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Ferlini L, Su F, Creteur J, Taccone FS, Gaspard N. Cerebral autoregulation and neurovascular coupling are progressively impaired during septic shock: an experimental study. Intensive Care Med Exp 2020; 8:44. [PMID: 32797301 PMCID: PMC7426896 DOI: 10.1186/s40635-020-00332-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/21/2020] [Indexed: 12/14/2022] Open
Abstract
Background Alteration of the mechanisms of cerebral blood flow (CBF) regulation might contribute to the pathophysiology of sepsis-associated encephalopathy (SAE). However, previous clinical studies on dynamic cerebral autoregulation (dCA) in sepsis had several cofounders. Furthermore, little is known on the potential impairment of neurovascular coupling (NVC) in sepsis. The aim of our study was to determine the presence and time course of dCA and NVC alterations in a clinically relevant animal model and their potential impact on the development of SAE. Methods Thirty-six anesthetized, mechanically ventilated female sheep were randomized to sham procedures (sham, n = 15), sepsis (n = 14), or septic shock (n = 7). Blood pressure, CBF, and electrocorticography were continuously recorded. Pearson’s correlation coefficient Lxa and transfer function analysis were used to estimate dCA. NVC was assessed by the analysis of CBF variations induced by cortical gamma activity (Eγ) peaks and by the magnitude-squared coherence (MSC) between the spontaneous fluctuations of CBF and Eγ. Cortical function was estimated by the alpha-delta ratio. Wilcoxon signed rank and rank sum tests, Friedman tests, and RMANOVA test were used as appropriate. Results Sepsis and sham animals did not differ neither in dCA nor in NVC parameters. A significant impairment of dCA occurred only after septic shock (Lxa, p = 0.03, TFA gain p = 0.03, phase p = 0.01). Similarly, NVC was altered during septic shock, as indicated by a lower MSC in the frequency band 0.03–0.06 Hz (p < 0.001). dCA and NVC impairments were associated with cortical dysfunction (reduction in the alpha-delta ratio (p = 0.03)). Conclusions A progressive loss of dCA and NVC occurs during septic shock and is associated with cortical dysfunction. These findings indicate that the alteration of mechanisms controlling cortical perfusion plays a late role in the pathophysiology of SAE and suggest that alterations of CBF regulation mechanisms in less severe phases of sepsis reported in clinical studies might be due to patients’ comorbidities or other confounders. Furthermore, a mean arterial pressure targeting therapy aiming to optimize dCA might not be sufficient to prevent neuronal dysfunction in sepsis since it would not improve NVC.
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Affiliation(s)
- Lorenzo Ferlini
- Department of Neurology, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Bruxelles, Belgium.
| | - Fuhong Su
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Nicolas Gaspard
- Department of Neurology, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Bruxelles, Belgium
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Sigurdsson ST, Bie P, Nielsen AH, Strandgaard S, Paulson OB. No effect of the angiotensin receptor blocker candesartan on cerebrovascular autoregulation in rats during very high and low sodium intake. J Renin Angiotensin Aldosterone Syst 2020; 20:1470320319874615. [PMID: 32154769 PMCID: PMC6732866 DOI: 10.1177/1470320319874615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Autoregulation of cerebral blood flow (CBF) denotes that CBF is constant despite
fluctuation of blood pressure within wide limits. Inhibition of the
renin–angiotensin system (RAS) is known to decrease the lower and upper limits
of CBF autoregulation. We have previously shown that this includes inhibition by
the angiotensin receptor blocker (ARB) candesartan. In the present study we
investigated the influence of the ARB candesartan on the lower limit of CBF
autoregulation in two groups of Sprague-Dawley rats, on high (4.0%
Na+) and low (0.004% Na+) sodium diet, respectively.
Control animals were given the same diet, but no ARB. CBF was studied with the
laser Doppler method. Blood pressure was lowered by controlled bleeding. Results
revealed that both high and low sodium diet with low and high renin levels
respectively block the influence of candesartan on CBF autoregulation. This was
expected in rats on a high salt diet with a low renin level, but unexpected in
rats with a low salt intake with a high renin level.
