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Correction to: European Journal of Clinical Nutrition (2015) 69, 309­313; doi: 10.1038/ejcn.2014.261; published online 14 January 2015 Since the publication of this article, the authors have noticed that several of the author names were published incorrectly. The correct author names are listed above. The .html and online PDF versions have also been amended. The authors apologise for any inconvenience caused.

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BACKGROUND/OBJECTIVES: The level of skin autofluorescence (AF) at a given moment is an independent predictor of mortality in hemodialysis (HD) patients. Skin AF is a measure of the accumulation of advanced glycation end products (AGEs). The aim of the study was to estimate the influence of nutrition on the 1-year increase of skin AF (ΔAF) in HD patients. SUBJECTS/METHODS: A total of 156 HD patients were enrolled in this study. Skin AF, body mass index (BMI), superoxide dismutase, myeloperoxidase, C-reactive protein, inter-cellular adhesion molecule-1, von Willebrand factor and heart-type fatty acid-binding protein were measured four times at intervals of approximately half a year. Data from the monthly routine blood analysis were also used. Daily calorie, protein and AGE intakes were assessed from food recordings over a period of 1 week. RESULTS: A J-shaped relation was found between baseline BMI and ΔAF (P=0.01). The lowest point of the J-shaped curve is found for BMI=24.3 kg/m(2). In the univariate analysis of the contributors to the 1-year ΔAF, we found that beside BMI=24.3 kg/m(2), AGE and calorie intakes, as well as myeloperoxidase and HD vintage, had a P <0.10. The sole independent predictor of the 1-year ΔAF was BMI=24.3 kg/m(2) (P=0.01). CONCLUSIONS: It appears that calorie, protein and AGE intakes hardly influence the 1-year ΔAF in HD patients. BMI of HD patients of around 24 kg/m(2) resulted in a lower 1-year ΔAF.

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ISO 10993-4 is an international standard describing the methods of testing of medical devices for interactions with blood for regulatory purpose. The complexity of blood responses to biomaterial surfaces and the variability of blood functions in different individuals and species pose difficulties in standardisation. Moreover, in vivo or in vitro testing, as well as the clinical relevance of certain findings, is still matter of debate. This review deals with the major remaining problems, including a brief explanation of surface interactions with blood, the current ISO 10993 requirements for testing, and the role of in vitro test models. The literature is reviewed on anticoagulation, shear rate, blood-air interfaces, incubation time, and the importance of evaluation of the surface area after blood contact. Two test categories deserve further attention: complement and platelet function, including the effects on platelets from adhesion proteins, venipuncture, and animal derived- blood. The material properties, hydrophilicity, and roughness, as well as reference materials, are discussed. Finally this review calls for completing the acceptance criteria in the ISO standard based on a panel of test results.

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In this split mouth experiment, the feasibility ofpolyurethane foam as a local hemostatic agent after dental extractions was studied. Ten healthy patients underwent 2 extractions ofa dental element in 1 treatment session. The 10 patients were subsequently randomly divided in a gelatin group and a collagen group. In the gelatin group, a polyurethane foam (PU) was applied in 1 extraction socket, while in the other socket a commercially available gelatin foam was applied. In the collagen group, a PU was applied in 1 socket, and a collagen wadding in the other. All hemostats were removed after 2 minutes, after which the degree of coagulation was measured using a thrombin/antithrombin test and a fibrinogen test. This study suggests that polyurethane foam has hemostatic capacity. Large scale clinical research is needed to confirm this finding, and should indicate whether this hemostatic capacity is clinically relevant.

