Effect of poly(2-methoxyethyl acrylate)-coated oxygenators on haemolysis

Abstract

Blood contact with artificial device surfaces and mechanical trauma are two major factors for haemolysis. Poly(2-methoxyethyl acrylate) (PMEA) is an amphiphilic polymer with a polyethylene chain that is hydrophobic and a mildly hydrophilic tail. PMEA coating has showed positive effects on protein adsorption, platelet loss, platelet aggregation and post-operative bleeding in previous studies. In this study, effects of poly(2-metoxyethyl acrylate) (PMEA)-coated oxygenators on haemolysis was investigated. PMEA-coated (SX18-Capiox) oxygenators were used. Desorbed erythrocyte, free haemoglobin indirect bilirubin and total bilirubin quantities from fibre samples of oxygenators were studied. Erythrocyte, total bilirubin and direct bilirubin values were measured from blood aliquots taken in five different times during cardiopulmonary by-pass (CPB); baseline (T1), during CPB (T2), at the end of CPB (T3), after protamine injection (T4) and in intensive care (T5). In both coated and non-coated oxygenators haemolysis rate was in clinically acceptable safety range. Average desorbed free haemoglobin was 6663 mg/dl from coated and 29.405 mg/dl from non-coated fibres. Average desorbed total bilirubin was 0.0068 mg/dl from coated and 0.023 mg/dl from non-coated fibres. We observed less haemolysis, as reflected by lower desorbed free haemoglobin and indirect bilirubin from coated oxygenators and less decrease in blood erythrocyte number. Blood bilirubin concentration was low in the coated group when compared to the control group. This study describes the relationship between PMEA coating and haemolysis at the blood contacting surface. PMEA coating reduces red blood cell damage during extracorporeal circulation.