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Affiliation(s)
- Sigurdur T Sigurdsson
- Department of Nephrology, Copenhagen University Hospital at Herlev, Denmark.,Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark.,Department of Intensive Care, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Peter Bie
- Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Arne H Nielsen
- Department of Nephrology, Copenhagen University Hospital at Herlev, Denmark
| | - Svend Strandgaard
- Department of Nephrology, Copenhagen University Hospital at Herlev, Denmark
| | - Olaf B Paulson
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark
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Fujita M, Tsuruta R. Sepsis and Sepsis-Associated Encephalopathy: Its Pathophysiology from Bench to Bed. Neurocrit Care 2019. [DOI: 10.1007/978-981-13-7272-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Crippa IA, Subirà C, Vincent JL, Fernandez RF, Hernandez SC, Cavicchi FZ, Creteur J, Taccone FS. Impaired cerebral autoregulation is associated with brain dysfunction in patients with sepsis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:327. [PMID: 30514349 PMCID: PMC6280405 DOI: 10.1186/s13054-018-2258-8] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/07/2018] [Indexed: 12/12/2022]
Abstract
Background Sepsis-associated brain dysfunction (SABD) is associated with high morbidity and mortality. The pathophysiology of SABD is multifactorial. One hypothesis is that impaired cerebral autoregulation (CAR) may result in brain hypoperfusion and neuronal damage leading to SABD. Methods We studied 100 adult patients with sepsis (July 2012–March 2017) (age = 62 [52–71] years; Acute Physiology and Chronic Health Evaluation II score on admission = 21 [15–26]). Exclusion criteria were acute or chronic intracranial disease, arrhythmias, extracorporeal membrane oxygenation, and known intra- or extracranial supra-aortic vessel disease. The site of infection was predominantly abdominal (46%) or pulmonary (28%). Transcranial Doppler was performed, insonating the left middle cerebral artery with a 2-MHz probe. Middle cerebral artery blood flow velocity (FV) and arterial blood pressure (ABP) signals were recorded simultaneously; Pearson’s correlation coefficient (mean flow index [Mxa]) between ABP and FV was calculated using MATLAB. Impaired CAR was defined as Mxa > 0.3. Results Mxa was 0.29 [0.05–0.62]. CAR was impaired in 50 patients (50%). In a multiple linear regression analysis, low mean arterial pressure, history of chronic kidney disease and fungal infection were associated with high Mxa. SABD was diagnosed in 57 patients (57%). In a multivariable analysis, altered cerebral autoregulation, mechanical ventilation and history of vascular disease were independent predictors of SABD. Conclusions Cerebral autoregulation was altered in half of the patients with sepsis and was associated with the development of SABD. These findings support the concept that cerebral hypoxia could contribute to the development of SABD. Electronic supplementary material The online version of this article (10.1186/s13054-018-2258-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ilaria Alice Crippa
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070, Brussels, Belgium
| | - Carles Subirà
- Department of Intensive Care, Althaia Xarxa Assistencial Universitària de Manresa, Barcelona, Spain
| | - Jean-Louis Vincent
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070, Brussels, Belgium
| | - Rafael Fernandez Fernandez
- Department of Intensive Care, Althaia Xarxa Assistencial Universitària de Manresa, Barcelona, Spain.,CIBERES, Madrid, Spain
| | - Silvia Cano Hernandez
- Department of Intensive Care, Althaia Xarxa Assistencial Universitària de Manresa, Barcelona, Spain
| | - Federica Zama Cavicchi
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070, Brussels, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070, Brussels, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070, Brussels, Belgium.
