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Chia PY, Teo A, Yeo TW. Overview of the Assessment of Endothelial Function in Humans. Front Med (Lausanne) 2020; 7:542567. [PMID: 33117828 PMCID: PMC7575777 DOI: 10.3389/fmed.2020.542567] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 08/27/2020] [Indexed: 12/26/2022] Open
Abstract
The endothelium is recognized to play an important role in various physiological functions including vascular tone, permeability, anticoagulation, and angiogenesis. Endothelial dysfunction is increasingly recognized to contribute to pathophysiology of many disease states, and depending on the disease stimuli, mechanisms underlying the endothelial dysfunction may be markedly different. As such, numerous techniques to measure different aspects of endothelial dysfunction have been developed and refined as available technology improves. Current available reviews on quantifying endothelial dysfunction generally concentrate on a single aspect of endothelial function, although diseases may affect more than one aspect of endothelial function. Here, we aim to provide an overview on the techniques available for the assessment of the different aspects of endothelial function in humans, human tissues or cells, namely vascular tone modulation, permeability, anticoagulation and fibrinolysis, and the use of endothelial biomarkers as predictors of outcomes.
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Affiliation(s)
- Po Ying Chia
- National Centre for Infectious Diseases, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
| | - Andrew Teo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Medicine and Radiology and Doherty Institute, University of Melbourne, Victoria, VIC, Australia
| | - Tsin Wen Yeo
- National Centre for Infectious Diseases, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
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Yan J, van Smeden L, Merkx M, Zijlstra P, Prins MWJ. Continuous Small-Molecule Monitoring with a Digital Single-Particle Switch. ACS Sens 2020; 5:1168-1176. [PMID: 32189498 PMCID: PMC8177406 DOI: 10.1021/acssensors.0c00220] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
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The
ability to continuously measure concentrations of small molecules
is important for biomedical, environmental, and industrial monitoring.
However, because of their low molecular mass, it is difficult to quantify
concentrations of such molecules, particularly at low concentrations.
Here, we describe a small-molecule sensor that is generalizable, sensitive,
specific, reversible, and suited for continuous monitoring over long
durations. The sensor consists of particles attached to a sensing
surface via a double-stranded DNA tether. The particles transiently
bind to the sensing surface via single-molecular affinity interactions,
and the transient binding is optically detected as digital binding
events via the Brownian motion of the particles. The rate of binding
events decreases with increasing analyte concentration because analyte
molecules inhibit binding of the tethered particle to the surface.
The sensor enables continuous measurements of analyte concentrations
because of the reversibility of the intermolecular bonds and digital
read-out of particle motion. We show results for the monitoring of
short single-stranded DNA sequences and creatinine, a small-molecule
biomarker (113 Da) for kidney function, demonstrating a temporal resolution
of a few minutes. The precision of the sensor is determined by the
statistics of the digital switching events, which means that the precision
is tunable by the number of particles and the measurement time.
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Affiliation(s)
- Junhong Yan
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - Laura van Smeden
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - Maarten Merkx
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - Peter Zijlstra
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - Menno W. J. Prins
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
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Ilias I, Apollonatou S, Nikitas N, Theodorakopoulou M, Vassiliou AG, Kotanidou A, Dimopoulou I. Microdialysis-Assessed Adipose Tissue Metabolism, Circulating Cytokines and Outcome in Critical Illness. Metabolites 2018; 8:metabo8040062. [PMID: 30301230 PMCID: PMC6316198 DOI: 10.3390/metabo8040062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 01/02/2023] Open
Abstract
Microdialysis (MD) can provide continuous information about tissue composition. To assess in critically ill patients adipose tissue metabolic patterns, the relationships between metabolic patterns and blood cytokine concentration associations of adipose tissue energy metabolism and clinical outcome we studied 203 mechanically ventilated general intensive care unit (ICU) patients. Upon ICU admission an MD catheter was inserted into the subcutaneous adipose tissue of the upper thigh to measure lactate (L), glucose, pyruvate (P), and glycerol. Serum concentrations of IL-10, IL-6, IL-8, and TNF-α were determined within 48 h from ICU admission. Mitochondrial dysfunction was defined as L/P ratio >30 and pyruvate ≥70 μmol/L, ischemia as L/P ratio >30 and pyruvate <70 μmol/L and no ischemia/no mitochondrial dysfunction (i.e., aerobic metabolism) was as L/P ratio ≤30. Metabolism was aerobic in 74% of patients. In 13% of patients there was biochemical evidence of ischemia and in 13% of patients of mitochondrial dysfunction. Mitochondrial dysfunction was associated with poor outcome. In conclusion, MD showed that about two thirds of critically ill patients have normal aerobic adipose tissue metabolism. Mitochondrial dysfunction was not common but was associated with poor outcome. Identifying subgroups of critically ill patients is crucial as different treatment strategies may improve survival.
