Vishnav Ramesh
Research Mentor: Alvaro Rojas-Peña
Mentor Department: Department of Surgery-Transplantation, Medicine
Author(s): Vishnav Ramesh, Ninette Musili , Ryan Kauffman, Ronald Shebuski, Lauren Griffin, Alvaro Rojas-Peña
Session: Session 5 (2:00 PM – 2:50 PM)
Presentation Type: Poster 81
Abstract
Extracorporeal life support (ECLS) provides critical support for patients with acute cardiorespiratory failure, but thrombosis within the extracorporeal circuit is a frequent complication. To prevent clotting, systemic anticoagulation is required, which in turn substantially increases the risk of major hemorrhagic complications. Nitric oxide (NO) is an endogenous molecule involved in regulating platelet adhesion and activation. NO as a surface anticoagulant has the potential to create a non-thrombogenic surface. A 5-day ovine model of venovenous (VV) extracorporeal membrane oxygenation (ECMO) was used to examine systemic and extracorporeal effects of NO-treated extracorporeal circuits (ECCs). Methods: Ten sheep were instrumented for VV ECMO under general anesthesia, recovered, and assigned to one of two groups: 1) NO-treated ECC (experimental) and 2) untreated ECC (control) with systemic heparinization. Data collected included: animal hemodynamics, Activated Clotting Time (ACT), complete blood count (CBC), plasma-free Hemoglobin (PfHb), and methemoglobin (met-Hb). Animals were observed for 5 days post-cannulation. Results: In the NO-releasing (experimental) group, three (60%) animals completed the full 120 hours of ECLS. In the other two (40%), acute hypotension resulting in hemodynamic instability and early termination, due to high acute NO-release of the circuit. In the control group 4 (80%) animals completed 120 hours, one (20%) animal was terminated early due to hemorrhagic complications. Mean hemoglobin was 8.7±0.78 g/dL in the experimental group and 7.5±1.0 g/dL in the control. Mean plasma free hemoglobin (PfHb) was 8.2±6.5 mg/dL in the experimental group and 11.6±14.4 mg/dL in the control. Mean activated clotting time (ACT) across the study was 176.4±34.1 s for the experimental group and 234.2±51.3 s for the control. Methemoglobin remained <5% throughout the study in the NO-treated animals, indicating no systemic NO toxicity. Conclusion: Preliminary results suggest NO-treated extracorporeal circuits may reduce thrombotic complications in an ovine venovenous ECMO model over five days without detectable systemic effects. The circuit’s NO-release was adjusted to avoid acute systemic exposure as observed with the first 2 animals.
