References of "LAMBERMONT, Bernard"
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See detailAlgorithmic Processing of Pressure Waveforms to FacilitateEstimation of Cardiac Elastance
Stevenson, D.; Revie, J.; Chase, J. G. et al

in BioMedical Engineering OnLine (2012), 11

Introduction: Cardiac elastances are highly invasive to measure directly, but are clinically useful due tothe amount of information embedded in them. Information about the cardiac elastance, which can be ... [more ▼]

Introduction: Cardiac elastances are highly invasive to measure directly, but are clinically useful due tothe amount of information embedded in them. Information about the cardiac elastance, which can be used toestimate it, can be found in the downstream pressure waveforms of aortic pressure (Pao) and the pulmonaryartery (Ppa). However these pressure waveforms are typically noisy and biased, and require processing in orderto locate the specific information required for the cardiac elastance estimation. This paper presents the methodto algorithmically process the pressure waveforms. Methods: A shear transform is developed in order to helplocate information in the pressure waveforms. This transform turns difficult to locate corners into easy to locatemaximum or minimum points as well as providing error correction. Results: The method located all points 87out of 88 waveforms for Ppa to within the sampling frequency. For Pao, out of 616 total points, 605 were foundwithin 1%, 5 within 5%, 4 within 10% and 2 within 20%. Conclusions: The presented method provides arobust, accurate and dysfunction independent way to locate points on the aortic and pulmonary artery pressurewaveforms, allowing the non-invasive estimation of the left and right cardiac elastance. [less ▲]

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See detailComputer-based monitoring of global cardiovascular dynamics during acute pulmonary embolism and septic shock in swine
Revie, JA; Stevenson, D; Chase, JG et al

in Critical Care (2012), 16 (Suppl 1)

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See detailProcalcitonin usefulness for the initiation of antibiotic treatment in intensive care unit patients.
LAYIOS, Nathalie ULg; LAMBERMONT, Bernard ULg; CANIVET, Jean-Luc ULg et al

in Critical Care Medicine (2012), 40(8), 2304-9

OBJECTIVES: : To test the usefulness of procalcitonin serum level for the reduction of antibiotic consumption in intensive care unit patients. DESIGN: : Single-center, prospective, randomized controlled ... [more ▼]

OBJECTIVES: : To test the usefulness of procalcitonin serum level for the reduction of antibiotic consumption in intensive care unit patients. DESIGN: : Single-center, prospective, randomized controlled study. SETTING: : Five intensive care units from a tertiary teaching hospital. PATIENTS: : All consecutive adult patients hospitalized for > 48 hrs in the intensive care unit during a 9-month period. INTERVENTIONS: : Procalcitonin serum level was obtained for all consecutive patients suspected of developing infection either on admission or during intensive care unit stay. The use of antibiotics was more or less strongly discouraged or recommended according to the Muller classification. Patients were randomized into two groups: one using the procalcitonin results (procalcitonin group) and one being blinded to the procalcitonin results (control group). The primary end point was the reduction of antibiotic use expressed as a proportion of treatment days and of daily defined dose per 100 intensive care unit days using a procalcitonin-guided approach. Secondary end points included: a posteriori assessment of the accuracy of the infectious diagnosis when using procalcitonin in the intensive care unit and of the diagnostic concordance between the intensive care unit physician and the infectious-disease specialist. MEASUREMENTS AND MAIN RESULTS: : There were 258 patients in the procalcitonin group and 251 patients in the control group. A significantly higher amount of withheld treatment was observed in the procalcitonin group of patients classified by the intensive care unit clinicians as having possible infection. This, however, did not result in a reduction of antibiotic consumption. The treatment days represented 62.6 +/- 34.4% and 57.7 +/- 34.4% of the intensive care unit stays in the procalcitonin and control groups, respectively (p = .11). According to the infectious-disease specialist, 33.8% of the cases in which no infection was confirmed, had a procalcitonin value >1microg/L and 14.9% of the cases with confirmed infection had procalcitonin levels <0.25 microg/L. The ability of procalcitonin to differentiate between certain or probable infection and possible or no infection, upon initiation of antibiotic treatment was low, as confirmed by the receiving operating curve analysis (area under the curve = 0.69). Finally, procalcitonin did not help improve concordance between the diagnostic confidence of the infectious-disease specialist and the ICU physician. CONCLUSIONS: : Procalcitonin measuring for the initiation of antimicrobials did not appear to be helpful in a strategy aiming at decreasing the antibiotic consumption in intensive care unit patients. [less ▲]

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See detailArterial dP/dtmax accurately reflects left ventricular contractility during shock when adequate vascular filling is achieved
MORIMONT, Philippe ULg; LAMBERMONT, Bernard ULg; Desaive, Thomas ULg et al

in BMC Cardiovascular Disorders (2012), 12:13

Background: Peak first derivative of femoral artery pressure (arterial dP/dt max) derived from fluid-filled catheter remains questionable to assess left ventricular (LV) contractility during shock. The ... [more ▼]

