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Vollmer C, Weber APM, Wallenfang M, Hoffmann T, Mettler-Altmann T, Truse R, Bauer I, Picker O, Mathes AM. Melatonin pretreatment improves gastric mucosal blood flow and maintains intestinal barrier function during hemorrhagic shock in dogs. Microcirculation 2018; 24. [PMID: 28316127 DOI: 10.1111/micc.12345] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 12/12/2016] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Melatonin improves hepatic perfusion after hemorrhagic shock and may reduce stress-induced gastric lesions. This study was designed to investigate whether pretreatment with melatonin may influence gastric mucosal microcirculatory perfusion (μflow), oxygenation (μHbO2 ), or intestinal barrier function during physiological and hemorrhagic conditions in dogs. METHODS In a randomized crossover study, five anesthetized foxhounds received melatonin 100 μg kg-1 or vehicle (ethanol 5%) intravenously in the absence or presence of hemorrhagic shock (60 minutes, -20% blood volume). Systemic hemodynamic variables, gastric mucosal perfusion, and oxygenation were recorded continuously; intestinal barrier function was assessed intermittently via xylose absorption. RESULTS During hemorrhagic shock, melatonin significantly attenuated the decrease in μflow, compared with vehicle (-19±9 vs -43±10 aU, P<.05), without influence on μHbO2 . A significant increase in xylose absorption was detected during hemorrhage in vehicle-treated dogs, compared with sham-operated animals (13±2 vs 8±1 relative amounts, P<.05); this was absent in melatonin-treated animals (6±1 relative amounts). Melatonin did not influence macrocirculation. CONCLUSIONS Melatonin improves regional blood flow suggesting improved oxygen delivery in gastric mucosa during hemorrhagic shock. This could provide a mechanism for the observed protection of intestinal barrier function in dogs.
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Affiliation(s)
- Christian Vollmer
- Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Martin Wallenfang
- Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Till Hoffmann
- Department of Hemostaseology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Tabea Mettler-Altmann
- Plant Metabolism and Metabolomics Laboratory, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Richard Truse
- Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Inge Bauer
- Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Olaf Picker
- Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Alexander M Mathes
- Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.,Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, Cologne, Germany
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Vollmer C, Nommensen J, Watolla M, Bauer I, Picker O. Influence of thoracic epidural anesthesia on gastric oxygenation during hypothermia and hemorrhage. Auton Neurosci 2016; 195:1-7. [PMID: 26905213 DOI: 10.1016/j.autneu.2016.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/26/2016] [Accepted: 01/27/2016] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Hypothermia preserves gastric mucosal microvascular oxygenation (μHbO2) during hemorrhagic shock. Additionally, hypothermia activates the sympathetic nervous system that leads to the release of vasopressin. The aim of this study was to evaluate whether the effect of hypothermia is mediated via the sympathetic nervous system and/or via vasopressin. METHODS In prospective and randomized experiments on five anesthetized dogs (foxhounds, cross-over design, 6 groups with n=5 per group) we analyzed the effects of hemorrhage on μHbO2 during mild hypothermia (HT, 34 °C), during additional thoracic epidural anesthesia (HT/TEA) and during additional vasopressin V1 receptor blockade (HT/VB). As control groups, effects of hemorrhage were studied under normothermia alone (NT), during additional thoracic epidural anesthesia (NT/TEA) and during additional vasopressin V1 receptor blockade (NT/VB). RESULTS Hemorrhage decreased μHbO2 from 81 ± 3 to 49 ± 8%. In contrast, in the presence of hypothermia, μHbO2 was significantly higher during hemorrhagic shock (from 79 ± 3 to 66 ± 9%) despite a similar decrease in DO2. The effect of hypothermia on μHbO2 was reduced in the presence of thoracic epidural anesthesia or vasopressin receptor blockade. CONCLUSIONS Hypothermia preserves μHbO2 during hemorrhagic shock. This effect is partially abolished during thoracic epidural anesthesia or during vasopressin receptor blockade. The sympathetic nervous system and the vasopressin V1 receptor are partially involved in mediating the effect of hypothermia on gastric oxygenation during hemorrhage.
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Affiliation(s)
- Christian Vollmer
- Department of Anesthesiology, University Hospital Dusseldorf, Moorenstrasse 5, 40225 Dusseldorf, Germany.
