcardiotomy. It may also be used to manage heart failure with a plan to bridge to permanent ventricular assist device placement or transplant.Answer: DYannopoulos D, Bartos J, Raveendran G, et al. Advanced reperfusion strategies for patients with out‐of‐hospital cardiac arrest and refractory ventricular fibrillation (ARREST): a phase 2, single centre, open‐label, randomised controlled trial. Lancet. 2020 Nov 12:S0140–6736(20)32338‐2. doi: https://doi.org/10.1016/S0140‐6736(20)32338‐2. Epub ahead of print. PMID: 33197396.Lee SN, Jo MS, Yoo KD . Impact of age on extracorporeal membrane oxygenation survival of patients with cardiac failure. Clin Interv Aging. 2017 Aug 24; 12:1347–1353. doi: https://doi.org/10.2147/CIA.S142994. PMID: 28883715; PMCID: PMC5576703.Salna M, Chicotka S, Biscotti M III, et al. Morbid obesity is not a contraindication to transport on extracorporeal support. Eur J Cardiothorac Surg. 2018; 53(4):793–798. doi: https://doi.org/10.1093/ejcts/ezx452. PMID: 29253111.Makdisi G, Wang IW . Extra Corporeal Membrane Oxygenation (ECMO) review of a lifesaving technology. J Thorac Dis. 2015; 7(7):E166–76. doi: https://doi.org/10.3978/j.issn.2072‐1439.2015.07.17. PMID: 26380745; PMCID: PMC4522501.

3 A 45‐year‐old previously healthy man was a pedestrian struck by a motor vehicle resulting in multiple injuries including traumatic brain injury with a subarachnoid hemorrhage (SAH), multiple rib fractures, pulmonary contusion, hemothorax, splenic laceration, and a pelvic fracture. On postinjury day 5, he developed severe hypoxemic respiratory failure (PaO2:FiO2 ratio of 70 on FiO2 of 100%) and was diagnosed with an MRSA pneumonia. Workup for other causes of respiratory failure or sepsis was negative, and there was no evidence of SAH progression or torso hemorrhage on his most recent imaging. His hypoxemic respiratory failure did not improve with proning and neuromuscular blockade. What is the optimal ECMO cannulationstrategy for this patient?Femoral venous drainage, carotid arterial reinfusionFemoral venous drainage, femoral arterial reinfusionFemoral venous drainage, jugular venous reinfusionFemoral venous drainage, femoral venous reinfusionJugular venous drainage, right atrial reinfusion (dual lumen cannula)This patient has no evidence of cardiac failure, so veno‐arterial cannulation is unnecessary. This approach increases the potential for an arterial injury or thromboembolic event, will significantly increase the patient’s cardiac afterload, and may not provide adequate oxygenation.The most common cannulation strategy for venovenous ECMO is femoral drainage and jugular reinfusion. A multistage, large‐bore venous drainage cannula will adequately support the gas exchange needs for most adult patients (4–6 L/min flow) without risking flow limitations or recirculation that can be a problem with the bilateral femoral‐femoral venovenous approach. Single site cannulation with a dual lumen cannula facilitates early ambulation for ECMO patients; it is commonly used for those awaiting a lung transplant.Answer: CCannon JW, Gutsche JT, Brodie D . Optimal strategies for severe acute respiratory distress syndrome. Crit Care Clin. 2017; 33(2):259–275. doi: https://doi.org/10.1016/j.ccc.2016.12.010. PMID: 28284294.ELSO Guidelines for Adult Respiratory Failure (2017). Extracorporeal Life Support Organization, Version 1. https://www.elso.org/Portals/0/ELSO%20Guidelines%20For%20Adult%20Respiratory%20Failure%201_4.pdf (accessed 4 August 2017).ELSO Guidelines for Cardiopulmonary Extracorporeal Life Support (2017). Extracorporeal Life Support Organization, Version 1. https://www.elso.org/Portals/0/ELSO%20Guidelines%20General%20All%20ECLS%20Version%201_4.pdf (accessed 4 August 2017).

4 A 58‐year‐old man is on day 2 of veno‐arterial ECMO support after an aspiration event led to a cardiac arrest. He is cannulated via his left common femoral vein for drainage and right common femoral artery for reinfusion. He is on a low‐dose epinephrine infusion with a blood pressure of 110/60 mm Hg and a normal lactate level. He has no signs of renal, hepatic, or neurologic injury. On transthoracic echocardiography, his left ventricular ejection fraction has improved from 10% on day 1 to 30% on day 2. His left ventricular size appears normal with no obvious valvular abnormalities. He has responded well to furosemide and his fluid balance is 3L negative since initiation of ECMO. His pulmonary capillary wedge pressure is 12 mm Hg. His chest x‐ray shows bilateral lower lobe infiltrates. However, his upper body peripheral oxygen PaO2 is 40 mm Hg despite maximal ARDSnet appropriate ventilator settings, while his lower body PaO2 remains > 200 mm Hg. What is the next best step in his management?Place a left ventricular microaxial percutaneous ventricular assist device for left ventricular venting.Increase total VA ECMO flows to improve upper body saturation.Add a second‐line inopressor in addition to epinephrine.Place a venous reinfusion ECMO cannula and convert the patient’s configuration to VA‐V ECMO.Perform an atrial septostomy for left ventricular unloading.Left ventricular venting is commonly employed in patients supported on peripheral VA ECMO when the native cardiac function is not robust enough to overcome the increased afterload generated by the VA ECMO circuit, which leads to left ventricular distention. This patient shows no signs of left ventricular distention with a normal PCWP, no signs of aortic or mitral insufficiency, and an improving ejection fraction. Performing LV decompression with a septostomy or mechanical device is likely unnecessary in this patient.There is no evidence of renal or hepatic impairment and cardiac function has improved, making an increase in cardiac output, especially to the lower body (whether increased arterial flow or increased inopressor support), unnecessary. Rather, this patient is likely suffering from severe respiratory failure from aspiration pneumonitis rather than left‐sided heart failure and pulmonary edema. While his lower body oxygen delivery is adequate, the oxygen delivery to the coronary and cerebral circulation is likely not, with a PaO2 of 40 mm Hg. Addition of a venous reinfusion limb to convert to a hybrid VA‐V ECMO circuit will provide additional oxygenation support and is the most useful next step.Answer: DRusso JJ, Aleksova N, Pitcher I, et al. Left ventricular unloading during extracorporeal membrane oxygenation in patients with cardiogenic shock. J Am Coll Cardiol. 2019; 73(6):654–662. doi: https://doi.org/10.1016/j.jacc.2018.10.085. PMID: 30765031.

