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Extracorporeal Membrane Oxygenator Rotational Cannula Catastrophe: A Role of Echocardiography in Rescue
CASE REPORT
Extracorporeal Membrane Oxygenator Rotational Cannula Catastrophe: A Role of Echocardiography in Rescue Adam Kessler, DO, Bradley Coker, MD, Matthew Townsley, MD, and Ahmed Zaky, MD, MPH
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ENO-VENOUS EXTRACORPOREAL membrane oxygenation (VV-ECMO) has evolved as a salvage therapy for adults with refractory hypoxemia and hypercapnia that is resistant to maximal conventional mechanical ventilation. By providing a direct mechanism for oxygenation and elimination of carbon dioxide, VV-ECMO can provide a period of “lung rest,” in which a protective lung ventilation strategy—in the form of low tidal volumes, low inspired oxygen fraction, and low inspiratory pressures—can be instituted and may further improve outcomes by mitigating ventilator-induced lung injury.1,2 In most approaches to VV-ECMO, a cannula is placed in a central vein. Blood is withdrawn from the central vein into an extracorporeal circuit with use of a mechanical pump before the blood enters a membrane-type oxygenator. Within the oxygenator, blood passes along one side of the membrane, which provides a blood-gas interface for gas exchange. The oxygenated extracorporeal blood then may be warmed or cooled as needed and is returned to the central vein. This specific technique is termed “veno-venous” ECMO because blood is both withdrawn from and returned to the central venous system. Cannulation for VV-ECMO may involve a 2-site or a single-site approach. In the 2-site approach, blood typically is withdrawn from the inferior vena cava through a drainage cannula in the femoral vein, and oxygenated blood is returned into the right atrium through an additional cannula in the internal jugular vein. This 2-site approach results in recirculation of blood in which the returned oxygenated blood is drawn back (or “sucked in”) into the circuit in a closed loop without contributing to systemic oxygenation.3 The recent introduction of a bicaval dual-lumen cannula (Avalon Elite Bi-Caval Dual Lumen Catheter; Maquet Cardiopulmonary, Rastatt, Germany) allows single-site cannulation of the internal jugular vein. Venous blood is withdrawn through 1 lumen with ports in both the superior and inferior vena cavae. Extracorporeal oxygenated blood is returned through the second lumen and is directed across the tricuspid valve. The advantages of the single-site approach include improved patient mobility because of avoidance of femoral site cannulation and reduced recirculation when the cannula is properly positioned.4 In the authors’ institution, bicaval dual-lumen central venous cannulation is performed using fluoroscopic guidance, and adequate cannula positioning is confirmed by daily chest x-ray. Echocardiography is used when there is a question about cannula position despite radiographic confirmation. The majority of reports on bicaval cannula malposition describe a longitudinal displacement of the cannula, in which the cannula
migrates superiorly or inferiorly in the vena cavae, resulting in recirculation, hypoxemia, and pump flow reductions.5,6 In this case report, the authors describe an unusual “rotational” malposition of the bicaval dual-lumen cannula, in which oxygenated blood was directed in a suboptimal position away from the tricuspid valve, resulting in recirculation and lifethreatening hypoxemia. This malposition occurred despite adequate vertical cannula position and was discovered only by echocardiography. CASE PRESENTATION
A 41-year-old, 175-cm, 115.6-kg white male presented to the authors’ institution as a transfer to the ECMO service. The patient was involved in a motor vehicle accident 7 days before being transferred and had developed acute respiratory distress syndrome secondary to pulmonary contusions and pneumonia. He was transferred to the authors’ facility to undergo VVECMO to alleviate severe refractory hypoxemia, hypercapnia, and reduced lung compliance. The patient’s trachea was intubated with an endotracheal tube (size #7.5), and he was sedated and placed under general anesthesia with the use of propofol, fentanyl, and cisatracurium (Table 1). Even though the inspired oxygen fraction (FIO2) and positive end-expiratory pressure (PEEP) levels were increased, general anesthesia was administered, and nitric oxide was initiated, the patient’s condition remained hypoxemic and hypercapnic (Table 1). Subsequently, the patient developed sinus tachycardia and hypertension that most likely resulted from the patient’s worsening respiratory status (see Table 1). As a result of progressive deterioration in the patient’s respiratory status, a decision was made to initiate VV-ECMO using the dual-lumen bicaval cannula (Avalon Elite Bi-Caval Dual Lumen Catheter). Using Seldinger’s technique under fluoroscopic guidance, the right internal jugular vein was
From the Department of Emergency Medicine, Department of Anesthesiology, Division of Critical Care and Perioperative Medicine, University of Alabama School of Medicine, Birmingham, AL. Address reprint requests to Adam Kessler, DO, 619 19th St. S, 251 Old Hillman Building, Birmingham, AL, 35249-7013. E-mail: akessler @uabmc.edu © 2015 Elsevier Inc. All rights reserved. 1053-0770/2602-0033$36.00/0 http://dx.doi.org/10.1053/j.jvca.2015.07.010 Key words: complications of extracorporeal membrane oxygenation, extracorporeal membrane oxygenation, venovenous extracorporeal membrane oxygenation
Journal of Cardiothoracic and Vascular Anesthesia, Vol ], No ] (Month), 2015: pp ]]]–]]]
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Table 1. Patient’s Admission Information ABG
Ventilator settings
Medications
Vital signs
PH 7.32 Mode AC/VC Proprofol (μg/kg/min) 50 37.51C
PaCO2 (mmHg) 72 PEEP (cmH2O) 16 Fentanyl (μg/h) 200 136 bpm
PaO2 (mmHg) 54 FIO2
HCO3
1 Cisatracurium (μg/kg/min) 3 180/89 (108)
36 PIP (cmH2O) 42 NO PPM 20
SpO2 % 83 F bpm 25
VT mL/PBW 6
Abbreviations: ABG, arterial blood gases; AC/VC, assist control/volume control; bpm, breaths per minute; F, frequency; FIO2, inspired oxygen fraction; HCO3, bicarbonate “calculated”; NO, nitric oxide; PaCO2, arterial partial pressure of carbon dioxide; PaO2, arterial partial pressure of oxygen; PBW, predicted body weight; PEEP, positive end-expiratory pressure; PPM, parts per million; SpO2, arterial oxygen saturation; μg/kg/min, microgram per kilogram per minute; VT, tidal volume.
