Indications for VA-ECMO and Management of ECMO Support
VA-ECMO indications were: acute refractory cardiovascular failure,
defined as evidence of tissue hypoxia concomitant with adequate
intravascular volume status; severely diminished RV function or LVEF;
low cardiac index (≤2.1 L/min/m2); sustained hypotension despite
high-dose catecholamine infusion (epinephrine ≥1 γ/kg/min or dobutamine
≥20 γ/kg/min + norepinephrine ≥1 γ/kg/min).
All patients, regardless of age or comorbid conditions, were considered
candidates for this intervention, unless their predicted survival
independent of the PE, was less than 1 year. ECMO consist of a
centrifugal pump, a hollow fiber oxygenator (Livanova, Sorin Group,
Italy) and cannulas (Xenios AG-Medos, Heilbronn Germany). Cannulation
was performed under ultrasound guidance, with a 23F to 25F venous
drainage cannula placed in a femoral vein and a 17F to 19F arterial
return cannula placed in a common femoral artery in the contralateral
groin whether in the ICU or in the operation room. A 6F distal perfusion
cannula was placed in the superficial femoral artery as a first step
previously, unless the patient was actively requiring cardiopulmonary
resuscitation (CPR), to allow for better ultrasound visualization of the
superficial femoral artery.
ECMO Flows were maintained in the range of 2 to 4 L/minute, requiring
pump speeds of approximately 3,000 to 4,000 rpm, and were adjusted with
the goals of reversing acidosis while maintaining arterial saturation
and cardiac output. Support flow was also titrated up until the right
ventricle was decompressed by TTE and maintain a systemic blood pressure
of 90 mmHg. However, some pulmonary blood pulmonary flow was maintained
to allow for APT. Systemic anticoagulation was maintained with activated
clotting time of 180-200 seconds by unfractionated heparine infusion.
Figure 1. shows one survivor patient who have high-risk PE and cardiac
arrest, stabilized hemodynamically with VA-ECMO; just before
catheter-based intervention with EKOS APT.