Reproducibility of sublingual microcirculation parameters obtained from sidestream darkfield imaging

Σκοπός: Διερευνήσαμε τη συσχέτιση της βλάβης του ενδοθηλιακού γλυκοκάλυκα με την αρτηριακή σκληρία, τη δυσλειτουργία της στεφανιαίας μικροκυκλοφορίας και την εξασθένιση της μυοκαρδιακής παραμόρφωσης, σε νεοδιαγνωσθέντες υπερτασικούς ασθενείς χωρίς φαρμακευτική αγωγή.Μέθοδοι και αποτελέσματα: Σε 320 νεοδιαγνωσθέντες υπερτασικούς ασθενείς χωρίς φαρμακευτική αγωγή και σε 160 φυσιολογικά άτομα της ομάδας ελέγχου, μετρήσαμε: α) το perfused boundary region (PBR) στην υπογλώσσια αρτηριακή μικροκυκλοφορία, β) το δείκτη του πάχους του γλυκοκάλυκα, χρησιμοποιώντας Sidestream Darkfield Imaging, γ) τη στεφανιαία εφεδρεία ροής (CFR) με τη ηχωκαρδιογραφία Doppler, δ) τη συνολική επιμήκης παραμόρφωση (GLS) και το ρυθμό συνολικούς επιμήκους παραμόρφωσης (GLSr) με την ηχωκαρδιογραφική μέθοδο speckle tracking, ε) την καρωτιδική και μηριαία ταχύτητα παλμικού κύματος (PWV) και τη συστολική κεντρική αρτηριακή πίεση (cSBP. Συγκριτικά με τα φυσιολογικά άτομα, οι υπερτασικοί είχαν υψηλότερες τιμές του PBR, του PWV, της cSPB και χαμηλότερες τιμές του GLS και GLSr (p<0.05). Στους υπερτασικούς ασθενείς υπήρξε στενή συσχέτιση στο μειωμένο πάχος του ενδοθηλιακού γλυκοκάλυκα όπως εκτιμήθηκε με το αυξημένο PBR, την αυξημένη κεντρική συστολική αρτηριακή πίεση και την αυξημένη ταχύτητα παλμικού κύματος όπως και στη μείωση της στεφανιαίας εφεδρείας ροής (CFR) (p<0,05), την οριακή σχέση του PBR με τη συστολική αρτηριακή πίεση του ιατρείου (p=0,06) μετά από προσαρμογή της ηλικίας, του φύλλου, του δείκτη μάζας σώματος, του καπνίσματος, της μάζας της αριστερής κοιλίας, της καρδιακής συχνότητας ,της δυσλιπιδαιμίας και της συστολικής αρτηριακής πίεσης του ιατρείου.Το PBR είχε μία επιπρόσθετη αξία του πολυπαραγοντικού μοντέλου που περιλάμβανε το PWV, τη CFR και τη συστολική αρτηριακή πίεση του ιατρείου στην πρόβλεψη του παθολογικού GLS (x2=2.4 έναντι 3.8 μετά από την προσθήκη του PBR 5-25, p για αλλαγή=0,03). Συμπεράσματα: Ο ενδοθηλιακός γλυκοκάλυκας είναι παθολογικός στους νεοδιαγνωσθέντες υπερτασικούς ασθενείς. Αυτή η βλάβη σχετίζεται με την ανωμαλία των ελαστικών ιδιοτήτων της αορτής και την παθολογική λειτουργία της στεφανιαίας μικροκυκλοφορίας, που συμβάλλει στην εξασθένηση της επιμήκους παραμόρφωσης της αριστερής κοιλίας.

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Association of preoperative plasma suPAR levels with intraoperative sublingual microvascular perfusion in patients undergoing major non-cardiac surgery

10.1101/2021.07.03.21259960 ◽

2021 ◽

Author(s):

Athanasios Chalkias ◽

Nikolaos Papagiannakis ◽

Bernd Saugel ◽

Moritz Flick ◽

Konstantina Kolonia ◽

...