5 While on venovenous ECMO, which of the following ventilator strategies should be used to provide lung protection and recovery?Figure 3.1 VA‐V ECMO circuit.Source: From Biscotti M., Lee A,, Basner RC., et al. Hybrid configurations via percutaneous access for extracorporeal membrane oxygenation: a single‐center experience. ASAIO J. 2014;60(6):635–42. with permission.T‐piece or tracheostomy collarHigh‐frequency percussive ventilationHigh‐frequency oscillatory ventilationVolume control 8 mL/kg ideal body weightPressure control with PEEP of 10 cm H20Lung protective ventilation should continue after ECMO initiation. In fact, so‐called ultra‐lung protective ventilation is often feasible once the majority of the patient’s gas exchange needs are provided by the ECMO circuit. The best current approach is likely reflected in the recently conducted EOLIA trial in which plateau airway pressure was limited to a maximum of 24 cm H2O in conjunction with PEEP > = 10 cm H2O (corresponding to a driving pressure < = 14 cm H2O), respiratory rate of 10–30 breaths/min, and FiO2 of 0.3–0.5. This can be achieved with either a volume control or a pressure control mode, but in our view, a pressure control mode is easier to apply in the setting of very low lung compliance. Often the tidal volumes will be much lower than 4 mL/kg, especially early after ECMO initiation. Furthermore, the respiratory rate should be minimized to further decrease ventilator‐induced lung injury.Early after ECMO initiation, patients may have significant air hunger and may also need moderate‐to‐deep sedation for a period of time. As a result, spontaneous modes of ventilation are not employed until the patient has shown some signs of stabilization or even recovery. High‐frequency percussive ventilation can help with mobilizing secretions, particular in patients with inhalation injury, but this approach is not routinely used in ECMO patients. High‐frequency oscillatory ventilation has no proven benefit in this population and may actually cause harm in some cases. Finally, volume control ventilation at this level typically results in extremely high driving pressures, especially early after ECMO initiation.Answer: EAbrams D, Schmidt M, Pham T, et al. Mechanical ventilation for acute respiratory distress syndrome during extracorporeal life support. Research and practice. Am J Respir Crit Care Med. 2020; 201(5):514–525. doi: https://doi.org/10.1164/rccm.201907‐1283CI. PMID: 31726013.Brodie D, Bacchetta M . Extracorporeal membrane oxygenation for ARDS in adults. N Engl J Med. 2011; 365(20):1905–14. doi: https://doi.org/10.1056/NEJMct1103720. PMID: 22087681.ELSO Guidelines for Cardiopulmonary Extracorporeal Life Support (2017). Extracorporeal Life Support Organization, Version 1. https://www.elso.org/Portals/0/ELSO%20Guidelines%20For%20Adult%20Respiratory%20Failure%201_4.pdf (accessed 4 August 2017).

6 A 30‐year‐old previously healthy man is placed on venovenous (VV) ECMO for severe COVID‐19 pneumonia. On ECMO day 5, he is intubated but awake and interactive on minimal sedation. His morning chest x‐ray demonstrates a new right‐sided pneumothorax. After insertion of a tube thoracostomy, he continues to have a large, continuous air leak on ECMO day 7. His pulmonary compliance remains moderate‐to‐high, with a tidal volume of 7 mL/kg IBW on a positive end‐expiratory pressure (PEEP) of 5, a driving pressure of 10 cm H2O, a fraction of inspired oxygen (FiO2) of 0.5, and a respiratory rate of 20 breaths/min. He remains on ECMO support with a sweep gas flow rate of 6 liters/min. His peripheral arterial blood gas shows a pH of 7.36, PaCO2 of 47, and a PaO2 of 78. What is the best management approach for this patient’s mechanical ventilation?Extubate to high flow nasal cannula.Increase PEEP.Convert to airway pressure release ventilation (APRV) with a PHI of 30 and PLOW of 0.Sedate, paralyze, and prone positioning.Increase tidal volumes.This patient has a persistent continuous air leak, which can be exacerbated by continuous positive pressure ventilation. Ventilator strategies to aid in healing of bronchopleural fistulae typically include lowering airway pressures and PEEP. Strategies that include increasing PEEP, tidal volumes, or APRV can lead to higher airway pressures, which may preclude lung healing. In select cases, extubation may be a reasonable strategy, provided the patient can be sufficiently supported without tracheal intubation.Answer: AXia J, Gu S., Li M,s et al. Spontaneous breathing in patients with severe acute respiratory distress syndrome receiving prolonged extracorporeal membrane oxygenation. BMC Pulm Med. (2019); 19 : 237. https://doi.org/10.1186/s12890‐019‐1016‐2

