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Journal of Vascular Research 2022Monitoring the sublingual and oral microcirculation (SM-OM) using hand-held vital microscopes (HVMs) has provided valuable insight into the (patho)physiology of...
PURPOSE
Monitoring the sublingual and oral microcirculation (SM-OM) using hand-held vital microscopes (HVMs) has provided valuable insight into the (patho)physiology of diseases. However, the microvascular anatomy in a healthy population has not been adequately described yet.
METHODS
Incident dark field-based HVM imaging was used to visualize the SM-OM. First, the SM was divided into four different fields; Field-a (between incisors-lingua), Field-b (between the canine-first premolar-lingua), Field-c (between the first-second premolar-lingua), Field-d (between the second molar-wisdom teeth-lingua). Second, we investigated the buccal area, lower and upper lip. Total/functional vessel density (TVD/FCD), focus depth (FD), small vessel mean diameters (SVMDs), and capillary tortuosity score (CTS) were compared between the areas.
RESULTS
Fifteen volunteers with a mean age of 29 ± 6 years were enrolled. No statistical difference was found between the sublingual fields in terms of TVD (p = 0.30), FCD (p = 0.38), and FD (p = 0.09). SVMD was similar in Field-a, Field-b, and Field-c (p = 0.20-0.30), and larger in Field-d (p < 0.01, p = 0.015). The CTS of the buccal area was higher than in the lips.
CONCLUSION
The sublingual area has a homogenous distribution in TVD, FCD, FD, and SVMD. This study can be a description of the normal microvascular anatomy for future researches regarding microcirculatory assessment.
Topics: Capillaries; Healthy Volunteers; Humans; Microcirculation; Mouth Floor; Skin
PubMed: 35313312
DOI: 10.1159/000522394 -
Journal of Orthopaedic Research :... May 2018Polytraumatised patients with haemorrhagic shock are prone to develop systemic complications, such as SIRS (systemic inflammatory response syndrome), ARDS (acute...
Polytraumatised patients with haemorrhagic shock are prone to develop systemic complications, such as SIRS (systemic inflammatory response syndrome), ARDS (acute respiratory distress syndrome) and MOF (multiple organ failure). The pathomechanism of severe complications following trauma is multifactorial, and it is believed that microcirculatory dysfunction plays an important role. The aim of this study was to determine the changes in the microcirculation in musculature over time during shock and subsequent resuscitation in a porcine model of haemorrhagic shock and polytrauma. Twelve pigs (German Landrace) underwent femur fracture, liver laceration, blunt chest trauma, and haemorrhagic shock under standard anaesthesia and intensive care monitoring. Microcirculation data were measured from the vastus lateralis muscle using a combined white light spectrometry and laser spectroscopy system every 15 min during the shock and resuscitation period, and at 24, 48, and 72 h. Oxygen delivery and oxygen consumption were calculated and compared to baseline. The relative haemoglobin, local oxygen consumption, and saturation values in the microcirculation were observed significantly lower during shock, however, no changes in the microcirculatory blood flow and microcirculatory oxygen delivery were observed. After resuscitation, the microcirculatory blood flow and relative haemoglobin increased and remained elevated during the whole observation period (72 h). In this study, we observed changes in microcirculation during the trauma and shock phases. Furthermore, we also measured persistent dysfunction of the microcirculation over the observation period of 3 days after resuscitation and haemorrhagic shock. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1377-1382, 2018.
Topics: Animals; Disease Models, Animal; Male; Microcirculation; Multiple Trauma; Muscle, Skeletal; Oxygen Consumption; Shock, Hemorrhagic; Swine
PubMed: 28975653
DOI: 10.1002/jor.23759 -
Critical Care (London, England) Oct 2022The sublingual microcirculation presumably exhibits disease-specific changes in function and morphology. Algorithm-based quantification of functional microcirculatory...