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Late Recovery from Severe Streptococcus pneumoniae Comatose Meningitis with Concomitant Diffuse Subcortical Cytotoxic Edema and Cortical Hypometabolism. Case Rep Neurol Med 2018; 2018:9439021. [PMID: 30402310 PMCID: PMC6198566 DOI: 10.1155/2018/9439021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 09/04/2018] [Accepted: 09/26/2018] [Indexed: 12/03/2022] Open
Abstract
A 75-year-old woman was admitted to ICU with coma following Streptococcus pneumoniae meningitis with bacteremia. Her Glasgow Coma Scale (GCS) score fluctuated around 4 to 6 over the next four weeks. There was no evidence of increased intracranial pressure (ICP). Electroencephalogram (EEG) showed only diffuse aspecific slowing. Impaired cerebral blood flow (CBF) autoregulation was suggested at transcranial Doppler (TCD). Repeated brain magnetic resonance imaging (MRI) examination failed to demonstrate venous thrombosis, arterial ischemic stroke, or brain abscesses but revealed diffuse but reversible cortical cytotoxic edema at diffusion-weighted (DW) sequences. The brain FDG-positron emission tomography (FDG-PET) showed diffuse cortical hypometabolism. The patient unexpectedly experienced a complete neuropsychological recovery the next few weeks. The suggested hypothesis to explain this unusual disease course could be a transient alteration of CBF autoregulation due to some degree of diffuse subcortical microangiopathy. A concomitant reduction of brain metabolism probably prevented the progression towards cortical irreversible ischemic damage.
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Tariq A, Aguilar-Salinas P, Hanel RA, Naval N, Chmayssani M. The role of ICP monitoring in meningitis. Neurosurg Focus 2018; 43:E7. [PMID: 29088943 DOI: 10.3171/2017.8.focus17419] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Intracranial pressure (ICP) monitoring has been widely accepted in the management of traumatic brain injury. However, its use in other pathologies that affect ICP has not been advocated as strongly, especially in CNS infections. Despite the most aggressive and novel antimicrobial therapies for meningitis, the mortality rate associated with this disease is far from satisfactory. Although intracranial hypertension and subsequent death have long been known to complicate meningitis, no specific guidelines targeting ICP monitoring are available. A review of the literature was performed to understand the pathophysiology of elevated ICP in meningitis, diagnostic challenges, and clinical outcomes in the use of ICP monitoring.
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Affiliation(s)
- Areej Tariq
- Department of Neurology, Division of Cerebrovascular Disease and Neurocritical Care, The Ohio State University, Columbus, Ohio; and
| | | | - Ricardo A Hanel
- Lyerly Neurosurgery, Baptist Neurological Institute, Jacksonville, Florida
| | - Neeraj Naval
- Lyerly Neurosurgery, Baptist Neurological Institute, Jacksonville, Florida
| | - Mohamad Chmayssani
- Lyerly Neurosurgery, Baptist Neurological Institute, Jacksonville, Florida
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Williams M, Lee JK. Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals. Paediatr Anaesth 2014; 24:657-67. [PMID: 24725244 PMCID: PMC4154320 DOI: 10.1111/pan.12401] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/06/2014] [Indexed: 01/24/2023]
Abstract
Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monitoring techniques.