| | - Jan Nommensen
- Department of Anesthesiology, University Hospital Dusseldorf, Moorenstrasse 5, 40225 Dusseldorf, Germany
| | - Markus Watolla
- Department of Anesthesiology, University Hospital Dusseldorf, Moorenstrasse 5, 40225 Dusseldorf, Germany
| | - Inge Bauer
- Department of Anesthesiology, University Hospital Dusseldorf, Moorenstrasse 5, 40225 Dusseldorf, Germany
| | - Olaf Picker
- Department of Anesthesiology, University Hospital Dusseldorf, Moorenstrasse 5, 40225 Dusseldorf, Germany
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Vollmer C, Weiß S, Beck C, Bauer I, Picker O. Hypothermia improves oral and gastric mucosal oxygenation during hypoxic challenges. Br J Anaesth 2014; 113:433-42. [PMID: 24390551 DOI: 10.1093/bja/aet462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Therapeutic hypothermia, used primarily for protective effects after hypoxia, improves oral and gastric mucosal microvascular oxygenation (μHbO₂) during additional haemorrhage. Therefore, we questioned whether hypothermia likewise improves μHbO₂ during hypoxic challenges. Since both hypothermia and hypoxia reduce cardiac output (e.g. by myofilament Ca(2+) desensitization), and modulate vasomotor tone via K(+) ATP channels, we hypothesized that the Ca(2+) sensitizer levosimendan and K(+) ATP channel blocker glibenclamide would support the cardiovascular system. METHODS The effects of mild hypothermia (34°C) on μHbO₂ during hypoxia [Formula: see text] were analysed in a cross-over study on five anaesthetized dogs and compared with normothermia (37.5°C) and hypoxia. During hypothermia, but before hypoxia, glibenclamide (0.2 mg kg(-1)) or levosimendan (20 µg kg(-1)+0.25 µg kg(-1) min(-1)) was administered. Systemic haemodynamic variables, gastric and oral mucosal microvascular oxygenation (reflectance spectrophotometry), and perfusion (laser Doppler flowmetry) were recorded continuously. Data are presented as mean (sem), P<0.05. RESULTS Hypoxia during normothermia reduced gastric μHbO₂ by 27 (3)% and oral μHbO₂ by 28 (3)% (absolute change). During hypothermia, this reduction was attenuated to 16 (3)% and 13 (1)% (absolute change). This effect was independent of microvascular flow that did not change during hypoxia and hypothermia. Additional administration of levosimendan during hypothermia restored reduced cardiac output but did not change flow or μHbO₂ compared with hypothermia alone. Glibenclamide did not exert any additional effects during hypothermia. CONCLUSIONS Hypothermia attenuates the decrease in μHbO₂ during additional hypoxic challenges independent of systemic or regional flow changes. A reduction in cardiac output during hypothermia is prevented by Ca(2+) sensitization with levosimendan but not by K(+) ATP channel blockade with glibenclamide.
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Affiliation(s)
- C Vollmer
- Department of Anaesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany
| | - S Weiß
- Department of Anaesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany
| | - C Beck
- Department of Anaesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany
| | - I Bauer
- Department of Anaesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany
| | - O Picker
- Department of Anaesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany
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Hypothermia improves oral and gastric mucosal microvascular oxygenation during hemorrhagic shock in dogs. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:589606. [PMID: 24327826 PMCID: PMC3845851 DOI: 10.1155/2013/589606] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 09/03/2013] [Accepted: 10/01/2013] [Indexed: 11/30/2022]
Abstract
Hypothermia is known to improve tissue function in different organs during physiological and pathological conditions. The aim of this study was to evaluate the effects of hypothermia on oral and gastric mucosal microvascular oxygenation (μHbO2) and perfusion (μflow) under physiological and hemorrhagic conditions. Five dogs were repeatedly anesthetized. All animals underwent each experimental protocol (randomized cross-over design): hypothermia (34°C), hypothermia during hemorrhage, normothermia, and normothermia during hemorrhage. Microcirculatory and hemodynamic variables were recorded. Systemic (DO2) and oral mucosal (μDO2) oxygen delivery were calculated. Hypothermia increased oral μHbO2 with no effect on gastric μHbO2. Hemorrhage reduced oral and gastric μHbO2 during normothermia (−36 ± 4% and −27 ± 7%); however, this effect was attenuated during additional hypothermia (−15 ± 5% and −11 ± 5%). The improved μHbO2 might be based on an attenuated reduction in μflow during hemorrhage and additional hypothermia (−51 ± 21 aU) compared to hemorrhage and normothermia (−106 ± 19 aU). μDO2 was accordingly attenuated under hypothermia during hemorrhage whereas DO2 did not change. Thus, in this study hypothermia alone improves oral μHbO2 and attenuates the effects of hemorrhage on oral and gastric μHbO2. This effect seems to be mediated by an increased μDO2 on the basis of increased μflow.
