Cardiocentric Inotropic Optimization in Spinal Cord Injury

This is a pilot study in which the efficacy of Dobutamine (DOB) will be evaluated within 48 hours post-surgery in acute cervical SCI participants. A total of 8 participants between 18-75 years of age who have sustained an acute traumatic cervical SCI prior will be recruited from the emergency department, intensive care unit, post anesthesia care unit, or spine stepdown unit.

Recruitment will be isolated to those individuals who require an arterial line as part of standard clinical care, and who will (or already are) receive(ing) norepinephrine (NE) as part of their standard clinical hemodynamic management. In addition to the standard clinical measurements, we will utilize right-heart catheterization to measure continuous cardiac output and non-invasive transthoracic echocardiography to measure left ventricular (LV) structure and function. All study procedures will be conducted in the intensive care unit within the first 48 hours after surgery and will be completed over a 2.5hr period. The main procedure in this study is a "cross-over" from NE to DOB, in which we will assess cardiac function while switching the hemodynamic management from NE to DOB. After spine surgery, but before the start of the cross-over, an Intensivist will place a right-heart catheter. With the right heart catheter in situ, the research nurse will record baseline blood pressure, heart rate, and cardiac output over a 15-min period. A research sonographer will then perform a comprehensive baseline echocardiography exam. Next, we will begin infusion of DOB and gradually wean the patient off of NE (the "cross-over"). The DOB will be titrated to maintain the baseline MAP for a period of 35-40 minutes whilst simultaneously titrating the NE down, to the point where the participant's blood pressure will be maintained solely on DOB. When the participant is solely on DOB, an abbreviated 2nd echocardiography exam will be performed, approximately 20 min after blood pressure support has been achieved with DOB alone. Following completion of the echocardiography exam, we will begin infusion of NE and titrate this up, whilst simultaneously gradually titrating down the DOB to wean the patient fully off of DOB (i.e. cross-over from DOB back to NE alone). Following 20 min of transition back to exclusive management with NE, we will conduct an abbreviated 3rd echocardiography exam. The right-heart catheter will then be removed unless there is a clinical indication to keep the right-heart catheter in place.