Multimodality blood conservation strategy in cardiac surgery with cardiopulmonary bypass : the CHU of Liège experience

Poster (2012, September 29)

Introduction: The aim of this study is to analyze the transfusion rates of cardiac surgery patients in a single centre following an in-house strategy of blood conservation. Methods: The data of all adult ... [more ▼]

Introduction: The aim of this study is to analyze the transfusion rates of cardiac surgery patients in a single centre following an in-house strategy of blood conservation. Methods: The data of all adult patients undergoing normothermic cardiac surgery with cardiopulmonary bypass (CPB) over a 1 year period were retrospectively collected (n=491). Management protocols were described. The transfusion rates of allogeneic blood components were recorded: red blood cells (RBC), fresh frozen plasma (FFP) and platelets (PT), as well as the number of units transfused. The timing of transfusion was categorized: during CPB (peroperative period), within the first 48 postoperative hours after wean out CPB (early postoperative period) and during the hospitalisation from surgery until discharge (hospitalisation). The hematocrit values were recorded during CPB, 10 minutes after wean out CPB, after the first 48 postoperative hours and at discharge from hospital. Results: Two hundred and forty-eight patients (50%) received an allogeneic blood component transfusion during hospitalisation. One hundred and twenty-one patients (25%) received RBC during the operative period; the median of units transfused was 2(1-2).The lowest hematocrit value during CPB was 21(19-24) % in median. A cell salvage device was used in each case: the median volume of washed red blood cells transfused was 678(512-891) mL. The median hematocrit value after CPB was 23(21-25) %. One hundred and sixty-five patients (34%) were transfused in the early postoperative period: 27% received RBC, 18% received FFP and 18% received PT. The median of units transfused was 2(1-3) for RBC, 4(2-6) for FFP and 1(1-2) for PT. The median hematocrit value after 48 hours was 32(29-34) % and 32(30-35) % at discharge. Conclusion: The transfusion rates observed in this series are relatively high compared with the literature. Improvements will be made in our practice and protocols management in order to decrease the need of transfusion. This detailed audit of the transfusion practices in our cardiac surgery centre would be helpful to value the effectiveness of further improvements. [less ▲]

Multimodular Penicillin-Binding Proteins: An Enigmatic Family of Orthologs and Paralogs

in Microbiology & Molecular Biology Reviews (1998), 62(4), 1079-1093

The monofunctional penicillin-binding DD-peptidases and penicillin-hydrolyzing serine beta-lactamases diverged from a common ancestor by the acquisition of structural changes in the polypeptide chain ... [more ▼]

The monofunctional penicillin-binding DD-peptidases and penicillin-hydrolyzing serine beta-lactamases diverged from a common ancestor by the acquisition of structural changes in the polypeptide chain while retaining the same folding, three-motif amino acid sequence signature, serine-assisted catalytic mechanism, and active-site topology. Fusion events gave rise to multimodular penicillin-binding proteins (PBPs). The acyl serine transferase penicillin-binding (PB) module possesses the three active-site defining motifs of the superfamily; it is linked to the carboxy end of a non-penicillin-binding (n-PB) module through a conserved fusion site; the two modules form a single polypeptide chain which folds on the exterior of the plasma membrane and is anchored by a transmembrane spanner; and the full-size PBPs cluster into two classes, A and B. In the class A PBPs, the n-PB modules are a continuum of diverging sequences; they possess a five-motif amino acid sequence signature, and conserved dicarboxylic amino acid residues are probably elements of the glycosyl transferase catalytic center. The PB modules fall into five subclasses: A1 and A2 in gram-negative bacteria and A3, A4, and A5 in gram-positive bacteria. The full-size class A PBPs combine the required enzymatic activities for peptidoglycan assembly from lipid-transported disaccharide-peptide units and almost certainly prescribe different, PB-module specific traits in peptidoglycan cross-linking. In the class B PBPs, the PB and n-PB modules cluster in a concerted manner. A PB module of subclass B2 or B3 is linked to an n-PB module of subclass B2 or B3 in gram-negative bacteria, and a PB module of subclass B1, B4, or B5 is linked to an n-PB module of subclass B1, B4, or B5 in gram-positive bacteria. Class B PBPs are involved in cell morphogenesis. The three motifs borne by the n-PB modules are probably sites for module-module interaction and the polypeptide stretches which extend between motifs 1 and 2 are sites for protein-protein interaction. The full-size class B PBPs are an assortment of orthologs and paralogs, which prescribe traits as complex as wall expansion and septum formation. PBPs of subclass B1 are unique to gram-positive bacteria. They are not essential, but they represent an important mechanism of resistance to penicillin among the enterococci and staphylococci. Natural evolution and PBP- and beta-lactamase-mediated resistance show that the ability of the catalytic centers to adapt their properties to new situations is limitless. Studies of the reaction pathways by using the methods of quantum chemistry suggest that resistance to penicillin is a road of no return. [less ▲]

