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Critical Care (London, England) 2015This article presents a personal viewpoint of the shortcoming of conventional hemodynamic resuscitation procedures in achieving organ perfusion and tissue oxygenation...
This article presents a personal viewpoint of the shortcoming of conventional hemodynamic resuscitation procedures in achieving organ perfusion and tissue oxygenation following conditions of shock and cardiovascular compromise, and why it is important to monitor the microcirculation in such conditions. The article emphasizes that if resuscitation procedures are based on the correction of systemic variables, there must be coherence between the macrocirculation and microcirculation if systemic hemodynamic-driven resuscitation procedures are to be effective in correcting organ perfusion and oxygenation. However, in conditions of inflammation and infection, which often accompany states of shock, vascular regulation and compensatory mechanisms needed to sustain hemodynamic coherence are lost, and the regional circulation and microcirculation remain in shock. We identify four types of microcirculatory alterations underlying the loss of hemodynamic coherence: type 1, heterogeneous microcirculatory flow; type 2, reduced capillary density induced by hemodilution and anemia; type 3, microcirculatory flow reduction caused by vasoconstriction or tamponade; and type 4, tissue edema. These microcirculatory alterations can be observed at the bedside using direct visualization of the sublingual microcirculation with hand-held vital microscopes. Each of these alterations results in oxygen delivery limitation to the tissue cells despite the presence of normalized systemic hemodynamic variables. Based on these concepts, we propose how to optimize the volume of fluid to maximize the oxygen-carrying capacity of the microcirculation to transport oxygen to the tissues.
Topics: Capillaries; Hemodynamics; Humans; Microcirculation; Resuscitation; Shock; Vasoconstriction
PubMed: 26729241
DOI: 10.1186/cc14726 -
Critical Care (London, England) May 2018Adrenaline has been used in the treatment of cardiac arrest for many years. It increases the likelihood of return of spontaneous circulation (ROSC), but some studies... (Review)
Review
Adrenaline has been used in the treatment of cardiac arrest for many years. It increases the likelihood of return of spontaneous circulation (ROSC), but some studies have shown that it impairs cerebral microcirculatory flow. It is possible that better short-term survival comes at the cost of worse long-term outcomes. This narrative review summarises the rationale for using adrenaline, significant studies to date, and ongoing research.
Topics: Epinephrine; Humans; Microcirculation; Propensity Score; Resuscitation; Treatment Outcome
PubMed: 29843791
DOI: 10.1186/s13054-018-2058-1 -
Microcirculation (New York, N.Y. : 1994) Oct 2022
Topics: Microcirculation
PubMed: 36125801
DOI: 10.1111/micc.12785 -
Physiological Research 2014The microcirculation, like all physiological systems undergoes modifications during the course of pregnancy. These changes aid the adaption to the new anatomical and... (Review)
Review
The microcirculation, like all physiological systems undergoes modifications during the course of pregnancy. These changes aid the adaption to the new anatomical and physiological environment of pregnancy and ensure adequate oxygen supply to the fetus. Even though the microcirculation is believed to be involved in major pregnancy related pathologies, it remains poorly understood. The availability of safe and non-interventional technologies enabling scientists to study the intact microcirculation of the pregnant patient will hopefully expand our understanding. In this article we review the physiological changes occurring in the microcirculation during pregnancy and the role of the microcirculation in gestational related pathologies. We will also describe the available techniques for the measurement and evaluation of the microcirculation. Lastly we will highlight the possible fields in which these techniques could be utilized to help provide a clearer view of the microcirculation in the pregnant woman.
Topics: Adult; Animals; Female; Humans; Microcirculation; Pregnancy; Pregnancy Complications
PubMed: 24702490
DOI: 10.33549/physiolres.932511 -
Arquivos Brasileiros de Cardiologia Aug 2018
Topics: Cardiovascular Diseases; Humans; Microcirculation
PubMed: 30183978
DOI: 10.5935/abc.20180149 -
Seminars in Nephrology Mar 2015Endothelin (ET) is one of the most potent renal vasoconstrictors. Endothelin plays an essential role in the regulation of renal blood flow, glomerular filtration, sodium... (Review)
Review
Endothelin (ET) is one of the most potent renal vasoconstrictors. Endothelin plays an essential role in the regulation of renal blood flow, glomerular filtration, sodium and water transport, and acid-base balance. ET-1, ET-2, and ET-3 are the three distinct endothelin isoforms comprising the endothelin family. ET-1 is the major physiologically relevant peptide and exerts its biological activity through two G-protein-coupled receptors: ET(A) and ET(B). Both ET(A) and ET(B) are expressed by the renal vasculature. Although ET(A) are expressed mainly by vascular smooth muscle cells, ET(B) are expressed by both renal endothelial and vascular smooth muscle cells. Activation of the endothelin system, or overexpression of downstream endothelin signaling pathways, has been implicated in several pathophysiological conditions including hypertension, acute kidney injury, diabetic nephropathy, and immune nephritis. In this review, we focus on the effects of endothelin on the renal microvasculature, and update recent findings on endothelin in the regulation of renal hemodynamics.