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Tissue engineering and regenerative medicine have furnished a vast range of modalities to treat either damaged tissue or loss of soft tissue or its function. In most approaches, a temporary porous scaffold is required to support tissue regeneration. The scaffold should be designed such that the turnover synchronizes with tissue remodeling and regeneration at the implant site. Segmented polyester urethanes (PUs) used in this study were based on epsilon-caprolactone (CL) and co-monomers D,L-lactide (D,L-L) and gamma-butyrolactone (BL), and 1,4-butanediisocyanate (BDI). In vitro, the PUs were nontoxic and haemocompatible. To test in vivo biocompatibility, the PUs were further processed into porous structures and subcutaneously implanted in rats for a period up to 21 days. Tissue remodeling and scaffold turnover was associated with a mild tissue response. The tissue response was characterized by extensive vascularization through the interconnected pores, with low numbers of macrophages on the edges and stroma formation inside the pores of the implants. The tissue ingrowth appeared to be related to the extent of microphase separation of the PUs and foam morphology. By day 21, all of the PU implants were highly vascularized, confirming the pores were interconnected. Degradation of P(CL/D,L-L)-PU was observed at this time, whereas the other two PU types remained intact. The robust method reported here of manufacturing and processing, good mechanical properties, and in vivo tissue response of the porous P(CL/D,L-L)-PU and PBCL-PU makes them excellent candidates as biomaterials with an application for soft tissue remodeling, for example, for cardiovascular regeneration.

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BACKGROUND: Iron and (stainless) steel are potent platelet aggregation activators, and may be involved in stent thrombosis, a serious complication after intracoronary stenting. Current platelet function tests are suboptimal, because of inappropriate agonists and/or lack of reproducibility. We tested the feasibility and reproducibility of a novel platelet function test using stainless steel as an agonist and compared it with other platelet function tests. MATERIALS AND METHODS: In 111 patients with acute ST segment elevation myocardial infarction (STEMI), duplo measurements of iron (Fe)-induced platelet aggregation (FIPA) were performed after clopidogrel, acetylsalicylic acid and/or tirofiban treatment. Within 1 h, citrated blood samples drawn from the femoral sheath before primary percutaneous coronary intervention were added to 100 mg of low carbon steel and after 5 s mixing with vortex, the samples were incubated for 15 min. The ratio between the non-aggregated platelets in the agonist sample and platelets in a reference sample was calculated as the platelet aggregation inhibition. RESULTS: FIPA measurement was highly reproducible (correlation coefficient (R)=0.942, P<0.001 between duplo samples). FIPA correlated well with adenosine diphosphate-induced platelet aggregation (R=0.83, P<0.001) but weakly with platelet function analyser-100 bleeding time (R=0.56, P<0.001). FIPA could be measured in patients in which platelet aggregation could not be measured by platelet function analyser-100 or after adenosine diphosphate. CONCLUSION: This study showed good reproducibility of a novel platelet function test using stainless steel as an agonist and showed correlation with validated platelet function tests. We found that the novel platelet function test is a suitable test for measurement of platelet aggregation inhibition in patients undergoing stenting for STEMI, even when they are taking multiple antiplatelet regimens.

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BACKGROUND: Cardiac surgery with cardiopulmonary bypass (CPB) is commonly perceived as a risk factor for decline in renal function, especially in patients with preoperative renal dysfunction. There are few data on the effects of CPB on renal function in patients with mild preoperative renal dysfunction. The purpose of this study was to evaluate renal function in patients with pre-existing mild renal dysfunction undergoing cardiac surgery with CPB. METHODS: In a multicentre study cohort we measured prospectively the glomerular filtration rate (GFR) by radioactive markers both before operation and on the 7th postoperative day in cardiac surgical patients with preoperative serum creatinine >120 micromol l(-1) (n=56). In a subgroup of patients (n=14) in addition to the GFR, the effective renal plasma flow (ERPF) and the filtration fraction (FF) were measured. RESULTS: While preoperative GFR [77.9 (25.5) ml min(-1)] increased to 84.4 (23.7) ml min(-1) (P=0.005) 1 week after surgery, ERPF did not change [295.8 (75.2) ml min(-1) and 295.9 (75.9) ml min(-1), respectively; P=0.8]. In accordance, the FF increased from 0.27 (0.05) (before operation) to 0.30 (0.04) (Day 7, P=0.01). CONCLUSION: Our results oppose the view that cardiac surgery with CPB adversely affects renal function in patients with preoperative mild renal dysfunction and an uncomplicated clinical course.

