Can Ince - Academia.edu (original) (raw)

Papers by Can Ince

Research paper thumbnail of Oxygen saturation determined from the mouth is an early indicator of central hypovolemia in humans

Research paper thumbnail of Fentanyl-fluanisone-midazolam combination results in more stable hemodynamics than does urethane alpha-chloralose and 2,2,2-tribromoethanol in mice

Contemporary topics in laboratory animal science / American Association for Laboratory Animal Science, 2002

Near-physiologic hemodynamic conditions for several hours were needed to study cardiovascular phy... more Near-physiologic hemodynamic conditions for several hours were needed to study cardiovascular physiology in a murine model. We compared two commonly used anesthetic treatments, urethane alpha-chloralose (U-alphaCh; 968 mg U and 65 mg alphaCh/kg) and 2,2,2-tribromoethanol (TBE; 435 mg/kg) and fentanyl fluanisone midazolam (FFM; 3.313 mg fentanyl, 104.8 mg fluanisone, and 52.42 mg midazolam/kg) with respect to mean arterial blood pressure (MAP) and heart rate (HR) for 100 min at similar levels of surgical anesthesia. Assessed every 10 to 15 min, the U-alphaCh+TBE group maintained a significantly (P < 0.001) lower mean MAP (49 4 mmHg) than did the FFM group (78 5 mmHg). Mean HR in the U-alphaCh+TBE group significantly (P < 0.001) increased from 308 34 bpm at the beginning to 477 43 bpm at the end of the experiment. In comparison, the FFM group showed a stable HR of 431 37 bpm. The MAP and HR of the U-alphaCh+TBE group were extremely unstable, with sudden and unpredictable changes...

Research paper thumbnail of Laser-assisted optical rotational cell analyzer measurements reveal early changes in human RBC deformability induced by photodynamic treatment

Transfusion, 2003

ABBREVIATIONS: DMMB = 1,9-dimethylmethylene blue; LORCA = laser-assisted optical rotational cell ... more ABBREVIATIONS: DMMB = 1,9-dimethylmethylene blue; LORCA = laser-assisted optical rotational cell analyzer; ROS = reactive oxygen species; SAG-M, saline, adenine, glucose-mannitol.

Research paper thumbnail of How to evaluate the microcirculation: report of a round table conference

Critical Care, 2007

INTRODUCTION: Microvascular alterations may play an important role in the development of organ fa... more INTRODUCTION: Microvascular alterations may play an important role in the development of organ failure in critically ill patients and especially in sepsis. Recent advances in technology have allowed visualization of the microcirculation, but several scoring systems have been used so it is sometimes difficult to compare studies. This paper reports the results of a round table conference that was organized

Research paper thumbnail of Plasma Free Hemoglobin and Microcirculatory Response to Fresh or Old Blood Transfusions in Sepsis

PLOS ONE, 2015

Free hemoglobin (fHb) may induce vasoconstriction by scavenging nitric oxide. It may increase in ... more Free hemoglobin (fHb) may induce vasoconstriction by scavenging nitric oxide. It may increase in older blood units due to storage lesions. This study evaluated whether old red blood cell transfusion increases plasma fHb in sepsis and how the microvascular response may be affected. This is a secondary analysis of a randomized study. Twenty adult septic patients received either fresh or old (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10 or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;15 days storage, respectively) RBC transfusions. fHb was measured in RBC units and in the plasma before and 1 hour after transfusion. Simultaneously, the sublingual microcirculation was assessed with sidestream-dark field imaging. The perfused boundary region was calculated as an index of glycocalyx damage. Tissue oxygen saturation (StO2) and Hb index (THI) were measured with near-infrared spectroscopy and a vascular occlusion test was performed. Similar fHb levels were found in the supernatant of fresh and old RBC units. Despite this, plasma fHb increased in the old RBC group after transfusion (from 0.125 [0.098-0.219] mg/mL to 0.238 [0.163-0.369] mg/mL, p = 0.006). The sublingual microcirculation was unaltered in both groups, while THI increased. The change in plasma fHb was inversely correlated with the changes in total vessel density (r = -0.57 [95% confidence interval -0.82, -0.16], p = 0.008), De Backer score (r = -0.63 [95% confidence interval -0.84, -0.25], p = 0.003) and THI (r = -0.72 [95% confidence interval -0.88, -0.39], p = 0.0003). Old RBC transfusion was associated with an increase in plasma fHb in septic patients. Increasing plasma fHb levels were associated with decreased microvascular density. ClinicalTrials.gov NCT01584999.