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Vollmer C, Schwartges I, Behmke R, Bauer I, Picker O. Hypercapnia counteracts captopril-induced depression of gastric mucosal oxygenation. J Endocrinol 2013; 218:245-53. [PMID: 23757508 DOI: 10.1530/joe-13-0132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hypercapnia (HC) increases systemic oxygen delivery (DO2) and gastric mucosal oxygenation. However, it activates the renin-angiotensin-aldosterone system (RAAS), which conversely reduces mesenteric perfusion. The aims of this study were to evaluate the effect of RAAS inhibition during normocapnia and HC on oral and gastric mucosal oxygenation (μHbO2) and to assess the effect of blood pressure under these circumstances. Five dogs were repeatedly anesthetized to study the effects of ACE inhibition (ACE-I; 5 mg/kg captopril, followed by 0.25 mg/kg per h) on μHbO2 (reflectance spectrophotometry) and hemodynamic variables during normocapnia (end-tidal CO2=35 mmHg) and HC (end-expiratory carbon dioxide (etCO2)=70 mmHg). In the control group, the dogs were subjected to HC alone. To exclude the effects of reduced blood pressure, in one group, blood pressure was maintained at baseline values via titrated phenylephrine (PHE) infusion during HC and additional captopril infusion. ACE-I strongly reduced gastric μHbO2 from 72±2 to 65±2% and mean arterial pressure (MAP) from 64±2 to 48±4 mmHg, while DO2 remained unchanged. This effect was counteracted in the presence of HC, which increased gastric μHbO2 from 73±3 to 79±6% and DO2 from 15±2 to 22±4 ml/kg per min during ACE-I without differences during HC alone. However, MAP decreased similar to that observed during ACE-I alone from 66±3 to 47±5 mmHg, while left ventricular contractility (dPmax) increased from 492±63 to 758±119 mmHg/s. Titrated infusion of PHE had no additional effects on μHbO2. In summary, our data suggest that RAAS inhibition reduces gastric mucosal oxygenation in healthy dogs. HC not only abolishes this effect, but also increases μHbO2, DO2, and dPmax. The increase in μHbO2 during ACE-I under HC is in accordance with our results independent of blood pressure.
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Affiliation(s)
- Christian Vollmer
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstraße 5, 40225 Duesseldorf, Germany.
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Vollmer C, Schwartges I, Naber S, Beck C, Bauer I, Picker O. Vasopressin V(1A) receptors mediate the increase in gastric mucosal oxygenation during hypercapnia. J Endocrinol 2013; 217:59-67. [PMID: 23359662 DOI: 10.1530/joe-12-0526] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hypercapnia (HC) improves systemic oxygen delivery (DO₂) and microvascular hemoglobin oxygenation of the mucosa (μHbO₂). Simultaneously, HC increases plasma levels of vasopressin. Although vasopressin is generally regarded a potent vasoconstrictor particularly in the splanchnic region, its effects on splanchnic microcirculation during HC is unclear. The aim of this study was to evaluate the role of endogenous vasopressin on gastric mucosal oxygenation and hemodynamic variables during physiological (normocapnia) and hypercapnic conditions. Five dogs were repeatedly anesthetized to study the effect of vasopressin V(1A) receptor blockade ([Pmp¹,Tyr(Me)²]-Arg⁸-Vasopressin, 35 μg/kg) on hemodynamic variables and μHbO₂ during normocapnia or HC (end-tidal CO₂ 70 mmHg). In a control group, animals were subjected to HC alone. μHbO₂ was measured by reflectance spectrophotometry, systemic DO₂ was calculated from intermittent blood gas analysis, and cardiac output was measured by transpulmonary thermodilution. Data are presented as mean±s.e.m. for n=5 animals. During HC alone, DO₂ increased from 12±1 to 16±1 ml/kg per min and μHbO₂ from 70±4 to 80±2%. By contrast, additional vasopressin V(1A) receptor blockade abolished the increase in μHbO₂ (80±2 vs. 69±2%) without altering the increase in DO₂ (16±1 vs. 19±2 ml/kg per min). Vasopressin V1A receptor blockade (VB) during normocapnia neither affected DO₂ (13±1 vs. 14±1 ml/kg per min) nor μHbO₂ (75±3 vs. 71±5%). Vasopressin V(1A) receptor blockade abolished the increase in μHbO₂ during HC independent of DO₂. Thus, in contrast to its generally vasoconstrictive properties, the vasopressin V1A receptors seem to mediate the increase in gastric microcirculatory mucosal oxygenation induced by acute HC.
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Affiliation(s)
- Christian Vollmer
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany.