7 After initiating venovenous ECMO, which strategy is most likely to minimize bleeding while also preventing clot formation in the circuit or around the cannulas?Heparin bolus and infusionLow molecular weight heparin 1.5 mg/kg twice dailyArgatroban infusionDual antiplatelet therapyWithholding systemic anticoagulation for 24 hoursBlood exposure to the surface of the gas exchange membrane and the circuit activates the intrinsic clotting cascade, the complement system, and platelets. This results in a state of both hyper‐ and hypo‐coagulation. In some cases such as a recent intracranial bleed or solid organ injury, patients on venovenous ECMO may have anticoagulation withheld. However, in most cases, low‐dose anticoagulation is used to preserve the gas exchange membrane’s efficiency, increase the circuit longevity, and mitigate the risk of thromboembolic complications. Patients on veno‐arterial ECMO are generally maintained on higher doses of anticoagulation given the more significant implications of an arterial thromboembolic event.The most common anticoagulation approach is a heparin bolus upon cannula insertion (50–100 units/kg) followed by a continuous heparin infusion (7.5‐20 units/kg/hr). Heparin titration has historically been performed based on activated clotting time (ACT) measured at the bedside (target 180–220 seconds); however, recent evidence suggests that either a PTT‐based approach (1.5‐2 times baseline) or an anti‐Xa approach (0.25 units/mL) may be preferable.Therapeutic low molecular weight injections are not typically performed on ECMO. Argatroban, a direct thrombin inhibitor, can be used but is generally reserved for patients with a history of, or concern for, HITT. Withholding anticoagulation can be done as described above, and some evidence suggests this may actually be safe for the entirety of a short ECMO run. However, this is not currently a standard approach. Likewise, dual antiplatelet therapy (DAPT) alone is not a standard approach although it may be used in patients with other indications for DAPT, which is more common in patients on veno‐arterial ECMO.Answer: AELSO Anticoagulation Guidelines (2017). Extracorporeal Life Support Organization, Version 2014. https://www.elso.org/portals/0/files/elsoanticoagulationguideline8‐2014‐table‐contents.pdf (accessed 30 July 2021).Kurihara C, Walter JM, Karim A, et al. Feasibility of venovenous extracorporeal membrane oxygenation without systemic anticoagulation. Ann Thorac Surg. 2020; 110(4):1209–1215. doi: https://doi.org/10.1016/j.athoracsur.2020.02.011. Epub 2020 Mar 12. PMID: 32173339; PMCID: PMC7486253.Parker RI . Anticoagulation monitoring during extracorporeal membrane oxygenation: continuing progress. Crit Care Med. 2020; 48(12):1920–1921. doi: https://doi.org/10.1097/CCM.0000000000004635. PMID: 33255117.Vandenbriele C, Vanassche T, Price S . Why we need safer anticoagulant strategies for patients on short‐term percutaneous mechanical circulatory support. Intensive Care Med. 2020; 46(4):771–774. doi: https://doi.org/10.1007/s00134‐019‐05897‐3. Epub 2020 Jan 23. PMID: 31974917.

8 Since the inception of ECMO technology in the 1970s, the rates of bleeding and thrombotic complications have decreased significantly, though they remain a significant cause of morbidity and mortality. Which factor is likely the most significant contributor to the observed decrease in bleeding and thrombotic complications over the past several decades?Novel anticoagulants including direct thrombin inhibitorsChanges in ECMO device technologies The invention and use of thromboelastographyMore accurate assays for activated clotting time and activated partial thromboplastin timeDiscovery of modern‐day antiplatelet therapyThe use of novel anticoagulants and antiplatelet therapies in ECMO has been described but has not been studied sufficiently to make any recommendations for or against their use.Use of TEG and ACT monitors, as well as protocols targeting low or high PTT goals, is often implemented; however, current evidence is insufficient to recommend one specific approach over the others. The improvements in ECMO circuit technology and heparin‐coated cannulas have likely led to a decrease in total dose and duration of anticoagulation required and an improvement in circuit‐related hemorrhagic or thrombotic complications.Answer: BSklar MC, Sy E, Lequier L, et al. Anticoagulation practices during venovenous extracorporeal membrane oxygenation for respiratory failure. A systematic review. Ann Am Thorac Soc. 2016; 13(12):2242–2250. doi: https://doi.org/10.1513/AnnalsATS.201605‐364SR. PMID: 27690525.

9 Acute kidney injury (AKI) is a common problem in patients requiring ECMO therapy. As such, the use of renal replacement therapy (RRT) is necessary in 40–60% of cases. Which of the following statements regarding use of RRT and ECMO is most accurate?RRT access should never be provided via an in‐line approach with ECMO circuits. It should always be provided via separate vascular access.Fluid overload is an uncommon problem in the pediatric ECMO population and has no significant effect on morbidity and mortality.Uremia and electrolyte derangements are the most common indications for RRT initiation in both children and adults on ECMO.The polymethylpentene oxygenator used in ECMO circuits can also be used as a hemofilter to deliver RRT in patients with concomitant AKI.Negative fluid balance on RRT is independently associated with improved outcomes for both the adult and pediatric ECMO population.The most common indication for RRT in both adult and pediatric ECMO patients is fluid overload. Specifically, in the pediatric population, fluid overload is associated with increased mortality and longer duration of ECMO support. Further, several studies have associated a net negative fluid balance while on RRT with improved patient outcomes.It is safe and feasible to provide RRT via either separate vascular access or direct integration into the ECMO circuit, depending on patient‐specific circumstances. However, the polymethylpentene oxygenator will provide gas exchange but will not function as a hemofilter to provide RRT.Answer: EOstermann M, Connor M Jr, Kashani K . Continuous renal replacement therapy during extracorporeal membrane oxygenation: why, when and how? Curr Opin Crit Care. 2018; 24(6):493–503. doi: https://doi.org/10.1097/MCC.0000000000000559. PMID: 30325343.Gorga SM, Sahay RD, Askenazi DJ,et al. Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy: a multicenter retrospective cohort study. Pediatr Nephrol. 2020; 35(5):871–882. doi: https://doi.org/10.1007/s00467‐019‐04468‐4. Epub 2020 Jan 17. PMID: 31953749; PMCID: PMC7517652.Dado DN, Ainsworth CR, Thomas SB, et al. Outcomes among patients treated with renal replacement therapy during extracorporeal membrane oxygenation: a single‐center retrospective study. Blood Purif. 2020; 49(3):341–347. doi: https://doi.org/10.1159/000504287. Epub 2019 Dec 19. PMID: 31865351; PMCID: PMC7212702.

