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.