Paul W G Elbers

Onze Lieve Vrouwe Gasthuis, Amsterdamo, North Holland, Netherlands

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Publications (22)94.38 Total impact

  • Paul Elbers, Rainer Gatz, Chris Anstey
    JAMA The Journal of the American Medical Association 02/2013; 309(6):542-3. · 29.98 Impact Factor
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    ABSTRACT: This study tested the hypothesis that there is a discrepancy between global hemodynamic parameters and microvascular flow in patients before and after successful elective electrical cardioversion (ECV) for atrial fibrillation (AF). Prospective observational study. Preanesthesia holding area in a teaching hospital. Adult patients who underwent successful elective ECV for AF. ECV. Routine measurements of heart rate and noninvasive blood pressure were recorded and the sublingual microcirculation was visualized by sidestream darkfield imaging before and after the conversion of AF to sinus rhythm by elective ECV. The conversion to sinus rhythm significantly improved the microvascular flow index for smaller and larger microvessels. For smaller microvessels, perfused vessel density did not reach significance after conversion to sinus rhythm, whereas the proportion of perfused vessels was significantly larger and indices of heterogeneity for microvascular flow index decreased significantly. No correlation could be identified for the changes in mean blood pressure, perfused vessel density, and microvascular flow index for smaller microvessels. Successful ECV in patients with AF improves indices of sublingual microvascular perfusion. This change has no clear relation to the change in blood pressure and cannot be predicted from it. It may be prudent not to rely solely on global hemodynamic parameters to assess end-organ perfusion in this setting.
    Journal of cardiothoracic and vascular anesthesia 06/2012; 26(5):799-803. · 1.06 Impact Factor
  • Paul Elbers, Rainer Gatz
    Resuscitation 04/2012; 83(8):e172; author reply e173. · 4.10 Impact Factor
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    Rainer Gatz, Paul Elbers
    The Scientific World Journal 01/2012; 2012:234628. · 1.73 Impact Factor
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    ABSTRACT: Objective. The pulmonary artery catheter (PAC) remains topic of debate. Despite abundant data, it is of note that many trials did not incorporate a treatment protocol. Methods. We retrospectively evaluated fluid balances and catecholamine doses in septic patients after the introduction of a PAC-based treatment protocol in comparison to historic controls. Results. 2 × 70 patients were included. The first day the PAC group had a significantly higher positive fluid balance in comparison to controls (6.1 ± 2.6 versus 3.8 ± 2.4 litre, P < 0.001). After 7 days the cumulative fluid balance in the PAC group was significantly lower than in controls (9.4 ± 7.4 versus 13 ± 7.6 litre, P = 0.001). Maximum dose of norepinephrine was significantly higher in the PAC group. Compared to controls this was associated with a significant reduction in ventilator and ICU days. Conclusions. Introduction of a PAC-based treatment protocol in sepsis changed the administration of fluid and vasopressors significantly.
    Critical care research and practice 01/2012; 2012:161879.
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    ABSTRACT: The purpose of this study was to develop a rapid and fully automatic method for the assessment of microvascular density and perfusion in sidestream dark field (SDF) images. We modified algorithms previously developed by our group for microvascular density assessment and introduced a new method for microvascular perfusion assessment. To validate the new algorithm for microvascular density assessment, we reanalyzed a selection of SDF video clips (n = 325) from a study in intensive care patients and compared the results to (semi-)manually found microvascular densities. The method for microvascular perfusion assessment (temporal SDF image contrast analysis, tSICA) was tested in several video simulations and in one high quality SDF video clip where the microcirculation was imaged before and during circulatory arrest in a cardiac surgery patient. We found that the new method for microvascular density assessment was very rapid (<30 s/clip) and correlated excellently with (semi-)manually measured microvascular density. The new method for microvascular perfusion assessment (tSICA) was shown to be limited by high cell densities and velocities, which severely impedes the applicability of this method in real SDF images. Hence, here we present a validated method for rapid and fully automatic assessment of microvascular density in SDF images. The new method was shown to be much faster than the conventional (semi-)manual method. Due to current SDF imaging hardware limitations, we were not able to automatically detect microvascular perfusion.
