Complications-
Thrombotic complications were the most prevalent problem and were
identified in 66% of the patients. Thrombotic complications were
defined as excessive clotting during cannulation (clotted cannula
despite pre-cannulation heparin bolus), early excessive fibrin formation
in the oxygenator leading to a decreased post-oxygenator
PaO2, repeated CRRT filter clot (in the presence of
therapeutic anticoagulation), visible ECMO circuit thrombosis requiring
emergent circuit change, pulmonary embolus (PE), type 2 HIT, and post
ECMO deep venous thrombosis. Secondary infections occurred in seven of
the fifteen patients and were treated effectively with broad spectrum
antibiotics. The most common secondary infection was pneumonia. One
patient developed a multidrug resistant Pseudomonas pneumonia infection
after ECMO decannulation from ECMO. Two patients developed a
pneumothorax after decannulation that required small bore chest tube
placement.
Gastrointestinal (GI) bleeding requiring massive transfusion occurred in
two patients. In one patient the GI bleed occurred after a tissue
plasminogen activator (tPA) infusion while receiving a concurrent
heparin infusion followed by a tPA/bivalirudin infusion. The tPA
infusion was attempted to treat a presumed pulmonary micro-thrombosis in
a patient with right ventricular (RV) failure after a PE that had caused
a cardiac arrest. His cardiac arrest responded quickly to 50mg of tPA
infusion and 1mg of epinephrine. The tPA infusion improved his RV
failure minimally, but not significantly enough to avoid a period of VVA
ECMO (14). This patient required VVA ECMO after an initial 21 days of VV
ECMO. He was successfully decannulated after 5 days of VVA ECMO. In
addition to the patient with the large PE, two other patients developed
RV failure. One required VVAV ECMO cannulation, with drainage from the
femoral vein and superior vena cava and return to the femoral artery and
right atrium. The third patient with RV failure also required VAV
support along with milrinone and an epinephrine infusion.