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Pharmacologic Interventions to Improve Splanchnic Oxygenation During Ventilation with Positive End-Expiratory Pressure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 737:235-8. [DOI: 10.1007/978-1-4614-1566-4_34] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Scheeren TWL, Martin K, Maruschke M, Hakenberg OW. Prognostic value of intraoperative renal tissue oxygenation measurement on early renal transplant function. Transpl Int 2011; 24:687-96. [DOI: 10.1111/j.1432-2277.2011.01258.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hypercapnic Acidosis Preserves Gastric Mucosal Microvascular Oxygen Saturation in a Canine Model of Hemorrhage. Shock 2010; 34:636-42. [DOI: 10.1097/shk.0b013e3181e68422] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sevoflurane and propofol anaesthesia differentially modulate the effects of epinephrine and norepinephrine on microcirculatory gastric mucosal oxygenation. Br J Anaesth 2010; 105:421-8. [DOI: 10.1093/bja/aeq215] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hypercapnia induces a concentration-dependent increase in gastric mucosal oxygenation in dogs. Intensive Care Med 2008; 34:1898-906. [DOI: 10.1007/s00134-008-1183-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Accepted: 03/02/2008] [Indexed: 11/30/2022]
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Fournell A, Picker O, Schwartges I, Scheeren TWL, Schwarte LA. Clonidine elicits a long-term depression in mucosal red cell flux. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 599:17-22. [PMID: 17727242 DOI: 10.1007/978-0-387-71764-7_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
OBJECTIVE To evaluate the impact of clonidine on mucosal red cell flux during baseline sedation with propofol or sevoflurane, respectively. MATERIALS AND METHODS Six healthy, chronically instrumented dogs for the measurement of cardiac output (CO) were repeatedly studied. During baseline sedation with either propofol (15 mg x kg(-1) x h(-1)) or sevoflurane (1.5 MAC), local tissue cell flux was assessed using laser Doppler flowmetry at the enoral mucosa. After baseline measurements, a bolus of clonidine (2.0 microg/kg) was infused within 1 min. Data are presented as mean +/- SEM; STATISTICS ANOVA, Scheffé's post hoc test, p < 0.05. RESULTS Clonidine significantly reduced CO from 75 +/- 4 and 75 +/- 6 ml x kg(-1) x min(-1) (sedation with propofol or sevoflurane, respectively) to 40 +/- 3 and 49 +/- 5 ml x kg(-1) x min(-1), however, with almost complete recovery to baseline after 30 min (70 +/- 4 and 71 +/- 6 ml x kg(-1) x min(-1), NS from baseline). Similarly, clonidine decreased mucosal red cell flux by 44 +/- 8% and 54 +/- 4%. However, mucosal perfusion did not return to baseline (-25 +/- 5% and -27 +/- 3%). CONCLUSIONS In spite of the rapid return to baseline in systemic perfusion, the mucosal red cell flux of the enoral mucosa remained markedly reduced after a single bolus of clonidine. Given the crucial role of preserved microcirculatory perfusion for an intact mucosal barrier function, our data suggest that clonidine might impair this important mechanism to prevent the translocation of bacteria and endotoxins into the systemic circulation.
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Affiliation(s)
- Artur Fournell
- Department of Anesthesiology, Heinrich-Heine-University Duesseldorf, 40001 Duesseldorf, Germany.
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Schwarte LA, Picker O, Bornstein SR, Fournell A, Scheeren TWL. Levosimendan is superior to milrinone and dobutamine in selectively increasing microvascular gastric mucosal oxygenation in dogs*. Crit Care Med 2005; 33:135-42; discussion 246-7. [PMID: 15644660 DOI: 10.1097/01.ccm.0000150653.89451.6f] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The effect of levosimendan, a novel inotropic vasodilator (inodilator), on the microvascular gastric mucosal hemoglobin oxygenation (muHbo(2)) is unknown. A possible effect could thereby be selective for the splanchnic region or could primarily reflect changes in systemic oxygen transport (Do(2)) and/or oxygen consumption (Vo(2). We compared systemic and regional effects of levosimendan with those of established inotropes, milrinone and dobutamine. DESIGN Laboratory experiment. SETTING University animal research laboratory of experimental anesthesiology. SUBJECTS Chronically instrumented dogs with flow probes for cardiac output measurement. INTERVENTIONS Anesthetized, mechanically ventilated dogs (each group n = 6) on different days randomly received levosimendan (10 microg.kg, followed by four infusion steps: 0.125-1.0 microg.kg.min), milrinone (5.0 microg.kg, followed by 1.25-10 microg.kg.min), or dobutamine (2.5-10.0 microg.kg.min). Since these drugs may modify regional or systemic responses to fluid load, an additional predefined volume challenge was subsequently performed with hydroxyethyl starch 6% (10 mL.kg). MEASUREMENTS AND MAIN RESULTS We measured muHbo(2) (reflectance spectrophotometry), Do(2), Vo(2), and systemic hemodynamics. Levosimendan significantly increased muHbo(2) from baseline (approximately 55% for all groups) to 64 +/- 4% and further to 69 +/- 2% with volume challenge (mean +/- sem). At the systemic level, levosimendan alone only slightly increased Do(2) at a Vo(2). Milrinone elicited similar systemic effects (Do(2), Vo(2), hemodynamics) but failed to increase muHbo(2). Dobutamine, conversely, increased muHbo(2) to a similar extent as levosimendan; however, this was accompanied by marked increases in Do(2) and Vo(2). The gastric mucosa selectivity of these interventions, expressed as slope of the muHbo(2)/Do2 relation, was highest for levosimendan (+1.89 and +1.14, without and with volume challenge), compared with milrinone (+0.45 and + 0.47) and dobutamine (+0.48 and + 0.33). CONCLUSIONS Levosimendan is superior to milrinone (no significant regional effects) and dobutamine (marked systemic effects) in increasing gastric mucosal oxygenation selectively (i.e., at only moderately increased Do(2) and stable Vo(2). If our experimental data apply to the clinical setting, levosimendan may serve as an option to selectively increase gastrointestinal mucosa oxygenation in patients at risk to develop splanchnic ischemia.
