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Cardiopulmonary bypass (CPB) leads to a generalized inflammatory reaction, resulting in increased postoperative leucocyte counts and decreased pulmonary function. In adults, removal of leucocytes from the residual heart-lung machine blood after CPB improved postoperative oxygenation. In children, however, the clinical effects of leucocyte filtration of the residual heart-lung machine blood are unknown. Therefore, we measured postoperative leucocyte counts and arterial blood oxygenation in children undergoing congenital cardiac surgery in a randomized prospective study. Anaesthesia and CPB were standardized. After CPB, the residual heart-lung machine blood was collected as usual. In a group of 25 children, this blood was filtered with a leucocyte depletion filter before transfusion. A control group of 25 children received this blood unfiltered. We found that the postoperative leucocyte counts were significantly lower in the filter group than in the control group (p = 0.02, repeated measurements ANOVA). This difference reached a maximum on the second postoperative day (12.9 x 10(9)/L filter versus 15.9 x 10(9)/L control, p = 0.02, Student's t-test). Values for the arterial blood oxygenation on the first postoperative day were not different between the two groups (15.5 +/- 1 kPa filter versus 14.6 +/- 1.3 kPa control, p = 0.57, Student's t-test). We conclude that leucocyte filtration of the residual heart-lung machine blood reduced systemic leucocyte counts, but did not improve arterial blood oxygenation in children after congenital heart surgery. [ABSTRACT FROM AUTHOR]

Improved filter technology may enable the removal of specific substances such as lipids from the blood. Lipids form a heterogeneous group of compounds, but during surgery, the main interest is focussed on triglycerides, glycerol and free fatty acids. Fat emboli have been demonstrated in the brain after cardiac surgery and are associated with ischaemic brain injury. Fat emboli have also been demonstrated in lung and kidney tissue. Lung tissue and leucocytes are especially vulnerable to the effects of free fatty acids. The surgical wound suction blood during cardiac surgery contains a considerable quantity of microemboli. Therefore, as a first step to determining the place of fat filtration during cardiac surgery, the use of a fat removal filter for surgical wound suction blood is advocated. [ABSTRACT FROM AUTHOR]

The method of leucocyte depletion has been recently introduced to the field of cardiopulmonary bypass to reduce leucocyte-mediated organ dysfunction. In this study, we evaluated the efficacy and biocompatibility of the Pall RC400 filters for leucocyte depletion of heparinized cardiopulmonary bypass (CPB) perfusate taken from the heart-lung machine during routine cardiac surgery. For each filter, 700 ml blood were used as filtrate. Filtration was divided into the following groups to study the effect of loading pressure on the efficacy of the filters: under gravity pressure as a control (n = 8), under 100 mmHg (n = 8), 200 mmHg (n = 8), and 300 mmHg loading pressure (n = 8) driven by a roller pump. In addition, heparinized predonation blood taken at the beginning of CPB (n = 8) was filtered under gravity in comparison with the perfusate taken at the end of CPB. The results showed that the average leucocyte removal rate by an RC400 filter for 700 ml of blood was 96.8%. There was no significant difference of leucocyte removal rate between filtration under gravity and under loading pressure up to 300 mmHg. This allows clinical filtration at a speed up to 500 ml/min. The platelet removal rate was significantly higher in blood taken at the beginning of CPB than in blood taken at the end of CPB. Complement split product, C5a, increased only slightly during filtration indicating that this filter, made from polyester, has a good blood compatible characteristic. We conclude that the Pall RC400 leucocyte removal filter is suitable and safe to be used for leucocyte filtration of heparinized CPB perfusate during cardiac surgery. [ABSTRACT FROM AUTHOR]

The method of leucocyte depletion has been recently introduced to the field of cardiopulmonary bypass to reduce leucocyte-mediated organ dysfunction. In this study, we evaluated the efficacy and biocompatibility of the Pall RC400 filters for leucocyte depletion of heparinized cardiopulmonary bypass (CPB) perfusate taken from the heart-lung machine during routine cardiac surgery. For each filter, 700 ml blood were used as filtrate. Filtration was divided into the following groups to study the effect of loading pressure on the efficacy of the filters: under gravity pressure as a control (n = 8), under 100 mmHg (n = 8), 200 mmHg (n = 8), and 300 mmHg loading pressure (n = 8) driven by a roller pump. In addition, heparinized predonation blood taken at the beginning of CPB (n = 8) was filtered under gravity in comparison with the perfusate taken at the end of CPB. The results showed that the average leucocyte removal rate by an RC400 filter for 700 ml of blood was 96.8%. There was no significant difference of leucocyte removal rate between filtration under gravity and under loading pressure up to 300 mmHg. This allows clinical filtration at a speed up to 500 ml/min. The platelet removal rate was significantly higher in blood taken at the beginning of CPB than in blood taken at the end of CPB. Complement split product, C5a, increased only slightly during filtration indicating that this filter, made from polyester, has a good blood compatible characteristic. We conclude that the Pall RC400 leucocyte removal filter is suitable and safe to be used for leucocyte filtration of heparinized CPB perfusate during cardiac surgery. [ABSTRACT FROM PUBLISHER]

Surface treatment of a cardiopulmonary bypass circuit with heparin improves its haemocompatibility. However, potential side effects of this layer of heparin are impairment of O2 transfer and CO2 transfer in the oxygenator and heat transfer in the heat exchanger.Therefore we studied these side effects during extracorporeal circulation with moderate hypothermia in 30 patients who underwent elective coronary artery bypass grafting surgery. All patients were heparinized systemically. In 15 patients (Duraflo II-group) we used an extracorporeal circuit (including a Bentley Bos-CM50 membrane oxygenator) which was treated with heparin. The results of this group were compared with those obtained from another group of 15 patients (control-group), who were operated upon with an identical extracorporeal circuit but without heparin surface treatment.We found no significant differences between the two groups in O2 transfer, CO2 transfer or heat transfer during normothermia or hypothermia.We concluded that neither O2 transfer and CO2 transfer of the oxygenator nor heat transfer of the heat exchanger were impaired by Duraflo II heparin surface treatment during clinical cardiopulmonary bypass with moderate hypothermia. [ABSTRACT FROM PUBLISHER]

This clinical study was performed to evaluate the inhibiting effects of heparin- coated extracorporeal circuits on thrombin formation during cardiopulmonary bypass (CPB). Thirty patients undergoing coronary artery bypass grafting were randomly divided into two groups with (Duraflo II, n=15) orwithout (control, n=15) the use of heparin-coated circuits. Standard systemic heparinization was performed in all the patients before CPB. The results showed that thrombin formation during the first phase of CPB was inhibited by heparin-coating identified by the significantly lower concentrations of thrombin-antithrombin III (TAT) complex formed in plasma in the Duraflo II group than in the control group (p <0.05). Heparin concentrations were higher in the Duraflo II group than in the control group at the end of CPB (p <0.05). However, after release of the aortic crossclamp in the second phase of CPB, thrombin became strongly activated in both the Duraflo II and the control groups indicated by a sharp increase of TAT complex as well as fibrinopeptide A. Thus, Duraflo II heparin-coating reduces thrombin formation in the early phase of CPB, however, this beneficial effect was counteracted after aortic crossclamp release by material-independent stimuli. Therefore, adequate systemic heparinization is still required despite improved haemocompatibility of the circuits offered by heparin-coating. [ABSTRACT FROM PUBLISHER]