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Affiliation(s)
- Ioannis Ilias
- Endocrine Unit, Elena Venizelou Hospital, GR-11521 Athens, Greece.
| | - Sofia Apollonatou
- Second Department of Critical Care Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, Medical School, GR-12462 Athens, Greece.
| | - Nikitas Nikitas
- Department of Critical Care Medicine, North Middlesex Hospital, London N18 1QX, UK.
| | - Maria Theodorakopoulou
- Second Department of Critical Care Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, Medical School, GR-12462 Athens, Greece.
| | - Alice G Vassiliou
- First Department of Critical Care Medicine, Evangelismos Hospital, National and Kapodistrian University of Athens, Medical School, GR-10552 Athens, Greece.
| | - Anastasia Kotanidou
- First Department of Critical Care Medicine, Evangelismos Hospital, National and Kapodistrian University of Athens, Medical School, GR-10552 Athens, Greece.
| | - Ioanna Dimopoulou
- First Department of Critical Care Medicine, Evangelismos Hospital, National and Kapodistrian University of Athens, Medical School, GR-10552 Athens, Greece.
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Corrie SR, Coffey JW, Islam J, Markey KA, Kendall MAF. Blood, sweat, and tears: developing clinically relevant protein biosensors for integrated body fluid analysis. Analyst 2016; 140:4350-64. [PMID: 25909342 DOI: 10.1039/c5an00464k] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Biosensors are being developed to provide rapid, quantitative, diagnostic information to clinicians in order to help guide patient treatment, without the need for centralised laboratory assays. The success of glucose monitoring is a key example of where technology innovation has met a clinical need at multiple levels – from the pathology laboratory all the way to the patient's home. However, few other biosensor devices are currently in routine use. Here we review the challenges and opportunities regarding the integration of biosensor techniques into body fluid sampling approaches, with emphasis on the point-of-care setting.
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Affiliation(s)
- S R Corrie
- The University of Queensland, Australian Institute for Bioengineering and Nanotechnology, Delivery of Drugs and Genes Group (D2G2), St Lucia, Queensland 4072, Australia.