Keyword(s):

Cardiac Surgery ◽

Mean Arterial Pressure ◽

Postoperative Complications ◽

Arterial Pressure ◽

Primary Objective ◽

Microvascular Perfusion ◽

Sublingual Microcirculation ◽

Supar Level ◽

Flow Reserve ◽

Sidestream Darkfield

Introduction: The plasma suPAR level has previously been associated with postoperative complications and has been shown to be an independent predictor of coronary microvascular function and flow reserve. We investigated the association between preoperative suPAR levels and intraoperative sublingual microvascular perfusion in patients undergoing elective major non-cardiac surgery. Methods: This study included 100 patients undergoing major non-cardiac surgery between February 2019 and September 2020. The primary objective was to investigate the association between preoperative suPAR and intraoperative sublingual De Backer score, Consensus Proportion of Perfused Vessels (Consensus PPV), and Consensus PPV (small). Secondary objectives were to investigate the associations between these sublingual microcirculatory variables and (1) complications and (2) mean arterial pressure. EDTA blood was collected before induction of anesthesia and plasma suPAR levels were determined using the suPARnostic quick triage lateral flow assay. Sublingual microcirculation was monitored with Sidestream DarkField (SDF+) imaging technique at 20 minutes after induction of anesthesia before surgical incision (baseline) and then every 30 minutes until emergence from anesthesia. Results: A decrease of 0.7 mm-1 in the De Backer score, 2.5% in the Consensus PPV, and 2.8% in the Consensus PPV (small) from baseline measurement was observed for every 1 ng/ml increase of suPAR or 1 additional minute of intraoperative time. De Baker score did not change significantly from baseline (p=0.404), while Consensus PPV and Consensus PPV (small) decreased significantly from baseline (p<0.001 in both cases). The De Backer score, the Consensus PPV, and the Consensus PPV (small) correlated with postoperative complications. Mean arterial pressure correlated with De Backer score (p=0.487) but not with Consensus PPV (p=0.506) or Consensus PPV (small) (p=0.697) during the intraoperative period. Conclusion: Preoperative suPAR levels and prolonged operative duration were associated with intraoperative impairment of sublingual microvascular perfusion in patients undergoing elective major non-cardiac surgery.

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A Technique for Reliably Preparing Full-Length Metallographic Cross-Sections of Integrated Circuit Bond Wires

ISTFA 2006: Conference Proceedings from the 32nd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2006p0268 ◽

2006 ◽

Author(s):

Carl Nail

Keyword(s):

Integrated Circuits ◽

High Precision ◽

Cross Sections ◽

Integrated Circuit ◽

Radiographic Analysis ◽

Good Resolution ◽

Metallographic Preparation ◽

Bond Wires ◽

Darkfield Imaging ◽

Bond Wire

Abstract To overcome the obstacles in preparing high-precision cross-sections of 'blind' bond wires in integrated circuits, this article proposes a different technique that generates reliable, repeatable cross-sections of bond wires across most or all of their lengths, allowing unencumbered and relatively artifact-free analysis of a given bond wire. The basic method for cross-sectioning a 'blind' bond wire involves radiographic analysis of the sample and metallographic preparation of the sample to the plane of interest. This is followed by tracking the exact location of the plane on the original radiograph using a stereomicroscope and finally darkfield imaging in which the wire is clearly visible with good resolution.

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Effects of remote ischemic conditioning on microcirculatory alterations in patients with sepsis: a single-arm clinical trial

Annals of Intensive Care ◽

10.1186/s13613-021-00848-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Inga Kiudulaite ◽

Egle Belousoviene ◽

Astra Vitkauskiene ◽

Andrius Pranskunas

Keyword(s):

