**6. Management of v-a ECMO**

Systemic heparinization is obtained with an intravenous bolus of 5,000 UI of heparin, 5 minutes prior to vessels cannulation. ECMO blood flow is calculated to maintain a Cardiac Output (CO) index of 2.5 L/min/m2 , an SvO2 of about 70% and a mean blood arterial pressure of 60-70 mmHg during the first 24-48 hours. Continuous intravenous heparin is administered in order to achieve an activate clotting time (ACT) of 160-180 seconds and a prothrombin time value of 50-60 seconds. Small doses of inotrope (dobutamine, 5 to 7 μg/Kg/min) are given to maintain the ventricular ejection, to allow the opening of aortic valve and to prevent the formation of clots inside the left ventricle (LV). Oxygenator is always connected with a heat exchange to maintain a body temperature of 36 °C. Those patients who had a cardiac arrest before ECMO implantation are gradually cooled to 32-34°C during the first 24-36 hours. The assessment of the neurologic status is initiated by electroencephalography after body rewarming; serial neurologic evaluations and cerebral computed tomography scan are always considered to assess cerebral hemorrhage, stroke or hypoxic encephalopathy. In those patients with criteria of irreversible brain damage, ECMO withdrawn is usually considered.

Multiple heart examinations by transesophageal echo are performed to monitor the LV pulsatility. Left ventricular venting is considered in case of irreversible pulmonary edema, LV distension or pulseless heart with blood stasis. If the heart needs to be decompressed, several techniques can be considered. An 18-20 Fr catheter could be inserted into the apex of LV after surgery when patient cannot be weaned from cardiopulmonary bypass (Figure 11).

**Figure 12.** The cannula is inserted in the right jugular vein and advanced up to the main arterial pulmonary trunk.

cannula [33].

Other techniques of LV decompression have been described such as the use of Pulse-Cath [31], Insertion of a pigtail inside the LV through the aortic valve [32], use of a transeptal atrial

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Red blood cells (RBCs) transfusions are given to achieve a hematocrit of 30-32% and platelets are infused when the platelet count is less than 50,000-60,000/μL. Mechanical ventilation is continued throughout the ECMO support with the same management for each patient. Ventilator setting is commonly set at a tidal volume of 8 ml/Kg, 4 breaths/min, positive end

Intraortic balloon pump (IABP) [24, 34] is employed with the aim to reduce the afterload, to

No attempts to wean off ECMO are usually considered during the first 48 hours. Step by step is the main strategy for weaning off ECMO using transesophageal echocardiography monitoring. This consists to reduce the pump flow at 1.0 L/min/m2 for about 40-60 mi‐ nutes after having obtained an ACT of 180 seconds. In patients who are supported also with IABP, this is set to 1:1 ratio. If systemic pressure, LV contractility, central venous pressure, wedge pressure and SvO2 had not significant changes without the addition of new inotropes, then heparin is stopped and ECMO is removed at patient's bedside or in

Transthoracic and transesophageal echocardiography play a very important role in the assessment of LV and RV function and during the delicate phase of weaning from ECMO. Echocardiographic knowledge and facilities are becoming mandatory to start and continue an ECMO program with the aim to improve the outcome. Such echocardiographic parameters, such as transmitral E velocity, E/e' ratio, LV ejection fraction, aortic valve velocity-time integral, tissue Doppler lateral Ea, Sa, and parameters derived from Velocity Vector Imaging,

increase the coronary and cerebral perfusion [35] and to maintain a pulsatile flow.

expiratory pressure of 10 cm H20 and a FiO2 of 0.40-0.60.

operating room within the next few hours.

**Figure 11.** The left ventricle is decompressed by a 20 Fr catheter inserted in the apex of the ventricle.

Alternatively, the LV can be indirectly decompressed with a 16-Fr percutaneous venous cannula inserted in the right internal jugular vein and advanced into the main pulmonary artery; the cannula was connected to the venous arm of the ECMO circuit [30] (Figure 12).

**6. Management of v-a ECMO**

282 Principles and Practice of Cardiothoracic Surgery

(CO) index of 2.5 L/min/m2

Systemic heparinization is obtained with an intravenous bolus of 5,000 UI of heparin, 5 minutes prior to vessels cannulation. ECMO blood flow is calculated to maintain a Cardiac Output

mmHg during the first 24-48 hours. Continuous intravenous heparin is administered in order to achieve an activate clotting time (ACT) of 160-180 seconds and a prothrombin time value of 50-60 seconds. Small doses of inotrope (dobutamine, 5 to 7 μg/Kg/min) are given to maintain the ventricular ejection, to allow the opening of aortic valve and to prevent the formation of clots inside the left ventricle (LV). Oxygenator is always connected with a heat exchange to maintain a body temperature of 36 °C. Those patients who had a cardiac arrest before ECMO implantation are gradually cooled to 32-34°C during the first 24-36 hours. The assessment of the neurologic status is initiated by electroencephalography after body rewarming; serial neurologic evaluations and cerebral computed tomography scan are always considered to assess cerebral hemorrhage, stroke or hypoxic encephalopathy. In those patients with criteria

Multiple heart examinations by transesophageal echo are performed to monitor the LV pulsatility. Left ventricular venting is considered in case of irreversible pulmonary edema, LV distension or pulseless heart with blood stasis. If the heart needs to be decompressed, several techniques can be considered. An 18-20 Fr catheter could be inserted into the apex of LV after

surgery when patient cannot be weaned from cardiopulmonary bypass (Figure 11).

