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Featured researches published by Koen Ameloot.


Hepatology | 2013

Embolization of large spontaneous portosystemic shunts for refractory hepatic encephalopathy: A multicenter survey on safety and efficacy

Wim Laleman; Macarena Simón-Talero; Geert Maleux; Mercedes Pérez; Koen Ameloot; Germán Soriano; Jordi Villalba; Juan Carlos García-Pagán; Marta Barrufet; Rajiv Jalan; Jocelyn A.S. Brookes; Evangelos Thalassinos; Andrew K. Burroughs; Juan Córdoba; Frederik Nevens

Refractory hepatic encephalopathy (HE) remains a major cause of morbidity in cirrhosis patients. Large spontaneous portosystemic shunts (SPSSs) have been previously suggested to sustain HE in these patients. We aimed to retrospectively assess the efficacy and safety of patients treated with embolization of large SPSSs for the treatment of chronic therapy‐refractory HE in a European multicentric working group and to identify patients who may benefit from this procedure. Between July 1998 and January 2012, 37 patients (Child A6‐C13, MELD [Model of Endstage Liver Disease] 5‐28) with refractory HE were diagnosed with single large SPSSs that were considered eligible for embolization. On a short‐term basis (i.e., within 100 days after embolization), 22 out of 37 patients (59.4%) were free of HE (P < 0.001 versus before embolization) of which 18 (48.6% of patients overall) remained HE‐free over a mean follow‐up period of 697 ± 157 days (P < 0.001 versus before embolization). Overall, we noted improved autonomy, decreased number of hospitalizations, and severity of the worst HE episode after embolization in three‐quarters of the patients. Logistic regression identified the MELD score as strongest positive predictive factor of HE recurrence with a cutoff of 11 for patient selection. As to safety, we noted one major nonlethal procedure‐related complication. There was no significant increase in de novo development or aggravation of preexisting varices, portal hypertensive gastropathy, or ascites. Conclusion: This multicenter European cohort study demonstrated a role for large SPSSs in chronic protracted or recurrent HE and substantiated the effectiveness and safety of embolization of these shunts, provided there is sufficient functional liver reserve. (HEPATOLOGY 2013;57:2448–2457)


The Scientific World Journal | 2013

Nexfin noninvasive continuous hemodynamic monitoring: validation against continuous pulse contour and intermittent transpulmonary thermodilution derived cardiac output in critically ill patients.

Koen Ameloot; Katrijn Van De Vijver; Ole Broch; Niels Van Regenmortel; Inneke De laet; Karen Schoonheydt; Hilde Dits; Berthold Bein; Manu L.N.G. Malbrain

Introduction. Nexfin (Bmeye, Amsterdam, Netherlands) is a noninvasive cardiac output (CO) monitor based on finger arterial pulse contour analysis. The aim of this study was to validate Nexfin CO (NexCO) against thermodilution (TDCO) and pulse contour CO (CCO) by PiCCO (Pulsion Medical Systems, Munich, Germany). Patients and Methods. In a mix of critically ill patients (n = 45), NexCO and CCO were measured continuously and recorded at 2-hour intervals during the 8-hour study period. TDCO was measured at 0–4–8 hrs. Results. NexCO showed a moderate to good (significant) correlation with TDCO (R 2 0.68, P < 0.001) and CCO (R 2 0.71, P < 0.001). Bland and Altman analysis comparing NexCO with TDCO revealed a bias (± limits of agreement, LA) of 0.4 ± 2.32 L/min (with 36% error) while analysis comparing NexCO with CCO showed a bias (±LA) of 0.2 ± 2.32 L/min (37% error). NexCO is able to follow changes in TDCO and CCO during the same time interval (level of concordance 89.3% and 81%). Finally, polar plot analysis showed that trending capabilities were acceptable when changes in NexCO (ΔNexCO) were compared to ΔTDCO and ΔCCO (resp., 89% and 88.9% of changes were within the level of 10% limits of agreement). Conclusion. we found a moderate to good correlation between CO measurements obtained with Nexfin and PiCCO.