    Medical & Biological Engineering 08/2011; 49(11):1269-78. · 1.76 Impact Factor
  • Paul W G Elbers
    Journal of cardiothoracic and vascular anesthesia 04/2011; · 1.06 Impact Factor
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    ABSTRACT: Possible benefits of pulsatile perfusion during cardiopulmonary bypass often are attributed to enhanced microvascular flow. However, there is no evidence to support this in humans. Therefore, the authors assessed whether pulsatile perfusion alters human microvascular flow. A prospective, randomized observational crossover study. A tertiary cardiothoracic surgery referral center. Sixteen patients undergoing routine cardiopulmonary bypass for cardiac surgery. All patients underwent both pulsatile and nonpulsatile perfusion in random order. The authors used sidestream dark-field imaging to record video clips of the sublingual human microcirculation. Perfusion was started either in the pulsatile (n = 8) or the nonpulsatile mode. After 10 minutes, microvascular recordings were made. The perfusion mode was then switched, and after 10 minutes, new microvascular recordings were taken. The authors quantified pulsatile perfusion-generated surplus hemodynamic energy by calculating pulse pressure and energy-equivalent pressure. Microvascular analysis included determination of the perfused vessel density (mean ± standard deviation). This did not differ between nonpulsatile and pulsatile perfusion (6.65 ± 1.39 v 6.83 ± 1.23 mm(-1), p = 0.58, and 2.16 ± 0.64 v 1.96 ± 0.48 mm(-1), p = 0.20 for small and large microvessels, respectively, cutoff diameter = 20 μm). Pulse pressure and energy-equivalent pressure was higher during pulsatile perfusion. However, there was no correlation between the difference in energy-equivalent pressure or pulse pressure and perfused vessel density (r = -0.43, p = 0.13, and r = -0.09, p = 0.76, respectively). Pulsatile perfusion does not alter human microvascular perfusion using standard equipment in routine cardiac surgery. Changes in pulse pressure or energy-equivalent pressure bear no obvious relationship with microcirculatory parameters.
    Journal of cardiothoracic and vascular anesthesia 04/2011; 25(2):250-5. · 1.06 Impact Factor
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    Rainer K H Gatz, Paul W G Elbers
    Kidney International 10/2010; 78(7):711. · 8.52 Impact Factor
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    ABSTRACT: The behavior of the human microcirculation in the setting of cardiac arrest is largely unknown. Animal experiments have consistently revealed that global hemodynamics do not necessarily reflect microvascular perfusion. In addition, the time it takes for capillary blood flow to stop after the heart arrests is debated. Estimations range from 50 seconds to 5 mins, but data in humans are lacking. Aortic arch surgery frequently necessitates deep hypothermic circulatory arrest and subsequent selective antegrade cerebral perfusion. To elucidate microvascular behavior surrounding cessation of human circulation, we used sublingual microvascular imaging in this setting. Prospective, observational study. Operating room of a large tertiary referral center for cardiac surgery. Seven patients undergoing elective aortic arch repair. We used sidestream dark field imaging to study the sublingual microcirculation immediately before circulatory arrest, during circulatory arrest, and immediately after selective antegrade cerebral perfusion. Results are reported as mean (sd) unless indicated otherwise. Before circulatory arrest, perfused vessel density was 6.41 (1.18) for small (<20 microm) and 1.57 (0.88) mm for large (>20 microm) microvessels. Microvascular flow index was a median of 3.0 (interquartile range 3.0-3.0) for both vessel sizes. After circulatory arrest, there was no equilibration of arterial and venous blood pressure before onset of selective antegrade cerebral perfusion after 59 (17) secs (range, 40-80 secs). Flow in small microvessels came to a complete stop after 45 (9) secs (range, 34-57 secs) after transition to circulatory arrest. However, flow in larger microvessels did not completely stop before selective antegrade cerebral perfusion started. Selective antegrade cerebral perfusion restored microvascular flow, reaching precirculatory arrest levels after 45 (27) secs (range, 20-85 secs). In a controlled surgical setting, circulatory arrest in humans induces a complete sublingual small microvessel shutdown within 1 min. However, flow in larger microvessels persists. Selective antegrade cerebral perfusion was able to restore microvascular flow to precirculatory arrest levels within a similar timeframe.
