ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
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Left ventricular assist device (LVAD) therapy is associated with thrombophilia despite anticoagulation. Of interest, LVAD patients have increased carboxyhemoglobin, a measure of upregulated heme oxygenase (Hmox) activity that releases carbon monoxide (CO) and iron. Given that CO and iron enhance plasmatic coagulation, we determined if LVAD patients had hypercoagulability and decreased fibrinolytic vulnerability with measurable CO and iron-mediated effects. ⋯ Critically, hemolysis as assessed by circulating lactate dehydrogenase activity was small in this cohort, and only four patients without comorbid states (e.g., obesity, diabetes, sleep apnea) were hypercoagulable with evidence of Hmox upregulation. However, seven patients with comorbidities were hypercoagulable with Hmox upregulation. Future investigation of CO and iron-related thrombophilia and comorbid disease is warranted to define its role in LVAD-related thrombosis.
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Since 2012, citrate anticoagulation is the recommended anticoagulation strategy for continuous renal replacement therapy (CRRT). The main drawback using citrate as anticoagulant compared with heparin is the need for calcium replacement and the rigorous control of calcium levels. This study investigated the possibility to achieve anticoagulation while eliminating the need for calcium replacement. ⋯ All filter pressures were normal indicating no clotting problems, and no visible clotting was observed. No calcium replacement was needed. This pilot study suggests that it is possible to perform regional citrate anticoagulation without the need for separate calcium infusion during CRRT.
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Review
Management of refractory hypoxemia during venovenous extracorporeal membrane oxygenation for ARDS.
Venovenous extracorporeal membrane oxygenation (VV ECMO) in acute respiratory distress syndrome (ARDS) is currently a widely used therapeutic strategy. However, patients are often still hypoxemic despite complete ECMO support. The major determinants of peripheral oxygen saturation (SpO2) during VV ECMO are pump flow, degree of recirculation, patient's systemic venous return and its oxygen saturation, hemoglobin concentration and residual lung function. ⋯ Transfusional strategy during VV ECMO, administration of neuromuscular blocking agents and sedatives, therapeutic hypothermia, and prone positioning is also reviewed. The potential advantages of β-blockers are discussed. Finally, transition from VV ECMO to venoarterial ECMO (VA ECMO) or a hybrid configuration is also examined.
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Historically, patients on extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome have received ventilatory "lung rest" with conventional or high-frequency oscillating ventilators. We present a series of adults treated with high-frequency percussive ventilation (HFPV) to enhance recovery and recruitment during ECMO. Adult respiratory patients, treated between January 2009 and December 2012 were cared for with a combination of standard ECMO practices and a protocol of recruitment strategies, including HFPV. ⋯ HFPV patients required a mean of 143.1 ± 17.6 hours and a median of 106 hours (range 45.75-350.25) of ECMO support and had a 62% survival to discharge. The post-ECMO PF ratio in the HFPV cohort was 301.8 ± 16.7. A protocolized practice of active recruitment that includes HFPV is associated with reduced duration of ECMO support in adults with respiratory failure.
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The optimum heparin monitoring method during extracorporeal membrane oxygenation (ECMO) is unknown. We report a protocol utilizing only anti-factor Xa (anti-Xa) to manage anticoagulation in 22 consecutive ECMO patients. Anti-Xa was monitored with heparin titration every hour until goal 0.4-0.8 IU/ml. ⋯ Change-out was associated with blood product administration and bleeding but not with heparin-free period (p = 0.39). Survival to discharge was higher among those who did not require circuit/oxygenator change-outs, 4/7 versus 7/7 (p < 0.01). Anti-factor Xa-based ECMO heparin management protocol is feasible, decreases blood sampling and heparin infusion adjustments, and does not appear to increase complications.