Current Opinion in Critical Care | 2015

The accuracy of noninvasive cardiac output and pressure measurements with finger cuff: a concise review.

Koen Ameloot; Pieter-Jan Palmers; Manu L.N.G. Malbrain

Purpose of reviewThe present review aims to summarize literature on the accuracy of the finger cuff method to measure cardiac output (CO) and blood pressure, its ability to track hemodynamic changes, and to predict fluid responsiveness. Recent findingsFinger cuff is an easy-to-use hemodynamic monitoring technique. Different devices are currently available, which provide continuous arterial blood pressure (Finapress), whereas only ClearSight (previously known as Nexfin; BMEYE) provides an estimate of CO. In most studies, the criteria for clinical interchangeability (for CO) were not met, when compared with the currently used invasive monitoring systems such as uncalibrated CO via a radial artery line, and calibrated CO either via a pulmonary artery catheter or a femoral artery catheter connected to the PiCCO (Pulsion Medical Systems) or VolumeView (Edwards Lifesciences) devices. In particular, ClearSight obtained CO seems to be less accurate in patients with a low CO. However, in most patients, ClearSight is able to track hemodynamic changes induced by a fluid challenge or passive leg raising test. We will discuss in this review the relevant literature with regard to validation of the finger cuff technique for both arterial blood pressure and CO. SummaryThe finger cuff method provides a reasonable estimate of CO and blood pressure, which does not meet the criteria for clinical interchangeability with the currently used invasive devices.


Resuscitation | 2015

Hemodynamic targets during therapeutic hypothermia after cardiac arrest: A prospective observational study ☆

Koen Ameloot; Ingrid Meex; Cornelia Genbrugge; Frank Jans; Willem Boer; David Verhaert; Wilfried Mullens; Bert Ferdinande; Matthias Dupont; C. De Deyne; J. Dens

AIM In analogy with sepsis, current post-cardiac arrest (CA) guidelines recommend to target mean arterial pressure (MAP) above 65 mmHg and SVO2 above 70%. This is unsupported by mortality or cerebral perfusion data. The aim of this study was to explore the associations between MAP, SVO2, cerebral oxygenation and survival. METHODS Prospective, observational study during therapeutic hypothermia (24h - 33 °C) in 82 post-CA patients monitored with near-infrared spectroscopy. RESULTS Forty-three patients (52%) survived in CPC 1-2 until 180 days post-CA. The mean MAP range associated with maximal survival was 76-86 mmHg (OR 2.63, 95%CI [1.01; 6.88], p = 0.04). The mean SVO2 range associated with maximal survival was 67-72% (OR 8.23, 95%CI [2.07; 32.68], p = 0.001). In two separate multivariate models, a mean MAP (OR 3.72, 95% CI [1.11; 12.50], p=0.03) and a mean SVO2 (OR 10.32, 95% CI [2.03; 52.60], p = 0.001) in the optimal range persisted as independently associated with increased survival. Based on more than 1625000 data points, we found a strong linear relation between SVO2 (range 40-90%) and average cerebral saturation (R(2) 0.86) and between MAP and average cerebral saturation for MAPs between 45 and 101 mmHg (R(2) 0.83). Based on our hemodynamic model, the MAP and SVO2 ranges associated with optimal cerebral oxygenation were determined to be 87-101 mmHg and 70-75%. CONCLUSION we showed that a MAP range between 76-86 mmHg and SVO2 range between 67% and 72% were associated with maximal survival. Optimal cerebral saturation was achieved with a MAP between 87-101 mmHg and a SVO2 between 70% and 75%. Prospective interventional studies are needed to investigate whether forcing MAP and SVO2 in the suggested range with additional pharmacological support would improve outcome.