cannulated uneventfully. Subsequently, the ECMO circuit was connected to the cannula, and ECMO flow was initiated at a flow rate of 4 L/min, delivered oxygen fraction of 1.0, and a sweep rate of 5 L/min. A heparin infusion was administered for anticoagulation to maintain an activated clotting time of 160 to 240 msec. An immediate post-procedure chest x-ray was obtained to confirm correct positing of the cannula. Shortly after confirmation of cannula position, the patient’s clinical condition began to deteriorate. A progressive decline in arterial oxygen saturation occurred, coupled with tachycardia and hypertension (Fig 1). This coincided with a reduction in ECMO flows and a rise in ECMO venous saturation (ECMO SvO2, 96%), indicative of recirculation. A chest x-ray was obtained immediately and showed adequate cannula position. As a result of the progressive clinical deterioration, transesophageal echocardiography (TEE) was performed to further confirm cannula
position. Midesophageal bicaval TEE showed that the cannula had rotated in such a way that the port for oxygenated blood was directed toward the interatrial septum rather than toward the tricuspid valve (Video 1). Despite the inadequate rotational position, the longitudinal position of the cannula in both vena cavae appeared adequate. The ECMO surgical team was notified immediately, and the cannula was repositioned using TEE guidance (Video 2). The repositioning of the cannula was accompanied by dramatic improvement in the patient’s hemodynamics, as evidenced by an increase in arterial oxygen saturation and the gradual resolution of tachycardia and hypertension. In addition, ECMO flows increased to 4 L/min with no chattering events, phenomena that result from excessive negative pressure created by the pump, causing intermittent collapse of the venous circulation. A confirmatory transthoracic echocardiogram (TTE) was obtained and showed
Recognition and TEE- guided repositioning
Fig 1. Patient’s hemodynamic profile over time during VV-ECMO cannulation. Heart rate (HR, green) and mean arterial pressure (MAP, red) increased from baseline because of VV-ECMO cannula malposition. Meanwhile, arterial oxygen saturation (SpO2, blue) declined from baseline values. With optimal cannula repositioning (arrow), HR, MAP, and SpO2 returned to normal values.
EXTRACORPOREAL MEMBRANE OXYGENATOR ROTATIONAL CANNULA CATASTROPHE
adequate longitudinal and rotational positioning of the venovenous cannula via the sub-xiphoid long axis and parasternal long axis right ventricular inflow windows. After the cannula was repositioned, the patient experienced multiple episodes of severe sepsis secondary to pneumonia and catheter-related infections, which were treated successfully. The patient also underwent bedside percutaneous tracheostomy on ECMO day 5 to facilitate pulmonary hygiene (anticoagulation was held for 90 minutes before the procedure). After 15 days of VV-ECMO support, the patient’s pulmonary status started to improve, as evidenced on chest x-rays, the ability to clear carbon dioxide, and an increase in PaO2 at the same FIO2. Therefore, a trial of weaning from ECMO was attempted. The authors adhered to institutional protocol for weaning the patient from ECMO; after the patient’s pulmonary status improved, the paralytic medication was discontinued and reversed using glycopyrrolate and neostigmine (0.2 mg and 40 μg/kg, respectively). Switching from a propofol to dexmedetomidine infusion to maintain a Richmond Agitation Sedation Scale of –2 to 0 lightened the patient’s level of sedation. Ventilator FIO2 was reduced gradually, and PEEP was adjusted to a goal partial pressure of arterial oxygen (PaO2) of 460 mmHg. Mechanical ventilation frequency was adjusted to maintain a partial pressure of carbon dioxide (PaCO2) o60 mmHg. The oxygenator fresh gas flow rate (sweep) and FIO2 then were reduced gradually, while the same ECMO pump flows were maintained and the same PaO2 and PaCO2 goals were achieved for 12 to 24 hours. ECMO decannulation could now be performed and took place in the operating room. Conventional lung protective ventilation after ECMO decannulation was administered as follows: assist control/pressure control (AC/PC), peak inspiratory pressure (PIP) of 15 cmH2O, bpm frequency of 18, FIO2 of 0.6, and PEEP of 12 with the aid of nitric oxide at 20 PPM. Eventually, the patient was weaned successfully from mechanical ventilation and was discharged to a rehabilitation facility. DISCUSSION
This case report emphasizes the indispensable role of echocardiography in achieving and confirming adequate VVECMO cannula positioning. Even though chest x-ray showed adequate longitudinal ECMO cannula position, there was a rotational displacement that led to life-threatening hypoxemia, which was diagnosed only by echocardiography. There are several potential imaging modalities to guide cannula placement and/or cannula repositioning during ECMO initiation and management. These include echocardiography (TTE and TEE), plain chest x-ray, and fluoroscopy. Although each modality has advantages and disadvantages, the modality used must fit the context of the clinical situation and the skill set of the physician performing the procedure. The utility of echocardiography extends throughout all phases of management of the patient requiring VV-ECMO— from patient selection through cessation of ECMO support. Before ECMO is instituted, a comprehensive echocardiographic examination must be performed to identify any cardiac conditions that may complicate venous cannula placement. In particular, the right side of the heart should be assessed carefully for the presence of a patent foramen ovale; atrial
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septal defect; intracardiac devices (ie, pacemaker or defibrillator leads); or Chiari network, Eustachian valve, or tricuspid valve abnormalities.7 Echocardiographic examination also can be used to help identify cardiac pathology that may be contributing to, or resulting from, the patient’s acute respiratory failure (eg, right ventricular dysfunction). The presence of significant left or severe right ventricular dysfunction may warrant consideration of veno-arterial ECMO, as opposed to VV-ECMO, to provide hemodynamic support.7 Either TTE or TEE can be used for this purpose. The less invasive TTE examination often may be preferred for this initial screening and assessment. During ECMO cannulation, the superior spatial resolution of TEE often is preferred over TTE to guide adequate cannula placement.7 The sterile field required for cannula placement also may make the simultaneous performance of TTE challenging, with TEE being a more technically feasible approach. Because multiple cannulation strategies may be used to initiate VV-ECMO, it is critical for the echocardiographer to clearly understand the specific cannulation approach being performed. For dual-lumen cannula placement via percutaneous insertion into the right internal jugular vein, optimal positioning for the access orifice is in the proximal IVC, whereas the return orifice is positioned optimally in the mid-right atrium with flow directed across the tricuspid valve.7 This anatomy and orientation are obtained easily in most patients with standard midesophageal bicaval and 4-chamber views. Color-flow Doppler can be used to confirm correct position of the return orifice by demonstrating adequate flow directed across the tricuspid valve. Despite the potential advantages of TEE, TTE also may be used to guide initial cannula placement and also serves as an invaluable tool for the evaluation of catheter migration in a dynamic clinical setting after initial insertion and placement. Two views that can be obtained easily at the bedside for this purpose are the parasternal right ventricular (RV) inflow and subcostal views.5 The RV inflow view allows for visualization of the right atrium and tricuspid valve and aligns properly for the use of color-flow Doppler to ensure proper flow of the return jet across the tricuspid valve (Video 3). The subcostal view allows for excellent visualization of the right atrium, inferior cavoatrial junction, distal IVC, and hepatic veins.5 The noninvasive aspect of TTE and the ability to perform Doppler ultrasound at the bedside in a timely manner to diagnosis catheter migration make TTE a powerful tool. A significant advantage of echocardiography for cannula placement and positioning is the ability to obtain data in real time, resulting in fewer cannula manipulations, less risk for breaching sterility with subsequent infection, and less risk of trauma to the patient. Other advantages of echocardiography include mobility/access to the patient, familiarity among a large cohort of physicians (eg, surgeon, cardiologist, intensivist, and anesthesiologist), direct visualization of the anatomy, no requirement for contrast medium, and no exposure to radiation. Limitations of TTE include poor acoustic windows (often because of patient body habitus) and physical limitations to probe placement in a critically ill patient (eg, cannulae and monitoring devices that limit access to the patient’s chest wall).
