Monitoring Considerations
Prior to surgery, the surgical and anesthesia teams formulate a plan
regarding the surgical approach, cannulation sites, need for and type of
ECC to be used. In the operating room, prior to induction of anesthesia,
a variety of monitors are placed on the patient including pulse
oximetry, electrocardiogram leads, non-invasive blood pressure
monitoring, and a combination bilateral cerebral oximetry/anesthetic
depth monitor (Masimo O3TM Regional Oximetry with
SedlineTM Brain Function Monitor, Masimo, Neuchatel,
Switzerland). The timing of placement of the radial arterial line is at
the discretion of the anesthesiologist, and may be placed prior to
induction of anesthesia in the setting of severe ventricular dysfunction
or when hemodynamic compromise is anticipated upon the application of
positive pressure ventilation after endotracheal
intubation.3 After induction of anesthesia and
endotracheal intubation with a dual lumen endotracheal tube, we place a
femoral arterial line, central venous catheter, pulmonary arterial
catheter, end-tidal carbon dioxide (ETCO2) monitor and
transesophageal echocardiogram (TEE) probe. A TEE probe is placed in
every lung transplant in order to guide ECMO cannula placement, monitor
biventricular function, and assess the patency of pulmonary vasculature
both prior to and following surgical anastomoses.4After initiation of veno-arterial ECMO (VA-ECMO), we obtain a whole
blood lactate, arterial blood gas (ABG), and activated clotting time
(ACT) every 30 minutes. Additionally, we check a fibrinogen and
prothrombin time/international normalized ratio (PT/INR) every 2 hours.
In addition to these structured blood draws, we use an in-line device
(Terumo CDI 550, Terumo Cardiovascular, Ann Arbor, MI, USA) to monitor
real-time trends of pH, partial pressures of oxygen and carbon dioxide
(PO2 and PCO2), potassium, oxygen
delivery (DO2), and hemoglobin within the hybrid
ECMO-CPB circuit.