Introduction
Veno-venous extracorporeal membrane oxygenation (ECMO) is now being
applied to spontaneously breathing, awake patients when traditional,
mechanical ventilation is not possible1. Current ECMO
therapies provide a variety of options for the multidisciplinary teams
involved in management5. Veno-venous ECMO can provide
complete respiratory support, however, with substantial risks, including
bleeding, thromboembolic events and infection5. Still,
the advantage of veno-venous ECMO on awake patients minimizes the
adverse effects of mechanical ventilation, including barotrauma,
hypotension, and arrhythmias 2,4. It also minimizes
the duration of neuromuscular blockade use that is usually used to
improve patient ventilator dyssynchrony2,3. This
method decreases the risk of critical care associated polyneuromyopathy
and delirium as well2.
In the classic configuration, veno-venous ECMO support is achieved with
two cannulae, one usually inserted in the right femoral vein and
advanced to the junction between the inferior vena cava (IVC) and the
right atrium (RA) and the other inserted in the right internal jugular
vein (IJV) and advanced through the superior vena cava (SVC) into the
RA5. This configuration was implemented in our patient
procedure (Figure 1).
The decision was also made to not use anticoagulation during the
procedure. With thromboembolic complications remaining the major causes
of death in patients undergoing ECMO treatments, this decision was
unique and a crucial component of our particular
procedure6. With complications commencing upon blood
contact with artificial surfaces of the circuit, blood pump, and
oxygenator system, ECMO use naturally increases the risk of hemorrhagic
and thromboembolic events6. Therefore, anticoagulation
therapy, predominantly with unfractionated heparin, is almost always
required in cases to prevent these problems6. Still,
with a lack of high-quality data to guide anticoagulation management in
ECMO patients, results in marked practice vary considerably among
centers7. In our particular case, increased risk of
bleeding and small area of operating site were taken into consideration,
therefore leading to the decision to not use anticoagulation. Although
highly effective at the prevention and treatment of thromboembolism,
anticoagulants are by their very nature associated with
significant bleeding risks8. Numerous individual
clinical factors have been linked to an increased risk of hemorrhage,
with our particular patient being susceptible, given her older age and
history of renal disease8. More specific details of
the patient and Otolaryngology procedure will follow.