View clinical trials related to Microcirculation.
Filter by:Changes in tissue microcirculation during ischemic conditioning (4 cycles of 5-min ischemia and 5-min reperfusion) has not been well documented. In previous studies, there was difference in changes in microcirculation, such as recovery slope and occlusion slope, between healthy subjects and cardiac surgery patients. Moreover, the occlusion slope, which reflects local tissue oxygen consumption during ischemic period, is anticipated to decrease during repeated ischemia-reperfusion cycle by its protecting effect, however there has not been well-conducted study. The purpose of the study is to evaluate the changes in microcirculation measured by tissue oxygen saturation during ischemic conditioning between healthy volunteers and cardiac surgery patients.
The large current uptake of e-cigarettes (2.8 million U.K. users in 2016; 26), the continuous involvement of e-cigarettes (which potentially affects their contents as well), the uncertainty about their medium- and longer-term effects, and the need to promote smoking cessation as means of reducing Cardiovascular disease, dictate that more research is urgently needed. Research exploring the impact of e-cigarettes on cardiovascular function/ health has been requested by the European Parliament, the British Medical Association, regulatory agencies, clinicians and researchers, as there is currently no consensus within the smoking cessation community as to the potential impact of e-cigarettes. With e-cigarettes being successful in replacing traditional cigarettes (i.e. up to 42% within a month), such studies should not only be efficacy-focused, but should also explore the physiological effects of e-cigarettes, as preliminary work in the field is contrasting and limited, in both the acute- and longer-term timeframe. Furthermore, as e-cigarettes are not simple nicotine-based products, the general public, researchers and government agencies cannot rely on the existing research exploring the effects of nicotine on the cardio-vasculature (e.g. coronary and peripheral vasoconstriction, intravascular inflammation and deregulation of cardiac autonomic function as well as inhibition of microcirculation). Thus, the lack of direct evidence - which would clarify the degree of safety of e-cigarettes for the user's vascular system and determine their longer-term cardiovascular disease risk - increases the need for research in the field. Such studies will supply in-depth information to service-users and policy-makers, especially as the recently-initiated U.K.'s "Medicines and Healthcare Products Regulatory Agency" validation of e-cigarettes will increase likelihood of their introduction in smoking cessation clinics. This study will bridge the existing knowledge gap and inform the general public, the scientific and the smoking cessation community in respect to the physiological (e.g. cardiovascular health) and participants' experience of both nicotine-inclusive and nicotine-free, e-cigarettes (when combined with behavioural change support) and compare it against a currently NHS-applied smoking cessation pathway that combines Nicotine Replacement Therapy and behavioural change support. This will allow future research to advance and optimize the pharmacological treatment of tobacco and nicotine dependence, by taking into consideration the study's physiological and Health Economics' findings.
When infection strikes, the body's immune system reacts by producing chemicals in the bloodstream and changes in white blood cells to attack the infecting organism (bacteria, viruses or other organisms) and prevent it spreading. This is termed the 'inflammatory response'. Though beneficial in fighting infection, this response can sometimes be excessive, causing harmful effects on body organs. This is termed the 'systemic inflammatory response syndrome' and when linked to infection is termed 'sepsis'. Previous research has shown that in patients who have sepsis, the small blood vessels supplying oxygen and nutrients to muscles and other organs (the microcirculation) become abnormal and do not function as they would in health. However, it is difficult to assess the function of microcirculation in clinical practice, and we want to find new, easier ways of doing so. The aim of this study is to test a new method for assessing the function of these small blood vessels, by directly visualising them using a highly sensitive microscope, the size of a pen, placed under the tongue. By understanding the flow of blood in these vessels in healthy individuals, we will gain a better understanding of how these vessels are affected in illness.
This study measures the sublingual microcirculation of patients with kidney transplant using MicroScan. The data will be compared with data of health volunteers and end stage renal disease patients on hemodialysis.