**Figure 11.** The left ventricle is decompressed by a 20 Fr catheter inserted in the apex of the ventricle.

Alternatively, the LV can be indirectly decompressed with a 16-Fr percutaneous venous cannula inserted in the right internal jugular vein and advanced into the main pulmonary artery; the cannula was connected to the venous arm of the ECMO circuit [30] (Figure 12).

of irreversible brain damage, ECMO withdrawn is usually considered.

, an SvO2 of about 70% and a mean blood arterial pressure of 60-70

**Figure 12.** The cannula is inserted in the right jugular vein and advanced up to the main arterial pulmonary trunk.

Other techniques of LV decompression have been described such as the use of Pulse-Cath [31], Insertion of a pigtail inside the LV through the aortic valve [32], use of a transeptal atrial cannula [33].

Red blood cells (RBCs) transfusions are given to achieve a hematocrit of 30-32% and platelets are infused when the platelet count is less than 50,000-60,000/μL. Mechanical ventilation is continued throughout the ECMO support with the same management for each patient. Ventilator setting is commonly set at a tidal volume of 8 ml/Kg, 4 breaths/min, positive end expiratory pressure of 10 cm H20 and a FiO2 of 0.40-0.60.

Intraortic balloon pump (IABP) [24, 34] is employed with the aim to reduce the afterload, to increase the coronary and cerebral perfusion [35] and to maintain a pulsatile flow.

No attempts to wean off ECMO are usually considered during the first 48 hours. Step by step is the main strategy for weaning off ECMO using transesophageal echocardiography monitoring. This consists to reduce the pump flow at 1.0 L/min/m2 for about 40-60 mi‐ nutes after having obtained an ACT of 180 seconds. In patients who are supported also with IABP, this is set to 1:1 ratio. If systemic pressure, LV contractility, central venous pressure, wedge pressure and SvO2 had not significant changes without the addition of new inotropes, then heparin is stopped and ECMO is removed at patient's bedside or in operating room within the next few hours.

Transthoracic and transesophageal echocardiography play a very important role in the assessment of LV and RV function and during the delicate phase of weaning from ECMO. Echocardiographic knowledge and facilities are becoming mandatory to start and continue an ECMO program with the aim to improve the outcome. Such echocardiographic parameters, such as transmitral E velocity, E/e' ratio, LV ejection fraction, aortic valve velocity-time integral, tissue Doppler lateral Ea, Sa, and parameters derived from Velocity Vector Imaging, including lateral systolic velocity, strain, and strain rate, are now considered important data [36] to drive a safe weaning from ECMO and they should be frequently collected in each ECMO patient.

Bleeding and transfusion requiring can negatively affect the ECMO course and the early outcome and they are considered important complications during ECMO [23, 24, 47]. It is worthy to point out that lower number of RBCs transfused the number of RBCs units trans‐ fused was an independent predictor of in-hospital and late mortality. The need for RBCs transfusion depends not only by the fact that some patients on ECMO have undergone surgery; other factors such as systemic heparinization during ECMO and the use of platelet inhibitors after PTCA can cause bleeding and need for transfusions with increased risk of early mortality. Alternative therapy to conventional heparin anticoagulation therapy, such as bivalirudin or fondaparinux, to reduce the risk of bleeding and for the treatment of heparine induced

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High incidences of central nervous system (CNS) injury meeting the criteria of brain death are reported. These patients usually are withdrawn from ECMO sooner than the rest of the other patients. Brain death is frequent in patients who presented with cardiac arrest and received V-A ECMO implantation during cardiopulmonary resuscitation maneuvers. The incidence of brain death is ranging between 10% and 40% [6, 7, 39, 51]. Thiagarajan et al.[5] analyzing data of 297 patients supported by ECPR and extracted from the Extracorporeal Life Support Organization (ELSO) Registry reported an incidence of 33% of CNS damage and 21% had irreversible hypoxic encephalopathy. Other Authors [3, 4] described a very low survival when cardiopulmonary resuscitation (CPR) time is 60 minutes and a survival approaching to 0%

Left ventricular decompression during ECMO support is an important priority in cases in which the contractile activity of the heart is inadequate to allow the opening of the aortic valve. In such scenario, the risk of clotting formation inside the left cavities is very high and the clots

Several techniques to unload the left ventricle such as atrial septostomy [4, 33], direct LV apex cannulation [21], insertion of PulseCath iVAC [31], use of Impella [52, 53], percutaneous insertion of a pigtail [32] or percutaneous pulmonary truck drainage [30] have been described. One of the most followed strategies is to use as soon as the IABP associated with low dose of inotrope (dobutamine 5 mcg/min/Kg) with the aim to reduce the systemic resistance, improve the coronary and cerebral flow and increase the cardiac contractility. Whether the use of IABP is a useful tool to dramatically reduce the afterload mainly in such patients with a peripheral retrograde arterial return [21], and whether the IABP simply increases the coronary blood flow

Peripheral percutaneous cannulation represents a big challenging for all ECMO teams. Several peripheral complications such as retroperitoneal hemorrhage, cannula dislocation, cannula‐ tion failure, leg ischemia and leg amputation are described [43, 54]. According to early or late vascular complication following peripheral cannulation, Huang et al. [25] suggested measur‐ ing the mean pressure of the superficial femoral artery and they indicate to insert a catheter for a distal perfusion if the mean pressure is lower than 50 mmHg. It is extremely important to verify the pulsatility of the anterior and posterior tibial artery by an ultrasound vascular Doppler and to restore the limb perfusion signs of hypoperfusion are observed. In such case an 8-9 F catheter is placed distally to the arterial cannula by means of vascular ultrasound scan.

thrombocitopenya have been recently published [49, 50].

when the CPR was more than 90 minutes.

may embolize.

[35], is still debated.