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Medina-Torres CE, Underwood C, Pollitt CC, Castro-Olivera EM, Hodson MP, Richardson DW, van Eps AW. Microdialysis measurements of equine lamellar perfusion and energy metabolism in response to physical and pharmacological manipulations of blood flow. Equine Vet J 2015; 48:756-764. [DOI: 10.1111/evj.12511] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/12/2015] [Indexed: 11/30/2022]
Affiliation(s)
- C. E. Medina-Torres
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - C. Underwood
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - C. C. Pollitt
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - E. M. Castro-Olivera
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - M. P. Hodson
- Australian Institute for Bioengineering and Nanotechnology (AIBN); The University of Queensland; Brisbane St Lucia Australia
- Metabolomics Australia - Queensland Node; AIBN; The University of Queensland; Brisbane St Lucia Australia
| | - D. W. Richardson
- New Bolton Center; Department of Clinical Studies; School of Veterinary Medicine; University of Pennsylvania; Kennett Square USA
| | - A. W. van Eps
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
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de Lima Oliveira M, Kairalla AC, Fonoff ET, Martinez RCR, Teixeira MJ, Bor-Seng-Shu E. Cerebral microdialysis in traumatic brain injury and subarachnoid hemorrhage: state of the art. Neurocrit Care 2015; 21:152-62. [PMID: 24072457 DOI: 10.1007/s12028-013-9884-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cerebral microdialysis (CMD) is a laboratory tool that provides on-line analysis of brain biochemistry via a thin, fenestrated, double-lumen dialysis catheter that is inserted into the interstitium of the brain. A solute is slowly infused into the catheter at a constant velocity. The fenestrated membranes at the tip of the catheter permit free diffusion of molecules between the brain interstitium and the perfusate, which is subsequently collected for laboratory analysis. The major molecules studied using this method are glucose, lactate, pyruvate, glutamate, and glycerol. The collected substances provide insight into the neurochemical features of secondary injury following traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) and valuable information about changes in brain metabolism within a short time frame. In this review, the authors detail the CMD technique and its associated markers and then describe pertinent findings from the literature about the clinical application of CMD in TBI and SAH.
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Affiliation(s)
- Marcelo de Lima Oliveira
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, Rua Loefgreen, 1.272 - Vila Clementino, São Paulo, SP, 04040-001, Brazil
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Does tissue ischemia actually contribute to leak after sleeve gastrectomy? An experimental study. Obes Surg 2015; 24:675-83. [PMID: 24374891 DOI: 10.1007/s11695-013-1156-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Staple line leak, although rare, is among the most common postoperative complications after sleeve gastrectomy (SG) and usually occurs in the gastroesophageal (GE) junction. Increased intragastric pressure, regional ischemia, and technical failure of stapling devices have been reported as the main risk factors of postoperative leak. The aim of this study was to evaluate the impact of ischemia and intraluminal pressure in leak appearance. METHODS Landrace swine (n = 12) were subjected to SG and total gastrectomy subsequently. Lactic acid, glycerol, and pyruvate were measured by microdialysis in GE junction and pylorus before and nine times after operation, and lactate/pyruvate (L/P) ratio was calculated as well. Moreover, ex vivo air was insufflated inside the tubularized stomach till a rupture of the staple line occurs. Maximum air pressure reached and location of rupture were recorded. RESULTS Increase of lactic acid and L/P ratio were demonstrated in GE junction measurements; however, when the measurements between GE junction and pylorus were compared, no statistically significant differences were found, with the exception of a slightly increased lactate concentration in pylorus in the midst of measurements. The maximum air pressure recorded varied from 3 to 75 mmHg (mean 24.5 mmHg) and the majority of ruptures (n = 8) occurred in GE junction. In one of them, clip displacement was noticed. CONCLUSIONS No evidence of increased ischemia in GE junction compared to pylorus was recorded. Increased intraluminal pressure and stapling malfunction may play the most important role in leak appearance.