Research paper thumbnail of PO2 measurements in the rat intestinal microcirculation

The American journal of physiology

Microvascular partial oxygen pressure (PO2) data measured with the quenched phosphorescence of pa... more Microvascular partial oxygen pressure (PO2) data measured with the quenched phosphorescence of palladium-porphyrin (Pd-porphyrin) with the use of optical fibers have provided new insight into the behavior of the microvascular oxygenation in models of shock. However, the actual microcirculatory compartment measured by this fiber technique has not yet been demonstrated. The purpose of this study was to investigate whether the PO2 of the intestines, as measured using a fiber phosphorometer, reflects the microvascular compartment. To this end, a new intravital phosphorometer with an improved sensitivity to high-PO2 levels (up to 180 mmHg) was developed and validated. With this setup, PO2 values were measured at different inspired oxygen fractions (15, 25, and 50% oxygen) in first-order arterioles, capillaries, and venules of the ileum of rats. Simultaneously, the PO2 was measured with an optical fiber attached to another phosphorometer. PO2 measurements with the fiber phosphorometer sho...

Research paper thumbnail of Assessment of ventilation inhomogeneity and gas exchange with volume controlled ventilation and pressure regulated volume controlled ventilation on pigs with surfactant depleted lungs

Advances in Experimental Medicine and Biology

Research paper thumbnail of The Microcirculation of the Septic Kidney

Seminars in nephrology, 2015

The renal microcirculation plays a major role in the delivery of blood and oxygen to the kidney. ... more The renal microcirculation plays a major role in the delivery of blood and oxygen to the kidney. In sepsis, alterations in renal microvascular perfusion, in conjunction with increased oxygen requirements, may contribute to renal failure even when renal macrovascular perfusion is preserved. In this review, we discuss the pathophysiology of the renal microcirculation during sepsis and how it contributes to acute kidney injury. Endothelial dysfunction largely is owing to inflammatory, oxidative, and nitrosative factors. Coagulative disorders and glycocalyx disruption also may contribute to the microcirculatory dysfunction. New technologies in experimental models and human beings are being developed to explore renal microcirculation in vivo. These technologies will allow a better understanding of the pathophysiopathology of the renal microcirculation and will help guide specific therapeutic strategies in sepsis-induced acute kidney injury.

Research paper thumbnail of The case for 0.9% NaCl: is the undefendable, defensible?

Kidney international, 2014

Although 0.9% NaCl solution is by far the most-used fluid for fluid therapy in resuscitation, it ... more Although 0.9% NaCl solution is by far the most-used fluid for fluid therapy in resuscitation, it is difficult to find a paper advocating its use over other types of crystalloid solutions. Literature on the deleterious effects of 0.9% NaCl has accumulated over the last decade, but critical appraisal of alternative crystalloid solutions is lacking. As such, the literature seems to suggest that 0.9% NaCl should be avoided at all costs, whereas alternative crystalloid solutions can be used without scrutiny. The basis of this negative evaluation of 0.9% NaCl is almost exclusively its effect on acid-base homeostasis, whereas the potentially deleterious effects present in other types of crystalloids are neglected. We have the challenging task of defending the use of 0.9% NaCl and reviewing its positive attributes, while an accompanying paper will argue against the use of 0.9% NaCl. It is challenging because of the large amount of literature, including our own, showing adverse effects of 0....

Research paper thumbnail of Counter statement to open letter to the Executive Director of the European Medicines Agency concerning the licensing of hydroxyethyl starch solutions for fluid resuscitation

British journal of anaesthesia, 2014

Research paper thumbnail of Study Design of the Microcirculatory Shock Occurrence in Acutely Ill Patients (microSOAP): an International Multicenter Observational Study of Sublingual Microcirculatory Alterations in Intensive Care Patients

Critical care research and practice, 2012

Objective. Sublingual microcirculatory alterations are associated with an adverse prognosis in se... more Objective. Sublingual microcirculatory alterations are associated with an adverse prognosis in several critical illness subgroups. Up to now, single-center studies have reported on sublingual microcirculatory alterations in ICU patient subgroups, but an extensive evaluation of the prevalence of these alterations is lacking. We present the study design of an international multicenter observational study to investigate the prevalence of microcirculatory alterations in critically ill: the Microcirculatory Shock Occurrence in Acutely ill Patients (microSOAP). Methods. 36 ICU's worldwide have participated in this study aiming for inclusion of over 500 evaluable patients. To enable communication and data collection, a website, an Open Clinica 3.0 database, and image uploading software have been designed. A one-session assessment of the sublingual microcirculation using Sidestream Dark Field imaging and data collection on patient characteristics has been performed in every ICU patient ...