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Affiliation(s)
- Lothar A Schwarte
- Department of Anesthesiology, University Hospital of Düsseldorf, Germany
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Schwarte LA, Picker O, Höhne C, Fournell A, Scheeren TWL. Effects of thoracic epidural anaesthesia on microvascular gastric mucosal oxygenation in physiological and compromised circulatory conditions in dogs. Br J Anaesth 2004; 93:552-9. [PMID: 15277300 DOI: 10.1093/bja/aeh235] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The effects of thoracic epidural anaesthesia (TEA) on gastric mucosal microvascular haemoglobin oxygenation (microHbO(2)) are unclear. At the splanchnic level, reduction of sympathetic tone may promote vasodilation and increase microHbO(2). However, these splanchnic effects are counteracted by systemic effects of TEA (e.g., decreased cardiac output (CO) and mean arterial pressure (MAP)), thus making the net effect on microHbO(2) difficult to predict. In this respect, effects of TEA on microHbO(2) may differ between physiological and compromised circulatory conditions, and additionally may depend on adequate fluid resuscitation. Furthermore, TEA may alter the relationship between regional microHbO(2) and systemic oxygen-transport (DO(2)). METHODS Chronically instrumented dogs (flow probes for CO measurement) were anaesthetized, their lungs ventilated and randomly received TEA with lidocaine (n=6) or epidural saline (controls, n=6). Animals were studied under physiological and compromised circulatory conditions (PEEP 10 cm H(2)O), both with and without fluid resuscitation. We measured gastric mucosal microHbO(2) by reflectance spectrophotometry, systemic DO(2), and systemic haemodynamics (CO, MAP). RESULTS Under physiological conditions, TEA preserved microHbO(2) (47 (3)% and 49 (5)%, mean (sem)) despite significantly decreasing DO(2) (11.3 (0.8) to 10.0 (0.7) ml kg(-1) min(-1)) and MAP (66 (2) to 59 (3) mm Hg). However, during compromised circulatory conditions, TEA aggravated the reduction in microHbO(2) (to 32 (1)%), DO(2) (to 6.7 (0.8) ml kg(-1) min(-1)) and MAP (to 52 (4) mm Hg), compared with controls. During TEA, fluid resuscitation completely restored these variables. TEA preserved the correlation between microHbO(2) and DO(2), compared with controls. CONCLUSIONS TEA maintains microHbO(2) under physiological conditions, but aggravates the reduction of microHbO(2) induced by cardiocirculatory depression, thereby preserving the relationship between gastric mucosal and systemic oxygenation.
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Affiliation(s)
- L A Schwarte
- Department of Anaesthesiology, University Hospital of Düsseldorf, Germany.
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Fournell A, Scheeren TWL, Schwarte LA. Simultaneous assessment of microvascular oxygen saturation and laser-Doppler flow in gastric mucosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 540:47-53. [PMID: 15174601 DOI: 10.1007/978-1-4757-6125-2_8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Affiliation(s)
- Artur Fournell
- Department of Anesthesiology, Heinrich-Heine-University, 40001 Duesseldorf, Germany.
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Schilling T, Gründling M, Strang CM, Möritz KU, Siegmund W, Hachenberg T. Effects of dopexamine, dobutamine or dopamine on prolactin and thyreotropin serum concentrations in high-risk surgical patients. Intensive Care Med 2004; 30:1127-33. [PMID: 15138671 DOI: 10.1007/s00134-004-2279-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2003] [Accepted: 03/04/2004] [Indexed: 01/11/2023]
Abstract
OBJECTIVES Catecholamines are often used for optimisation of cardiac index and oxygen delivery in high-risk surgical patients; however, infusions of dopamine and dopexamine are associated with dose-dependent hypophysiotropic and thyreotropic properties. The objective was to compare endocrine effects of equipotent inotropic doses of dopexamine, dobutamine and dopamine on prolactin and thyreotropin release perioperatively. DESIGN A prospective, randomised, blinded clinical trial. SETTING Adult surgical intensive care unit in a university hospital. PATIENTS Thirty male patients (ASA III) undergoing elective major abdominal surgery. INTERVENTIONS Patients were randomised to receive dopexamine (DX, n=10), dobutamine (DO, n=10) or dopamine (DA, n=10) on the first postoperative day for 8 h. MEASUREMENTS AND RESULTS All patients received a catecholamine infusion in doses adjusted to increase cardiac index by 35% within the first hour. Blood samples were obtained and prolactin and thyreotropin serum concentrations were determined by radioimmunoassays. Mean doses of dopexamine, dobutamine and dopamine used were 0.73+/-0.27, 4.06+/-1.95 and 5.0+/-1.84 micro g kg(-1)min(-1), respectively. Cardiac index was increased by 36% (DX group), 38% (DO group) and 38% (DA group). Alterations of oxygen delivery and oxygen consumption were not significantly different between the study groups. Dopexamine and dobutamine had no hypophysiotropic effects. In contrast, dopamine suppressed prolactin and thyreotropin secretion with a maximal effect after 4 h. After dopamine withdrawal, a rebound release of prolactin and thyreotropin was observed. CONCLUSIONS In high-risk surgical patients dopexamine or dobutamine produced fewer effects on prolactin and thyreotropin serum concentrations in comparison with DA when used in equivalent dosages.