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Medina-Torres CE, Underwood C, Pollitt CC, Castro-Olivera EM, Hodson MP, Richardson DW, van Eps AW. The effect of weightbearing and limb load cycling on equine lamellar perfusion and energy metabolism measured using tissue microdialysis. Equine Vet J 2014; 48:114-9. [DOI: 10.1111/evj.12377] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/30/2014] [Indexed: 11/26/2022]
Affiliation(s)
- C. E. Medina-Torres
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - C. Underwood
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - C. C. Pollitt
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - E. M. Castro-Olivera
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
| | - M. P. Hodson
- Metabolomics Australia; Queensland Node; Australian Institute for Bioengineering and Nanotechnology; The University of Queensland; St Lucia Australia
| | - D. W. Richardson
- Department of Clinical Studies; New Bolton Center; School of Veterinary Medicine; University of Pennsylvania; Kennett Square USA
| | - A. W. van Eps
- Australian Equine Laminitis Research Unit; School of Veterinary Science; The University of Queensland; Gatton Australia
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Equine lamellar energy metabolism studied using tissue microdialysis. Vet J 2014; 201:275-82. [DOI: 10.1016/j.tvjl.2014.05.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/18/2014] [Accepted: 05/21/2014] [Indexed: 11/19/2022]
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Coronary flow reserve is associated with tissue ischemia and is an additive predictor of intensive care unit mortality to traditional risk scores in septic shock. Int J Cardiol 2014; 172:103-8. [PMID: 24447732 DOI: 10.1016/j.ijcard.2013.12.155] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 10/31/2013] [Accepted: 12/26/2013] [Indexed: 01/31/2023]
Abstract
BACKGROUND Reduced coronary velocity flow reserve (CFR) is associated with poor outcome in patients with cardiovascular disease. We investigated whether CFR is associated with tissue ischemia and acidosis, impaired myocardial deformation and adverse outcome in patients with septic shock. METHODS In 70 mechanically-ventilated patients with septic shock, we examined: a) S' and E' mitral annular velocities using tissue Doppler imaging (TDI), b) CFR of the left anterior descending artery after adenosine infusion using transesophageal Doppler echocardiography and c) lactate, pyruvate and glycerol in tissue by means of a microdialysis (MD) catheter inserted into the subcutaneous adipose tissue as markers of tissue ischemia and acidosis. SOFA and APACHE II prognostic scores and mortality in the intensive care unit (ICU) were recorded. RESULTS Reduced CFR, S' and E' as well as increased E/E' correlated with increased SOFA, APACHE II and MD lactate to pyruvate ratio (p<0.05 for all correlations). Impaired TDI markers also correlated with increased MD glycerol (p<0.05). Reduced CFR correlated with decreased E' (p<0.05). CFR was 1.8 ± 0.42 in non-survivors (n=34) versus 2.08 ± 0.44 in survivors (p=0.007). A CFR<1.90 predicted mortality with sensitivity of 70% and specificity of 69% (area under the curve 77%; p=0.003). CFR had an additive value to APACHE (chi-square change: 4.358, p=0.03) and SOFA (chi-square change: 3.692, p=0.04) for the prediction of mortality. CONCLUSION Tissue ischemia and acidosis is a common pathophysiological link between decreased CFR and impaired LV myocardial deformation in septic shock. CFR is an additive predictor of ICU mortality to traditional risk scores in septic shock.
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Interstitial cortisol obtained by microdialysis in mechanically ventilated septic patients: Correlations with total and free serum cortisol. J Crit Care 2013; 28:158-65. [DOI: 10.1016/j.jcrc.2012.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/06/2012] [Accepted: 07/04/2012] [Indexed: 01/13/2023]
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Larentzakis A, Toutouzas KG, Papalois A, Lapidakis G, Doulgerakis S, Doulami G, Drimousis P, Theodorou D, Katsaragakis S. Porcine model of hemorrhagic shock with microdialysis monitoring. J Surg Res 2012; 179:e177-82. [PMID: 22480841 DOI: 10.1016/j.jss.2012.01.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/23/2011] [Accepted: 01/25/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND A number of experimental protocols have been used to try to reproduce the clinical scenarios of hemorrhagic shock. The present study reports on an experimental swine model of controlled hemorrhagic shock that incorporates microdialysis monitoring for the evaluation of tissue perfusion and oxygenation. The aim of our study was to provide a reproducible, accurate, and reliable model for the testing and evaluation of therapeutic interventions in the area of hemorrhagic shock. METHODS Landrace swine (n = 8) were subjected to controlled hemorrhagic shock, with a mean arterial pressure of 35 ± 5 as the endpoint. Six more pigs were used as the control group. Microdialysis monitoring of the tissue lactate/pyruvate ratio was used. The mean arterial pressure, heart rate, hematocrit, hemoglobin, and lactate/pyruvate ratio measurements were obtained just before (phase A) and 30 min after (phase B) hemorrhage in the study group; the control group underwent the same measurements at the corresponding points. RESULTS The mean arterial pressure, hematocrit, and hemoglobin were lower (P < 0.05) in the study group than in the control group at phase B and compared with the values for the study group at phase A. Also, the lactate/pyruvate ratio and heart rate were greater (P < 0.05) in the study group than in control group at phase B and compared with the values for the study group at phase A. CONCLUSIONS This model of hemorrhagic shock is effective and correlates with the clinical parameters of tissue oxygenation, as documented by microdialysis.
