Regional perfusion during venoarterial extracorporeal membrane oxygenation: a case report and educational modules on the concept of dual circulations.

UNLABELLED: A challenging aspect of managing patients on venoarterial extracorporeal membrane oxygenation (V-A ECMO) is a thorough understanding of the relationship between oxygenated blood from the ECMO circuit and blood being pumped from the patient's native heart. We present an adult V-A ECMO case report, which illustrates a unique encounter with the concept of "dual circulations." Despite blood gases from the ECMO arterial line showing respiratory acidosis, this patient with cardiogenic shock demonstrated regional respiratory alkalosis when blood was sampled from the right radial arterial line. In response, a sample was obtained from the left radial arterial line, which mimicked the ECMO arterial blood but was dramatically different from the blood sampled from the right radial arterial line. A retrospective analysis of patient data revealed that the mismatch of blood gas values in this patient corresponded to an increased pulse pressure. Having three arterial blood sampling sites and data on the patient's pulse pressure provided a dynamic view of blood mixing and guided proper management, which contributed to a successful patient outcome that otherwise may not have occurred. As a result of this unique encounter, we created and distributed graphics representing the concept of "dual circulations" to facilitate the education of ECMO specialists at our institution. KEYWORDS: ECMO, education, cardiopulmonary bypass, cannulation.

Bridge to decision: SWAT team approach used by Mayo Clinic Arizona's cardiac transport team.

OBJECTIVE: Patients in acute cardiogenic shock are the most challenging patients to manage. Unless a mechanical circulatory assist device is placed, maintaining end-organ function can be difficult. Transporting cardiogenic shock patients to tertiary care centers for higher level care also is difficult. The Mayo Clinic Arizona uses a SWAT team approach to deploy a specialized medical or surgical multidisciplinary team to implant mechanical circulatory assist devices at referring hospitals and transport patients back to Mayo Clinic Arizona. RESULTS: The cardiac transport team at Mayo Clinic Arizona got 23 referrals from 15 local community hospitals from February 2006 to September 2009. The medical team deployed for transfers of 6 patients, 3 of whom survived to hospital discharge. The surgical transport team deployed for transfers of 17 patients (6 with left ventricular assist devices, 2 with right ventricular assist devices, 5 with biventricular assist devices, and 4 with extracorporeal membrane oxygenation), of whom 8 survived to hospital discharge. Ten of the 17 referrals (59%) required a surgeon to place a mechanical circulatory assist device at the referring hospital. CONCLUSION: The SWAT team approach allows cardiogenic shock patients to be stabilized at the referring hospital by heart failure and cardiac surgical specialists. If necessary, a surgeon from Mayo Clinic Arizona places a mechanical circulatory assist device at the referring hospital to stabilize the patient. Doing so allows safe transport back to the tertiary care center for higher level care and possible transplant evaluation with placement of a long-term durable device.