10 A 40‐year‐old man is placed on venovenous (VV) ECMO via a 25 Fr right femoral vein drainage cannula and a 17 Fr right internal jugular vein reinfusion cannula for refractory ARDS secondary to aspiration pneumonitis. He is 6’ 2” tall and weighs 240 lbs (BMI 30.8 kg/m2, BSA 2.35 m2). His initial circuit flow is 5.0 L/min at an RPM of 4000 and drainage pressure of −120 cm H2O; the ECMO specialist is unable to flow > 5.0 L/min because of excessively high drainage pressures (chatter) in the line. Over the next 48 hours, his SpO2 remains at 70% on maximal ventilator settings with a hemoglobin of 14 g/dL; no signs of untreated sepsis, infection, or shock; normal biventricular function on echocardiogram, and a persistently elevated lactate. His circuit flows remain the same and the oxygenator health is excellent. What is the next most appropriate step?Consider adding an additional arterial reinfusion limb to provide increased ECMO support.Consider adding a 21Fr venous reinfusion limb to provide increased ECMO support.Transfuse the patient to a supranormal hemoglobin to improve oxygen delivery.Begin aggressive intravenous fluid resuscitation to improve circuit venous drainage.Consider adding an additional drainage cannula to increase overall ECMO flows. Inadequate ECMO flows is a common problem, and because of fluid dynamics, venous drainage (access) insufficiency is typically the limiting factor rather than reinfusion cannula size. Venous drainage pressures more negative than −100 mm Hg are typically associated with “chatter” in the lines and, therefore, flow limitations. Conversely, flow is often not limited by reinfusion pressures until the reinfusion line pressure is > 300–400 mm Hg. In patients with drainage insufficiency, the addition of a venous or arterial reinfusion limb will not increase ECMO flows and will not provide any additional benefit.Some ECMO physicians advocate for transfusions to normal hemoglobin levels, instead of using typical ICU transfusion practices with a transfusion threshold of 7 or 8 g/dL. However, supplementing the patient’s already normal hemoglobin (14 g/dL) is unlikely to add additional benefit. Additionally, patients with severe ARDS typically benefit from volume removal rather than volume expansion. While fluid boluses may temporarily improve flows by improving venous drainage, this is not an effective long‐term solution.In patients with a large body size, they may require higher than typical ECMO flows, and addition of an extra drainage cannula via the contralateral femoral vein may improve total circuit flow capacity, which will mitigate the hypoxemia and resultant tissue hypoxia.Answer: EDado DN, Ainsworth CR, Thomas SB, et al. Outcomes among patients treated with renal replacement therapy during extracorporeal membrane oxygenation: a single‐center retrospective study. Blood Purif. 2020; 49(3):341–347. doi: https://doi.org/10.1159/000504287. Epub 2019 Dec 19. PMID: 31865351; PMCID: PMC7212702.

11 A 55‐year‐old man is emergently placed on femoral‐femoral veno‐arterial (VA) ECMO for a cardiac arrest caused by an acute MI. The culprit coronary lesion was stented in the cardiac catheterization lab, and he was taken to the ICU to recover. On hospital day 1, his post‐oxygenator PaO2 is 400 mm Hg and radial arterial PaO2 is also 400 mm Hg. Transthoracic echocardiogram demonstrates a left ventricular ejection fraction of 10%. He remains intubated with a positive end‐expiratory pressure (PEEP) of 5 cm H2O and a fraction of inspired oxygen (FiO2) of 40%. On hospital day 3, with the same ventilator settings, his right radial arterial line demonstrates a PaO2 of 150 mm Hg and his post‐oxygenator blood gas PaO2 remains at 400 mm Hg. His lactate levels remain normal. The total ECMO flows have decreased by 0.5 L/min with the same device RPMs. What is the most likely explanation for this finding?The oxygenator efficiency has decreased.There is inadequate oxygen delivery to the tissue resulting in tissue hypoxia.The patient now has severe ARDS.The patient’s heart and left ventricular ejection fraction are beginning to recover.The right radial blood gas is likely venous.As the cardiac function improves in patients on peripheral VA ECMO, the native cardiac output will compete with retrograde aortic ECMO flow, thereby “pushing” left ventricular blood further across the aortic arch. This phenomenon of moving the mixing point more distally into the aortic arch demonstrates the “Harlequin syndrome” that is often seen with femoral‐femoral veno‐arterial ECMO. A sample of arterial blood from a right radial arterial line may demonstrate a more “normal” PaO2 rather than the supranormal PaO2 that is indicative of ECMO circuit blood, and this is often a sign that the cardiac function is beginning to recover. Because most modern ECMO circuits utilize an afterload‐sensitive centrifugal pump, total VA ECMO flows will often decrease as cardiac function improves and the circuit afterload increases.A high post‐oxygenator PaO2 suggests adequate and unchanged oxygenator function, and so long as end‐organ perfusion remains normal, it is unlikely that tissue hypoxia is occurring.A PaO2:FiO2 ratio > 300 does not meet clinical criteria for severe ARDS, and a PaO2 > 100 mm Hg is unlikely to be from a venous blood sample.Answer: DEckman PM, Katz JN, El Banayosy A, et al. Veno‐Arterial extracorporeal membrane oxygenation for cardiogenic shock: an introduction for the busy clinician. Circulation. 2019; 140(24):2019–2037. doi: https://doi.org/10.1161/CIRCULATIONAHA.119.034512. Epub 2019 Dec 9. PMID: 31815538.

