2016 FSA Posters

P024: THE ROLE OF INTRAOPERATIVE ECHOCARDIOGRAPHY IN THE EARLY DETECTION OF FAT EMBOLISM IN ORTHOPEDIC SURGERY
Matthew Mello, MD, Joanna Runkle, MD, MPH, Idania Mejias, MD; University of Florida - Jacksonville

Introduction: A fat embolism is an embolism typically released by bone marrow into the blood stream in trauma patients and repair of orthopedic injuries.  The incidence of this phenomena can approach near 90% in major trauma cases.  Barring a right to left shunt, a fat embolus may lead to cardiopulmonary collapse in addition to the possible progression to triggering a systemic inflammatory cascade.  The insult and propagated emboli into the pulmonary vasculature can decrease venous return, left heart volume and create a lethal V/Q mismatch, leading to cardiopulmonary collapse with impending death as the right heart fails and the left ventricle has no left ventricular end diastolic volume (LVEDV).  Here we present management and early diagnosis of fat embolus with intraoperative transesophageal echocardiogram (TEE). 

Case Report: A 22-year-old Caucasian female with a high-velocity gunshot to her left femur has undergone a reconstruction with a large bone void and antibiotic cement spacer approximately 6 weeks ago is ready for grafting.  When reaming of the femoral bone began she developed hemodynamic instability: heart rate increase from 90bpm to 141bpm, 30% decrease in blood pressure, oxygen saturation drop from 100 to 85% and a drop in EtCO2 from 34mmHg to13mmHg.  The surgery was immediately stopped and incision closed while resuscitation with epinephrine 4-12mcg boluses were given.  The patient never lost pulses throughout the event and did not require inotropic support after 2 hours. 

The patient was stabilized in the intensive care unit and rescheduled for completion of the operative procedure with planned intraoperative TEE for management two days later.  Upon return to the operating room the baseline echo revealed no regional wall abnormalities, no evidence of atrial shunt and ejection fraction of 65%.  Tight communication with the surgeon occurred throughout the procedure.  Real time monitoring of the right side of the heart with mid-esophageal 4-chamber and bicaval views were interrogated continuously.  As the surgical reaming of the femur progressed there were minor emboli visualized with minimal change in the vitals: heart rate increase from 92bpm to 111bpm, 15% decrease in blood pressure, oxygen saturation drop from 100 to 97% and a drop in EtCO2 from 34mmHg to 29mmHg. The surgeon adjusted his technique with an intermittent wash to reduce the incidence of emboli.  As the final reaming maneuver was completed there was evidence of a substantial shower of emboli in the right atrium noticed in the mid-esophageal bicaval TEE view.  The surgeon was informed.  The procedure was completed, the patient required minimal hemodynamic support with three 100mcg boluses of phenylephrine.

Discussion: Although fat embolism in these cases is >90%, the majority are not noticed clinically.  The ability to provide real time feedback to the surgeon to adjust the procedure through TEE and provide earlier hemodynamic support may be indicative of better outcomes.  

References: Kropfl A, Davies J, Berger U. Intra-medullary pressure and bone marrow fat embolization in reamed and undreamed femoral nailing. J Orthop Res. 2005;17:261–8.