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Affiliation(s)
- Andreas Larentzakis
- First Propaedeutic Surgical Clinic, Hippocratio Hospital, Athens Medical School, University of Athens, Athens, Greece.
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Kinetics of adipose tissue microdialysis-derived metabolites in critically ill septic patients: associations with sepsis severity and clinical outcome. Shock 2011; 35:343-8. [PMID: 21102374 DOI: 10.1097/shk.0b013e318206aafa] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Microdialysis (MD) provides the opportunity to monitor tissue metabolic changes. This study aimed to describe the kinetics of MD-derived metabolites during the course of critical sepsis, to assess whether these metabolites are useful in grading sepsis severity, and to investigate their prognostic use. To this end, 54 mechanically ventilated septic patients were prospectively studied, out of which 39 had shock. Upon sepsis onset, an MD catheter was inserted into the subcutaneous adipose tissue of the upper thigh. Dialysate samples were analyzed for glucose, pyruvate, lactate, and glycerol. Sampling was performed six times per day for a maximum of 6 days. The daily mean values of MD measurements were calculated for each patient. Arterial blood was analyzed for glucose, lactate, and glycerol concomitantly with dialysate sampling. Blood glucose and tissue glucose levels along with lactate levels were high during the entire study period. Tissue pyruvate and glycerol were also raised, whereas the lactate-pyruvate ratio was preserved. At study entry, patients with septic shock had higher tissue lactate (3.3 vs. 1.9 mmol/L, P = 0.01) and glycerol (340 vs. 169 μmol/L, P = 0.04) levels compared with those without shock. Nonsurvivors had higher tissue lactate (P = 0.008), glycerol (P = 0.004), and pyruvate (P = 0.002) levels than survivors during the whole observation period. Logistic regression analysis showed that age (odds ratio [OR], 1.075; 95% confidence interval [CI], 1.004-1.150; P = 0.03), Sequential Organ Failure Assessment score on day 1 (OR, 1.550; 95% CI, 1.043-2.312; P = 0.03), and tissue glycerol on day 1 (OR, 1.007; 95% CI, 1.001-1.012; P = 0.01) predicted mortality independently. In conclusion, critical sepsis is characterized by high tissue lactate and pyruvate levels and a preserved lactate-pyruvate ratio, suggesting a nonischemic mechanism for raised blood lactate levels. Septic shock is associated with higher tissue lactate and glycerol levels compared with sepsis without shock. Elevated tissue lactate, pyruvate, and glycerol levels are related to poor clinical outcome, with the latter constituting an independent predictor.
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Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection. Anesthesiol Res Pract 2011; 2011:949034. [PMID: 21776255 PMCID: PMC3137975 DOI: 10.1155/2011/949034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 03/16/2011] [Accepted: 06/07/2011] [Indexed: 11/18/2022] Open
Abstract
During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.