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Limitations of TEE include contraindications to probe placement (eg, previous esophageal surgery) and risks for esophageal or gastric injury or bleeding in a patient receiving anticoagulation therapy. Even though plain chest x-rays and fluoroscopy provide possible advantages, such as cannula placement in a sterile field, continuous visualization of wire position and wire bending, cannula advancement and positioning, and hence theoretically guarding against the potentially catastrophic complication of cardiac perforation,8 both have significant drawbacks. The major limitation of both fluoroscopy and plain chest x-rays lies in the inability to directly visualize vascular structures or cardiac chambers without the use of contrast medium and exposure of the patient to multiple doses of ionizing radiation. Thomas et al14 demonstrated that even though plain chest x-rays are readily available, economical, and require less operator expertise, they also lack sensitivity in detecting cannula position. Cannula malposition is a common complication in patients receiving ECMO support, with malposition of a venous cannula occurring more often than with an arterial cannula.7 As demonstrated in this patient, cannula malposition occurs when the venous cannula is directed toward the interatrial septum. Typically, this manifests as inadequate flows through the ECMO circuit and/or inadequate gas exchange with failure to improve oxygenation. Similarly, malposition also may be seen if the venous cannula is placed across the tricuspid valve into the right ventricle, into the coronary sinus, or through a patent foramen ovale into the left atrium.7 A cannula introduced via the femoral vein and advanced too superiorly may extend beyond the right atrium to obstruct the superior vena cava, whereas a cannula placed too inferiorly via a superior approach (ie, internal jugular vein) may extend into the IVC, leading to obstructed hepatic outflow.9 A case of acute BuddChiari syndrome has been described in which hepatic venous thrombosis occurred as a result of a venous drainage cannula being placed in close proximity to the insertion point of the hepatic veins.10 Miranda et al11 described a rare case of myocardial infarction occurring as a result of malposition of a doublelumen venous cannula. The cannula was unable to be advanced adequately into the IVC and was left in the right atrium. Echocardiography subsequently showed inferior wall motion abnormalities along with elevated cardiac markers, resulting in emergency cardiac catheterization, which demonstrated occlusion of the right coronary artery by the ECMO cannula. Distal
migration of a double-lumen VV-ECMO cannula also can lead to significant complications as described by Yastrebov et al.12 In this report, the patient developed repeated episodes of hypoxemia with positional changes to the patient’s head. Subcostal views obtained using TTE demonstrated significant advancement of the cannula into the IVC, causing the return port of the cannula to enter the IVC and severely compromise hepatic venous drainage. Cannula malposition was identified early using TTE, and appropriate repositioning of the cannula was undertaken, thus saving the patient from the likelihood of developing a massive degree of retrograde flow into the hepatic veins with the potential to cause severe hepatic venous congestion, hepatic insufficiency, severe portal hypertension, and capsular distention and rupture.12 Even though TEE may provide superior spatial resolution for the visualization of ECMO cannulae, this case demonstrates that TTE still can play an important role in the management of the patient requiring ECMO support. Because cannula malposition can lead to rapid clinical deterioration with potentially fatal consequences, the use of a noninvasive, focused TTE examination to quickly and easily identify and correct cannula malposition is obvious. In particular, a parasternal RV inflow view allows for color-flow Doppler examination of blood flow from the return cannula orifice in the right atrium. As in this patient, when the color-flow Doppler jet is not directed toward the tricuspid valve (ie, directed toward the interatrial septum), cannula malposition is identified immediately and the cannula can be repositioned correctly. This view also can be used to identify whether the cannula has migrated across the tricuspid valve and into the right ventricle, necessitating cannula withdrawal into the right atrium.13 Subcostal views allow for excellent visualization of the IVC to determine the extent of cannula position within the IVC and whether cannula advancement or withdrawal may be necessary. In summary, echocardiography is an invaluable tool in confirming VV-ECMO cannula position and is superior to other imaging modalities used for the same purpose. Both TTE and TEE can be used to confirm cannula position. Therefore, the authors advise that echocardiography be used routinely and in conjunction with fluoroscopy to aid in the initiation and maintenance of bicaval dual-lumen VV-ECMO cannulation. APPENDIX A. SUPPLEMENTARY INFORMATION
Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1053/j.jvca.2015. 07.010.
REFERENCES 1. Brown JK, Haft JW, Bartlett RH, et al: Acute lung injury and acute respiratory distress syndrome: extracorporeal life support and liquid ventilation for severe acute respiratory distress syndrome in adults. Semin Respir Crit Care Med 27:416-425, 2006 2. Peek GJ, Mugford M, Tiruvoipati R, et al: Efficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): a multicentre randomised controlled trial. Lancet 374: 1351-1363, 2009
3. Brodie D, Bacchetta M: Extracorporeal membrane oxygenation for ARDS in adults. New Engl J Med 365:1905-1914, 2011 4. Abrams D, Brodie D, Combes A: What is new in extracorporeal membrane oxygenation for ARDS in adults? Intensive Care Med 39: 2028-2030, 2013 5. Yastrebov K, Manganas C, Kapalli T, et al: Right ventricular loop indicating malposition of J-wire introducer for double lumen bicaval venovenous extracorporeal membrane oxygenation (VV ECMO) cannula. Heart Lung Circ 23:e4-e7, 2014
EXTRACORPOREAL MEMBRANE OXYGENATOR ROTATIONAL CANNULA CATASTROPHE
6. Rubino A, Vuylsteke A, Jenkins DP, et al: Direct complications of the Avalon bicaval dual-lumen cannula in respiratory extracorporeal membrane oxygenation (ECMO): single-center experience. Int J Artif Organs 37:741-747, 2014 7. Platts DG, Sedgwick JF, Burstow DJ, et al: The role of echocardiography in the management of patients supported by extracorporeal membrane oxygenation. J Am Soc Echocardiogr 25: 131-141, 2012 8. Teman NR, Haft JW, Napolitano LM: Optimal endovascular methods for placement of bicaval dual-lumen cannulae for venovenous extracorporeal membrane oxygenation. ASAIO J 59: 442-447, 2013 9. Lee S, Chaturvedi A: Imaging adults on extracorporeal membrane oxygenation (ECMO). Insights Imaging 5:731-742, 2014 10. Victor K, Barrett N, Glover G, et al: Acute Budd-Chiari syndrome during veno-venous extracorporeal membrane oxygenation
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diagnosed using transthoracic echocardiography. Br J Anaesth 108: 1043-1044, 2012 11. Reis Miranda D, Dabiri Abkenari L, Nieman K, et al: Myocardial infarction due to malposition of ECMO cannula. Intensive Care Med 38:1233-1234, 2012 12. Yastrebov K, Kapalli T: Malposition of double lumen bicaval venovenous extracorporeal membrane oxygenation (VV ECMO) cannula resulting in hepatic venous congestion. Australasian J Ultrasound Med 16:193-197, 2013 13. Bermudez CA, Rocha RV, Sappington PL, et al: Initial experience with single cannulation for venovenous extracorporeal oxygenation in adults. Ann Thorac Surg 90:991-995, 2010 14. Thomas TH, Price R, Ramaciotti C, et al: Echocardiography, not chest radiography, for evaluation of cannula placement during pediatric extracorporeal membrane oxygenation. Pediatr Crit Care Med 10: 56-59, 2009
Extracorporeal Membrane Oxygenator Rotational Cannula Catastrophe: A Role of Echocardiography in Rescue Adam Kessler, DO, Bradley Coker, MD, Matthew Townsley, MD, and Ahmed Zaky, MD, MPH
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ENO-VENOUS EXTRACORPOREAL membrane oxygenation (VV-ECMO) has evolved as a salvage therapy for adults with refractory hypoxemia and hypercapnia that is resistant to maximal conventional mechanical ventilation. By providing a direct mechanism for oxygenation and elimination of carbon dioxide, VV-ECMO can provide a period of “lung rest,” in which a protective lung ventilation strategy—in the form of low tidal volumes, low inspired oxygen fraction, and low inspiratory pressures—can be instituted and may further improve outcomes by mitigating ventilator-induced lung injury.1,2 In most approaches to VV-ECMO, a cannula is placed in a central vein. Blood is withdrawn from the central vein into an extracorporeal circuit with use of a mechanical pump before the blood enters a membrane-type oxygenator. Within the oxygenator, blood passes along one side of the membrane, which provides a blood-gas interface for gas exchange. The oxygenated extracorporeal blood then may be warmed or cooled as needed and is returned to the central vein. This specific technique is termed “veno-venous” ECMO because blood is both withdrawn from and returned to the central venous system. Cannulation for VV-ECMO may involve a 2-site or a single-site approach. In the 2-site approach, blood typically is withdrawn from the inferior vena cava through a drainage