This is a single-blind randomized clinical trial. Patients undergoing abdominal surgery will be enrolled and randomly divided into two groups: dexmedetomidine group and propofol group. In the dexmedetomidine group, patients will receive continuous intravenous infusion of dexmedetomidine (infusion dosage range: 0.1 ~ 0.7 mcg/kg/h). In the propofol group, patients will receive continuous intravenous infusion of propofol (infusion dosage range: 0.3 ~ 1.6 mg/kg/h). Hemodynamics will be continuously monitored using a non-invasive monitoring with chest bioreactance technique at preset time points (0, 2, 4, 6, 12h and 24h). Clinical data such as vital signs, hemodynamic parameters, laboratory results and fluid balance will be recorded. The microcirculation will be examined by Cytocam. The following microcirculatory parameters will be investigated: total small vessel density, perfused small vessel density, microvascular flow index, and heterogeneity index. The enzyme-linked immunosorbent assays will be used to measure serum level of endocan, diamine oxidase, and neutrophil gelatinase-associated lipocalin at preset time points. The primary goal of this study is to compare the effect on microcirculation between dexmedetomidine and propofol in intensive care unit patients after abdominal surgery.
To establish if, in patients with new diagnosis of left ventricular dilatation without documentation at the coronary artery angiography of significant coronary artery lesions, there is a damage of the coronary microcirculation at the IMR (index of microcirculatory resistance) assessment
Rationale: The interaction between macro and microcirculation remains uncertain. Microvascular alterations can occur when systemic hemodynamic parameters are within an acceptable range. Perfusion changes and microvascular alterations may play an important role in anastomotic healing and the onset of anastomotic leakage after gastrointestinal surgery. Nowadays, assessment of bowel perfusion is macroscopically performed by the surgeon prior to anastomosis creation. However, local oxygen delivery may still be compromised as little is known about microcirculatory alterations of the bowel during colorectal surgery. Dark Field (DF) imaging is a technique using a stroboscopic light-emitting diode ring-based imaging modality incorporated in a hand-held device, which illuminates an area of interest and provides high contrast dynamic images of the microvasculature. DF-imaging enables to visualize the bowel's microcirculation. Objective: To describe the human gastrointestinal microcirculation during gastrointestinal surgery under general anesthesia and to observe whether there is a correlation between bowel microcirculation and systemic hemodynamic parameters. Study design: A prospective, single center, observational, clinical, pilot study. Study population: 70 patients undergoing elective, gastrointestinal surgery during which the gastrointestinal tract is accessible for DF-imaging. Main study parameters/endpoints: To describe human gastrointestinal microcirculation on both the serosal and mucosal side of the bowel during gastrointestinal surgery under general anesthesia. Main parameter: Microvascular perfusion is quantified using the Microvascular Flow Index (MFI). Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The extend of burden and risk associated with participation is negligible. Using DF imaging on the bowel is a non-invasive technique requiring a minimal amount of time as is described in the study procedure. Previous studies did not show any safety concerns. Measuring will be performed under sterile conditions and the occurrence of tissue damage is highly unlikely. Patients are under general anesthesia and will thus not experience any inconvenience.
The microcirculatory alterations is common in circulatory failure, especially during sepsis. The severity of these changes and their sustainability are responsible of multi organ failure and ultimately death. The optimization of microcirculatory flow could be a central objective of the management of patients hospitalized in intensive care. Microcirculation includes all blood vessels of a diameter smaller than 100 micrometer. It represents the largest heat exchange surface of the body and is involved in tissue oxygenation. Microcirculatory flow is conditioned by the macrocirculation (heart rate and blood pressure) and the state of the microcirculation (thrombosis, vasoconstriction ...). The role of the CO2 in regulating microcirculatory flow is little studied. A recent work of our team and the oldest work in the literature lead to believe that CO2 has a specific role in modulating microcirculatory flow. No study to date precisely studied the impact of changes in the microcirculatory flow carbonemia . The hypocapnia test is carried out in a standardized manner by inhalation of a mixture enriched in CO2 7% allows a significant increase in carbonemia. Hypocapnia will in turn obtained by a calibrated voluntary hyperventilation test. Direct visualization of microcirculation by confocal microscopy is now considered the gold standard for exploring the microcirculation.
Aim of the study is to prove the utility and safety of the negative pressure wound therapy (NPWT) in the postoperative management of free flaps. The quantitative assessment of the entirety of clinical main relevant parameters like edema formation, microcirculation, macrocirculation and wound healing should create a better and comprehensive understanding of the NPWT effects in this field.
Investigation of the acute effects of a single dose of Careless™, a Mangifera indica fruit powder on cutaneous microcirculation and endothelial function.