BACKGROUND
The sublingual microcirculation presumably exhibits disease-specific changes in function and morphology. Algorithm-based quantification of functional microcirculatory hemodynamic variables in handheld vital microscopy (HVM) has recently allowed identification of hemodynamic alterations in the microcirculation associated with COVID-19. In the present study we hypothesized that supervised deep machine learning could be used to identify previously unknown microcirculatory alterations, and combination with algorithmically quantified functional variables increases the model's performance to differentiate critically ill COVID-19 patients from healthy volunteers.
METHODS
Four international, multi-central cohorts of critically ill COVID-19 patients and healthy volunteers (n = 59/n = 40) were used for neuronal network training and internal validation, alongside quantification of functional microcirculatory hemodynamic variables. Independent verification of the models was performed in a second cohort (n = 25/n = 33).
RESULTS
Six thousand ninety-two image sequences in 157 individuals were included. Bootstrapped internal validation yielded AUROC(CI) for detection of COVID-19 status of 0.75 (0.69-0.79), 0.74 (0.69-0.79) and 0.84 (0.80-0.89) for the algorithm-based, deep learning-based and combined models. Individual model performance in external validation was 0.73 (0.71-0.76) and 0.61 (0.58-0.63). Combined neuronal network and algorithm-based identification yielded the highest externally validated AUROC of 0.75 (0.73-0.78) (P < 0.0001 versus internal validation and individual models).
CONCLUSIONS
We successfully trained a deep learning-based model to differentiate critically ill COVID-19 patients from heathy volunteers in sublingual HVM image sequences. Internally validated, deep learning was superior to the algorithmic approach. However, combining the deep learning method with an algorithm-based approach to quantify the functional state of the microcirculation markedly increased the sensitivity and specificity as compared to either approach alone, and enabled successful external validation of the identification of the presence of microcirculatory alterations associated with COVID-19 status.
Topics: Artificial Intelligence; COVID-19; Critical Illness; Humans; Microcirculation; Sensitivity and Specificity
PubMed: 36242010
DOI: 10.1186/s13054-022-04190-y -
Critical Care (London, England) 2006Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hypovolemic, cardiogenic, obstructive and distributive shock. The first... (Review)
Review
Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hypovolemic, cardiogenic, obstructive and distributive shock. The first three categories have in common that they are associated with a fall in cardiac output. Distributive shock, such as occurs during sepsis and septic shock, however, is associated with an abnormal distribution of microvascular blood flow and metabolic distress in the presence of normal or even supranormal levels of cardiac output. This Bench-to-bedside review looks at the recent insights that have been gained into the nature of distributive shock. Its pathophysiology can best be described as a microcirculatory and mitochondrial distress syndrome, where time and therapy form an integral part of the definition. The clinical introduction of new microcirculatory imaging techniques, such as orthogonal polarization spectral and side-stream dark-field imaging, have allowed direct observation of the microcirculation at the bedside. Images of the sublingual microcirculation during septic shock and resuscitation have revealed that the distributive defect of blood flow occurs at the capillary level. In this paper, we classify the different types of heterogeneous flow patterns of microcirculatory abnormalities found during different types of distributive shock. Analysis of these patterns gave a five class classification system to define the types of microcirculatory abnormalities found in different types of distributive shock and indicated that distributive shock occurs in many other clinical conditions than just sepsis and septic shock. It is likely that different mechanisms defined by pathology and treatment underlie these abnormalities observed in the different classes. Functionally, however, they all cause a distributive defect resulting in microcirculatory shunting and regional dysoxia. It is hoped that this classification system will help in the identification of mechanisms underlying these abnormalities and indicate optimal therapies for resuscitating septic and other types of distributive shock.
Topics: Critical Illness; Humans; Microcirculation; Mouth Floor; Shock
PubMed: 16879732
DOI: 10.1186/cc4969 -
The New England Journal of Medicine May 2007
Topics: Aged; Aging; Coronary Circulation; Heart Diseases; Humans; Microcirculation; Risk Factors
PubMed: 17538094
DOI: 10.1056/NEJMc070666 -
Advances in Skin & Wound Care Aug 2022To analyze the blood oxygen concentrations (StO 2 ) of different stages of pressure injury (PI) tissue using hyperspectral images to serve as a guideline for the...