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Affiliation(s)
- Monica Williams
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, USA
| | - Jennifer K. Lee
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, USA
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Holler JG, Brandt CT, Leib SL, Rowland IJ, Østergaard C. Increase in hippocampal water diffusion and volume during experimental pneumococcal meningitis is aggravated by bacteremia. BMC Infect Dis 2014; 14:240. [PMID: 24886045 PMCID: PMC4016615 DOI: 10.1186/1471-2334-14-240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/25/2014] [Indexed: 11/22/2022] Open
Abstract
Background The hippocampus undergoes apoptosis in experimental pneumococcal meningitis leading to neurofunctional deficits in learning and memory function. The aim of the present study was 1) to investigate hippocampal apparent diffusion coefficient (ADC) and volume with MRI during the course of experimental pneumococcal meningitis, 2) to explore the influence of accompanying bacteremia on hippocampal water distribution and volume, 3) and to correlate these findings to the extent of apoptosis in the hippocampus. Methods Experimental meningitis in rats was induced by intracisternal injection of live pneumococci. The study comprised of four experimental groups. I. Uninfected controls (n = 8); II. Meningitis (n = 11); III. Meningitis with early onset bacteremia by additional i.v. injection of live pneumococci (n = 10); IV. Meningitis with attenuated bacteremia by treatment with serotype-specific anti-pneumococcal antibodies (n = 14). T2 and diffusion weighted MR images were used to analyze changes in hippocampus volume and water diffusion (ADC). The results were correlated to ADC of the cortex, to ventricular volume, and to the extent of hippocampal apoptosis. Results Both ADC and the volume of hippocampus were significantly increased in meningitis rats compared to uninfected controls (Kruskal-Wallis test, p = 0.0001, Dunns Post Test, p < 0.05), and were significantly increased in meningitis rats with an early onset bacteremia as compared to meningitis rats with attenuated bacteremia (p < 0.05). Hippocampal ADC and the volume and size of brain ventricles were positively correlated (Spearman Rank, p < 0.05), whereas no association was found between ADC or volume and the extent of apoptosis (p > 0.05). Conclusions In experimental meningitis increase in volume and water diffusion of the hippocampus are significantly associated with accompanying bacteremia.
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Affiliation(s)
- Jon G Holler
- Department of Infectious Diseases, Copenhagen University Hospital Hvidovre, Kettegaard Alle 30, Hvidovre, Copenhagen 2650, Denmark.
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9
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Hansen MB, Olsen NV, Hyldegaard O. Combined administration of hyperbaric oxygen and hydroxocobalamin improves cerebral metabolism after acute cyanide poisoning in rats. J Appl Physiol (1985) 2013; 115:1254-61. [DOI: 10.1152/japplphysiol.00516.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hyperbaric oxygen therapy (HBOT) or intravenous hydroxocobalamin (OHCob) both abolish cyanide (CN)-induced surges in interstitial brain lactate and glucose concentrations. HBOT has been shown to induce a delayed increase in whole blood CN concentrations, whereas OHCob may act as an intravascular CN scavenger. Additionally, HBOT may prevent respiratory distress and restore blood pressure during CN intoxication, an effect not seen with OHCob administration. In this report, we evaluated the combined effects of HBOT and OHCob on interstitial lactate, glucose, and glycerol concentrations as well as lactate-to-pyruvate ratio in rat brain by means of microdialysis during acute CN poisoning. Anesthetized rats were allocated to three groups: 1) vehicle (1.2 ml isotonic NaCl intra-arterially); 2) potassium CN (5.4 mg/kg intra-arterially); 3) potassium CN, OHCob (100 mg/kg intra-arterially) and subsequent HBOT (284 kPa in 90 min). OHCob and HBOT significantly attenuated the acute surges in interstitial cerebral lactate, glucose, and glycerol concentrations compared with the intoxicated rats given no treatment. Furthermore, the combined treatment resulted in consistent low lactate, glucose, and glycerol concentrations, as well as in low lactate-to-pyruvate ratios compared with CN intoxicated controls. In rats receiving OHCob and HBOT, respiration improved and cyanosis disappeared, with subsequent stabilization of mean arterial blood pressure. The present findings indicate that a combined administration of OHCob and HBOT has a beneficial and persistent effect on the cerebral metabolism during CN intoxication.