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Vaddiraju S, Burgess DJ, Tomazos I, Jain FC, Papadimitrakopoulos F. Technologies for continuous glucose monitoring: current problems and future promises. J Diabetes Sci Technol 2010; 4:1540-62. [PMID: 21129353 PMCID: PMC3005068 DOI: 10.1177/193229681000400632] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Devices for continuous glucose monitoring (CGM) are currently a major focus of research in the area of diabetes management. It is envisioned that such devices will have the ability to alert a diabetes patient (or the parent or medical care giver of a diabetes patient) of impending hypoglycemic/hyperglycemic events and thereby enable the patient to avoid extreme hypoglycemic/hyperglycemic excursions as well as minimize deviations outside the normal glucose range, thus preventing both life-threatening events and the debilitating complications associated with diabetes. It is anticipated that CGM devices will utilize constant feedback of analytical information from a glucose sensor to activate an insulin delivery pump, thereby ultimately realizing the concept of an artificial pancreas. Depending on whether the CGM device penetrates/breaks the skin and/or the sample is measured extracorporeally, these devices can be categorized as totally invasive, minimally invasive, and noninvasive. In addition, CGM devices are further classified according to the transduction mechanisms used for glucose sensing (i.e., electrochemical, optical, and piezoelectric). However, at present, most of these technologies are plagued by a variety of issues that affect their accuracy and long-term performance. This article presents a critical comparison of existing CGM technologies, highlighting critical issues of device accuracy, foreign body response, calibration, and miniaturization. An outlook on future developments with an emphasis on long-term reliability and performance is also presented.
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Affiliation(s)
- Santhisagar Vaddiraju
- Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, University of ConnecticutStorrs, Connecticut
- Biorasis Inc., Technology Incubation Program, University of ConnecticutStorrs, Connecticut
| | - Diane J Burgess
- Department of Pharmaceutical Sciences, University of ConnecticutStorrs, Connecticut
| | - Ioannis Tomazos
- Biorasis Inc., Technology Incubation Program, University of ConnecticutStorrs, Connecticut
| | - Faquir C Jain
- Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, University of ConnecticutStorrs, Connecticut
| | - Fotios Papadimitrakopoulos
- Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, University of ConnecticutStorrs, Connecticut
- Department of Chemistry, University of ConnecticutStorrs, Connecticut
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Liljensten E, Skog G, Sönnergren H, Jensen-Waern M. Microdialysis as a method for biochemical and physiological studies of the porcine and human disc. Lab Anim 2010; 44:118-23. [PMID: 20357316 DOI: 10.1258/la.2010.009107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
At present, no minimally invasive technique exists for the continuous evaluation of the biochemistry of animal and human intervertebral discs, but for research purposes microdialysis may be such a new technique. Thus, the aims of this study were to (1) evaluate if microdialysis can be used successfully in lumbar porcine disc and (2) develop a suitable procedure for the application of microdialysis in the human disc. Conventional specific pathogen-free pigs were used to evaluate cannulation (n = 2) and then insertion of a 10 mm microdialysis membrane, including recovery of a dialysate from the nucleus pulposus (n = 6). The procedure was performed immediately after euthanasia and aided by fluoroscopy to guide the needle and confirm catheter placement. Access to lumbar porcine disc was obtained with an 18 G 2 in. needle applied at a 35-45 degrees angle from the sagittal plane, and took less than 8 min to perform. At a 0.5 microL/min flush rate, dialysates could be recovered and analysable amounts of glucose, lactate and pyruvate were obtained. In one human cadaver, the L4-L5 disc was accessed by a 19 G 3 in. needle inserted at a 35-40 degrees angle. It was possible to apply 10 mm as well as 30 mm microdialysis membranes in the nucleus. In both species the position of the membranes was verified by direct fluoroscopy and with contrast fluid. The results obtained from porcine and human cadavers are promising, and encourage further in vivo studies using microdialysis technique on intervertebral discs.