Research paper thumbnail of Influence of fluid resuscitation on renal microvascular PO2 in a normotensive rat model of endotoxemia

Critical care (London, England), 2006

Septic renal failure is often seen in the intensive care unit but its pathogenesis is only partly... more Septic renal failure is often seen in the intensive care unit but its pathogenesis is only partly understood. This study, performed in a normotensive rat model of endotoxemia, tests the hypotheses that endotoxemia impairs renal microvascular PO2 (microPO2) and oxygen consumption (VO2,ren), that endotoxemia is associated with a diminished kidney function, that fluid resuscitation can restore microPO2, VO2,ren and kidney function, and that colloids are more effective than crystalloids. Male Wistar rats received a one-hour intravenous infusion of lipopolysaccharide, followed by resuscitation with HES130/0.4 (Voluven), HES200/0.5 (HES-STERIL 6%) or Ringer's lactate. The renal microPO2 in the cortex and medulla and the renal venous PO2 were measured by a recently published phosphorescence lifetime technique. Endotoxemia induced a reduction in renal blood flow and anuria, while the renal microPO2 and VO2,ren remained relatively unchanged. Resuscitation restored renal blood flow, renal...

Research paper thumbnail of Preservation of intestinal microvascular Po2 during normovolemic hemodilution in a rat model

The Journal of laboratory and clinical medicine, 2000

The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim o... more The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2). Normovolemic hemodilution was performed in 13 anesthetized male Wistar rats. Systemic hemodynamic and intestinal oxygenation parameters were monitored. Intestinal microvascular Po2 was measured by using the oxygen-dependent quenching of palladium-porphyrin phosphorescence. Hemodilution decreased systemic hematocrit from 45.0% +/- 0.1% (average +/- SEM) to 24.6% +/- 1.6%. The mesenteric blood flow did not change from baseline values, resulting in a linear decrease in intestinal oxygen delivery (from 2.77 +/- 0.15 to 1.42 +/- 0.11 mLxkg(-1)xmin(-1)). The intestinal oxygen extraction ratio increased significantly from 24% +/- 1% to 42% +/- 4%. Pmvo2 decreased significantly (from 57 +/- 2 to 41 +/- 2 mm...

Research paper thumbnail of Intestinal microvascular pO2 measurement with Pd-porphyrin phosphorescence in the mechanically ventilated mouse

Advances in experimental medicine and biology, 1998

Research paper thumbnail of Effect of ketanserine on oxygenation and ventilation inhomogeneity in pigs with ARDS

Advances in experimental medicine and biology, 1994

Research paper thumbnail of Bench-to-bedside review: Mechanisms of critical illness – classifying microcirculatory flow abnormalities in distributive shock

Critical care (London, England)

Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hyp... more Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hypovolemic, cardiogenic, obstructive and distributive shock. The first three categories have in common that they are associated with a fall in cardiac output. Distributive shock, such as occurs during sepsis and septic shock, however, is associated with an abnormal distribution of microvascular blood flow and metabolic distress in the presence of normal or even supranormal levels of cardiac output. This Bench-to-bedside review looks at the recent insights that have been gained into the nature of distributive shock. Its pathophysiology can best be described as a microcirculatory and mitochondrial distress syndrome, where time and therapy form an integral part of the definition. The clinical introduction of new microcirculatory imaging techniques, such as orthogonal polarization spectral and side-stream dark-field imaging, have allowed direct observation of the microcirculation at the bedsid...

Research paper thumbnail of The Microcirculation Is a Vulnerable Organ in Sepsis

The microcirculation is a vulnerable organ in sepsis. At the same time, the diseased microcircula... more 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 en...