12 Which of the following sites of hemorrhage is most common during ECMO support?IntracranialCannula siteSolid organGastrointestinalPulmonaryBleeding complications occur in approximately 24% of ECMO patients. The ELSO registry records these complications. Participation in this registry is voluntary; however, in some instances, the exposure may not be 100% of patients resulting in an under‐representation of certain types of bleeding complications (e.g. the percentage of surgical site bleeding may be artificially lowered by including nonsurgical patients in the denominator). However, it appears that cannula site hemorrhage is the most common bleeding complication (8%) followed by surgical site bleeding (7%), gastrointestinal bleeding (6%), pulmonary hemorrhage (4%), and central nervous system bleeding (3%).Figure 3.2 Harlequin syndrome.Source: From Eckman PM, Katz JN, El Banayosy A, et al. Veno‐arterial extracorporeal membrane oxygenation for cardiogenic shock: an introduction for the busy clinician. Circulation. 2019;140(24):2019–2037, with permission.Strategies for managing cannula site bleeding include prevention by under‐sizing the insertion site incision for cannula insertion, application of topical hemostatics around the cannula site, placement of purse string sutures around the insertion site, or lowering the anticoagulation target.Answer: BBrodie D, Slutsky AS, Combes A . Extracorporeal life support for adults with respiratory failure and related indications: a review. JAMA. 2019; 322(6):557–568. doi: https://doi.org/10.1001/jama.2019.9302. PMID: 31408142.

13 General and trauma surgeons are often called upon to consult on ECMO patients. Which statement about surgical procedures for ECMO patients is most accurate?Intra‐abdominal operations should not be performed on ECMO patients, as intraoperative mortality typically exceeds 50%.Tracheostomy can be performed safely and effectively on ECMO patients.The use of antifibrinolytic agents (such as aminocaproic acid or tranexamic acid) for mitigating bleeding in ECMO patients has not been described.Interruption of anticoagulation for any period of time will result in immediate catastrophic circuit failure.Caesarean section is absolutely contraindicated during ECMO support.Noncardiac surgical procedures on ECMO patients are common and are required in as many as 50% of patients. Most studies have not demonstrated increased mortality among patients who underwent surgical procedures. Use of ECMO in pregnancy is also well described with Caesarean sections successfully performed in patients on ECMO.One of the most common procedures performed on ECMO patients is tracheostomy, and many reviews have demonstrated safety and efficacy of tracheostomy on ECMO patients. In fact, tracheostomy may decrease sedation requirements and decrease time on ECMO. Bleeding is still a risk; however, it is our approach to use electrocautery on the skin and soft tissue down to the trachea, turning the ventilator FiO2 < 60% and then proceeding with a percutaneous tracheostomy technique.Additionally, in many centers, antifibrinolytic medications are used prophylactically during surgical procedures or to treat bleeding complications in ECMO patients, and it is unlikely that short‐term interruption of anticoagulation infusions will cause circuit failure.Answer: BJuthani BK, Macfarlan J, Wu J, et al. Incidence of general surgical procedures in adult patients on extracorporeal membrane oxygenation. J Intensive Care Soc. 2019 May; 20(2):155–160. doi: https://doi.org/10.1177/1751143718801705. Epub 2018 Oct 2. PMID: 31037108; PMCID: PMC6475990.Salna M, Tipograf Y, Liou P, et al. Tracheostomy is safe during extracorporeal membrane oxygenation support. ASAIO J. 2020; 66(6):652–656. doi: https://doi.org/10.1097/MAT.0000000000001059. PMID: 31425269.Buckley LF, Reardon DP, Camp PC, et al. Aminocaproic acid for the management of bleeding in patients on extracorporeal membrane oxygenation: four adult case reports and a review of the literature. Heart Lung. 2016; 45(3):232–6. doi: https://doi.org/10.1016/j.hrtlng.2016.01.011. Epub 2016 Feb 20. PMID: 26907195.Agerstrand C, Abrams D, Biscotti M, et al. Extracorporeal membrane oxygenation for cardiopulmonary failure during pregnancy and postpartum. Ann Thorac Surg. 2016; 102(3):774–779. doi: https://doi.org/10.1016/j.athoracsur.2016.03.005. Epub 2016 May 4. PMID: 27154158.

14 A 45‐year‐old woman is placed on femoral‐femoral veno‐arterial ECMO via a 25 Fr venous cannula in the left femoral vein and a 17 Fr arterial cannula in the right femoral artery. Six hours after cannulation, the patient remains on moderate‐dose inopressors and is well supported with an ECMO flow of 3.5 L/min. The bedside nurse notices mottling of the right foot. What is the most likely etiology and reasonable next step?The patient has a right femoral DVT and is developing phlegmasia cerulea dolens. She requires a venous thrombolysis procedure.The patient has decreased cardiac output and requires an increase in inopressors.The arterial reinfusion cannula has thrombosed and must be replaced immediately.The arterial cannula is causing distal limb ischemia. A distal perfusion catheter should be placed emergently.The patient has an ischemic foot and a below‐the‐knee amputation should be performed.The incidence of distal limb ischemia is 10–70% in peripheral VA ECMO patients. It is associated with an increased risk of morbidity and mortality. It must be recognized and treated urgently by placement of a distal perfusion catheter/cannula. If not recognized promptly, amputation may be required; however, reperfusion to the ischemic limb should be attempted prior to any consideration for amputation.It is possible to have a DVT leading to phlegmasia in ECMO patients; however, it is more likely to occur in the leg with the venous cannula and unlikely immediately after cannulation.It is unlikely that decreases in cardiac output or insufficient/absent ECMO flows would result in localized ischemia.Answer: DBonicolini E, Martucci G, Simons J, et al. Limb ischemia in peripheral veno‐arterial extracorporeal membrane oxygenation: a narrative review of incidence, prevention, monitoring, and treatment. Crit Care. 2019; 23(1):266. doi: https://doi.org/10.1186/s13054‐019‐2541‐3. PMID: 31362770; PMCID: PMC6668078.