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Microdialysis-based sensing in clinical applications. Anal Bioanal Chem 2010; 397:909-16. [DOI: 10.1007/s00216-010-3626-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 02/24/2010] [Accepted: 02/26/2010] [Indexed: 12/30/2022]
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Serial lactate measurements using microdialysis of interstitial fluid do not correlate with plasma lactate in children after cardiac surgery. Pediatr Crit Care Med 2009; 10:66-70. [PMID: 19057429 DOI: 10.1097/pcc.0b013e31819374b0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVES Serial postoperative blood lactate (BL) concentrations have been shown to predict outcome of children after congenital heart surgery (CHS), and interventions aimed at lowering lactate can improve the outcome of these children. The cumulative blood loss for diagnostic purposes, such as repetitive arterial blood sampling in the intensive care unit, contributes, especially in small children, to anemia. Techniques to limit blood loss can therefore be of use. Microdialysis is a technique to monitor tissue chemistry in various clinical settings, and we hypothesized that it may be a valuable alternative for frequent blood sampling to monitor lactate in children after CHS. METHODS Fifteen children with a mean age of 40 months (range, 4-118 months) were prospectively enrolled after CHS. A CMA double lumen microdialysis catheter was inserted into the subcutaneous adipose tissue of the abdominal wall and infused with an isotone mannitol 5% solution at 1 microL/min via the inlet tubing. Microdialysate fluid was collected every hour for 48 hrs and stored at -80 degrees C for lactate determination (interstitial fluid lactate, IFL). Every hour arterial blood was taken for lactate determination. Individual profiles, correlation coefficient, and Bland-Altman analysis were used to compare BL and IFL results. RESULTS There were no complications with the microdialysis technique. All patients were discharged alive from hospital. Six hundred twenty paired samples were analyzed. Mean recovery of microdialysate fluid was 84%. Median (interquartile range) was 0.95 (0.70-1.15) mmol/L for BL and 1.13 (0.86-1.48) mmol/L for IFL (p < 0.0001). Individual profiles showed that IFL follows changes in BL in some, but not all children. With this study, we could not explain this discrepancy. The correlation between BL and IFL was poor (r = .77 (p < 0.0001) r = .59). Bland-Altman analysis confirmed the insufficient performance of the current microdialysis-based procedure compared with BL. CONCLUSION Serial lactate measurements in microdialysis fluid of subcutaneous adipose tissue are feasible, but cannot be used as a reliable interchangeable method for plasma lactate analysis in children after CHS at this time. Whether this technique has its own place in the assessment of the overall hemodynamic status and tissue perfusion in children after CHS needs to be addressed in future studies.
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Meybohm P, Cavus E, Bein B, Steinfath M, Weber B, Scholz J, Doerges V. Neurochemical monitoring using intracerebral microdialysis during systemic haemorrhage. Acta Neurochir (Wien) 2007; 149:691-8. [PMID: 17594051 DOI: 10.1007/s00701-007-1231-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Accepted: 02/23/2007] [Indexed: 11/27/2022]
Abstract
BACKGROUND Intracerebral microdialysis is a sensitive tool to analyse tissue biochemistry, but the value of this technique to monitor cerebral metabolism during systemic haemorrhage is unknown. The present study was designed to assess changes of intracerebral microdialysis parameters both during systemic haemorrhage and after initiation of therapy. METHODS Following approval of the Animal Investigational Committee, 18 healthy pigs underwent a penetrating liver trauma. Following haemodynamic decompensation, all animals received a hypertonic-hyperoncotic solution and either norepinephrine or arginine vasopressin, and bleeding was subsequently controlled. Extracellular cerebral concentrations of glucose (Glu), lactate (La), glycerol (Gly), and the lactate/pyruvate ratio (La/Py ratio) were assessed by microdialysis. Cerebral venous protein S-100B was determined. Haemodynamic data, blood gases, S-100B, and microdialysis variables were determined at baseline, at haemodynamic decompensation, and repeated after drug administration. RESULTS Microdialysis measurements showed an increase of La, Gly, and La/Py ratio at BL Th compared to BL (mean +/- SEM; La 2.4 +/- 0.2 vs. 1.4 +/- 0.2 mmol x l(-1), p < 0.01; Gly 37 +/- 7 vs. 27 +/- 6 micromol x l(-1), n.s.; La/Py ratio 50 +/- 8 vs. 30 +/- 4, p < 0.01), followed by a further increase during the therapy phase (La 3.4 +/- 0.3 mmol x l(-1); Gly 69 +/- 10 micromol x l(-1); La/Py ratio 58 +/- 8; p < 0.001, respectively). Cerebral venous protein S-100B increased at decompensation and after therapy, but decreased close to baseline values after 90 min of therapy. CONCLUSIONS In this model of systemic haemorrhage, changes of cerebral energy metabolism detected by intracerebral microdialysis indicated anaerobic glycolysis and degradation of cellular membranes throughout the study period.