Research paper thumbnail of Oxygen electrodes, optode microsensing, NIR and pectrophotometry

Research paper thumbnail of Large changes in renal microvascular PO2during acute normovolemic hemodilution

Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II ce... more Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II cells (A549). To study in vitro the direct influence of alveolar type II cells on mechanical stretch. Methods A549 were treated with different doses of lipopolysaccharide (LPS), 0 ng/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1000 ng/ml, and then A549 were lengthened 5%, 15%, 30% using a FLEXCELL tension unit 4000, a vacuum-driven device that applies strain to cells, which were cultured in six-well plates coated with collagen-I, and 12 cycles/min for 4 hours. Apoptosis was measured using the flow cytometry method that measures annexin V and propidium iodide (PI) staining. The morphological changes of apoptotic cells were observed by transmission electron microscope. Results Apoptosis could be induced in alveolar type II cells (A549) by mechanical stretch. The percentage of annexin V + PI cells increased after being treated with cyclic stretch for 4 hours by 5%, 15%, 30% in all groups. The morphological features of apoptotic cells demonstrated by transmission electron microscope were as follows: shrinkage of the cell, chromatin condensation and aggregation under the nuclear membrane as a crescent or lump, membrane-encapsulated nuclear fragment or cell organ formed by invagination of the cell membrane, and apoptotic body formation followed by vacuolization. Conclusion Apoptosis induced by mechanical stretch and LPS is dose dependent. Mechanical stretch aggravates apoptosis especially in cells treated with LPS. Annexin V and PI double staining is a specific, sensitive, and quantitative method for analyzing apoptotic cells. It is also helpful to clarify the protective mechanism of low-volume ventilation in ARDS. PaO 2 /FiO 2 430 [421; 440] # 380 [349; 397] 165 [68; 289] # C (ml/cmH 2 O) 28 [24; 32]* 18 [16; 21]* 12 [8; 17]* R i (cmH 2 O/l/s) 4.1 [3.9; 4.5] 4.5 [4.3; 5.1] 5.1 [3.7; 7.9] # P < 0.05 control vs 24-hour peritonitis, *P < 0.05 control vs 12-hour and 24-hour peritonitis.

Research paper thumbnail of Excitation Pulse Deconvolution in Luminescence Lifetime Analysis for Oxygen Measurements In Vivo

Research paper thumbnail of Oxygen saturation determined from the mouth is an early indicator of central hypovolemia in humans

Research paper thumbnail of Fentanyl-fluanisone-midazolam combination results in more stable hemodynamics than does urethane alpha-chloralose and 2,2,2-tribromoethanol in mice

Contemporary topics in laboratory animal science / American Association for Laboratory Animal Science, 2002

Near-physiologic hemodynamic conditions for several hours were needed to study cardiovascular phy... more Near-physiologic hemodynamic conditions for several hours were needed to study cardiovascular physiology in a murine model. We compared two commonly used anesthetic treatments, urethane alpha-chloralose (U-alphaCh; 968 mg U and 65 mg alphaCh/kg) and 2,2,2-tribromoethanol (TBE; 435 mg/kg) and fentanyl fluanisone midazolam (FFM; 3.313 mg fentanyl, 104.8 mg fluanisone, and 52.42 mg midazolam/kg) with respect to mean arterial blood pressure (MAP) and heart rate (HR) for 100 min at similar levels of surgical anesthesia. Assessed every 10 to 15 min, the U-alphaCh+TBE group maintained a significantly (P < 0.001) lower mean MAP (49 4 mmHg) than did the FFM group (78 5 mmHg). Mean HR in the U-alphaCh+TBE group significantly (P < 0.001) increased from 308 34 bpm at the beginning to 477 43 bpm at the end of the experiment. In comparison, the FFM group showed a stable HR of 431 37 bpm. The MAP and HR of the U-alphaCh+TBE group were extremely unstable, with sudden and unpredictable changes...

Research paper thumbnail of Laser-assisted optical rotational cell analyzer measurements reveal early changes in human RBC deformability induced by photodynamic treatment

Transfusion, 2003

ABBREVIATIONS: DMMB = 1,9-dimethylmethylene blue; LORCA = laser-assisted optical rotational cell ... more ABBREVIATIONS: DMMB = 1,9-dimethylmethylene blue; LORCA = laser-assisted optical rotational cell analyzer; ROS = reactive oxygen species; SAG-M, saline, adenine, glucose-mannitol.