cannula in the femoral vein, and oxygenated blood is returned into the right atrium through an additional cannula in the internal jugular vein. This 2-site approach results in recirculation of blood in which the returned oxygenated blood is drawn back (or “sucked in”) into the circuit in a closed loop without contributing to systemic oxygenation.3 The recent introduction of a bicaval dual-lumen cannula (Avalon Elite Bi-Caval Dual Lumen Catheter; Maquet Cardiopulmonary, Rastatt, Germany) allows single-site cannulation of the internal jugular vein. Venous blood is withdrawn through 1 lumen with ports in both the superior and inferior vena cavae. Extracorporeal oxygenated blood is returned through the second lumen and is directed across the tricuspid valve. The advantages of the single-site approach include improved patient mobility because of avoidance of femoral site cannulation and reduced recirculation when the cannula is properly positioned.4 In the authors’ institution, bicaval dual-lumen central venous cannulation is performed using fluoroscopic guidance, and adequate cannula positioning is confirmed by daily chest x-ray. Echocardiography is used when there is a question about cannula position despite radiographic confirmation. The majority of reports on bicaval cannula malposition describe a longitudinal displacement of the cannula, in which the cannula
migrates superiorly or inferiorly in the vena cavae, resulting in recirculation, hypoxemia, and pump flow reductions.5,6 In this case report, the authors describe an unusual “rotational” malposition of the bicaval dual-lumen cannula, in which oxygenated blood was directed in a suboptimal position away from the tricuspid valve, resulting in recirculation and lifethreatening hypoxemia. This malposition occurred despite adequate vertical cannula position and was discovered only by echocardiography. CASE PRESENTATION
A 41-year-old, 175-cm, 115.6-kg white male presented to the authors’ institution as a transfer to the ECMO service. The patient was involved in a motor vehicle accident 7 days before being transferred and had developed acute respiratory distress syndrome secondary to pulmonary contusions and pneumonia. He was transferred to the authors’ facility to undergo VVECMO to alleviate severe refractory hypoxemia, hypercapnia, and reduced lung compliance. The patient’s trachea was intubated with an endotracheal tube (size #7.5), and he was sedated and placed under general anesthesia with the use of propofol, fentanyl, and cisatracurium (Table 1). Even though the inspired oxygen fraction (FIO2) and positive end-expiratory pressure (PEEP) levels were increased, general anesthesia was administered, and nitric oxide was initiated, the patient’s condition remained hypoxemic and hypercapnic (Table 1). Subsequently, the patient developed sinus tachycardia and hypertension that most likely resulted from the patient’s worsening respiratory status (see Table 1). As a result of progressive deterioration in the patient’s respiratory status, a decision was made to initiate VV-ECMO using the dual-lumen bicaval cannula (Avalon Elite Bi-Caval Dual Lumen Catheter). Using Seldinger’s technique under fluoroscopic guidance, the right internal jugular vein was
From the Department of Emergency Medicine, Department of Anesthesiology, Division of Critical Care and Perioperative Medicine, University of Alabama School of Medicine, Birmingham, AL. Address reprint requests to Adam Kessler, DO, 619 19th St. S, 251 Old Hillman Building, Birmingham, AL, 35249-7013. E-mail: akessler @uabmc.edu © 2015 Elsevier Inc. All rights reserved. 1053-0770/2602-0033$36.00/0 http://dx.doi.org/10.1053/j.jvca.2015.07.010 Key words: complications of extracorporeal membrane oxygenation, extracorporeal membrane oxygenation, venovenous extracorporeal membrane oxygenation
Journal of Cardiothoracic and Vascular Anesthesia, Vol ], No ] (Month), 2015: pp ]]]–]]]
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Table 1. Patient’s Admission Information ABG
Ventilator settings
Medications
Vital signs
PH 7.32 Mode AC/VC Proprofol (μg/kg/min) 50 37.51C
PaCO2 (mmHg) 72 PEEP (cmH2O) 16 Fentanyl (μg/h) 200 136 bpm
PaO2 (mmHg) 54 FIO2
HCO3
1 Cisatracurium (μg/kg/min) 3 180/89 (108)
36 PIP (cmH2O) 42 NO PPM 20
SpO2 % 83 F bpm 25
VT mL/PBW 6
Abbreviations: ABG, arterial blood gases; AC/VC, assist control/volume control; bpm, breaths per minute; F, frequency; FIO2, inspired oxygen fraction; HCO3, bicarbonate “calculated”; NO, nitric oxide; PaCO2, arterial partial pressure of carbon dioxide; PaO2, arterial partial pressure of oxygen; PBW, predicted body weight; PEEP, positive end-expiratory pressure; PPM, parts per million; SpO2, arterial oxygen saturation; μg/kg/min, microgram per kilogram per minute; VT, tidal volume.