European Journal of Echocardiography | 2014

Clinical value of echocardiographic Doppler-derived right ventricular dp/dt in patients with pulmonary arterial hypertension

Koen Ameloot; Pieter-Jan Palmers; Alexander Van De Bruaene; Annelies Gerits; Werner Budts; Jens-Uwe Voigt; Marion Delcroix

AIMS Right ventricular (RV) dp/dt is the instantaneous rate of RV pressure rise during early systole and is a surrogate marker of RV contractility. The main objective of this study was to evaluate the ability of echocardiographic Doppler obtained RV dp/dt to predict long-term survival in patients with pulmonary arterial hypertension (PAH) and chronic thrombo-embolic pulmonary hypertension (CTEPH). METHODS AND RESULTS Seventy-eight consecutive newly diagnosed untreated patients (64 ± 15 years, 71% female, 57% PAH, 43% inoperable CTEPH) were included in the study. At baseline, patients were assessed clinically [New York Heart Association (NYHA) and 6 minutes walking distance (6MWD)], by transthoracic cardiac ultrasound and by right heart catherization. RV dp/dt was assessed using spectral Doppler recordings from the tricuspid regurgitation signal at a sweep speed of 200 mm/s by measuring the time interval in which the regurgitant velocity increased from 0.5 to 2 m/s. During a mean follow-up period of 3.5 ± 1.7 years, 31 patients died and 3 received a lung transplant [study endpoint reached in 34/78 (44%) patients]. The optimal RV dp/dt cut-off was determined by receiver operating characteristic analysis at 3 years to be 410 mmHg/s (specificity 84%, positive-predictive value 55%, and negative-predictive value 83%). In univariate analysis, RV dp/dt <410 mmHg/s (hazard ratio 2.67, 95% CI 1.30-5.47, P = 0.007), tricuspid annulus plane systolic excursion (TAPSE) <15 mm, NYHA, 6MWD, and right atrial pressure were predictors of mortality. In a multivariate model with TAPSE, RV dp/dt remained an independent predictor of mortality (P = 0.01). CONCLUSION A reduced baseline RV dp/dt is a clear indicator of poor outcome independent of TAPSE in patients with PAH/CTEPH.


Resuscitation | 2015

Low hemoglobin levels are associated with lower cerebral saturations and poor outcome after cardiac arrest

Koen Ameloot; Cornelia Genbrugge; Ingrid Meex; Stefan Janssens; Willem Boer; Wilfried Mullens; Bert Ferdinande; Matthias Dupont; J. Dens; C. De Deyne

PURPOSE Post-cardiac arrest (CA) patients have a large cerebral penumbra at risk for secondary ischemic damage in case of suboptimal brain oxygenation during ICU stay. The aims of this study were to investigate the association between hemoglobin, cerebral oxygenation (SctO2) and outcome in post-CA patients. METHODS Prospective observational study in 82 post-CA patients. Hemoglobin, a corresponding SctO2 measured by NIRS and SVO2 in patients with a pulmonary artery catheter (n=62) were determined hourly during hypothermia in the first 24h of ICU stay. RESULTS We found a strong linear relationship between hemoglobin and mean SctO2 (SctO2=0.70×hemoglobin+56 (R(2) 0.84, p=10(-6))). Hemoglobin levels below 10g/dl generally resulted in lower brain oxygenation. There was a significant association between good neurological outcome (43/82 patients in CPC 1-2 at 180 days post-CA) and admission hemoglobin above 13g/dl (OR 2.76, 95% CI 1.09:7.00, p=0.03) or mean hemoglobin above 12.3g/dl (OR 2.88, 95%CI 1.02:8.16, p=0.04). This association was entirely driven by results obtained in patients with a mean SVO2 below 70% (OR 6.25, 95%CI 1.33:29.43, p=0.01) and a mean SctO2 below 62.5% (OR 5.87, 95%CI 1.08:32.00, p=0.03). CONCLUSION Hemoglobin levels below 10g/dl generally resulted in lower cerebral oxygenation. Average hemoglobin levels below 12.3g/dl were associated with worse outcome in patients with suboptimal SVO2 or SctO2. The safety of a universal restrictive transfusion threshold of 7g/dl can be questioned in post-CA patients.