OBJECTIVE
To analyze the blood oxygen concentrations (StO 2 ) of different stages of pressure injury (PI) tissue using hyperspectral images to serve as a guideline for the treatment and care of PIs.
METHODS
This study used a prospective design. A total of 30 patients with sacral PIs were recruited from the rehabilitation ward of a teaching hospital. The authors used a hyperspectral detector to collect wound images and the Beer-Lambert law to estimate changes in tissue StO 2 in different stages of PI.
RESULTS
The tissue StO 2 of healthy skin and that of stage 1 PI skin were similar, whereas the tissue StO 2 of the wound in stage 2 PIs was significantly higher than that of healthy skin and scabbed tissue (medians, 82.5%, 74.4%, and 68.3%; P < .05). In stage 3 PIs, StO 2 was highest in subcutaneous tissue and adipose tissue (82.5%) and lowest in peripheral scabs (68.35%). The tissue StO 2 was highest in subcutaneous tissue in stage 4 PIs, and this tissue was red in the hyperspectral spectrum. The scab-covered area of unstageable PIs had the lowest StO 2 of all PI tissue types (median, 44.3%).
CONCLUSIONS
Hyperspectral imaging provides physiologic information on wound microcirculation, which can enable better evaluation of healing status. Assessing tissue StO 2 data can provide a clinical index of wound healing.
Topics: Humans; Hyperspectral Imaging; Microcirculation; Prospective Studies; Skin; Wound Healing; Pressure Ulcer
PubMed: 35819937
DOI: 10.1097/01.ASW.0000831888.39420.a6 -
Progress in Neurobiology Aug 2001The aging of the central nervous system and the development of incapacitating neurological diseases like Alzheimer's disease (AD) are generally associated with a wide... (Review)
Review
The aging of the central nervous system and the development of incapacitating neurological diseases like Alzheimer's disease (AD) are generally associated with a wide range of histological and pathophysiological changes eventually leading to a compromised cognitive status. Although the diverse triggers of the neurodegenerative processes and their interactions are still the topic of extensive debate, the possible contribution of cerebrovascular deficiencies has been vigorously promoted in recent years. Various forms of cerebrovascular insufficiency such as reduced blood supply to the brain or disrupted microvascular integrity in cortical regions may occupy an initiating or intermediate position in the chain of events ending with cognitive failure. When, for example, vasoconstriction takes over a dominating role in the cerebral vessels, the perfusion rate of the brain can considerably decrease causing directly or through structural vascular damage a drop in cerebral glucose utilization. Consequently, cerebral metabolism can suffer a setback leading to neuronal damage and a concomitant suboptimal cognitive capacity. The present review focuses on the microvascular aspects of neurodegenerative processes in aging and AD with special attention to cerebral blood flow, neural metabolic changes and the abnormalities in microvascular ultrastructure. In this context, a few of the specific triggers leading to the prominent cerebrovascular pathology, as well as the potential neurological outcome of the compromised cerebral microvascular system are also going to be touched upon to a certain extent, without aiming at total comprehensiveness. Finally, a set of animal models are going to be presented that are frequently used to uncover the functional relationship between cerebrovascular factors and the damage to neural networks.
Topics: Aging; Alzheimer Disease; Animals; Basement Membrane; Blood-Brain Barrier; Brain; Capillaries; Cerebrovascular Circulation; Cholinergic Fibers; Cognition; Humans; Learning; Microcirculation
PubMed: 11311463
DOI: 10.1016/s0301-0082(00)00068-x -
Annals of Palliative Medicine Jan 2021Alprostadil can effectively dilate blood vessels, improve cardiac microcirculation, and reduce cardiac load. Tanshinone IIa injection can protect against atherosclerosis... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Alprostadil can effectively dilate blood vessels, improve cardiac microcirculation, and reduce cardiac load. Tanshinone IIa injection can protect against atherosclerosis and reduce myocardial oxygen consumption. However, the effects of alprostadil combined with tanshinone IIa injection on microcirculation disorder, outcomes, and cardiac function in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI) are still not fully clear.