Dark Field ◽

Historical Control ◽

Flow Index ◽

Control Group ◽

Remote Ischemic Conditioning ◽

Ischemic Conditioning ◽

Sublingual Microcirculation ◽

Link Type ◽

Microcirculatory Flow ◽

Tertiary Teaching

Abstract Background Remote ischemic conditioning (RIC) is a promising technique that may protect organs and tissues from the effects of additional ischemic episodes. However, the therapeutic efficacy of RIC in humans with sepsis remains unknown. We hypothesized that RIC might improve sublingual microcirculation in patients with sepsis. Methods This prospective single-arm trial was performed in a mixed ICU at a tertiary teaching hospital. We included patients with sepsis or septic shock within 24 h of ICU admission. The RIC procedure comprised 3 cycles of brachial cuff inflation to 200 mmHg for 5 min followed by deflation to 0 mmHg for another 5 min. The procedure took 30 min. RIC was performed at the time of study inclusion and repeated after 12 and 24 h. Sublingual microcirculatory measurements were obtained before and after each RIC procedure using a Cytocam®-incident dark-field (IDF) device (Braedius Medical, Huizen, The Netherlands). The microcirculatory data were compared with a historical control. Data are reported as the medians along with the 25th and 75th percentiles. Results Twenty-six septic patients with a median age of 65 (57–81) years were enrolled in this study. The median Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores at admission were 20 (13–23) and 10 (9–12), respectively. All patients were receiving vasopressors. After the 1st RIC procedure, the microvascular flow index (MFI) and the proportion of perfused vessels (PPV) among small vessels were significantly higher than before the procedure, with pre- and post-treatment values of 2.17 (1.81–2.69) and 2.59 (2.21–2.83), respectively, for MFI (p = 0.003) and 87.9 (82.4–93.8) and 92.5 (87.9–96.1) %, respectively, for PPV (p = 0.026). This result was confirmed by comparison with a historical control group. We found no change in microcirculatory flow or density parameters during repeated RIC after 12 h and 24 h. Conclusion In patients with sepsis, the first remote ischemic conditioning procedure improved microcirculatory flow, whereas later procedures did not affect sublingual microcirculation. Trial registration NCT04644926, http://www.clinicaltrials.gov. Date of registration: 25 November 2020. Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04644926.

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Effects of whole-body neuromuscular electrical stimulation device on hemodynamics, arrhythmia, and sublingual microcirculation

Heart and Vessels ◽

10.1007/s00380-020-01755-1 ◽

2021 ◽

Author(s):

Megumi Hoshiai ◽

Kaori Ochiai ◽

Yuma Tamura ◽

Tomoki Tsurumi ◽

Masato Terashima ◽

...

Keyword(s):

Electrical Stimulation ◽

Blood Glucose ◽

Blood Lactate ◽

Neuromuscular Electrical Stimulation ◽

Whole Body ◽

Left Ventricular Ejection ◽

Sublingual Microcirculation ◽

Blood Fluidity ◽

Lactate Levels ◽

Blood Lactate Levels

AbstractNeuromuscular electrical stimulation has been used to treat cardiovascular diseases and other types of muscular dysfunction. A novel whole-body neuromuscular electrical stimulation (WB-NMES) wearable device may be beneficial when combined with voluntary exercises. This study aimed to investigate the safety and effects of the WB-NMES on hemodynamics, arrhythmia, and sublingual microcirculation. The study included 19 healthy Japanese volunteers, aged 22–33 years, who were not using any medication. Electrocardiogram (ECG), echocardiography, and blood sampling were conducted before a 20-min WB-NMES session and at 0 and 10 min after termination of WB-NMES. Their tolerable maximum intensity was recorded using numeric rating scale. Arrhythmia was not detected during neuromuscular electrical stimulation or during 10 min of recovery. Blood pressure, heart rate, left ventricular ejection fraction, and diastolic function remained unchanged; however, mild mitral regurgitation was transiently observed during WB-NMES in a single male participant. A decrease in blood glucose and an increase in blood lactate levels were observed, but no changes in blood fluidity, sublingual microcirculation, blood levels of noradrenaline, or oxidative stress were shown. WB-NMES is safe and effective for decreasing blood glucose and increasing blood lactate levels without changing the blood fluidity or microcirculation in healthy people.

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Intestinal and sublingual microcirculation are more severely compromised in hemodilution than in hemorrhage

Journal of Applied Physiology ◽

10.1152/japplphysiol.00007.2016 ◽

2016 ◽

Vol 120 (10) ◽

pp. 1132-1140 ◽

Cited By ~ 9

Author(s):

Gonzalo Ferrara ◽

Vanina Siham Kanoore Edul ◽

Enrique Martins ◽

Héctor Saúl Canales ◽

Carlos Canullán ◽

...

Keyword(s):

