Sushaant Chawla
Pronouns: he/him
Research Mentor(s): William Lynch
Research Mentor School/College/Department: / Medicine
Program:
Authors: Jensyn VanZalen, Megan Stein, William Strode, Gergely Lautner, Orsolya Lautner-Csorba, Robert Bartlett, Alvaro Rojas-Pena
Session: Session 6: 3:40 pm – 4:30 pm
Poster: 72
Abstract
Introduction: Veno-venous extracorporeal membrane oxygenation (VV ECMO) is a common practice to support patients in lung or heart failure. Heparin is the standard anticoagulant used during ECMO support; however, it is associated with bleeding and hemolysis risk. Nitric oxide (NO), naturally released from the vascular endothelium, is an alternative form of anticoagulation that has antiplatelet properties, hypothesized to prevent thrombosis. This study hypothesizes that a NO-releasing ECMO-coated circuit in an ovine model of VV ECMO will lead to a decrease in hemolysis and thrombogenicity when compared to a control circuit without anticoagulation. Methods: Healthy sheep (40-50 kg) underwent VV ECMO cannulation under general anesthesia. Animals were allocated to one of three groups (n=3, per group). 1) control group, no anticoagulant present; 2) positive control group, sham CarboSil® coated circuit; and 3) experimental group, NO releasing coating + 100 ppm NO gas. The study lasts until the completion of 5 days or if 2 out of 3 end-point criteria are met. The end-point criteria were: 1) device resistance at x5 baseline value with a matching increase in pressure drop; 2) a decrease of blood flow by >50% after adjusting the RPMs by 30% of their baseline; or a registered post-oxygenator SO2 % value <95%. The experimental protocol included 1000 mL/min for the first 24 hours, 750 mL/min for the next 24 hours, and 500 mL/min for the remainder of the study. Animal hemodynamics, ECMO circuit characteristics, activated clotting time, blood gas values, and blood cell and chemistry counts were recorded throughout the study. Data analyzed include hematocrit percentage, extracorporeal circuit (ECC) patency survival, plasma-free hemoglobin (pfHb) maximum peak, and platelet count throughout the study. All values are reported as mean ± standard deviation. Results: All animals were successfully instrumented on VV ECMO and demonstrated hemodynamic stability throughout the study. Average ECC patency and calculated resistance were 69.3±52.1h, 52.7±60.7h, and 120±0h; 10x, 8x, 4x of baseline in the control, sham, and experimental groups, respectively. The average baseline pfHb for all animals was 1.6±0.4mg/dL and the average maximum peak throughout the study were 17.4±7.8 mg/dL, 17.3±5.5 mg/dL, 4.1±0.4 mg/dL in the control, sham, and experimental groups, respectively. The average platelet count at the end of the study was reported and normalized to baseline: 65.0%±16.5%, 67.7%±17.1K/uL%, 124.4%±50.8% for the control, positive control, and experimental groups, respectively. The average hematocrit for all animals throughout the study was reported to be 27.2±2.6%, 30.5±7.5%, 23.2±2.9% for the control, sham, and experimental groups, respectively. Conclusion: The preliminary results demonstrate that NO-releasing ECCs may reduce the degree of hemolysis and decrease thrombogenicity. Further studies are required to increase the power of these findings.