METHODS
A total of 300 AMI patients who underwent PCI in our hospital from January 2013 to June 2018 were randomly selected and divided into group A, B, C by using the random number table method, with 100 patients in each group. The group A was treated with alprostadil, the group B was treated with tanshinone IIa injection, and the group C was treated with alprostadil combined with tanshinone IIa injection. 7 days after treatment, the cardiac functions of all patients were observed by ultrasonic Doppler, as were the microcirculations by myocardial contrast echocardiography (MCE). The major adverse cardiac events (MACEs) in both groups were observed in the 12-month follow-up.
RESULTS
After treatment, the left ventricular end-diastolic diameter (LVEDD), end-diastolic left ventricular posterior wall thickness (LVPWD), left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESD), interventricular septum thickness (IVST), and ratio of maximal early to late diastolic filling velocities (E/A) in the group C were superior to those in the group A and B, the differences were statistically significant (PP<0.05). After treatment, MCE showed that the Aβ value of the group aC was higher than that of the group A and B, the difference was statistically significant (P<0.05). The thrombolysis in myocardial infarction myocardial perfusion grade classification showed that the patients with grades 2‒3 were more abundant in the group C than the group A and B, the difference was statistically significant (PP<0.05). The incidences of MACEs, such as malignant arrhythmia, recurrent heart failure (HF), recurrent myocardial infarction, and death, in the group C were significantly lower than those in the group A and B (PP<0.05).
CONCLUSIONS
For AMI patients after PCI, alprostadil combined with tanshinone IIa injection can effectively improve microcirculation and ventricular remodeling, improve cardiac function and reduce the occurrence of MACEs. This combination can be widely used in clinical practice.
Topics: Abietanes; Alprostadil; Humans; Microcirculation; Myocardial Infarction; Percutaneous Coronary Intervention; Stroke Volume; Ventricular Function, Left
PubMed: 33545751
DOI: 10.21037/apm-20-2147 -
Journal of Pharmacological Sciences Nov 2003Activity of blood cells, erythrocytes, leucocytes, and platelets, in microcirculation was observed by using an intravital microscope and confocal laser scanning... (Review)
Review
Activity of blood cells, erythrocytes, leucocytes, and platelets, in microcirculation was observed by using an intravital microscope and confocal laser scanning microscope connected with an image processing system including fluorescence and phosphorescence emission methods. Dynamic functions of the blood flow were mainly observed in mesentery, brain, and liver tissues of rats. The results are summarized as follows: Deformability of diabetic erythrocytes was significantly lower than that of healthy controls, particularly at high shear rate. The spring constant and Young's modulus of diabetic erythrocytes obviously stiffened, making them hard to deform in the capillary. During hemorrhagic shock and thrombosis, flow velocity and oxygen partial pressure of blood decreased in the brain and liver tissues that can be visualized by using FITC stained erythrocytes and Pd-porphyrin derivative as a pO(2) probe. Platelet adhesion and thrombus formation in the micro-vessels accelerated under the photodynamic reaction; diabetic platelets showed augmented adhesion and aggregation on the vessel wall which was followed by acute thromboembolism. Active oxygen radicals take part in thrombus formation, accompanied with adhesion of the activated leucocytes. Fluorescent dye probes, rhodamine G and acridine orange, are quite useful for visualization of the flow behavior of platelets and leucocytes, respectively.
Topics: Animals; Blood Flow Velocity; Diagnostic Imaging; Humans; Microcirculation; Optics and Photonics; Regional Blood Flow
PubMed: 14646237
DOI: 10.1254/jphs.93.227 -
The Journal of Physiology Mar 2017
Topics: Microcirculation; Neovascularization, Physiologic
PubMed: 28078687
DOI: 10.1113/JP273786