title: Nitric oxide added to the sweep gas infusion reduces local clotting formation in adult blood oxygenators.
abstract: Nitric oxide (NO) is an inhibitor of platelet aggregation. We analyzed the effect of direct infusion of NO into adult blood oxygenators on local clot formation. Nonheparinized calves in a control group (n = 3) and NO group (n = 4) were connected to a jugulocarotid cardiopulmonary bypass (CPB; centrifugal pump) for 6 hours. The venous line and pumphead were heparin coated, whereas the oxygenator, the heat exchanger, and the arterial line were not. A total of 80 ppm of NO was mixed with the sweep gas infusion in the NO group. The pressure gradient through the oxygenator (delta<gd>P.Ox.) was monitored, and its evolution was compared between groups. Oxygenators membranes were analyzed and photographed, allowing for calculation of the percentage of surface area covered with clots by using a computer image analysis program. The delta<gd>P.Ox. reached a plateau of 193 +/- 26% of the basal value in the NO group after 120 minutes, whereas a similar plateau of 202 +/- 22% was reached after only 20 minutes in the control group (p < 0.05). The surface area of the oxygenator covered with clots was significantly reduced in the NO group (0.54 +/- 0.41%) compared with the control group (5.78 +/- 3.80%, p < 0.05). However, general coagulation parameters were not modified by local NO administration. The activated coagulation time remained stable between 110 and 150 seconds in both groups (p = not significant [ns]), and there were no differences in hematocrit, thrombin time, partial thromboplastin time, or fibrinogen between groups during the 6 hours of CPB. Thus, the mixed infusion of a continuous low dose of NO into adult oxygenators during prolonged CPB prevented local clot formation, whereas the general coagulation pattern remained unchanged.
authors: Department of Cardiovascular Surgery, University Hospital, Lausanne, Switzerland.
authors: H T
authors: HT
authors: Tevaearai
authors: X M
authors: XM
authors: Mueller
authors: S
authors: S
authors: Tepic
authors: J
authors: J
authors: Cotting
authors: Y
authors: Y
authors: Boone
authors: P M
authors: PM
authors: Montavon
authors: L K
authors: LK
authors: von Segesser
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D002417:Cattle; D005740:Gases; D066298:In Vitro Techniques; D009569:Nitric Oxide / Q000008:administration & dosage*; D010107:Oxygenators, Membrane / Q000009:adverse effects; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*
chemical_list: D005740:Gases; D010975:Platelet Aggregation Inhibitors; D009569:Nitric Oxide