    Critical care medicine 07/2010; 38(7):1548-53. · 6.37 Impact Factor
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    Rainer Gatz, Paul Elbers
    Blood transfusion = Trasfusione del sangue 02/2010; 9(1):107. · 1.86 Impact Factor
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    ABSTRACT: The Intra-Aortic Balloon Pump (IABP) is frequently used to mechanically support the heart. There is evidence that IABP improves microvascular flow during cardiogenic shock but its influence on the human microcirculation in patients deemed ready for discontinuing IABP support has not yet been studied. Therefore we used sidestream dark field imaging (SDF) to test our hypothesis that human microcirculation remains unaltered with or without IABP support in patients clinically ready for discontinuation of mechanical support. We studied 15 ICU patients on IABP therapy. Measurements were performed after the clinical decision was made to remove the balloon catheter. We recorded global hemodynamic parameters and performed venous oximetry during maximal IABP support (1:1) and 10 minutes after temporarily stopping the IABP therapy. At both time points, we also recorded video clips of the sublingual microcirculation. From these we determined indices of microvascular perfusion including perfused vessel density (PVD) and microvascular flow index (MFI). Ceasing IABP support lowered mean arterial pressure (74 ± 8 to 71 ± 10 mmHg; P = 0.048) and increased diastolic pressure (43 ± 10 to 53 ± 9 mmHg; P = 0.0002). However, at the level of the microcirculation we found an increase of PVD of small vessels <20 μm (5.47 ± 1.76 to 6.63 ± 1.90; P = 0.0039). PVD for vessels >20 μm and MFI for both small and large vessels were unaltered. During the procedure global oxygenation parameters (ScvO2/SvO2) remained unchanged. In patients deemed ready for discontinuing IABP support according to current practice, SDF imaging showed an increase of microcirculatory flow of small vessels after ceasing IABP therapy. This observation may indicate that IABP impairs microvascular perfusion in recovered patients, although this warrants confirmation.
    Critical care (London, England) 01/2010; 14(4):R161. · 4.72 Impact Factor
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    Critical Care 01/2010; · 4.93 Impact Factor
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    ABSTRACT: The microcirculation is essential for delivery of oxygen and nutrients to tissue. However, the human microvascular response to cardiopulmonary resuscitation (CPR) is unknown. We report on the first use of sidestream dark field imaging to assess the human microcirculation during CPR with a mechanical chest compression/decompression device (mCPR). mCPR was able to provide microvascular perfusion. Capillary flow persisted even during brief mCPR interruption. However, indices of microvascular perfusion were low and improved vastly after return of spontaneous circulation. Microvascular perfusion was relatively independent from blood pressure. The microcirculation may be a useful monitor for determining the adequacy of CPR.
    Resuscitation 12/2009; 81(1):123-5. · 4.10 Impact Factor
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    BJA British Journal of Anaesthesia 07/2009; · 4.24 Impact Factor
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    P Elbers, R Gatz
    Critical Care 01/2009; 13. · 4.93 Impact Factor
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    ABSTRACT: It has become possible to image the human microcirculation at the bedside using sidestream dark field (SDF) imaging. This may help the clinician when correlation between global and microvascular hemodynamics may not be straightforward. Ketanserin, a serotonin and alpha-1 adrenoceptor antagonist, is used in some countries to treat elevated blood pressure after extracorporeal circulation. This might hamper microcirculatory perfusion. Conversely, it is also conceivable that microcirculatory flow is maintained or improved as a result of flow redistribution. In order to introduce SDF imaging in cardiac anesthesia, the authors set out to directly observe the sublingual microcirculation in this setting. An observational study. A large teaching hospital. Mechanically ventilated patients with elevated arterial blood pressure immediately after extracorporeal circulation (ECC). An intravenous bolus of ketanserin, 0.15 mg/kg. Five minutes before and 10 minutes after ketanserin administration, global hemodynamic variables were recorded. In addition, the authors used SDF imaging to record video clips of the microcirculation. Analysis of these allowed for quantification of microvascular hemodynamics including determination of perfused vessel density (PVD) and microcirculatory flow index (MFI). After ketanserin administration, there