cannulated uneventfully. Subsequently, the ECMO circuit was connected to the cannula, and ECMO flow was initiated at a flow rate of 4 L/min, delivered oxygen fraction of 1.0, and a sweep rate of 5 L/min. A heparin infusion was administered for anticoagulation to maintain an activated clotting time of 160 to 240 msec. An immediate post-procedure chest x-ray was obtained to confirm correct positing of the cannula. Shortly after confirmation of cannula position, the patient’s clinical condition began to deteriorate. A progressive decline in arterial oxygen saturation occurred, coupled with tachycardia and hypertension (Fig 1). This coincided with a reduction in ECMO flows and a rise in ECMO venous saturation (ECMO SvO2, 96%), indicative of recirculation. A chest x-ray was obtained immediately and showed adequate cannula position. As a result of the progressive clinical deterioration, transesophageal echocardiography (TEE) was performed to further confirm cannula
position. Midesophageal bicaval TEE showed that the cannula had rotated in such a way that the port for oxygenated blood was directed toward the interatrial septum rather than toward the tricuspid valve (Video 1). Despite the inadequate rotational position, the longitudinal position of the cannula in both vena cavae appeared adequate. The ECMO surgical team was notified immediately, and the cannula was repositioned using TEE guidance (Video 2). The repositioning of the cannula was accompanied by dramatic improvement in the patient’s hemodynamics, as evidenced by an increase in arterial oxygen saturation and the gradual resolution of tachycardia and hypertension. In addition, ECMO flows increased to 4 L/min with no chattering events, phenomena that result from excessive negative pressure created by the pump, causing intermittent collapse of the venous circulation. A confirmatory transthoracic echocardiogram (TTE) was obtained and showed
Recognition and TEE- guided repositioning
Fig 1. Patient’s hemodynamic profile over time during VV-ECMO cannulation. Heart rate (HR, green) and mean arterial pressure (MAP, red) increased from baseline because of VV-ECMO cannula malposition. Meanwhile, arterial oxygen saturation (SpO2, blue) declined from baseline values. With optimal cannula repositioning (arrow), HR, MAP, and SpO2 returned to normal values.
EXTRACORPOREAL MEMBRANE OXYGENATOR ROTATIONAL CANNULA CATASTROPHE
adequate longitudinal and rotational positioning of the venovenous cannula via the sub-xiphoid long axis and parasternal long axis right ventricular inflow windows. After the cannula was repositioned, the patient experienced multiple episodes of severe sepsis secondary to pneumonia and catheter-related infections, which were treated successfully. The patient also underwent bedside percutaneous tracheostomy on ECMO day 5 to facilitate pulmonary hygiene (anticoagulation was held for 90 minutes before the procedure). After 15 days of VV-ECMO support, the patient’s pulmonary status started to improve, as evidenced on chest x-rays, the ability to clear carbon dioxide, and an increase in PaO2 at the same FIO2. Therefore, a trial of weaning from ECMO was attempted. The authors adhered to institutional protocol for weaning the patient from ECMO; after the patient’s pulmonary status improved, the paralytic medication was discontinued and reversed using glycopyrrolate and neostigmine (0.2 mg and 40 μg/kg, respectively). Switching from a propofol to dexmedetomidine infusion to maintain a Richmond Agitation Sedation Scale of –2 to 0 lightened the patient’s level of sedation. Ventilator FIO2 was reduced gradually, and PEEP was adjusted to a goal partial pressure of arterial oxygen (PaO2) of 460 mmHg. Mechanical ventilation frequency was adjusted to maintain a partial pressure of carbon dioxide (PaCO2) o60 mmHg. The oxygenator fresh gas flow rate (sweep) and FIO2 then were reduced gradually, while the same ECMO pump flows were maintained and the same PaO2 and PaCO2 goals were achieved for 12 to 24 hours. ECMO decannulation could now be performed and took place in the operating room. Conventional lung protective ventilation after ECMO decannulation was administered as follows: assist control/pressure control (AC/PC), peak inspiratory pressure (PIP) of 15 cmH2O, bpm frequency of 18, FIO2 of 0.6, and PEEP of 12 with the aid of nitric oxide at 20 PPM. Eventually, the patient was weaned successfully from mechanical ventilation and was discharged to a rehabilitation facility. DISCUSSION