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BACKGROUND AND OBJECTIVES: The use of an autotransfusion device to wash blood of the incision site is increasing. After washing, this blood is retransfused without side effects caused by activated plasma factors and cell release products. This procedure could be extended to washing of donor blood, which may be particularly useful for red blood cells (RBCs) stored for more than 4 weeks that contain high concentrations of free haemoglobin, potassium, lactate and other metabolites. It is not known whether stored RBCs can withstand the cell washing procedure with the use of an autotransfusion device, while keeping their primary functions intact. The objective of this study was to determine the quality of RBCs, after cell washing in comparison to untreated RBCs. MATERIALS AND METHODS: RBCs were studied in terms of integrity (free haemoglobin), stored energy (2,3-diphosphoglycerate, adenosine triphosphate), metabolites (lactate, potassium) and physical characteristics (osmotic resistance, aggregability, deformability). RESULTS: After washing, free lactate and potassium were significantly reduced as compared to the levels before washing. The osmotic resistance of RBCs slightly improved, whereas aggregation capacity reduced after washing. Fifteen per cent of haemoglobin was lost during washing. The deformability and free haemoglobin levels remained unchanged. CONCLUSION: Washing stored blood before transfusion may be of benefit, because the waste products are effectively removed from the stored RBC.

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Poly(2-methoxyethylacrylate) (PMEA) is a new coating material that appears to reduce protein and platelet adsorption. However, the exact performance of PMEA coated circuit remains to be revealed in well-controlled experiments. Therefore, we compared its hemocompatibility with covalent-bound heparin-, and non-coated circuits during 6 hours of in vitro circulation, using donor blood from six volunteers. In our model, simple tubing circuits containing one-way ball valve were placed on the rotary table, which moved alternatively to generate pulsatile recirculation of heparinized human blood inside the tubing. Using this model, we expected fine assessment of the material surface, because we could reduce blood damage by avoiding air and a blood pump. Moreover, the small capacity of circuit allowed us to compare three kinds of circuits using a single unit of donor blood, eliminating effects by possible variations between blood donors. The anti-thrombin capacity of the PMEA-coated circuits was maintained even after six hours blood circulation, whereas surface thrombin generation increased markedly after use in non-coated circuits (P<0.05). Deposition of fibrin onto PMEA circuits was reduced more than 30% compared with heparin and non-coated circuits (P<0.05). However, the increase of plasma Factor XIIa was similar in all circuits. Increase of CD11b expression on circulating leukocytes and of plasma C3a was ameliorated in the heparin- and PMEA-coated circuits (P<0.05). PMEA-coated circuits appear to maintain their anti-thrombogenicity during use, otherwise PMEA-coated and heparin-coated circuits showed a similar character in hemocompatibility. This long-standing anti-thrombogenicity might be attributable to less adsorption of activated blood components onto the surface.

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Erythrocyte aggregation is known to be affected by a number of factors including the concentration of various plasma proteins. This study was performed to examine the in vivo effect of hemodilution of plasma proteins on erythrocyte aggregation in patients undergoing cardiopulmonary bypass (CPB) surgery. Blood samples were taken before, during, and after operation from 40 coronary artery bypass grafting patients who were operated with CPB and concomitant hemodilution (CPB, n=20) and who without (nonCPB, n=20). Erythrocyte aggregation was determined with a LORCA aggregometer, during which all samples were standardized to a hematocrit level of 40%. Results showed that in the CPB patients the aggregation index (AI) dropped to 44% of its preoperative baseline level 5 minutes after the start of hemodilution (from 47.7+/-10.1 to 26.6+/-11.4, p<0.01). Meanwhile, plasma concentration of fibrinogen (Fb) dropped to 55%, haptoglobin to 85%, ceruloplasmin to 55%, and albumin to 67%. In the nonCPB patients, however, there was only a slight drop in AI and the concentrations of plasma proteins during the similar period of time. On postoperative day 1, AI was rebounded to 37.1+/-12.4 in CPB patients compared with 44.3+/-11.7 in nonCPB patients. At baseline, AI was correlated only with Fb. During CPB and hemodilution, AI was correlated not only with Fb but also with haptoglobin and ceruloplasmin. Postoperatively, significant correlationship was found between AI and Fb, CRP, haptoglobin, ceruloplasmin, as well as albumin. These results indicate that hemodilution of plasma proteins significantly reduces the aggregability of erythrocytes in patients undergoing CPB. Besides Fb, other plasma proteins also contribute to AI during the early postoperative period when patients are recovering from CPB surgery.

