Surgical Critical Care and Emergency Surgery. Группа авторов

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