Resuscitation | 2014

Accuracy of continuous thermodilution cardiac output monitoring by pulmonary artery catheter during therapeutic hypothermia in post-cardiac arrest patients

Koen Ameloot; Ingrid Meex; Cornelia Genbrugge; Frank Jans; M. Malbrain; Wilfried Mullens; J. Dens; C. De Deyne; Matthias Dupont

PURPOSE Thermodilution continuous cardiac output measurements (TDCCO) by pulmonary artery catheter (PAC) have not been validated during therapeutic hypothermia in post-cardiac arrest patients. The calculated cardiac output based on the indirect Fick principle (FCO) using pulmonary artery blood gas mixed venous oxygen saturation (FCO-BG-SvO2) is considered as the gold standard. Continuous SvO2 by PAC (PAC-SvO2) has also not been validated previously during hypothermia. The aims of this study were (1) to compare FCO-BG-SvO2 with TDCCO, (2) to compare PAC-SvO2 with BG-SvO2 and finally (3) to compare FCO with SvO2 obtained via PAC or blood gas. METHODS We analyzed 102 paired TDCCO/FCO-BG-SvO2 and 88 paired BG-SvO2/PAC-SvO2 measurements in 32 post-cardiac arrest patients during therapeutic hypothermia. RESULTS TDCCO was significantly although poorly correlated with FCO-BG-SvO2 (R2 0.21, p<0.01) without systematic bias (-0.15±1.76 l/min). Analysis according to Bland and Altman however showed broad limits of agreement ([-3.61; 3.45] l/min) and an unacceptable high percentage error (105%). None of the criteria for clinical interchangeability were met. Concordance analysis showed that TDCCO had limited trending ability (R2 0.03). FCO based on PAC-SvO2 was highly correlated with FCO-BG-SvO2 (R2 0.72) with a small bias (-0.08±0.72 l/min) and slightly too high percentage error (44%). CONCLUSION Our results show an extreme inaccuracy of TDCCO by PAC in post-cardiac arrest patients during therapeutic hypothermia. We found a reasonable correlation between BG-SvO2 and PAC-SvO2 and subsequently between FCO calculated with SvO2 obtained either via blood gas or PAC. The decision to start or titrate inotropics should therefore not be guided by TDCCO in this setting.


Anaesthesiology Intensive Therapy | 2015

From therapeutic hypothermia towards targeted temperature management: a decade of evolution

Pieter-Jan Palmers; Nick Hiltrop; Koen Ameloot; Philippe Timmermans; Bert Ferdinande; Peter Sinnaeve; Rogier Nieuwendijk; Manu L.N.G. Malbrain

More than a decade after the first randomised controlled trials with targeted temperature management (TTM), it remains the only treatment with proven favourable effect on postanoxemic brain damage after out-of-hospital cardiac arrest. Other well-known indications include neurotrauma, subarachnoidal haemorrhage, and intracranial hypertension. When possible pitfalls are taken into consideration when implementing TTM, the side effects are manageable. After the recent TTM trials, it seems that classic TTM (32-34°C) is as effective and safe as TTM at 36°C. This supports the belief that fever prevention is one of the pivotal mechanisms that account for the success of TTM. Uncertainty remains concerning cooling method, timing, speed of cooling and rewarming. New data indicates that TTM is safe and feasible in cardiogenic shock, one of its classic contra-indications. Moreover, there are limited indications that TTM might be considered as a therapy for cardiogenic shock per se.


American Heart Journal | 2017

Mean arterial pressure of 65 mm Hg versus 85-100 mm Hg in comatose survivors after cardiac arrest: Rationale and study design of the Neuroprotect post–cardiac arrest trial

Koen Ameloot; Cathy De Deyne; Bert Ferdinande; Matthias Dupont; Pieter-Jan Palmers; Thibault Petit; Ward Eertmans; Clara Moonen; Ann Belmans; Robin Lemmens; Joseph Dens; Stefan Janssens