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BACKGROUND: Current pulsatile pumps for cardiopulmonary bypass (CPB) are far from satisfactory because of the poor pulsatility. This study was undertaken to examine the efficiency of a novel pulsatile catheter pump on pulsatility and its effect on abdominal organ perfusion during CPB. METHODS: Twelve pigs weighing 89+/-11 kg were randomly divided into a pulsatile group (n=6) and a non-pulsatile group (n=6). All animals had a CPB for 120 min, aorta clamped for 60 min, temperature down to 32 degrees C, and a perfusion flow of 60 ml/kg/min. In the pulsatile group, a 21 Fr intra-aortic pulsatile catheter, which was connected to a 40 mL membrane pump, was placed in the descending aorta and activated by a balloon pump driver during the first 90 minutes of CPB until aortic declamping. Hemodynamics, organ blood flow, body metabolism, and blood trauma were studied during experiments. RESULTS: Compared with the non-pulsatile group during CPB, the pulsatile group had a higher systolic blood pressure (p<0.01), higher mean arterial pressure (p<0.05), and higher blood flow to the superior mesenteric artery (p<0.05). The hemodynamic energy, indicated by the energy equivalent pressure (EEP) was higher in the gastrointestinal tract and kidney in the pulsatile group (p<0.01, p<0.01). Abdominal organ perfusion status, as indicated by SvO 2 in the inferior vena cava, was higher in the pulsatile group (p<0.05) 30 min after cessation of CPB. Hemolysis indicated by release of free hemoglobin during CPB was similar in the two groups. CONCLUSION: Applying the pulsatile catheter pump in the descending aorta is effective in supplying the pulsatile flow to the abdominal organs and results in improved abdominal organ perfusion during the ischemic phase of CPB.

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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.

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OBJECTIVE: In the present study the relationship was evaluated between perioperative inflammation and the postoperative acute phase response in patients undergoing elective coronary artery bypass grafting (CABG) assisted by cardiopulmonary bypass (CPB). CPB circuits contained either non-coated- (UMS), Carmeda- (BPS) or Trillium-coated oxygenators (BAS). METHODS: Prospectively, 71 CABG patients were randomly allocated to one of the oxygenator groups (UMS: n=25, BPS: n=25 and BAS: n=21). Terminal complement complexes (TCC) and elastase were determined in plasma samples collected before, during and after bypass. Secretory phospholipase A2 (sPLA2) and C-reactive protein (CRP) were determined before and after bypass. RESULTS: Demographic, CPB and clinical outcome data were similar for the three groups. TCC and elastase increased during CPB, and decreased thereafter. Significant differences between the groups were present in the levels of TCC at the end of CPB (P=0.002) and at the first (P=0.012) and second (P<0.001) postoperative days, the BPS and BAS groups having reduced levels of TCC compared to the UMS group. Also elastase concentrations differed significantly between the groups at the end of CPB (P<0.001). The postoperative sPLA2 and CRP levels increased in all three groups on the first and second postoperative days, but no significant differences were present between the groups. CONCLUSIONS: Material-induced reduction of the inflammatory response during CPB does not affect the postoperative acute phase response. Thus, in CABG patients this response seems relatively unaffected by the composition and/or biocompatibility of the modern CPB circuit and rather to be evoked by surgical trauma, anesthetics and organ perfusion.