Background: Peak first derivative of femoral artery pressure (arterial dP/dt max) derived from fluid-filled catheter remains questionable to assess left ventricular (LV) contractility during shock. The aim of this study was to test if arterial dP/dt maxis reliable for assessing LV contractility during various hemodynamic conditions such as endotoxin-induced shock and catecholamine infusion.Methods: Ventricular pressure-volume data obtained with a conductance catheter and invasive arterial pressure obtained with a fluid-filled catheter were continuously recorded in 6 anaesthetized and mechanically ventilated pigs. After a stabilization period, endotoxin was infused to induce shock. Catecholamines were transiently administrated during shock. Arterial dP/dt maxwas compared to end-systolic elastance (Ees), the gold standard method for assessing LV contractility.Results: Endotoxin-induced shock and catecholamine infusion lead to significant variations in LV contractility. Overall, significant correlation (r = 0.51; p < 0.001) but low agreement between the two methods were observed. However, a far better correlation with a good agreement were observed when positive-pressure ventilation induced an arterial pulse pressure variation (PPV) ≤ 11% (r = 0.77; p < 0.001).Conclusion: While arterial dP/dt maxand Ees were significantly correlated during various hemodynamic conditions, arterial dP/dt maxwas more accurate for assessing LV contractility when adequate vascular filling, defined as PPV ≤ 11%, was achieved. © 2012 Morimont et al; licensee BioMed Central Ltd. [less ▲]

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See detailInterventricular septal rupture caused by vehicular trauma
ROBINET, Sébastien ULg; MORIMONT, Philippe ULg; LAMBERMONT, Bernard ULg et al

in Heart & Lung (2012), 41(2), 200-202

We report the case of a patient admitted at the emergency unit after a severe car accident. As ECG showed a ST segment elevation in all leads, the working diagnosis was coronary dissection. Coronary ... [more ▼]

We report the case of a patient admitted at the emergency unit after a severe car accident. As ECG showed a ST segment elevation in all leads, the working diagnosis was coronary dissection. Coronary angiography revealed a large interventricular septal rupture, confirmed by echocardiography. After discussion and as haemodynamics permitted, 6 weeks of medical observation were decided. A surgical repair was then performed, and provided a perfect repair of the shunt. We discuss about the prevalence and management of this rare traumatic complication. [less ▲]

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See detailPhysiological relevance and performance of a minimal lung model -- an experimental study in healthy and acute respiratory distress syndrome model piglets
Chiew, Y. S.; Chase, J. G.; LAMBERMONT, Bernard ULg et al

in BMC Pulmonary Medicine (2012), 12:59

Background: Mechanical ventilation (MV) is the primary form of support for acute respiratory distress syndrome (ARDS) patients. However, intra- and inter- patient-variability reduce the efficacy of ... [more ▼]

Background: Mechanical ventilation (MV) is the primary form of support for acute respiratory distress syndrome (ARDS) patients. However, intra- and inter- patient-variability reduce the efficacy of general protocols. Model-based approaches to guide MV can be patient-specific. A physiological relevant minimal model and its patient-specific performance are tested to see if it meets this objective above. Methods: Healthy anesthetized piglets weighing 24.0 kg [IQR: 21.0-29.6] underwent a step-wise PEEP increase manoeuvre from 5cmH2O to 20cmH2O. They were ventilated under volume control using Engstrom Care Station (Datex, General Electric, Finland), with pressure, flow and volume profiles recorded. ARDS was then induced using oleic acid. The data were analyzed with a Minimal Model that identifies patient-specific mean threshold opening and closing pressure (TOP and TCP), and standard deviation (SD) of these TOP and TCP distributions. The trial and use of data were approved by the Ethics Committee of the Medical Faculty of the University of Liege, Belgium.Results and discussions3 of the 9 healthy piglets developed ARDS, and these data sets were included in this study. Model fitting error during inflation and deflation, in healthy or ARDS state is less than 5.0% across all subjects, indicating that the model captures the fundamental lung mechanics during PEEP increase. Mean TOP was 42.4cmH2O [IQR: 38.2-44.6] at PEEP = 5cmH2O and decreased with PEEP to 25.0cmH2O [IQR: 21.5-27.1] at PEEP = 20cmH2O. In contrast, TCP sees a reverse trend, increasing from 10.2cmH2O [IQR: 9.0-10.4] to 19.5cmH2O [IQR: 19.0-19.7]. Mean TOP increased from average 21.2-37.4cmH2O to 30.4-55.2cmH2O between healthy and ARDS subjects, reflecting the higher pressure required to recruit collapsed alveoli. Mean TCP was effectively unchanged. Conclusion: The minimal model is capable of capturing physiologically relevant TOP, TCP and SD of both healthy and ARDS lungs. The model is able to track disease progression and the response to treatment. [less ▲]

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See detailLe débit de filtration glomérulaire est-il un déterminant de la concentration plasmatique du NGAL aux soins intensifs ?
DELANAYE, Pierre ULg; Claisse, Guillaume; Mehdi, Manoli et al

Poster (2012)

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See detailPhysiological Relevance of a Minimal Model in Healthy Pigs Lungs
Chiew, YS; Desaive, Thomas ULg; LAMBERMONT, Bernard ULg et al

in Proceedings of BMS 2012 (2012)