Background Post–cardiac arrest (CA) patients admitted to the intensive care unit (ICU) have a poor prognosis, with estimated survival rates of around 30%‐50%. On admission, these patients have a large cerebral penumbra at risk for additional damage in case of suboptimal brain oxygenation during their stay in the ICU. The aim of the Neuroprotect post‐CA trial is to investigate whether forcing mean arterial blood pressure (MAP) and mixed venous oxygen saturation (SVO2) in a specific range (MAP 85–100 mm Hg, SVO2 65%‐75%) with additional pharmacological support (goal‐directed hemodynamic optimization) may better salvage the penumbra, reduce cerebral ischemia, and improve functional outcome when compared with current standard of care (MAP 65 mm Hg). Design The Neuroprotect post‐CA trial (NCT02541591) is a multicenter, randomized, parallel‐group, open‐label, assessor‐blinded, monitored, and investigator‐driven clinical trial. The trial will be conducted in 2 tertiary care hospitals in Belgium (UZ Leuven and ZOL‐Genk). A total of 112 eligible patients will be randomly assigned in a 1:1 ratio to goal‐directed hemodynamic optimization or standard care strategy by an interactive voice response system. Patients will be stratified according to the presence of an initial shockable rhythm. Adult patients (≥18 years) resuscitated from out‐of‐hospital CA of a presumed cardiac cause who are unconscious upon hospital admission are eligible for inclusion. Patients can be included irrespective of their presenting heart rhythm but need to have a sustained return of spontaneous circulation. Trial interventions will take 36 hours starting from ICU admission. The primary outcome is the extent of cerebral ischemia as quantified by the apparent diffusion coefficient on diffusion‐weighted magnetic resonance imaging to be performed at day 4–5 post‐CA. Secondary outcomes include surrogate biomarkers of brain injury (neuron specific enolase) at day 1–5, neuropsychological and functional testing at hospital discharge, a Short Form–36 health questionnaire at 180 days, and outcome as assessed with cerebral performance category scores at ICU discharge and at 180 days. Conclusions The Neuroprotect post‐CA trial will investigate whether a more aggressive hemodynamic strategy to obtain a MAP 85–100 mm Hg and SVO2 65%‐75% reduces brain ischemia and improves outcome when compared with standard treatment (MAP 65 mm Hg) in comatose post‐CA survivors.


Intensive Care Medicine | 2013

The influence of continuous venovenous renal replacement therapy on the plasma disappearance rate of indocyanine green.

Koen Ameloot; Philippe Meersseman; Alexander Wilmer; Greet Hermans; Annelies Gerits; Isabel Spriet; Joost Wauters

Dear Editor, In critically ill patients, the plasma disappearance rate of indocyanine green (ICG-PDR) is used to assess dynamic liver function. Serum ICG concentrations can be monitored with a transcutaneous device (LiMON, Pulsion Medical Systems, Munich, Germany) [1]. No conclusive data exist on the potential influence of renal replacement therapy (RRT) on the reliability of ICG-PDR measurements. Therefore, we prospectively studied 10 adult medical ICU patients [60 ± 20 years, APACHE II score 32 (25; 41)] comparing ICG-PDR with and without RRT. All patients were mechanically ventilated, required continuous venovenous hemofiltration (CVVH), and received hemodynamic monitoring using transpulmonary thermodilution (TPTD) by a PiCCO system (PiCCO, Pulsion Medical Systems, Munich, Germany). Reasons for admission were septic shock (n = 6), acute on chronic liver failure (n = 3), and acute severe pancreatitis (n = 1). The study was approved by the institutional review board. Written informed consent was obtained. On day 1 of the study, two ICG-PDR measurements were done consecutively during CVVH followed by two measurements while CVVH was in recirculation. On day 2, this procedure was repeated in reverse order: two measurements with CVVH in recirculation were followed by two measurements during CVVH. Each ICG-PDR measurement was combined with a preceding TPTD measurement. mRRT(?) was defined as the mean of all four ICG-PDR measurements during RRT and mRRT(-) as the mean of all four measurements with CVVH in recirculation. mRRT(?) was 9.3 (7.4; 13.7) %/min and mRRT(-) was 10.5 (6.4; 15.6) %/min. RRT did not significantly influence ICG-PDR (mean

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Bert Ferdinande

Katholieke Universiteit Leuven

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J. Dens

University of Hasselt

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Jo Dens

Katholieke Universiteit Leuven

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Pieter-Jan Palmers

Katholieke Universiteit Leuven

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