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Affiliation(s)
- M. B. Hansen
- Laboratory for Hyperbaric Medicine, Department of Anesthesia, Centre of Head and Orthopedics, Copenhagen University Hospital, Rigshospitalet, Denmark
- Hyperbaric Unit, Department of Anesthesia, Centre of Head and Orthopedics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - N. V. Olsen
- Department of Neuroanesthesia, The Neuroscience Centre, Copenhagen University Hospital, Rigshospitalet, Denmark; and
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - O. Hyldegaard
- Laboratory for Hyperbaric Medicine, Department of Anesthesia, Centre of Head and Orthopedics, Copenhagen University Hospital, Rigshospitalet, Denmark
- Hyperbaric Unit, Department of Anesthesia, Centre of Head and Orthopedics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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Abstract
Pneumococcal meningitis continues to be associated with high rates of mortality and long-term neurological sequelae. The most common route of infection starts by nasopharyngeal colonization by Streptococcus pneumoniae, which must avoid mucosal entrapment and evade the host immune system after local activation. During invasive disease, pneumococcal epithelial adhesion is followed by bloodstream invasion and activation of the complement and coagulation systems. The release of inflammatory mediators facilitates pneumococcal crossing of the blood-brain barrier into the brain, where the bacteria multiply freely and trigger activation of circulating antigen-presenting cells and resident microglial cells. The resulting massive inflammation leads to further neutrophil recruitment and inflammation, resulting in the well-known features of bacterial meningitis, including cerebrospinal fluid pleocytosis, cochlear damage, cerebral edema, hydrocephalus, and cerebrovascular complications. Experimental animal models continue to further our understanding of the pathophysiology of pneumococcal meningitis and provide the platform for the development of new adjuvant treatments and antimicrobial therapy. This review discusses the most recent views on the pathophysiology of pneumococcal meningitis, as well as potential targets for (adjunctive) therapy.
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Intracranial pressure following resuscitation with albumin or saline in a cat model of meningitis. Crit Care Med 2011; 39:135-40. [PMID: 21037473 DOI: 10.1097/ccm.0b013e3181fb7c94] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the intracranial pressure after resuscitation to normovolemia by using 20% albumin or normal saline in a cat model of meningitis. DESIGN Prospective, randomized animal study. SETTING University hospital laboratory. SUBJECTS Twenty adult, male cats. INTERVENTIONS Meningitis was induced by intrathecal injection of Escherichia coli-derived lipopolysaccharide (0.8 × 10 units/kg). Four hours after the lipopolysaccharide injection, the animals were randomized to intravenous treatment with 0.4 mL/kg/hr of 20% albumin or 7.5 mL/kg/hr of 0.9% sodium chloride for 6 hrs (n = 7 per group). A control group receiving lipopolysaccharide but no fluid was also studied (n = 6). MEASUREMENTS AND MAIN RESULTS Effects on intracranial pressure, mean arterial pressure, plasma volume (I-albumin technique), plasma oncotic pressure, and brain metabolism via cerebral interstitial lactate/pyruvate ratio and glycerol and glucose levels (microdialysis technique) were evaluated. Plasma volume decreased by approximately 20% and intracranial pressure increased from 10 to approximately 20 mm Hg at 4 hrs after the lipopolysaccharide injection. Six hours later, plasma volume had returned to baseline in both fluid groups while there was a further reduction in the control group. Intracranial pressure was higher in the saline group than in the albumin and control groups and was 25.8 ± 2.8 mm Hg, 18.3 ± 0.6 mm Hg, and 20.4 ± 1.7 mm Hg, respectively. Plasma oncotic pressure was higher in the albumin group than in the saline and control groups. Mean arterial pressure and microdialysis data were within normal range and did not differ among the groups. CONCLUSIONS The results showed that the choice of resuscitation fluid may influence intracranial pressure in meningitis. The lower intracranial pressure in the colloid group may be explained by a higher plasma oncotic pressure and less fluid distribution to the brain interstitium.