This case report emphasizes the indispensable role of echocardiography in achieving and confirming adequate VVECMO cannula positioning. Even though chest x-ray showed adequate longitudinal ECMO cannula position, there was a rotational displacement that led to life-threatening hypoxemia, which was diagnosed only by echocardiography. There are several potential imaging modalities to guide cannula placement and/or cannula repositioning during ECMO initiation and management. These include echocardiography (TTE and TEE), plain chest x-ray, and fluoroscopy. Although each modality has advantages and disadvantages, the modality used must fit the context of the clinical situation and the skill set of the physician performing the procedure. The utility of echocardiography extends throughout all phases of management of the patient requiring VV-ECMO— from patient selection through cessation of ECMO support. Before ECMO is instituted, a comprehensive echocardiographic examination must be performed to identify any cardiac conditions that may complicate venous cannula placement. In particular, the right side of the heart should be assessed carefully for the presence of a patent foramen ovale; atrial
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septal defect; intracardiac devices (ie, pacemaker or defibrillator leads); or Chiari network, Eustachian valve, or tricuspid valve abnormalities.7 Echocardiographic examination also can be used to help identify cardiac pathology that may be contributing to, or resulting from, the patient’s acute respiratory failure (eg, right ventricular dysfunction). The presence of significant left or severe right ventricular dysfunction may warrant consideration of veno-arterial ECMO, as opposed to VV-ECMO, to provide hemodynamic support.7 Either TTE or TEE can be used for this purpose. The less invasive TTE examination often may be preferred for this initial screening and assessment. During ECMO cannulation, the superior spatial resolution of TEE often is preferred over TTE to guide adequate cannula placement.7 The sterile field required for cannula placement also may make the simultaneous performance of TTE challenging, with TEE being a more technically feasible approach. Because multiple cannulation strategies may be used to initiate VV-ECMO, it is critical for the echocardiographer to clearly understand the specific cannulation approach being performed. For dual-lumen cannula placement via percutaneous insertion into the right internal jugular vein, optimal positioning for the access orifice is in the proximal IVC, whereas the return orifice is positioned optimally in the mid-right atrium with flow directed across the tricuspid valve.7 This anatomy and orientation are obtained easily in most patients with standard midesophageal bicaval and 4-chamber views. Color-flow Doppler can be used to confirm correct position of the return orifice by demonstrating adequate flow directed across the tricuspid valve. Despite the potential advantages of TEE, TTE also may be used to guide initial cannula placement and also serves as an invaluable tool for the evaluation of catheter migration in a dynamic clinical setting after initial insertion and placement. Two views that can be obtained easily at the bedside for this purpose are the parasternal right ventricular (RV) inflow and subcostal views.5 The RV inflow view allows for visualization of the right atrium and tricuspid valve and aligns properly for the use of color-flow Doppler to ensure proper flow of the return jet across the tricuspid valve (Video 3). The subcostal view allows for excellent visualization of the right atrium, inferior cavoatrial junction, distal IVC, and hepatic veins.5 The noninvasive aspect of TTE and the ability to perform Doppler ultrasound at the bedside in a timely manner to diagnosis catheter migration make TTE a powerful tool. A significant advantage of echocardiography for cannula placement and positioning is the ability to obtain data in real time, resulting in fewer cannula manipulations, less risk for breaching sterility with subsequent infection, and less risk of trauma to the patient. Other advantages of echocardiography include mobility/access to the patient, familiarity among a large cohort of physicians (eg, surgeon, cardiologist, intensivist, and anesthesiologist), direct visualization of the anatomy, no requirement for contrast medium, and no exposure to radiation. Limitations of TTE include poor acoustic windows (often because of patient body habitus) and physical limitations to probe placement in a critically ill patient (eg, cannulae and monitoring devices that limit access to the patient’s chest wall).
