The Journal of extra-corporeal technology
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J Extra Corpor Technol · Mar 2015
Case ReportsVariability in End-Organ Perfusion with Femoral-Femoral Venoarterial Extracorporeal Membrane Oxygenation: Aortographic Evidence.
In femoral-femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO), the outflow of oxygenated blood from the circuit enters the aorta in retrograde fashion. As a result, variability in end-organ oxygenation (e.g., cerebral vs. splanchnic) may arise-particularly, when the heart is unable to contribute forward flow. We present the case of a 74-year-old man supported by femoral-femoral VA-ECMO in whom aortography was used to visualize the retrograde distribution of arterial ECMO flow that can produce such differences in end-organ perfusion. We do this by describing a series of still images captured during the aortography; we then discuss the importance of monitoring end-organ oxygenation in this setting and outline several interventions that can ameliorate this flow phenomenon.
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J Extra Corpor Technol · Mar 2015
EditorialPerspective on Cerebral Microemboli in Cardiac Surgery: Significant Problem or Much Ado About Nothing?
From the time an association was perceived between cardiac surgery and post-operative cognitive dysfunction (POCD), there has been interest in arterial microemboli as one explanation. A succession of studies in the mid-1990s reported a correlation between microemboli exposure and POCD and there followed a focus on microemboli reduction (along with other strategies) in pursuit of peri-operative neuroprotection. There is some evidence that the initiatives developed during this period were successful in reducing neurologic morbidity in cardiac surgery. ⋯ Improvements in CPB safety (including emboli reduction) achieved over the last 20 years may be partly responsible for difficulty demonstrating higher rates of POCD after cardiac surgery involving CPB in contemporary comparisons with other operations. Moreover, microemboli (including bubbles) have been proven harmful in experimental and clinical situations uncontaminated by other confounding factors. It remains important to continue to minimize patient exposure to microemboli as far as is practicable.
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Acute kidney injury (AKI) after cardiac surgery is a common and underappreciated syndrome that is associated with poor shortand long-term outcomes. AKI after cardiac surgery may be epiphenomenon, a signal for adverse outcomes by virtue of other affected organ systems, and a consequence of multiple factors. Subtle increases in serum creatinine (SCr) postoperatively, once considered inconsequential, have been shown to reflect a kidney injury that likely occurred in the operating room during cardiopulmonary bypass (CPB) and more often in susceptible individuals. ⋯ This review explores the pathophysiology of AKI and addresses the features of patients who are the most vulnerable to AKI. Preoperative strategies are discussed with particular attention to a readiness for surgery checklist. Intraoperative strategies include minimizing hemodilution and maximizing oxygen delivery with specific suggestions regarding fluid management and plasma preservation.
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J Extra Corpor Technol · Mar 2015
Case ReportsManagement of Heparin-Resistant Patients with Benefits? Maximizing Biocompatibility in Cardiopulmonary Bypass: Combining ATryn® Recombinant Antithrombin III and Carmeda® Heparin-Bonded Perfusion Circuits: A Case Series.
As many as 25% of our cardiopulmonary bypass (CPB) patients have a diminished heparin response and fail to reach a therapeutic activated clotting time (ACT). We treat a majority of these patients with antithrombin III (ATryn®, recombinant antithrombin III [rhAT], rEVO Biologics). Our current CPB circuit uses Medtronic Carmeda® coating. ⋯ We also observed decreased postoperative atrial fibrillation rates, improved platelet preservation, decreased intensive care unit and ventilator times in patients receiving rhAT compared to rates commonly observed at our center. Heparin-resistant patients can be treated with rhAT to achieve therapeutic ACTs. Our observations suggest that the use of rhAT in conjunction with Carmeda® heparin-bonded circuits may also have a positive benefit on some of the well-established negative clinical consequences of CPB and improve patient outcomes.
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J Extra Corpor Technol · Dec 2014
Case ReportsThe Need to Develop Standardized Protocols for the Timing of Extracorporeal Membrane Oxygenation Initiation among Adult Patients in Cardiac Arrest: A Case Study.
The duration of time between cardiac arrest, cardiopulmonary resuscitation (CPR), and initiation of extracorporeal membrane oxygenation (ECMO) among refractory patients is correlated with mortality. The duration of conventional CPR (CCPR) beyond which ECMO support should not be offered due to poor outcomes is not established. This case study describes a patient with heart failure with recurrent episodes of ventricular tachycardia who had a witnessed cardiac arrest in a coronary care unit. ⋯ Despite aggressive medical therapy, ECMO support was discontinued 48 hours later following absence of electroencephalographic activity and no evidence of cardiac function ultimately leading to the patient's death. This case study illustrates the possibility that prolonged ischemia resulting from duration of CCPR and time to initiate ECPR may contribute to adverse clinical outcomes. Systems of care that might reduce delays in ECMO initiation and improve patient outcomes are discussed including: 1) development of standardized protocols to allow for rapid initiation of ECMO support; 2) systematic evaluation of parameters such as biomarkers that might identify patients at risk for cardiac arrest in settings where ECMO is readily available; and 3) assessment of patient criteria to define subsets of individuals among whom late institution of ECMO, an expensive and labor-intensive mode of circulatory support, might be futile.