Research paper thumbnail of How to evaluate the microcirculation: report of a round table conference

Critical Care, 2007

INTRODUCTION: Microvascular alterations may play an important role in the development of organ fa... more INTRODUCTION: Microvascular alterations may play an important role in the development of organ failure in critically ill patients and especially in sepsis. Recent advances in technology have allowed visualization of the microcirculation, but several scoring systems have been used so it is sometimes difficult to compare studies. This paper reports the results of a round table conference that was organized

Research paper thumbnail of Plasma Free Hemoglobin and Microcirculatory Response to Fresh or Old Blood Transfusions in Sepsis

PLOS ONE, 2015

Free hemoglobin (fHb) may induce vasoconstriction by scavenging nitric oxide. It may increase in ... more Free hemoglobin (fHb) may induce vasoconstriction by scavenging nitric oxide. It may increase in older blood units due to storage lesions. This study evaluated whether old red blood cell transfusion increases plasma fHb in sepsis and how the microvascular response may be affected. This is a secondary analysis of a randomized study. Twenty adult septic patients received either fresh or old (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10 or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;15 days storage, respectively) RBC transfusions. fHb was measured in RBC units and in the plasma before and 1 hour after transfusion. Simultaneously, the sublingual microcirculation was assessed with sidestream-dark field imaging. The perfused boundary region was calculated as an index of glycocalyx damage. Tissue oxygen saturation (StO2) and Hb index (THI) were measured with near-infrared spectroscopy and a vascular occlusion test was performed. Similar fHb levels were found in the supernatant of fresh and old RBC units. Despite this, plasma fHb increased in the old RBC group after transfusion (from 0.125 [0.098-0.219] mg/mL to 0.238 [0.163-0.369] mg/mL, p = 0.006). The sublingual microcirculation was unaltered in both groups, while THI increased. The change in plasma fHb was inversely correlated with the changes in total vessel density (r = -0.57 [95% confidence interval -0.82, -0.16], p = 0.008), De Backer score (r = -0.63 [95% confidence interval -0.84, -0.25], p = 0.003) and THI (r = -0.72 [95% confidence interval -0.88, -0.39], p = 0.0003). Old RBC transfusion was associated with an increase in plasma fHb in septic patients. Increasing plasma fHb levels were associated with decreased microvascular density. ClinicalTrials.gov NCT01584999.

Research paper thumbnail of PO2 measurements in the rat intestinal microcirculation

The American journal of physiology

Microvascular partial oxygen pressure (PO2) data measured with the quenched phosphorescence of pa... more Microvascular partial oxygen pressure (PO2) data measured with the quenched phosphorescence of palladium-porphyrin (Pd-porphyrin) with the use of optical fibers have provided new insight into the behavior of the microvascular oxygenation in models of shock. However, the actual microcirculatory compartment measured by this fiber technique has not yet been demonstrated. The purpose of this study was to investigate whether the PO2 of the intestines, as measured using a fiber phosphorometer, reflects the microvascular compartment. To this end, a new intravital phosphorometer with an improved sensitivity to high-PO2 levels (up to 180 mmHg) was developed and validated. With this setup, PO2 values were measured at different inspired oxygen fractions (15, 25, and 50% oxygen) in first-order arterioles, capillaries, and venules of the ileum of rats. Simultaneously, the PO2 was measured with an optical fiber attached to another phosphorometer. PO2 measurements with the fiber phosphorometer sho...

Research paper thumbnail of Assessment of ventilation inhomogeneity and gas exchange with volume controlled ventilation and pressure regulated volume controlled ventilation on pigs with surfactant depleted lungs

Advances in Experimental Medicine and Biology

Research paper thumbnail of The Microcirculation of the Septic Kidney

Seminars in nephrology, 2015

The renal microcirculation plays a major role in the delivery of blood and oxygen to the kidney. ... more The renal microcirculation plays a major role in the delivery of blood and oxygen to the kidney. In sepsis, alterations in renal microvascular perfusion, in conjunction with increased oxygen requirements, may contribute to renal failure even when renal macrovascular perfusion is preserved. In this review, we discuss the pathophysiology of the renal microcirculation during sepsis and how it contributes to acute kidney injury. Endothelial dysfunction largely is owing to inflammatory, oxidative, and nitrosative factors. Coagulative disorders and glycocalyx disruption also may contribute to the microcirculatory dysfunction. New technologies in experimental models and human beings are being developed to explore renal microcirculation in vivo. These technologies will allow a better understanding of the pathophysiopathology of the renal microcirculation and will help guide specific therapeutic strategies in sepsis-induced acute kidney injury.