was a significant reduction in systolic arterial blood pressure (129 +/- 9 to 100 +/- 15 mmHg, p = 0.0001). At the level of the microcirculation, the mean MFI did not change significantly for small (diameter <20 microm, 2.79 [interquartile range, 1.38-3] to 2.38 [1.88-2.75], p = 0.62) or large (diameter >20 microm, 2.83 [1.4-3] to 2.67 [0.35-2.84] p = 1.0) vessels. There was a significant increase in mean PVD for large vessels (1.23 +/- 0.63 to 1.70 +/- 79 mm(-1), p = 0.017) but not for small vessels (5.59 +/- 2.60 to 5.87 +/- 1.22 mm(-1), p = 0.72) where red blood cell flow was maintained. SDF imaging clearly showed a discrepancy between global and microvascular hemodynamics after the administration of ketanserin for elevated blood pressure after ECC. Ketanserin effectively lowers arterial blood pressure. However, capillary perfusion is maintained at a steady value. Both effects may be explained by an increase in shunting in the larger vessels of the microcirculation.
    Journal of cardiothoracic and vascular anesthesia 01/2009; 23(1):95-101. · 1.06 Impact Factor
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    Paul W G Elbers
    Critical care (London, England) 02/2007; 11(6):426. · 4.72 Impact Factor
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    P. W. G. Elbers, C. Ince
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    ABSTRACT: The microcirculation is a vulnerable organ in sepsis. At the same time, the diseased microcirculation fuels sepsis, leading to organ failure. Direct monitoring of the microcirculation itself or at least some indicator of regional perfusion may, therefore, be useful in assessing the course of disease. However, it should be noted that the effectiveness of many microcirculatory recruitment maneuvers has not yet been confirmed in appropriate clinical trials. Similarly, although there is strong evidence that an improving microcirculation is associated with a better outcome, this is not necessarily a cause and effect relationship and resuscitation of the microcirculation has not been the subject of clinical investigation at the present time. Nevertheless, it is important to remember that normal or improving global hemodynamics or oxygen-derived parameters do not preclude microcirculatory dysfunction, multiple organ failure, and fatal outcome. The microcirculation may be the much-needed end-point of resuscitation of clinical sepsis and septic shock. In addition to accepted therapies, such as fluid resuscitation and inotropic support, promising microcirculatory resuscitating maneuvers including vasodilatation, iNOS inhibition, and multi-action drugs, such as APC, could complement the armamentarium of tomorrow’s ICUs.
    12/2006: pages 249-262;
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    ABSTRACT: Spinal cord ischemia and visceral ischemia may occur simultaneously during thoracoabdominal aortic aneurysm repair. The present rabbit study investigated the effect of a temporary interruption of the visceral perfusion on the development of ischemia-reperfusion injury of the spinal cord. Spinal cord ischemia was induced by occlusion of the infrarenal aorta for variable durations (6 to 20 minutes) in 32 rabbits. In the visceral ischemia group, 20-minute concurrent clamping of the celiac trunk and mesenteric arteries was performed. At 24, 48, and 72 hours after ischemia, neurologic outcome was assessed in the control and visceral ischemia group. The PD50 (the duration of ischemia that produces lower limb neurologic deficits in 50% of the animals) was determined by quantal bioassay analysis. At 72 hours, histologic evaluation of spinal cord infarct size was performed. Compared with control animals, PD50 was significantly longer in the visceral ischemia group at 48 hours and 72 hours after ischemia. Neurologic and histologic outcomes correlated well (r = -0.90). The results of the present rabbit study suggest that concurrent temporary visceral ischemia does not aggravate spinal cord ischemic injury in the rabbit. Moreover, the results suggest that concurrent visceral ischemia may increase the tolerance of the spinal cord to ischemic damage.
    The Annals of thoracic surgery 04/2006; 81(3):910-7. · 3.45 Impact Factor

Publication Stats

120 Citations
94.38 Total Impact Points

Institutions

  • 2010–2012
    • Onze Lieve Vrouwe Gasthuis
      • Department of Intensive Care
      Amsterdamo, North Holland, Netherlands
    • Herlev Hospital
      Herlev, Capital Region, Denmark
  • 2011
    • Medisch Centrum Leeuwarden
      Leewarden, Friesland, Netherlands
  • 2006–2011
    • University of Amsterdam
      • Faculty of Medicine AMC
      Amsterdam, North Holland, Netherlands
  • 2006–2009
    • St. Antonius Ziekenhuis
      • Department of Anesthesiology
      Nieuwegen, Utrecht, Netherlands