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Limitations of TEE include contraindications to probe placement (eg, previous esophageal surgery) and risks for esophageal or gastric injury or bleeding in a patient receiving anticoagulation therapy. Even though plain chest x-rays and fluoroscopy provide possible advantages, such as cannula placement in a sterile field, continuous visualization of wire position and wire bending, cannula advancement and positioning, and hence theoretically guarding against the potentially catastrophic complication of cardiac perforation,8 both have significant drawbacks. The major limitation of both fluoroscopy and plain chest x-rays lies in the inability to directly visualize vascular structures or cardiac chambers without the use of contrast medium and exposure of the patient to multiple doses of ionizing radiation. Thomas et al14 demonstrated that even though plain chest x-rays are readily available, economical, and require less operator expertise, they also lack sensitivity in detecting cannula position. Cannula malposition is a common complication in patients receiving ECMO support, with malposition of a venous cannula occurring more often than with an arterial cannula.7 As demonstrated in this patient, cannula malposition occurs when the venous cannula is directed toward the interatrial septum. Typically, this manifests as inadequate flows through the ECMO circuit and/or inadequate gas exchange with failure to improve oxygenation. Similarly, malposition also may be seen if the venous cannula is placed across the tricuspid valve into the right ventricle, into the coronary sinus, or through a patent foramen ovale into the left atrium.7 A cannula introduced via the femoral vein and advanced too superiorly may extend beyond the right atrium to obstruct the superior vena cava, whereas a cannula placed too inferiorly via a superior approach (ie, internal jugular vein) may extend into the IVC, leading to obstructed hepatic outflow.9 A case of acute BuddChiari syndrome has been described in which hepatic venous thrombosis occurred as a result of a venous drainage cannula being placed in close proximity to the insertion point of the hepatic veins.10 Miranda et al11 described a rare case of myocardial infarction occurring as a result of malposition of a doublelumen venous cannula. The cannula was unable to be advanced adequately into the IVC and was left in the right atrium. Echocardiography subsequently showed inferior wall motion abnormalities along with elevated cardiac markers, resulting in emergency cardiac catheterization, which demonstrated occlusion of the right coronary artery by the ECMO cannula. Distal
migration of a double-lumen VV-ECMO cannula also can lead to significant complications as described by Yastrebov et al.12 In this report, the patient developed repeated episodes of hypoxemia with positional changes to the patient’s head. Subcostal views obtained using TTE demonstrated significant advancement of the cannula into the IVC, causing the return port of the cannula to enter the IVC and severely compromise hepatic venous drainage. Cannula malposition was identified early using TTE, and appropriate repositioning of the cannula was undertaken, thus saving the patient from the likelihood of developing a massive degree of retrograde flow into the hepatic veins with the potential to cause severe hepatic venous congestion, hepatic insufficiency, severe portal hypertension, and capsular distention and rupture.12 Even though TEE may provide superior spatial resolution for the visualization of ECMO cannulae, this case demonstrates that TTE still can play an important role in the management of the patient requiring ECMO support. Because cannula malposition can lead to rapid clinical deterioration with potentially fatal consequences, the use of a noninvasive, focused TTE examination to quickly and easily identify and correct cannula malposition is obvious. In particular, a parasternal RV inflow view allows for color-flow Doppler examination of blood flow from the return cannula orifice in the right atrium. As in this patient, when the color-flow Doppler jet is not directed toward the tricuspid valve (ie, directed toward the interatrial septum), cannula malposition is identified immediately and the cannula can be repositioned correctly. This view also can be used to identify whether the cannula has migrated across the tricuspid valve and into the right ventricle, necessitating cannula withdrawal into the right atrium.13 Subcostal views allow for excellent visualization of the IVC to determine the extent of cannula position within the IVC and whether cannula advancement or withdrawal may be necessary. In summary, echocardiography is an invaluable tool in confirming VV-ECMO cannula position and is superior to other imaging modalities used for the same purpose. Both TTE and TEE can be used to confirm cannula position. Therefore, the authors advise that echocardiography be used routinely and in conjunction with fluoroscopy to aid in the initiation and maintenance of bicaval dual-lumen VV-ECMO cannulation. APPENDIX A. SUPPLEMENTARY INFORMATION
Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1053/j.jvca.2015. 07.010.
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EXTRACORPOREAL MEMBRANE OXYGENATOR ROTATIONAL CANNULA CATASTROPHE
6. Rubino A, Vuylsteke A, Jenkins DP, et al: Direct complications of the Avalon bicaval dual-lumen cannula in respiratory extracorporeal membrane oxygenation (ECMO): single-center experience. Int J Artif Organs 37:741-747, 2014 7. Platts DG, Sedgwick JF, Burstow DJ, et al: The role of echocardiography in the management of patients supported by extracorporeal membrane oxygenation. J Am Soc Echocardiogr 25: 131-141, 2012 8. Teman NR, Haft JW, Napolitano LM: Optimal endovascular methods for placement of bicaval dual-lumen cannulae for venovenous extracorporeal membrane oxygenation. ASAIO J 59: 442-447, 2013 9. Lee S, Chaturvedi A: Imaging adults on extracorporeal membrane oxygenation (ECMO). Insights Imaging 5:731-742, 2014 10. Victor K, Barrett N, Glover G, et al: Acute Budd-Chiari syndrome during veno-venous extracorporeal membrane oxygenation
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diagnosed using transthoracic echocardiography. Br J Anaesth 108: 1043-1044, 2012 11. Reis Miranda D, Dabiri Abkenari L, Nieman K, et al: Myocardial infarction due to malposition of ECMO cannula. Intensive Care Med 38:1233-1234, 2012 12. Yastrebov K, Kapalli T: Malposition of double lumen bicaval venovenous extracorporeal membrane oxygenation (VV ECMO) cannula resulting in hepatic venous congestion. Australasian J Ultrasound Med 16:193-197, 2013 13. Bermudez CA, Rocha RV, Sappington PL, et al: Initial experience with single cannulation for venovenous extracorporeal oxygenation in adults. Ann Thorac Surg 90:991-995, 2010 14. Thomas TH, Price R, Ramaciotti C, et al: Echocardiography, not chest radiography, for evaluation of cannula placement during pediatric extracorporeal membrane oxygenation. Pediatr Crit Care Med 10: 56-59, 2009