Management of ECPR Flow Rates to Avoid Hypertension and Cardiac Workload Complications

Initial Flow Rate Management

The American College of Critical Care Medicine recommends beginning with a goal of 3-4 L/min ECMO flow after cannulation, gradually increasing as tolerated rather than immediately maximizing flow 1
Monitoring arteriovenous O₂ difference is a reliable parameter for setting ECMO flow goals, maintaining between 3-5 cc O₂/100ml of blood 1
Assessing mixed venous saturation (SvO₂), targeting above 66%, and the ratio of O₂ delivery to consumption (DO₂:VO₂) above 3, are hemoglobin-dependent parameters 1
Using right radial arterial line for blood gas sampling best represents cerebral perfusion in peripherally cannulated patients 1

Peripheral VA-ECMO increases left ventricular afterload, which can negatively impact cardiac recovery and should be carefully managed 2
Maintaining mean arterial pressure (MAP) that provides adequate cerebral and end-organ perfusion while minimizing LV afterload ensures circulatory support and cardiac recovery 2
Weaning vasoactive inotropic support as tolerated after cannulation reduces cardiac workload 2
Monitoring for LV distension, which can be attenuated by supporting ejection with inotropic agents, is crucial 2

Gradually increasing ECMO flow avoids sudden increases in afterload that could precipitate hypertensive crisis 1
Avoiding rapid changes in PaCO₂ within the first 24 hours of ECMO support prevents cerebrovascular complications 3
Striving for a daily negative fluid balance after ECMO flows are optimized and the patient is hemodynamically stable is recommended 4

Continuously monitoring for signs of Harlequin syndrome, which occurs in approximately 10% of peripherally cannulated patients, is essential 1
Assessing for narrow pulse pressure from right radial arterial line suggests a mixing point proximal to the innominate artery, versus wide pulse pressure indicating more distal mixing point 1
Watching for signs of LV distension, which can lead to ventricular stasis, pulmonary congestion, and myocardial ischemia, is critical 2
Monitoring for fluid overload, which is frequent in ECMO patients and associated with increased mortality by the third day, is necessary 4

If signs of LV distension develop despite flow optimization, considering additional mechanical circulatory support for LV unloading is recommended 2
Options include percutaneous therapies such as intra-aortic balloon pump (IABP), Impella, or pulmonary artery venting via the internal jugular vein 2
Choosing the least invasive but most effective venting strategy based on patient condition is important 2

Maintaining mechanical ventilation despite ECMO support ensures lung expansion and prevents Harlequin syndrome 2
Titrating FiO₂ to maintain arterial O₂ saturation >92% is recommended 2
Employing lung-protective ventilation strategies with low ventilatory pressure and respiratory rate is essential 2
Using PEEP greater than 10 cmH₂O maintains alveolar inflation and prevents pulmonary edema and atelectasis 2

Avoiding early hyperoxia (PaO₂ >300 mmHg), which is associated with mortality and poor neurological outcomes, is crucial 3
Targeting arterial O₂ saturation of 92-97% by manipulating the ECMO sweep gas FiO₂ is recommended 3
Preventing excessive fluid administration, as positive fluid balance by the third day of ECMO is associated with increased mortality, is necessary 4