15 A 40‐year‐old man with severe influenza‐induced ARDS is placed on venovenous ECMO via left and right common femoral veins. He requires ECMO for 12 days, and throughout his course is maintained on a continuous heparin infusion with an average activated partial thromboplastin time (aPTT) of 60 seconds. He is successfully decannulated after improvement in lung function, and then maintained on a continuous heparin infusion for 48 hours after decannulation. Two days after decannulation the patient has sudden‐onset tachycardia, hypoxemia, and hypotension. There is no change in the physical exam, respiratory mechanics, or chest x‐ray. What is the next most appropriate step?Discontinue heparin as the patient may be bleeding from the cannulation sites.Perform a transthoracic echocardiogram and consider CT chest to evaluate for a pulmonary embolism.Place bilateral chest tubes.Make the patient DNR after a family meeting.Perform an emergent bronchoscopy.Venous thromboembolism is a very common complication after venovenous ECMO. It occurs in 30–50% of patients after decannulation, even despite appropriate anticoagulation. Pulmonary embolism should be high on every clinicians’ differential diagnosis and should be ruled out and must be suspected and potentially treated.Other causes of respiratory failure to include pneumothorax, worsening lung function, or mucous plugging are also common in patients recovering from severe lung disease and must be ruled out as well with physical exam, observation of respiratory mechanics, and chest x‐ray.Goals of care discussions are always valuable in the management of critically ill patients; however, in the young, recovering patient, a family meeting to address DNR status is probably premature.Answer: BTrudzinski FC, Minko P, Rapp D, et al. Runtime and aPTT predict venous thrombosis and thromboembolism in patients on extracorporeal membrane oxygenation: a retrospective analysis. Ann Intensive Care. 2016; 6(1):66. doi: https://doi.org/10.1186/s13613‐016‐0172‐2. Epub 2016 Jul 19. PMID: 27432243; PMCID: PMC4949188.

16 Which of the following is the strongest clinical indication to discontinue ECMO support?A patient is intubated for 16 days and requires a tracheostomy procedure.Arterial blood gas demonstrates a pH of 7.36 and a PaCO2 of 55 mm Hg on a sweep gas flow of 4 L/min.The patient has been on ECMO for 2 weeks.The patient is oozing blood from a left chest tube site and right femoral cannulation site.The patient has an SpO2 of 96% and arterial PaCO2 of 40 mm Hg on 0 L/min of VV ECMO sweep gas flow and low ventilator settings.As a rule of thumb, when extracorporeal support provides less than 30% of native cardiac or lung function, a trial off ECMO is indicated. If SpO2 > 95%, and arterial PaCO2 is < 50mm Hg for > 60 min off of sweep flow, decannulation from VV ECMO is reasonable. Patients with an elevated PaCO2 despite moderate sweep gas flow are likely not ready for a trial off ECMO.The need for a surgical procedure alone is not an indication for decannulation. In some cases, ECMO is indicated to provide additional support to patients undergoing high‐risk surgical procedures (such as complex airway or tracheal reconstructions or resections of anterior mediastinal masses). Additionally, prolonged duration of ECMO support should not be an isolated reason for decannulation.A small amount of oozing from surgical sites is not uncommon in ECMO patients. Premature decannulation may be considered only in rare cases of uncontrollable bleeding.Answer: EELSO Guidelines for Cardiopulmonary Extracorporeal Life Support (2017). Extracorporeal Life Support Organization, Version 1. Ann Arbor, MI, USA. www.elso.org (accessed 4 August 2017).

17 A 35‐year‐old woman suffering from COVID‐19 is decannulated from venovenous (VV) ECMO after 12 days. She remains on the ventilator and in the ECMO ICU. The family is asking what they can expect for her post‐ECMO course. Which statement is most accurate?Approximately 40% of patients who are decannulated from ECMO will ultimately die in the hospital.She will require more sedation and higher ventilator settings in the coming days.Approximately 40% of patients will suffer from a DVT post‐ECMO decannulation.Prior ECMO cannulation is a contraindication to future ECMO cannulation.Physical therapy is contraindicated in the week post‐ECMO for fear of cannula site bleeding.The survival‐to‐discharge for all‐comers in respiratory failure ECMO is approximately 60%, though this rate continues to improve year‐to‐year with improvements in ICU care and device technology; while the survival‐to‐discharge for cardiac failure ECMO is approximately 53%. Though data is limited and premature, the survival‐to‐discharge of ECMO patients with COVID‐19 is 54%. While these survival rates are all encompassing and have been gathered over several decades, there are several prediction tools to attempt to elucidate anticipated survival for the individual patient; one of which is the RESP score. This model uses data points including age, duration of mechanical ventilation, immunocompromised status, among several other patient‐specific data points.Except in cases of severe device‐related complications, patients decannulated from ECMO should be adequately and safely maintained on an amount of support that allows for expedient recovery, re‐conditioning, and physical therapy. If it is anticipated that a patient requires neuromuscular blockade, increased sedation, and increased ventilator settings, then they should not be decannulated. The in‐hospital mortality after ECMO decannulation is approximately 10%. In select cases, patients who were decannulated from ECMO may require a second ECMO run, and this is within reason.Approximately 30–50% of patients decannulated from VV ECMO will suffer from a DVT, and screening for DVT is typically performed 48–72 hours post‐ECMO decannulation.Answer: CELSO Guidelines for Cardiopulmonary Extracorporeal Life Support (2017). Extracorporeal Life Support Organization, Version 1. Ann Arbor, MI, USA. www.elso.org (accessed 4 August 2017).Trudzinski FC, Minko P, Rapp D, et al. Runtime and aPTT predict venous thrombosis and thromboembolism in patients on extracorporeal membrane oxygenation: a retrospective analysis. Ann Intensive Care. 2016; 6(1):66. doi: https://doi.org/10.1186/s13613‐016‐0172‐2. Epub 2016 Jul 19. PMID: 27432243; PMCID: PMC4949188.Schmidt M, Bailey M, Sheldrake J, et al. Predicting survival after extracorporeal membrane oxygenation for severe acute respiratory failure. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score. Am J Respir Crit Care Med. 2014; 189(11):1374–82.