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Affiliation(s)
- Thomas Schilling
- Department of Anaesthesiology and Intensive Care Medicine, Otto von Guericke University, Leipziger Strasse 44, 39120 Magdeburg, Germany.
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Schwarte LA, Picker O, Schindler AW, Fournell A, Scheeren TWL. Dopamine under α1-blockade, but not dopamine alone or fenoldopam, increases depressed gastric mucosal oxygenation*. Crit Care Med 2004; 32:150-6. [PMID: 14707574 DOI: 10.1097/01.ccm.0000099340.53754.5b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To compare the effects of dopamine, both in the presence and absence of alpha1-blockade, and fenoldopam on microvascular gastric mucosal oxygenation and systemic oxygen transport under compromised circulatory conditions, both without and with fluid resuscitation. DESIGN Randomized controlled animal study. SETTING University department of anesthesiology. SUBJECTS Eight anesthetized dogs with chronically implanted ultrasound flow probes around the pulmonary artery for continuous measurement of cardiac output. INTERVENTIONS On different days, the dogs received in random order either dopamine (2.5 and 5.0 microg.kg(-1).min(-1), with or without alpha1-blocker pretreatment), the selective DA1-agonist fenoldopam (0.1 and 1.0 microg.kg(-1).min(-1), with and without DA1-blocker pretreatment), or saline (control). These interventions were performed under compromised cardiocirculatory conditions (induced by ventilation with positive end-expiratory pressure [PEEP] of 10 cm H2O), both without and with fluid resuscitation. MEASUREMENTS AND MAIN RESULTS We continuously measured regional microvascular hemoglobin saturation (microHbO2) in gastric mucosa by reflectance spectrophotometry and systemic oxygen transport ([U1E0A]O2). Ventilation with PEEP significantly decreased [U1E0A]O2 (from 19 +/- 2 to 9 +/- 1 mL.kg(-1).min(-1), mean +/- sem) and gastric mucosal microHbO2 (from 57 +/- 2% to 37 +/- 3%). Fluid resuscitation restored [U1E0A]O2 back to baseline (from 9 +/- 1 to 19 +/- 2 mL.kg(-1).min(-1)) but only partially restored microHbO2 (from 37 +/- 3% to 50 +/- 4%). Under both conditions, dopamine with and without alpha1-blockade significantly increased [U1E0A]O2 (by about 5 mL.kg-1.min-1 in the nonresuscitated state and 10 mL.kg-1.min-1 in the fluid resuscitated state, respectively), but only dopamine in the presence of alpha1-blockade also significantly increased gastric mucosal microHbO2 (by 5 +/- 1% and 7 +/- 2% in the nonresuscitated and fluid resuscitated states, respectively). Fenoldopam under all study conditions did not significantly affect [U1E0A]O2 or microHbO2, either in the presence or absence of DA1-blockade. CONCLUSIONS During compromised cardiocirculatory conditions, alpha1-receptor activation during dopamine infusion prevented an increase in gastric mucosal oxygenation. Furthermore, selective DA1-stimulation (by fenoldopam) was insufficient to overcome the PEEP-induced depression of microHbO2. The responses of gastric mucosal oxygenation did not parallel changes in systemic oxygen transport. These findings were independent of fluid resuscitation.
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Affiliation(s)
- Lothar A Schwarte
- Department of Anesthesiology, University Hospital of Duesseldorf, Germany.