MULTIOBJECTIVE DESIGN OF CONTROL CHARTS

in International Conference on Applied Statistics 2011 : Ljubljana 24-29 September 2011 (2011, September 24)

Multiparametric observations and analysis in the Bay of Calvi (Corsica), an ideal site for studying the human activity effects and climate changes in the Mediterranean Sea; STARESO

Conference (2010, May)

STARESO (Station de REcherche Sous marine et Océanographique) is the marine and oceanographic research station of the University of Liège (Belgium) managed by the French company STARESO S.A.. Constructed ... [more ▼]

STARESO (Station de REcherche Sous marine et Océanographique) is the marine and oceanographic research station of the University of Liège (Belgium) managed by the French company STARESO S.A.. Constructed in 1969, it is located near Calvi (Corsica, Western Mediterranean Sea) in an oligotrophic area chosen for the exceptional quality of its coastal waters STARESO offers to the oceanographers, by diving or with boats, a direct access to the sea. The variety of the accessible ecosystems is remarkable and unique in the Mediterranean basin: -the Bay of Calvi is characterized by healthy and very diverse biocenosis (e.g. Posidonia meadows, rocky and sandy communities, -a steep submarine canyon, with depths greater than 1 000 meters, is accessible in 15 minutes of navigation; -the Liguro-Provençal front, a major hydrologic structure, is situated between 10 and 15 miles of the coast. STARESO is accessible all the year for everybody and is functioning like an oceanographic research vessel. The Station is a platform for all oceanographic disciplines with a scientific expertise widely based on a long tradition of interdisciplinary work, and a direct access to time series of physical, chemical and biological data registered with automated systems and variety of sensors deployed in the Bay of Calvi since 30 years. This platform provides the opportunity to reach coastal, pelagic, benthic, deep systems with a manageable cost and ship requirements in a pristine zone. [less ▲]

Multipartite entanglement criterion from uncertainty relations

Poster (2009)

Multiperiod vehicle loading optimization with stochastic supply

Scientific conference (2011, April 07)

A Multiphase Model for the Transport of Dispersed Phases in Environmental Flows: Theoretical Contribution

in European Journal of Mechanical and Environmental Engineering (2010), 3

Multiphase time dependent compression behaviour of two chalks

Conference (2005)

In this paper, the multiphase time dependent compression behaviour of two chalks are considered within a fully coupled general hydro-mechanical framework derived from the mechanics of unsaturated soil. In ... [more ▼]

In this paper, the multiphase time dependent compression behaviour of two chalks are considered within a fully coupled general hydro-mechanical framework derived from the mechanics of unsaturated soil. In the former case, reservoir chalks contain oil and water and subsidence appeared once enhanced oil recovery by waterflooding started. In the latter case, water saturated chalk is periodically desaturated by water evaporation, resulting in air penetration. In this paper, the fluid retention curves of both samples are determined and the data obtained are used in the interpretation of suction controlled compression tests where time effects appear to be significant. The experimental data obtained show the relevance of the approach adopted. [less ▲]

Multiphysic topology optimization of electromechanical micro-actuators considering pull-in effect

in Proceedings of the IVth European Conference on Computational Mechanics (ECCM 2010) (2010)

Multiphysics modeling and optimization of mechatronic multibody systems

in Multibody System Dynamics (2007), 18(3), 345-373

Modeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are ... [more ▼]

Modeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are currently proposed to deal with multiphysics modeling, e.g., graph theories, equational approaches, co-simulation techniques. Recent works have pointed out their relative advantages and drawbacks, depending on the application to deal with: model size, model complexity, degree of coupling, frequency range, etc. This paper is the result of a close collaboration between three laboratories, and aims at showing that for "non-academic" mechatronic applications (i.e., issuing from real industrial issues), multibody dynamics formulations can be generalized to mechatronic systems, for the model generation as well as for the numerical analysis phases. Model portability being also an important aspect of the work, they must be easily interfaced with control design and optimization programs. A global "demonstrator", based on an industrial case, is discussed: multiphysics modeling and mathematical optimization are carried out to illustrate the consistency and the efficiency of the proposed approaches. [less ▲]