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 This 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: C 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. 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. This 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: D Yannopoulos 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. strategy for this patient? 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: C 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). 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). 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: D Russo 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. Lung 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: E Abrams 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). 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: A Xia 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
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