18 A 6‐year‐old previously healthy girl is admitted to the PICU after being involved in a house fire resulting in acute respiratory distress with severe hypoxemic respiratory failure. Which of the following would indicate a need for venovenous ECMO in this patient?PaO2/FiO2 > 100–150Oxygenation index (OI) > 40Mean airway pressure > 15 cmH2O on high‐frequency oscillatory ventilationMean airway pressure > 15 cmH2O on conventional ventilationCarboxyhemoglobin level of 10%When evaluating a patient’s candidacy for extracorporeal support, the provider must consider the underlying pathology, the adequacy of gas exchange given the current mechanical ventilatory requirement, and the success/failure of adjunctive rescue therapies. Although significant variability in institutional protocols exists, salvage therapies for children on a conventional ventilator with mean airway pressure (MAP) > 20–25 cm H2O includes use of high‐frequency oscillatory ventilation (HFOV), nitric oxide, and prone positioning. MAP < 30 cm H2O are tolerable while on HFOV. The PaO2/FiO2 is the ratio of arterial oxygen partial pressure to fractional inspired oxygen and is a clinical indicator of hypoxemia (normal PaO2/FiO2 > 300). An alternative measure of oxygenation is the oxygenation index (OI), which is calculated as the reciprocal of the PaO2/FiO2 times 100 times the mean airway pressure: Severe respiratory failure as evidence by a sustained PaO2/FiO2 < 60–80 or OI > 40 predict high mortality and indicate a need for lung rescue with ECMO. For example, if the patient’s PaO2 were 60 mm Hg on an FiO2 of 1 and MAP of 30 cm H20, the OI would be 50, which is a strong indication for ECMO initiation in the pediatric population.Answer: BMaratta C, Potera RM, van Leeuwen G, et al. Extracorporeal Life Support Organization (ELSO): 2020 pediatric respiratory ELSO guideline. ASAIO J Am Soc Artif Intern Organs 1992. 2020; 66(9):975–979. doi: https://doi.org/10.1097/MAT.0000000000001223Zabrocki LA, Brogan TV, Statler KD, et al. Extracorporeal membrane oxygenation for pediatric respiratory failure: survival and predictors of mortality. Crit Care Med. 2011; 39(2):364–370. doi: https://doi.org/10.1097/CCM.0b013e3181fb7b35

19 A newborn male infant with a fetal diagnosis of congenital diaphragmatic hernia (CDH) is admitted to the neonatal intensive care unit immediately after delivery where he is found to be acidotic (pH = 7.1) and hypoxemic (PaO2 = 42 mm Hg). He is transitioned from a conventional ventilator to the high‐frequency oscillatory ventilator. However, this results in minimal improvement in gas exchange with worsening metabolic acidosis and a rising lactate on escalating vasopressor support. What is the most appropriate ECMO cannulation strategy for this neonate?Right femoral venous drainage, left femoral artery reinfusionRight femoral venous drainage, umbilical vein reinfusionRight femoral venous drainage, right carotid artery reinfusionRight internal jugular vein drainage, right carotid artery reinfusionRight internal jugular vein drainage and reinfusion with double‐lumen bicaval catheterExtracorporeal support for VA ECMO requires veno‐arterial access. In most situations, specific cannula selection occurs after surgical cut down with direct visual interrogation of the vessels of interest. Although some centers have started to implement percutaneous cannulation using Seldinger technique, this is best suited for femoral access that is inappropriate for children < 15 kg because of the size of the femoral vessels (answers A and C are therefore incorrect). Venous drainage via cannulation of the right internal jugular vein and reinfusion via the right common carotid artery is the standard approach for children < 15 kg (answer D). Right femoral venous drainage and umbilical vein reinfusion is not described as a mode of ECMO support. An umbilical vein catheter (UVC) can be used for infusions on a short‐term basis but has not been described for ECMO support (answer B). Finally, right internal jugular venous drainage and reinfusion with a double‐lumen bicaval catheter can be used for VV ECMO but is inappropriate to support the child necessitating both pulmonary and cardiac support (answer E).Answer: DJohnson K, Jarboe MD, Mychaliska GB, et al. Is there a best approach for extracorporeal life support cannulation: a review of the extracorporeal life support organization. J Pediatr Surg. 2018; 53(7):1301–1304. doi:https://doi.org/10.1016/j.jpedsurg.2018.01.015Wild KT, Rintoul N, Kattan J, et al. Extracorporeal Life Support Organization (ELSO): guidelines for neonatal respiratory failure. ASAIO J Am Soc Artif Intern Organs 1992. 2020; 66(5):463–470. doi:https://doi.org/10.1097/MAT.0000000000001153

