Endothelial hyperpermeability after cardiac surgery with cardiopulmonary bypass as assessed using an in vitro bioassay for endothelial barrier function  N.J. Koning, M.A.H. Overmars, C.E. van den Brom, J. van Bezu, L.E. Simon, A.B.A. Vonk, A.R.J. Girbes, G.P. van Nieuw Amerongen, C. Boer  British Journal of Anaesthesia  Volume 116, Issue 2, Pages 223-232 (February 2016) DOI: 10.1093/bja/aev411 Copyright © 2016 The Author(s) Terms and Conditions

Fig 1 Electric cell–substrate impedance sensing (ECIS). (a) Schematic representation of ECIS. Two endothelial cells are connected by cell–cell junctions and attached to the extracellular matrix by cell–matric connections. The ECIS measurements provide overall information on endothelial barrier function (resistance), which can be separated into a component for cell–cell binding (Rb) and a component for cell–matrix binding (α). Increases in resistance, Rb, and α indicate enhanced endothelial barrier function. (b) A typical example of the overall resistance during exposure of endothelial cells to plasma derived from a patient at baseline (pre-CPB), after cardiopulmonary bypass (post-CPB), and upon intensive care unit (ICU) admission. After a 30 min exposure of the endothelial cells to 1% human serum albumin (has), plasma is added, which induces a transient increase in resistance (point A), followed by a steady state (point B). The steady-state values were further used to define the effect of CPB on endothelial barrier function in patient groups with non-pulsatile and pulsatile blood flow. British Journal of Anaesthesia 2016 116, 223-232DOI: (10.1093/bja/aev411) Copyright © 2016 The Author(s) Terms and Conditions

Fig 2 Non-pulsatile and pulsatile arterial blood pressure waveform. Typical examples of radial arterial blood pressure waveforms during cardiopulmonary bypass with non-pulsatile flow (a) and pulsatile flow (b). British Journal of Anaesthesia 2016 116, 223-232DOI: (10.1093/bja/aev411) Copyright © 2016 The Author(s) Terms and Conditions

Fig 3 Plasma concentrations of vascular mediators. Changes in the vascular mediators P-selectin (a), intercellular cell adhesion molecule-1 (ICAM-1; b), vascular cell adhesion molecule-1 (VCAM-1; c), von Willebrand factor (vWF; d), and vascular endothelial growth factor (VEGF; e) in patients before (pre-CPB) and after cardiopulmonary bypass (post-CPB) and upon intensive care unit (ICU) admission. #P<0.001 vs pre-CPB values in non-pulsatile flow group; *P<0.001 vs pre-CPB values in pulsatile flow group. British Journal of Anaesthesia 2016 116, 223-232DOI: (10.1093/bja/aev411) Copyright © 2016 The Author(s) Terms and Conditions

Fig 4 Plasma concentrations of soluble Tie2 and angiopoietin-1 and -2. Changes in soluble Tie2 (sTie2; a), angiopoietin-1 (Ang-1; b), and angiopoietin-2 (Ang-2; c) and the Ang-2/Ang-1 ratio (d) in patients before (pre-CPB) and after cardiopulmonary bypass (post-CPB) and upon intensive care unit (ICU) admission. #P<0.001 vs pre-CPB values in non-pulsatile flow group; *P<0.001 vs pre-CPB values in pulsatile flow group. British Journal of Anaesthesia 2016 116, 223-232DOI: (10.1093/bja/aev411) Copyright © 2016 The Author(s) Terms and Conditions

Fig 5 Endothelial barrier function. Endothelial barrier function is represented as overall resistance (a), cell–cell interaction (Rb; b), and cell–matrix interaction (α; c) before cardiopulmonary bypass (pre-CPB) and cardiopulmonary bypass (post-CPB) and upon intensive care unit (ICU) admission in non-pulsatile (filled circles) and pulsatile (open circles) flow groups. #P<0.001 vs pre-CPB values in non-pulsatile flow group; *P<0.001 vs pre-CPB values in pulsatile flow group. British Journal of Anaesthesia 2016 116, 223-232DOI: (10.1093/bja/aev411) Copyright © 2016 The Author(s) Terms and Conditions

Fig 6 Effect of haemodilution on endothelial barrier function. Changes in resistance after exposure of endothelial cells to different concentrations of plasma, derived before or after cardiopulmonary bypass, and 1% HSA medium. The figure shows five different dilutions of plasma in the medium to which the cells were exposed: two dilutions of the pre-CPB sample (5× and 10× dilution) and three dilutions of the post-CPB sample (3.3×, 5×, and 10× dilution). A control sample of 1% HSA medium was used as the negative control. Resistances are averaged values of duplicate measurements. British Journal of Anaesthesia 2016 116, 223-232DOI: (10.1093/bja/aev411) Copyright © 2016 The Author(s) Terms and Conditions