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Lehtipalo S, Biber B, Fröjse R, Arnerlöv C, Johansson G, Winsö O. Effects of dopexamine and positive end-expiratory pressure on intestinal blood flow and oxygenation: the perfusion pressure perspective. Chest 2003; 124:688-98. [PMID: 12907561 DOI: 10.1378/chest.124.2.688] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
OBJECTIVE To evaluate the net effects of the concomitant use of positive end-expiratory pressure (PEEP) and dopexamine on intestinal tissue perfusion and oxygenation during predefined artificial reductions in intestinal perfusion pressure (IPP). DESIGN Prospective, self-controlled, experimental study. SETTING University hospital research laboratory. SUBJECTS Seven female pigs. MEASUREMENTS In barbiturate-anesthetized pigs, we measured mesenteric blood flow (QMES) [by transit-time ultrasonic flowmetry], jejunal mucosal perfusion (by laser Doppler flowmetry), and tissue PO(2) (by microoximetry). Based on blood sampling, we calculated the intestinal net lactate production and oxygenation. INTERVENTIONS These measurements and calculations were performed at three predefined and controlled IPP levels, which were obtained by an adjustable clamp around the superior mesenteric artery. At each IPP level, measurements were performed prior to and during PEEP (10 cm H(2)O), both with and without simultaneous dopexamine infusions (at 0.5 and 1.0 microg/kg/min). RESULTS Within the IPP range of 77 to 33 mm Hg, intestinal perfusion and oxygenation were maintained irrespective of whether PEEP and/or dopexamine were applied or not. At IPP < 33 mm Hg, QMES and intestinal oxygenation deteriorated, resulting in regional net lactate production. At this IPP range, tissue oxygen perfusion was entirely pressure-dependent, and even small reductions in IPP led to prominent increases in intestinal net lactate production. Dopexamine did not modify this pattern. CONCLUSIONS We describe maintained intestinal tissue oxygen perfusion within a wide perfusion pressure range. Within this perfusion pressure range, PEEP did not induce any adverse regional circulatory effects. Below the perfusion pressure range for effective autoregulation, intestinal tissue oxygen perfusion deteriorated, and regional ischemia occurred. In this situation, dopexamine was unable to counteract IPP-dependent decreases in intestinal tissue oxygen perfusion. The regional ischemic threshold can be defined either as an IPP of < 33 mm Hg or as an intestinal tissue PO(2) of < 45 mm Hg.
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Affiliation(s)
- Stefan Lehtipalo
- Anesthesiology and Intensive Care Unit, Department of Surgical and Perioperative Sciences, Umeå University Hospital, Umeå, Sweden.
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Tao W, Mathru M. Gut mucosal blood flow: regional regulation or systemic pressure dependence? Chest 2003; 124:427-8. [PMID: 12907524 DOI: 10.1378/chest.124.2.427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Schwarte LA, Picker O, Schindler AW, Fournell A, Scheeren TWL. Fenoldopam--but not dopamine--selectively increases gastric mucosal oxygenation in dogs. Crit Care Med 2003; 31:1999-2005. [PMID: 12847395 DOI: 10.1097/01.ccm.0000074718.04034.bf] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the effects of fenoldopam and dopamine on gastric mucosal and systemic oxygenation, and to identify the receptors involved. DESIGN Randomized controlled animal study. SETTING University research department of experimental anesthesiology. SUBJECTS Seven anesthetized dogs with chronically implanted ultrasound flow probes around the pulmonary artery for continuous measurement of cardiac output. INTERVENTIONS On different days, the dogs received in random order either the selective DA(1)-agonist fenoldopam (0.1 and 1.0 microg x kg-1.= x min-1, with or without DA(1)-blocker pretreatment), dopamine (2.5 and 5.0 microg.kg-1 x min-1, with or without alpha(1)-blocker pretreatment), or saline (control). MEASUREMENTS AND MAIN RESULTS We continuously measured regional microvascular hemoglobin oxygen saturation (muHbO(2)) in gastric mucosa by reflectance spectrophotometry, and systemic oxygen delivery. Fenoldopam increased gastric mucosal muHbO(2) by approximately 20%, and this effect was prevented by selective DA(1)-receptor blockade. In contrast, dopamine neither alone nor during alpha(1)-blockade altered muHbO(2). With respect to systemic measures of oxygen transport, fenoldopam had negligible effects, whereas dopamine (with and without alpha(1)-blocker pretreatment) dose-dependently increased cardiac output and systemic oxygen delivery by approximately 30%. CONCLUSIONS Fenoldopam dose-dependently increased microvascular oxygenation of the gastric mucosa without changing systemic oxygen transport, i.e., this drug acted selectively on the splanchnic mucosa. The increase in gastric mucosal oxygenation was mediated by DA(1)-receptors. In contrast, dopamine markedly increased systemic oxygen transport, but did not affect microvascular oxygenation of gastric mucosa. This lacking effect on gastric mucosal oxygenation was not caused by alpha(1)-mediated vasoconstriction. The regional effects of both catecholamines could not be deduced from systemic hemodynamics and oxygenation.