Research paper thumbnail of The case for 0.9% NaCl: is the undefendable, defensible?

Kidney international, 2014

Although 0.9% NaCl solution is by far the most-used fluid for fluid therapy in resuscitation, it ... more Although 0.9% NaCl solution is by far the most-used fluid for fluid therapy in resuscitation, it is difficult to find a paper advocating its use over other types of crystalloid solutions. Literature on the deleterious effects of 0.9% NaCl has accumulated over the last decade, but critical appraisal of alternative crystalloid solutions is lacking. As such, the literature seems to suggest that 0.9% NaCl should be avoided at all costs, whereas alternative crystalloid solutions can be used without scrutiny. The basis of this negative evaluation of 0.9% NaCl is almost exclusively its effect on acid-base homeostasis, whereas the potentially deleterious effects present in other types of crystalloids are neglected. We have the challenging task of defending the use of 0.9% NaCl and reviewing its positive attributes, while an accompanying paper will argue against the use of 0.9% NaCl. It is challenging because of the large amount of literature, including our own, showing adverse effects of 0....

Research paper thumbnail of Counter statement to open letter to the Executive Director of the European Medicines Agency concerning the licensing of hydroxyethyl starch solutions for fluid resuscitation

British journal of anaesthesia, 2014

Research paper thumbnail of Study Design of the Microcirculatory Shock Occurrence in Acutely Ill Patients (microSOAP): an International Multicenter Observational Study of Sublingual Microcirculatory Alterations in Intensive Care Patients

Critical care research and practice, 2012

Objective. Sublingual microcirculatory alterations are associated with an adverse prognosis in se... more Objective. Sublingual microcirculatory alterations are associated with an adverse prognosis in several critical illness subgroups. Up to now, single-center studies have reported on sublingual microcirculatory alterations in ICU patient subgroups, but an extensive evaluation of the prevalence of these alterations is lacking. We present the study design of an international multicenter observational study to investigate the prevalence of microcirculatory alterations in critically ill: the Microcirculatory Shock Occurrence in Acutely ill Patients (microSOAP). Methods. 36 ICU's worldwide have participated in this study aiming for inclusion of over 500 evaluable patients. To enable communication and data collection, a website, an Open Clinica 3.0 database, and image uploading software have been designed. A one-session assessment of the sublingual microcirculation using Sidestream Dark Field imaging and data collection on patient characteristics has been performed in every ICU patient ...

Research paper thumbnail of Influence of fluid resuscitation on renal microvascular PO2 in a normotensive rat model of endotoxemia

Critical care (London, England), 2006

Septic renal failure is often seen in the intensive care unit but its pathogenesis is only partly... more Septic renal failure is often seen in the intensive care unit but its pathogenesis is only partly understood. This study, performed in a normotensive rat model of endotoxemia, tests the hypotheses that endotoxemia impairs renal microvascular PO2 (microPO2) and oxygen consumption (VO2,ren), that endotoxemia is associated with a diminished kidney function, that fluid resuscitation can restore microPO2, VO2,ren and kidney function, and that colloids are more effective than crystalloids. Male Wistar rats received a one-hour intravenous infusion of lipopolysaccharide, followed by resuscitation with HES130/0.4 (Voluven), HES200/0.5 (HES-STERIL 6%) or Ringer's lactate. The renal microPO2 in the cortex and medulla and the renal venous PO2 were measured by a recently published phosphorescence lifetime technique. Endotoxemia induced a reduction in renal blood flow and anuria, while the renal microPO2 and VO2,ren remained relatively unchanged. Resuscitation restored renal blood flow, renal...