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During cardiopulmonary bypass (CPB) haemodynamic alterations, haemostasis and the inflammatory response are the main causes of homeostatic disruption. Even with CPB procedures of short duration, the homeostasis of a patient is disrupted and, in many cases, requires intensive postoperative treatment to re-establish the physiological state of the patient. Although mortality is low, disruption of homeostasis may contribute to increased morbidity, particularly in high-risk patients. Over the past decades, considerable technical improvements in CPB equipment have been made to prevent the development of the systemic inflammatory response syndrome (SIRS). Despite all these improvements, only the inflammatory response, to some extent, has been reduced. The microcirculation is still impaired, as measured by tissue degradation products of various organs, indicating that CPB may still be considered as an unphysiological procedure. The question is, therefore, whether we can detect the pathophysiological consequences of CPB in each individual patient with valid bedside markers, and whether we can relate this to determinant factors in the CPB procedure in order to assist the perfusionist in improving the adequacy of CPB. The use of these markers could play a pivotal role in decision making by providing an immediate feedback on the determinant quality of perfusion. Therefore, we suggest validating the proposed markers in a nomogram to optimize not only the CPB procedure, but also the patient's safety.

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BACKGROUND: In cardiac surgery with cardiopulmonary bypass (CPB), corticosteroids are administered to attenuate the physiological changes caused by the systemic inflammatory response. The effects of corticosteroids on CPB-associated renal damage have not been documented. The purpose of this study was to evaluate the effects of dexamethasone on perioperative renal dysfunction in patients undergoing cardiac surgery with CPB. METHODS: Renal damage was prospectively studied in 20 patients without concomitant morbidity undergoing coronary artery surgery with CPB. Patients were randomized in a double-blind fashion to receive dexamethasone or placebo. Markers of glomerular function (creatinine clearance) and damage (microalbuminuria), and markers of tubular function (fractional excretion of sodium and free water clearance) and damage (N-acetyl-beta-D glucosaminidase (NAG)) were evaluated in addition to plasma and urinary glucose levels. Plasma and urinary specimens were obtained at the following time periods: (1) baseline, during the 12 h before surgery; (2) skin incision before heparinization; (3) from heparinization until the end of CPB; (4) during the 2 h following weaning from CPB; (5) in the intensive care unit from 2 to 6 h after weaning of CBP; (6) and from 36 to 60 h after weaning of CPB. RESULTS: CPB was associated with an increase in markers in the placebo group, which returned to baseline during the second postoperative day, demonstrating a transient impairment of glomerular and tubular renal function. Similar patterns were observed in patients treated with dexamethasone. While postoperative glycosuria was significantly higher in the dexamethasone-treated group, no other differences between groups were observed. CONCLUSION: Dexamethasone administration before CPB has no protective effect on perioperative renal dysfunction in low-risk cardiac surgical patients.

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Not much is known about red cell aggregation during cardio-pulmonary bypass surgery (CPB). Blood samples from 19 patients undergoing CPB were anticoagulated with EDTA. Hematocrit was adjusted to 40%. A red blood cell aggregometer (LORCA) measured changes in light reflection from each blood sample after cessation of the rotation, and calculated an aggregation index (AI). Reflection measurements were stored. Because LORCA software failed for 87 of 171 samples, we developed new software, and applied it to the stored reflection measurements. This software failed only in 7 out of 171 cases and showed that all LORCA failures occurred for AI < 40%. The new calculations revealed that the aggregation index significantly decreased from 46.6 +/- 10.1 (mean +/- standard deviation) baseline to 22.8 +/- 8.3 at the end of CPB and recovered to 37.1 +/- 13.5 at day 1. It is concluded that the new software can be used to study decreased red cell aggregation during CPB.