Topics: Endothelins; Glomerular Filtration Rate; Humans; Microcirculation; Renal Circulation
PubMed: 25966346
DOI: 10.1016/j.semnephrol.2015.02.004 -
American Journal of Physiology. Heart... Dec 2022Microvascular disease plays a critical role in systemic end-organ dysfunction, and treatment of microvascular pathologies may greatly reduce cardiovascular morbidity and... (Review)
Review
Microvascular disease plays a critical role in systemic end-organ dysfunction, and treatment of microvascular pathologies may greatly reduce cardiovascular morbidity and mortality. The Call for Papers collection: New Developments in Translational Microcirculatory Research highlights key advances in our understanding of the role of microvessels in the development of chronic diseases as well as therapeutic strategies to enhance microvascular function. This Mini Review provides a concise summary of these advances and draws from other relevant research to provide the most up-to-date information on the influence of cutaneous, cerebrovascular, coronary, and peripheral microcirculation on the pathophysiology of obesity, hypertension, cardiovascular aging, peripheral artery disease, and cognitive impairment. In addition to these disease- and location-dependent research articles, this Call for Papers includes state-of-the-art reviews on coronary endothelial function and assessment of microvascular health in different organ systems, with an additional focus on establishing rigor and new advances in clinical trial design. These articles, combined with original research evaluating cellular, exosomal, pharmaceutical, exercise, heat, and dietary interventional therapies, establish the groundwork for translating microcirculatory research from bench to bedside. Although numerous studies in this collection are focused on human microcirculation, most used robust preclinical models to probe mechanisms of pathophysiology and interventional benefits. Future work focused on translating these findings to humans are necessary for finding clinical strategies to prevent and treat microvascular dysfunction.
Topics: Humans; Microcirculation; Microvessels; Hypertension; Endothelium; Peripheral Vascular Diseases
PubMed: 36306213
DOI: 10.1152/ajpheart.00566.2022 -
Anesthesiology Mar 2014Age-related changes in skin contribute to impaired wound healing after surgical procedures. Changes in skin with age include decline in thickness and composition, a... (Review)
Review
Age-related changes in skin contribute to impaired wound healing after surgical procedures. Changes in skin with age include decline in thickness and composition, a decrease in the number of most cell types, and diminished microcirculation. The microcirculation provides tissue perfusion, fluid homeostasis, and delivery of oxygen and other nutrients. It also controls temperature and the inflammatory response. Surgical incisions cause further disruption of the microvasculature of aged skin. Perioperative management can be modified to minimize insults to aged tissues. Judicious use of fluids, maintenance of normal body temperature, pain control, and increased tissue oxygen tension are examples of adjustable variables that support the microcirculation. Anesthetic agents influence the microcirculation of a combination of effects on cardiac output, arterial pressure, and local microvascular changes. The authors examined the role of anesthetic management in optimizing the microcirculation and potentially improving postoperative wound repair in older persons.
Topics: Aged; Aging; Anesthesia; Anesthetics; Humans; Microcirculation; Skin; Wound Healing
PubMed: 24195972
DOI: 10.1097/ALN.0000000000000036 -
The Journal of Physiology Mar 2011The microcirculation exemplifies the mesoscale in physiological systems, bridging larger and smaller scale phenomena. Microcirculatory research represents an example of... (Review)
Review
The microcirculation exemplifies the mesoscale in physiological systems, bridging larger and smaller scale phenomena. Microcirculatory research represents an example of a 'middle-out,' rather than 'top-down' or 'bottom-up,' approach to the study of biological function. Computational and mathematical approaches can be used to analyse the functioning of the microcirculation and to establish quantitative relationships between microvascular processes and phenomena occurring on larger and smaller scales, leading to insights which could not be obtained solely by reductionist biological experiments. Given its integrative approach to processes occurring on disparate scales and its emphasis on theoretical as well as experimental approaches, microcirculatory research belongs within current definitions of systems biology.
Topics: Animals; Computer Simulation; Microcirculation; Models, Biological; Systems Biology
PubMed: 21242255
DOI: 10.1113/jphysiol.2010.201541 -
Journal of Cardiothoracic and Vascular... Oct 2023Cardiogenic shock causes hypoperfusion within the microcirculation, leading to impaired oxygen delivery, cell death, and progression of multiple organ failure.... (Review)
Review
Cardiogenic shock causes hypoperfusion within the microcirculation, leading to impaired oxygen delivery, cell death, and progression of multiple organ failure. Mechanical circulatory support (MCS) is the last line of treatment for cardiac failure. The goal of MCS is to ensure end-organ perfusion by maintaining perfusion pressure and total blood flow. However, machine-blood interactions and the nonobvious translation of global macrohemodynamics into the microcirculation suggest that the use of MCS may not necessarily be associated with improved capillary flow. With the use of hand-held vital microscopes, it is possible to assess the microcirculation at the bedside. The paucity of literature on the use of microcirculatory assessment suggests the need for an in-depth look into microcirculatory assessment within the context of MCS. The purpose of this review is to discuss the possible interactions between MCS and microcirculation, as well as to describe the research conducted in this area. Regarding sublingual microcirculation, 3 types of MCS will be discussed: venoarterial extracorporeal membrane oxygenation, intra-aortic balloon counterpulsation, and microaxial flow pumps (Impella).
Topics: Humans; Microcirculation; Mouth Floor; Shock, Cardiogenic; Heart Failure; Hemodynamics; Heart-Assist Devices; Intra-Aortic Balloon Pumping
PubMed: 37330330
DOI: 10.1053/j.jvca.2023.05.028