Research paper thumbnail of Preservation of intestinal microvascular Po2 during normovolemic hemodilution in a rat model

The Journal of laboratory and clinical medicine, 2000

The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim o... more The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2). Normovolemic hemodilution was performed in 13 anesthetized male Wistar rats. Systemic hemodynamic and intestinal oxygenation parameters were monitored. Intestinal microvascular Po2 was measured by using the oxygen-dependent quenching of palladium-porphyrin phosphorescence. Hemodilution decreased systemic hematocrit from 45.0% +/- 0.1% (average +/- SEM) to 24.6% +/- 1.6%. The mesenteric blood flow did not change from baseline values, resulting in a linear decrease in intestinal oxygen delivery (from 2.77 +/- 0.15 to 1.42 +/- 0.11 mLxkg(-1)xmin(-1)). The intestinal oxygen extraction ratio increased significantly from 24% +/- 1% to 42% +/- 4%. Pmvo2 decreased significantly (from 57 +/- 2 to 41 +/- 2 mm...

Research paper thumbnail of Intestinal microvascular pO2 measurement with Pd-porphyrin phosphorescence in the mechanically ventilated mouse

Advances in experimental medicine and biology, 1998

Research paper thumbnail of Effect of ketanserine on oxygenation and ventilation inhomogeneity in pigs with ARDS

Advances in experimental medicine and biology, 1994

Research paper thumbnail of Bench-to-bedside review: Mechanisms of critical illness – classifying microcirculatory flow abnormalities in distributive shock

Critical care (London, England)

Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hyp... more Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hypovolemic, cardiogenic, obstructive and distributive shock. The first three categories have in common that they are associated with a fall in cardiac output. Distributive shock, such as occurs during sepsis and septic shock, however, is associated with an abnormal distribution of microvascular blood flow and metabolic distress in the presence of normal or even supranormal levels of cardiac output. This Bench-to-bedside review looks at the recent insights that have been gained into the nature of distributive shock. Its pathophysiology can best be described as a microcirculatory and mitochondrial distress syndrome, where time and therapy form an integral part of the definition. The clinical introduction of new microcirculatory imaging techniques, such as orthogonal polarization spectral and side-stream dark-field imaging, have allowed direct observation of the microcirculation at the bedsid...

Research paper thumbnail of The Microcirculation Is a Vulnerable Organ in Sepsis

The microcirculation is a vulnerable organ in sepsis. At the same time, the diseased microcircula... more 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 en...

Research paper thumbnail of Oxygen electrodes, optode microsensing, NIR and pectrophotometry

Research paper thumbnail of Large changes in renal microvascular PO2during acute normovolemic hemodilution

Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II ce... more Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II cells (A549). To study in vitro the direct influence of alveolar type II cells on mechanical stretch. Methods A549 were treated with different doses of lipopolysaccharide (LPS), 0 ng/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1000 ng/ml, and then A549 were lengthened 5%, 15%, 30% using a FLEXCELL tension unit 4000, a vacuum-driven device that applies strain to cells, which were cultured in six-well plates coated with collagen-I, and 12 cycles/min for 4 hours. Apoptosis was measured using the flow cytometry method that measures annexin V and propidium iodide (PI) staining. The morphological changes of apoptotic cells were observed by transmission electron microscope. Results Apoptosis could be induced in alveolar type II cells (A549) by mechanical stretch. The percentage of annexin V + PI cells increased after being treated with cyclic stretch for 4 hours by 5%, 15%, 30% in all groups. The morphological features of apoptotic cells demonstrated by transmission electron microscope were as follows: shrinkage of the cell, chromatin condensation and aggregation under the nuclear membrane as a crescent or lump, membrane-encapsulated nuclear fragment or cell organ formed by invagination of the cell membrane, and apoptotic body formation followed by vacuolization. Conclusion Apoptosis induced by mechanical stretch and LPS is dose dependent. Mechanical stretch aggravates apoptosis especially in cells treated with LPS. Annexin V and PI double staining is a specific, sensitive, and quantitative method for analyzing apoptotic cells. It is also helpful to clarify the protective mechanism of low-volume ventilation in ARDS. PaO 2 /FiO 2 430 [421; 440] # 380 [349; 397] 165 [68; 289] # C (ml/cmH 2 O) 28 [24; 32]* 18 [16; 21]* 12 [8; 17]* R i (cmH 2 O/l/s) 4.1 [3.9; 4.5] 4.5 [4.3; 5.1] 5.1 [3.7; 7.9] # P < 0.05 control vs 24-hour peritonitis, *P < 0.05 control vs 12-hour and 24-hour peritonitis.

Research paper thumbnail of Excitation Pulse Deconvolution in Luminescence Lifetime Analysis for Oxygen Measurements In Vivo