Cardiac Output ◽

Blood Cell ◽

Red Blood Cell ◽

Alternative Explanation ◽

Vascular Density ◽

Mechanically Ventilated ◽

Sublingual Microcirculation ◽

Intestinal Microcirculation ◽

Fast Red ◽

Last Stage

The alterations in O2 extraction in hemodilution have been linked to fast red blood cell (RBC) velocity, which might affect the complete release of O2 from Hb. Fast RBC velocity might also explain the normal mucosal-arterial Pco2 (ΔPco2). Yet sublingual and intestinal microcirculation have not been completely characterized in extreme hemodilution. Our hypothesis was that the unchanged ΔPco2 in hemodilution depends on the preservation of villi microcirculation. For this purpose, pentobarbital-anesthetized and mechanically ventilated sheep were submitted to stepwise hemodilution ( n = 8), hemorrhage ( n = 8), or no intervention (sham, n = 8). In both hypoxic groups, equivalent reductions in O2 consumption (V̇o2) were targeted. Microcirculation was assessed by videomicroscopy, intestinal ΔPco2 by air tonometry, and V̇o2 by expired gases analysis. Although cardiac output and superior mesenteric flow increased in hemodilution, from the very first step (Hb = 5.0 g/dl), villi functional vascular density and RBC velocity decreased (21.7 ± 0.9 vs. 15.9 ± 1.0 mm/mm2 and 1,033 ± 75 vs. 850 ± 79 μm/s, P < 0.01). In the last stage (Hb = 1.2 g/dl), these variables were lower in hemodiution than in hemorrhage (11.1 ± 0.5 vs. 15.4 ± 0.9 mm/mm2 and 544 ± 26 vs. 686 ± 70 μm/s, P < 0.01), and were associated with lower intestinal fractional O2 extraction (0.61 ± 0.04 vs. 0.79 ± 0.02, P < 0.01) but preserved ΔPco2 (5 ± 2 vs. 25 ± 4 mmHg, P < 0.01). Therefore, alterations in O2 extraction in hemodilution seemed related to microvascular shunting, not to fast RBC velocity. The severe microvascular abnormalities suggest that normal ΔPco2 was not dependent on CO2 washout by the villi microcirculation. Increased perfusion in deeper intestinal layers might be an alternative explanation.

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Darkfield Imaging of Platelet Cytoskeleton-Granule Interactions

Biophysical Journal ◽

10.1016/j.bpj.2013.11.2932 ◽

2014 ◽

Vol 106 (2) ◽

pp. 525a

Author(s):

Solaire Finkenstaedt-Quinn ◽

Christy L. Haynes

Keyword(s):

Darkfield Imaging

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Assessment of the sublingual microcirculation with the GlycoCheck system: Reproducibility and examination conditions

PLoS ONE ◽

10.1371/journal.pone.0243737 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243737

Author(s):

Mie Klessen Eickhoff ◽

Signe Abitz Winther ◽

Tine Willum Hansen ◽

Lars Jorge Diaz ◽

Frederik Persson ◽

...

Keyword(s):

Intraclass Correlation ◽

Coffee Consumption ◽

Boundary Region ◽

Microvascular Perfusion ◽

Controlled Study ◽

Coffee Intake ◽

Sublingual Microcirculation ◽

Randomised Controlled Study ◽

Multiple Measurements ◽

Randomised Controlled

Background The glycocalyx is an extracellular layer lining the lumen of the vascular endothelium, protecting the endothelium from shear stress and atherosclerosis and contributes to coagulation, immune response and microvascular perfusion. The GlycoCheck system estimates glycocalyx’ thickness in vessels under the tongue from perfused boundary region (PBR) and microvascular perfusion (red blood cell (RBC) filling) via a camera and dedicated software. Objectives Evaluating reproducibility and influence of examination conditions on measurements with the GlycoCheck system. Methods Open, randomised, controlled study including 42 healthy smokers investigating day-to-day, side-of-tongue, inter-investigator variance, intraclass-correlation (ICC) and influence of examination conditions at intervals from 0–180 minutes on PBR and RBC filling. Results Mean (SD) age was 24.9 (6.1) years, 52% were male. There was no significant intra- or inter-investigator variation for PBR or RBC filling nor for PBR for side-of-tongue. A small day-to-day variance was found for PBR (0.012μm, p = 0.007) and RBC filling (0.003%, p = 0.005) and side-of-tongue, RBC filling (0.025%, p = 0.009). ICC was modest but highly improved by increasing measurements. Small significant influence of cigarette smoking (from 40–180 minutes), high calorie meal intake and coffee consumption was found. The latter two peaking immediately and tapering off but remained significant up to 180 minutes, highest PBR changes for the three being 0.042μm (p<0.05), 0.183μm (p<0.001) and 0.160μm (p<0.05) respectively. Conclusions Measurements with the GlycoCheck system have a moderate reproducibility, but highly increases with multiple measurements and a small day-to-day variability. Smoking, meal and coffee intake had effects up to 180 minutes, abstinence is recommended at least 180 minutes before GlycoCheck measurements. Future studies should standardise conditions during measurements.

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