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Affiliation(s)
- Lothar A Schwarte
- Department of Anesthesiology, University Hospital of Dusseldorf, Germany
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Fournell A, Schwarte LA, Kindgen-Milles D, Müller E, Scheeren TWL. Assessment of microvascular oxygen saturation in gastric mucosa in volunteers breathing continuous positive airway pressure. Crit Care Med 2003; 31:1705-10. [PMID: 12794408 DOI: 10.1097/01.ccm.0000063281.47070.53] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Adequate oxygenation of the gastrointestinal mucosa to preserve its barrier function is a basic objective in the prevention of multiple organ failure. Sustaining a positive airway pressure during the entire respiratory cycle remains a cornerstone in the therapeutic regimen to improve systemic oxygenation. Whereas increased systemic oxygenation during breathing continuous positive airway pressure has been shown, the impact of continuous positive airway pressure on regional oxygenation in the gastrointestinal tract has not yet been evaluated. We hypothesized that continuous positive airway pressure decreases microvascular oxygen saturation in gastric mucosa. DESIGN Prospective, randomized study. SETTING University department of anesthesiology. PARTICIPANTS Twelve healthy volunteers. INTERVENTIONS Incremental increases of continuous positive airway pressure (0, 5, and 10 cm H(2)O) and subsequent release of continuous positive airway pressure. MEASUREMENTS AND MAIN RESULTS We continuously measured microvascular oxygen saturation in gastric mucosa by reflectance spectrophotometry. Systemic oxygen saturation, end-tidal Pco(2), respiratory rate, heart rate, and arterial blood pressure were obtained noninvasively. In every volunteer, microvascular oxygen saturation in gastric mucosa was reduced corresponding to the level of continuous positive airway pressure, although systemic variables, especially systemic oxygen saturation, did not change. Continuous positive airway pressure reduced microvascular oxygen saturation in gastric mucosa from 59 +/- 7% (baseline with 0 cm H(2)O continuous positive airway pressure, mean +/- sd) to 54 +/- 8% (p <.05) during 5 cm H(2)O continuous positive airway pressure and to 50 +/- 9% (p <.05) during 10 cm H(2)O continuous positive airway pressure, returning to 59 +/- 7% during spontaneous breathing with 0 cm H(2)O continuous positive airway pressure. End-tidal Pco(2), respiratory rate, as well as hemodynamic variables, remained stable. CONCLUSIONS Reflectance spectrophotometry meticulously monitored changes in microvascular oxygen saturation in gastric mucosa during breathing continuous positive airway pressure. Microvascular oxygen saturation in gastric mucosa decreased with increasing levels of continuous positive airway pressure despite steady systemic variables. These results suggest that the impact of altering airway pressures on splanchnic oxygenation is not mirrored necessarily by concomitant changes in systemic circulation. Moreover, if these findings also apply to critically ill patients, monitoring microvascular oxygen saturation in gastric mucosa would be useful to further optimize the setting of ventilation variables.
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Affiliation(s)
- Artur Fournell
- Department of Anesthesiology, Heinrich-Heine-University, Düsseldorf, Germany
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Fournell A, Schwarte LA, Scheeren TWL, Kindgen-Milles D, Feindt P, Loer SA. Clinical evaluation of reflectance spectrophotometry for the measurement of gastric microvascular oxygen saturation in patients undergoing cardiopulmonary bypass. J Cardiothorac Vasc Anesth 2002; 16:576-81. [PMID: 12407609 DOI: 10.1053/jcan.2002.126951] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To evaluate the impact of cardiopulmonary bypass (CPB) on gastric mucosal oxygen saturation assessed by reflectance spectrophotometry in patients undergoing coronary artery bypass graft surgery. DESIGN Prospective, observational study. SETTING A division of cardiothoracic anesthesia in a university hospital. PARTICIPANTS Twelve consecutive patients undergoing CPB. INTERVENTIONS Monitoring, anesthesia, surgical procedure, and CPB for the patients followed routine clinical protocol as established in the departments. Microvascular oxygen saturation in gastric mucosa was assessed by reflectance spectrophotometry before, during, and after CPB. MEASUREMENTS AND MAIN RESULTS Gastric mucosal oxygen saturation averaged 65 +/- 7% (mean +/- SD) before CPB, decreased significantly to 57 +/- 9% during CPB (p < 0.01), and was 59 +/- 8% after CPB. These changes in regional oxygen saturation were not mirrored in variables of systemic oxygenation. Gastric mucosal oxygen saturation always showed instantaneous reactions to various surgical and pharmacologic interventions. CONCLUSION Reflectance spectrophotometry allowed the authors to assess gastric mucosal oxygen saturation with a high repetition rate, regardless of spontaneous circulation with pulsatile flow or nonpulsatile flow during CPB. This technique provided the means to monitor on-line the course of tissue oxygen saturation throughout the operative procedure. Reflectance spectrophotometry is an appropriate and sensitive assessment tool to monitor gastric mucosal oxygen saturation in patients undergoing CPB.
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Affiliation(s)
- Artur Fournell
- Department of Anesthesiology, Heinrich-Heine-University, Düsseldorf, Germany.
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