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See detailPerformance of lung recruitment model in healthy anesthetised pigs
Chiew, YS; LAMBERMONT, Bernard ULg; JANSSEN, Nathalie ULg et al

in Proceedings of the World Congress on Medical Physics and Biomedical Engineering 2012 (2012)

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See detailRange90 as indicator for ventilator output versus patients demand: NAVA and pressure support for non-invasively ventilated patients
Chiew, YS; Piquilloud, L.; LAMBERMONT, Bernard ULg et al

in Proceedings of the World Congress on Medical Physics and Biomedical Engineering 2012 (2012)

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See detailEstimating afterload, systemic vascular resistance and pulmonary vascular resistance in an intensive care setting
Stevenson, D; Revie, J.; Chase, JG et al

in Proceedings of BMS2012 (2012)

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See detailCardiovascular modelling and the Intensive Care Unit clinician
Desaive, Thomas ULg; LAMBERMONT, Bernard ULg; Kolh, Philippe ULg et al

in Proceedings of BMS 2012 (2012)

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See detailModel-based Monitoring of Septic Shock Treated with Large-Pore Hemofiltration Therapy
Revie; Stevenson, D; Chase, JG et al

in Proceedings of BMS 2012 (2012)

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See detailAnalysis of Aortic Energetics from Pulse Wave Examination in a Porcine Study of Septic Shock
Revie, JA; Stevenson, D; Chase, JG et al

in Prceedings of BMS 2012 (2012)

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See detailStructural model of the mitral valve included in a cardiovascular closed loop model
Paeme, Sabine ULg; Moorhead, Kate; Chase, J. Geoffrey et al

Poster (2011, December)

A minimal cardiovascular system (CVS) model including mitral valve dynamics has been previously validated in silico. However parameters of this model are difficult to link with structural and anatomical ... [more ▼]

A minimal cardiovascular system (CVS) model including mitral valve dynamics has been previously validated in silico. However parameters of this model are difficult to link with structural and anatomical components of the valve. This research describes the integration of a structural model of the mitral valve in an existing closed-loop cardiovascular system (CVS) model [less ▲]

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See detailMathematical multi-scale model of the cardiovascular system including mitral valve dynamics. Application to ischemic mitral insufficiency
Paeme, Sabine ULg; Moorhead, Katherine; Chase, J. Geoffrey et al

in BioMedical Engineering OnLine (2011), 10(1), 86

Valve dysfunction is a common cardiovascular pathology. Despite significant clinical research, there is little formal study of how valve dysfunction affects overall circulatory dynamics. Validated models ... [more ▼]

Valve dysfunction is a common cardiovascular pathology. Despite significant clinical research, there is little formal study of how valve dysfunction affects overall circulatory dynamics. Validated models would offer the ability to better understand these dynamics and thus optimize diagnosis, as well as surgical and other interventions. A cardiovascular and circulatory system (CVS) model has already been validated in silico, and in several animal model studies. It accounts for valve dynamics using Heaviside functions to simulate a physiologically accurate “open on pressure, close on flow” law. However, it does not consider real-time valve opening dynamics and therefore does not fully capture valve dysfunction, particularly where the dysfunction involves partial closure. This research describes an updated version of this previous closed-loop CVS model that includes the progressive opening of the mitral valve, and is defined over the full cardiac cycle. Simulations of the cardiovascular system with healthy mitral valve are performed, and, the global hemodynamic behaviour is studied compared with previously validated results. The error between resulting pressure-volume (PV) loops of already validated CVS model and the new CVS model that includes the progressive opening of the mitral valve is assessed and remains within typical measurement error and variability. Simulations of ischemic mitral insufficiency are also performed. Pressure-Volume loops, transmitral flow evolution and mitral valve aperture area evolution follow reported measurements in shape, amplitude and trends. The resulting cardiovascular system model including mitral valve dynamics provides a foundation for clinical validation and the study of valvular dysfunction in vivo. The overall models and results could readily be generalised to other cardiac valves. [less ▲]

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See detailMinimal cardiovascular system model including a physiological description of progressive mitral valve orifice dynamics for studying valve dysfunction
Paeme, Sabine ULg; Moorhead, Katerine; Chase, J. Geoffrey et al

in XXIIIrd congress of the International Society of Biomechanics, July 3-7, 2011 (2011, July)

This research presents a new closed-loop cardiovascular system model including a description of the progressive opening and closing dynamic of the mitral valve. Furthermore, this model includes a ... [more ▼]

This research presents a new closed-loop cardiovascular system model including a description of the progressive opening and closing dynamic of the mitral valve. Furthermore, this model includes a mathematical description of the left atrium. This new CVS model enables the study of valve dysfunction in the appropriate clinical context of the overall cardiac and circulatory hemodynamics. [less ▲]

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See detailEFFECTS OF LARGE PORE HEMOFILTRATION IN A SWINE MODEL OF FULMINANT HEPATIC FAILURE
DETRY, Olivier ULg; JANSSEN, Nathalie ULg; CHERAMY-BIEN, Jean-Paul ULg et al

in Transplant International (2011, February), 24(1), 10-10

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