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Captopril Treatment Temporarily Restores Cerebral Blood Flow Autoregulation in Spontaneously Hypertensive Rats After Hemorrhagic Stroke. J Cardiovasc Pharmacol 2010; 56:255-62. [DOI: 10.1097/fjc.0b013e3181e8af62] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Østergaard C, Leib SL, Rowland I, Brandt CT. Bacteremia causes hippocampal apoptosis in experimental pneumococcal meningitis. BMC Infect Dis 2010; 10:1. [PMID: 20044936 PMCID: PMC2824701 DOI: 10.1186/1471-2334-10-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 01/03/2010] [Indexed: 11/26/2022] Open
Abstract
Background Bacteremia and systemic complications both play important roles in brain pathophysiological alterations and the outcome of pneumococcal meningitis. Their individual contributions to the development of brain damage, however, still remain to be defined. Methods Using an adult rat pneumococcal meningitis model, the impact of bacteremia accompanying meningitis on the development of hippocampal injury was studied. The study comprised of the three groups: I. Meningitis (n = 11), II. meningitis with attenuated bacteremia resulting from iv injection of serotype-specific pneumococcal antibodies (n = 14), and III. uninfected controls (n = 6). Results Pneumococcal meningitis resulted in a significantly higher apoptosis score 0.22 (0.18-0.35) compared to uninfected controls (0.02 (0.00-0.02), Mann Whitney test, P = 0.0003). Also, meningitis with an attenuation of bacteremia by antibody treatment resulted in significantly reduced apoptosis (0.08 (0.02-0.20), P = 0.01) as compared to meningitis. Conclusions Our results demonstrate that bacteremia accompanying meningitis plays an important role in the development of hippocampal injury in pneumococcal meningitis.
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Affiliation(s)
- Christian Østergaard
- Department of Clinical Microbiology, Copenhagen University Hospital Herlev, Herlev, Denmark.
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Prostacyclin reduces elevation of intracranial pressure and plasma volume loss in lipopolysaccharide-induced meningitis in the cat. ACTA ACUST UNITED AC 2009; 67:1345-51. [PMID: 20009688 DOI: 10.1097/ta.0b013e3181a5f211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Severe meningitis may compromise cerebral perfusion through increases in intracranial pressure (ICP) and through hypovolemia caused by a general inflammation with systemic plasma leakage. From its antiaggregative/antiadhesive and permeability-reducing properties, prostacyclin (PGI2) is a potential adjuvant treatment in meningitis, but previously published data have been ambiguous. The objective of this study was to evaluate the effects of PGI2 on meningitis on ICP, plasma volume, blood pressure, and cerebral oxidative metabolism. METHODS Meningitis was induced by intrathecal injection of lipopolysaccharide (LPS, 0.8 x 10 units/kg) in cats. Four hours after the injection, the animals were randomized to intravenous treatment with either low-dose PGI2 (1 ng/kg/min) or the vehicle for 6 hours (n = 7 in each group). No LPS and no PGI2 or vehicle was given to three cats (sham group). Effects of treatment on ICP, mean arterial pressure, plasma volume (I-albumin technique), and brain tissue lactate/pyruvate ratio (microdialysis technique) were evaluated. RESULTS ICP increased from 10.0 mm Hg +/- 1.3 mm Hg and 10.8 mm Hg +/- 1.7 mm Hg to 19.9 mm Hg +/- 1.7 mm Hg and 19.6 mm Hg +/- 3.3 mm Hg in the PGI2 and the vehicle group, respectively, 4 hours after the LPS injection (not significant). ICP increased further to 21.8 mm Hg +/- 4.5 mm Hg and to 25.8 mm Hg +/- 6.0 mm Hg after treatment for 6 hours with PGI2 or vehicle, respectively (p < 0.05). There was no significant difference in arterial pressure between groups. Plasma volume loss was less in the PGI2 group than in the vehicle group at the end of the experiment and urine production and arterial oxygenation was higher in the PGI2 group. Lactate/pyruvate ratio was within the normal range in all groups. CONCLUSION Low-dose PGI2 may be a beneficial adjuvant therapy for meningitis by reducing elevation of ICP and plasma volume loss.
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Taccone FS, Castanares-Zapatero D, Peres-Bota D, Vincent JL, Berre’ J, Melot C. Cerebral Autoregulation is Influenced by Carbon Dioxide Levels in Patients with Septic Shock. Neurocrit Care 2009; 12:35-42. [DOI: 10.1007/s12028-009-9289-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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