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UNLABELLED: Reduction of the inflammatory reaction with the use of heparin coating has been found during and after cardiopulmonary bypass (CPB). The question remains whether this reduced reaction also decreases the magnitude of CPB-induced pulmonary dysfunction. We therefore evaluated the effects of a heparin-coated circuit versus a similar uncoated circuit on pulmonary indices as well as on inflammatory markers of complement activation (C3b/c), elastase-alpha(1)-antitrypsin complex, and secretory phospholipase A(2) (sPLA(2)) during and after CPB. Fifty-one patients were randomly assigned into two groups undergoing coronary artery bypass grafting with either a heparin-coated (Group 1) or an uncoated (Group 2) circuit. During CPB, a continuous positive airway pressure of 5 cm H(2)O and a fraction of inspired oxygen (FIO(2)) of 0.21 were maintained. Differences in favor of the coated circuit were found in pulmonary shunt fraction (P < 0.05), pulmonary vascular resistance index (P < 0.05), and PaO(2)/FIO(2) ratio (P < 0.05) after CPB and in the intensive care unit. During and after CPB, the coated group demonstrated lower levels of sPLA(2). After CPB, C3b/c and the elastase-alpha(1)-antitrypsin complex were significantly less in the coated group (P < 0.001). The coated circuit was associated with a reduced inflammatory response, decreased pulmonary vascular resistance index and pulmonary shunt fraction, and increased PaO(2)/FIO(2) ratio, suggesting that the coated circuit may have beneficial effects on pulmonary function. The correlation with sPLA(2), leukocyte activation, and postoperative leukocyte count suggests reduced activation of pulmonary capillary endothelial cells. IMPLICATIONS: Heparin coating of the extracorporeal circuit reduces the inflammatory response during cardiopulmonary bypass. Analysis of indices of pulmonary function indicates that use of heparin coating may result in less impaired gas exchange.

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BACKGROUND AND AIM: Controversial reports have been published about the efficiency of potent platelet inhibitors in patients with coronary artery syndrome (CAS). We therefore questioned whether a functional change in platelets affects the patient's response to ASA. STUDY DESIGN AND METHODS: Nineteen consecutive patients presenting with unstable coronary syndrome and 15 healthy volunteers were included. No platelet inhibitory drugs or coumarin were used in either group before the study. Platelet aggregation tests were performed on baseline samples and after a single dose of ASA. Afterwards, all patients underwent coronary angiography to exclude non-CAS. RESULTS: In the patient group (n=15 after exclusion) no significant increase in bleeding constant was found after ASA, using a PFA analyser, in contrast to the control group. The maximal velocity and the maximal percentage optical platelet aggregation using ADP was significantly more reduced in the control group. ASA did not significantly reduce the thromboxane B2 production in the patient group. CONCLUSION: ASA has less platelet inhibitory effects in patients with unstable CAS in comparison with healthy volunteers. Platelets, in the hyperactive state of unstable CAS, prove to be less subject to inhibition. This might add to the explanation of the lack of efficiency of platelet inhibitory drugs to prevent thrombotic complications after PTCA and platelet aggregation onto stent surfaces in patients with acute CAS.

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In this review, we hypothesise that, next to biocompatibility, optimal blood compatibility depends on a combination of biomaterials wettability and the shear stress prevailing in the device. The wettability is discussed in seven different categories of devices, that differ substantially from each other with regard to shear stress and exposure time. These seven categories are stents, prosthetic heart valves, vascular prostheses, cardiopulmonary bypass, hemodialysis, vena cava filters and blood bags. In high shear applications, in combination with blood activation, platelet deposition and thrombosis appear to be major problems and platelet inhibitors are most effective. Exposure of blood to a large biomaterial surface, with or without antithrombotic coating, results in reduction of platelet function. Material-independent activation aggravates this process. In low shear applications, platelets only seem supportive for coagulation and anticoagulants should be used.

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