20 Monitoring of which of the following anticoagulation assays is independently associated with prolonged circuit life in children on ECMO support?FibrinogenAnti‐factor XaPTTACTPlateletsAnticoagulation is a critical component of ECMO management given the procoagulant properties of the ELCS circuit. Although clots in the circuit are the most common mechanical complications of ECMO, continuous anticoagulation with heparin or a direct thrombin inhibitor confers significant bleeding risk, the most catastrophic of which is intraventricular hemorrhage. In order to mitigate clotting and bleeding, anticoagulation monitoring is critical. Plasma anti‐factor Xa (Anti‐Xa) measures the anticoagulant impact of the heparin‐AT3 complex. Higher anti‐Xa levels have been independently associated with decreased circuit change due to clot formation in children on ECMO (answer B). In addition, monitoring protocols that include anti‐Xa, thromboelastography, and antithrombin levels are associated with decreased blood product use, decreased hemorrhagic complications, and increased circuit duration when compared to standard monitoring protocols including only ACT, platelet count, protime/international normalized ratio (INR), and hemoglobin/hematocrit. Although fibrinogen, PTT, ACT, and platelets provide important information to inform anticoagulation management, all are poorly correlated with circuit thrombosis in children on ECMO.Answer: BIrby K, Swearingen C, Byrnes J, et al. Unfractionated heparin activity measured by anti‐factor Xa levels is associated with the need for ECMO circuit/membrane oxygenator change: a retrospective pediatric study. Pediatr Crit Care Med J Soc Crit Care Med World Fed Pediatr Intensive Crit Care Soc. 2014; 15(4):e175–e182. doi:https://doi.org/10.1097/PCC.0000000000000101Northrop MS, Sidonio RF, Phillips SEM, et al. The use of an extracorporeal membrane oxygenation anticoagulation laboratory protocol is associated with decreased blood product use, decreased hemorrhagic complications, and increased circuit life. Pediatr Crit Care Med. 2015; 16(1):66–74. doi:https://doi.org/10.1097/PCC.0000000000000278

21 Which of the following parameters is evidence of myocardial recovery and thus a proxy of readiness for decannulation in a child supported on VA‐ECMO for myocarditis?Decreasing pulse pressureIncreasing systolic pressureLeft ventricular ejection fraction < 25% under low‐flow conditionsEscalating requirement of ECMO sweep gas flow rateRising end‐tidal CO2 in children with systemic‐to‐pulmonary shuntScant empirical data exists regarding the use of specific parameters to predict the readiness for decannulation of a child managed on ECMO. Moreover, although weaning protocols exist (i.e. wean ECMO flow to 100 mL/min and increasing ventilator support from rest to baseline settings), there is little data to support the appropriateness of one unit‐based protocol over another. Data suggests that increased systolic pressure as well as increased pulse pressure and echocardiographic evidence of left ventricular ejection fraction > 25% are indicators of myocardial recovery. Escalating requirement of ECMO sweep gas flow rate implies increasing support requirements and would not be an evidence of myocardial recovery. Although a rising end‐tidal CO2 in children without systemic‐to‐pulmonary shunt can be a helpful parameter for prediction of successful wean, the presence of a systemic‐to‐pulmonary shunt would increase CO2‐rich blood passing through the lungs, thus confounding the measurement of ETCO2.Answer: BAissaoui N, Luyt C‐E, Leprince P, et al. Predictors of successful extracorporeal membrane oxygenation (ECMO) weaning after assistance for refractory cardiogenic shock. Intensive Care Med. 2011; 37(11):1738. doi: https://doi.org/10.1007/s00134‐011‐2358‐2Naruke T, Inomata T, Imai H, et al. End‐Tidal carbon dioxide concentration can estimate the appropriate timing for weaning off from extracorporeal membrane oxygenation for refractory circulatory failure. Int Heart J. 2010; 51(2):116–120. doi: https://doi.org/10.1536/ihj.51.116Park B‐W, Seo D‐C, Moon I‐K, et al. Pulse pressure as a prognostic marker in patients receiving extracorporeal life support. Resuscitation. 2013; 84(10):1404–1408. doi: https://doi.org/10.1016/j.resuscitation.2013.04.009.

22 Which of the following conditions is associated with the lowest ECMO‐associated survival in neonates?Bacterial pneumoniaCongenital heart diseaseMeconium aspirationPersistent pulmonary hypertension of the newbornPersistent pulmonary hypertension of the newborn with hypoxic‐ischemic encephalopathyOverall survival to hospital discharge is 73% for patients treated with ECMO for neonatal respiratory disease, approximately 35–45% for congenital heart disease, and 40–50% where ECMO is used for extracorporeal cardiopulmonary resuscitation. Persistent pulmonary hypertension of the newborn (PPHN) occurs secondary to infectious etiologies (pneumonia or sepsis), congenital disease (premature closure of the ductus or congenital diaphragmatic hernia), or genetic abnormalities (surfactant protein B deficiency) and results in pathologic vasoconstriction with resultant severe hypoxemia (with or without hypercapnia). ECMO survival for PPHN is approximately 80% even in the presence of hypoxemic‐ischemic encephalopathy. Meconium increases the antibacterial milieu of amniotic fluid and predisposes to perinatal infection. Meconium aspiration syndrome (MAS) can also result in airway obstruction and/or a chemical pneumonitis with subsequent hypoxia. Although improvements in postnatal care and neonatal respiratory support have decreased the use of ECMO for management of MAS, survival for neonates cannulated for this indication remain high at 92%. Pneumonia is most commonly caused by group B beta‐hemolytic Streptococcus or gram‐negative organisms and is associated with a 60% ECMO survival. A number of prediction tools have been developed to assist with ECMO protocol development and clinical decision‐making.(https://www.elso.org/Resources/ECMOOutcomePredictionScores.aspx).Answer: BAgarwal P, Altinok D, Desai J, et al. In‐hospital outcomes of neonates with hypoxic‐ischemic encephalopathy receiving extracorporeal membrane oxygenation. J Perinatol. 2019; 39(5):661–665. doi: https://doi.org/10.1038/s41372‐019‐0345‐6Allen KY, Allan CK, Su L, et al. Extracorporeal membrane oxygenation in congenital heart disease. Semin Perinatol. 2018; 42(2):104–110. doi: https://doi.org/10.1053/j.semperi.2017.12.006International Summary of the ELSO Registry Report (2017). Extracorporeal Life Support Organization (ELSO). Ann Arbor, Michigan: 2017. Published by ELSO online at www.ELSO.orgLazar DA, Cass DL, Olutoye OO, et al. The use of ECMO for persistent pulmonary hypertension of the newborn: a decade of experience. J Surg Res. 2012; 177(2):263–7. doi: https://doi.org/10.1016/j.jss.2012.07.058.