Effect of Polymer Coating (Poly 2-Methoxyethylacrylate) of the Oxygenator on Hemostatic Markers During Cardiopulmonary Bypass in Children

Objective: Heparin and other oxygenator coatings have been used in attempts to reduce hemostatic activation during cardiopulmonary bypass (CPB). This study evaluated whether an oxygenator coated with poly 2-methoxyethylacrylate (PMEA) (X-coating; Terumo Corporation, Tokyo, Japan) would cause less activation of coagulation and fibrinolytic systems during CPB in children than a noncoated oxygenator. Design: Observational study. Setting: University-affiliated children's hospital. Patients: Twenty-six patients, 3 months to 5 years old, who underwent congenital heart surgery for repair of a ventricular septal defect, atrial septal defect, or both. Interventions: Patients were divided into 2 age-matched groups based on the type of oxygenator used: a noncoated oxygenator (group NC) versus a PMEA-coated oxygenator (group C). Measurements and Main Results: Blood samples for coagulation and fibrinolytic markers were compared before, during, and after CPB. Despite increases in thrombin generation markers (F1.2 and TAT) at certain times during CPB in group C compared to group NC, a comparison over all times during CPB were not statistically different between groups. Overall D-dimer concentrations during CPB were elevated in group C compared to group NC (p = 0.02). Active tPA and active PAI-1 were not different between groups during or after CPB. Group C had higher platelet counts (181,000 ± 29,000) during CPB than group NC (155,000 ± 57,000, p = 0.04) but not postoperatively. Twelve hours postoperatively, chest tube outputs were 8.8 ± 3 mL/kg in group C and 19.1 ± 12 mL/kg in group NC (p = 0.003). The corresponding outputs 24 hours after surgery were 12.4 ± 3 mL/kg and 24 ± 11 mL/kg, respectively (p = 0.005). Conclusions: Except for a somewhat higher platelet count during CPB, there was no indication that PMEA coating resulted in less activation of coagulation and fibrinolytic systems. The lower postoperative chest tube output observed after CPB with PMEA-coated oxygenators needs to be studied further.