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Affiliation(s)
- P Meybohm
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
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Solligård E, Wahba A, Skogvoll E, Stenseth R, Grønbech JE, Aadahl P. Rectal lactate levels in endoluminal microdialysate during routine coronary surgery. Anaesthesia 2007; 62:250-8. [PMID: 17300302 DOI: 10.1111/j.1365-2044.2006.04937.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The aim of this prospective study was to determine the feasibility of intestinal endoluminal microdialysis as a new method for clinical monitoring of the adequacy of splanchnic perfusion in the large bowel. A microdialysis catheter for continuous lactate, glycerol, glucose and pyruvate measurements attached to a tonometric catheter was placed into the lumen of the recto-sigmoid junction prior to surgery in 13 patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB). Lactate was also measured in blood and muscle. CPB was associated with a 10-fold increase in luminal lactate from 0.16 (0.01) to 1.67 (0.38) mmol x l(-1) (p < 0.001). Muscular lactate increased from baseline levels 1.20 (0.21) to 1.77 (0.36) mmol x l(-1) during CPB (p = 0.01), but the muscular lactate-pyruvate ratio remained unchanged. Arterial lactate increased only slightly from 0.9 (0.05) to 1.1 (0.06) mmol x l(-1) (p = 0.027) during CPB. Increased lactate concentrations in the large bowel during CPB are suggestive of local lactate production consistent with impaired oxygen delivery. Intestinal endoluminal microdialysis is a potential clinically applicable method for monitoring intestinal metabolism. Combined with tonometry, microdialysis provides the opportunity to monitor both circulation and metabolism in the rectal mucosa.
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Affiliation(s)
- E Solligård
- Department of Anaesthesiology and Intensive Care, St Olav University Hospital, Norwegian University of Science and Technology, N-7006 Trondheim, Norway.
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Machens HG, Pabst A, Dreyer M, Gliemroth J, Görg S, Bahlmann L, Klaus S, Kaun M, Krü Ger S, Mailänder P. C3a levels and occurrence of subdermal vascular thrombosis are age-related in deep second-degree burn wounds. Surgery 2006; 139:550-5. [PMID: 16627066 DOI: 10.1016/j.surg.2005.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 07/28/2005] [Accepted: 09/10/2005] [Indexed: 11/17/2022]
Abstract
BACKGROUND After second-degree burns, thrombosis of the subdermal vascular plexus may occur, necessitating epifascial necrectomy instead of tangential excision to ensure split skin graft healing. Until now, no parameter has been obtained to explain this phenomenon. METHODS Thirty-four patients with deep second-degree burn wounds were divided into 2 groups. In group 1, patients' age was < 60 years, in group 2, > 60 years. In each patient, 2 microdialysis catheters were introduced into subdermal tissue of deep second-degree thermal wounds immediately after admission. Another 2 catheters were introduced in control tissue. We measured biochemical parameters (lactate, glycerol and glucose) and complement 3a (C3a) until surgery was performed. The surgically removed tissue was examined histologically. RESULTS In thermal wounds of both groups, glucose levels fell, but lactate and glycerol levels rose compared to healthy tissue. Within the first 24 hours after trauma, C3a levels were significant higher in both groups, compared with controls (P < .01). After 24 hours the levels in group 1 had fallen to nonsignificant values, while in group 2 these levels remained high until surgery was performed (P < .001). We found significantly more thrombotic blood vessels in deep dermal tissue of group 2 (P < .005). Abbreviated burn severity index score was comparable in both groups. CONCLUSIONS C3a is continuously elevated in deep second-degree burned wounds in patients > 60 years. This finding may be related to the occurrence of significantly more thrombotic blood vessels in deep dermal tissue of elderly patients. Microdialysis therapy is a useful tool to measure metabolic and immunologic parameters in thermally damaged tissue.
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