Critical care clinics
-
Critical care clinics · Apr 2020
ReviewThrombotic Thrombocytopenic Purpura, Heparin-Induced Thrombocytopenia, and Disseminated Intravascular Coagulation.
Hemostatic abnormalities are common among critically ill patients and are associated with a high risk of bleeding. The abnormalities range from isolated thrombocytopenia or prolongation of global coagulation assays to complex disease states, such as thrombotic microangiopathic syndromes, and can be associated with a wide range of conditions, including trauma, surgery, acute disease processes, cardiopulmonary bypass, and exposure to drugs and blood products. Prompt identification of underlying causes is important because treatment strategies vary. Moreover, prompt initiation of both supportive and specific treatments is vital to decrease the morbidity and mortality in the intensive care unit.
-
Thrombocytopenia-associated multiple organ failure is a clinical phenotype encompassing a spectrum of syndromes associated with disseminated microvascular thromboses. Autopsies performed in patients that died with thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, or disseminated intravascular coagulation reveal specific findings that can differentiate these 3 entities. ⋯ Shiga toxins and the complement pathway drive the hemolytic uremic syndrome pathology. Tissue factor activity is vital in the development of disseminated intravascular coagulation.
-
Critical care clinics · Apr 2020
ReviewA Review on Microvascular Hemodynamics: The Control of Blood Flow Distribution and Tissue Oxygenation.
The microcirculation is a complex network of vessels ranging from as large as 100 μm to as small as 5 μm. This complex network is responsible for the regulation of oxygen to the surrounding tissues and ensures metabolite washout. With a more complete understanding of the microcirculation's physiologic and pathologic tendencies, engineers can create new solutions to combat blood pathologies and shock-related diseases. Over the last number of decades a grown interest in the microcirculation has resulted in the development of fundamental techniques to quantify the microvasculature flow and the release of oxygen to tissues.
-
Nitric oxide is a strong vasodilatory and anti-inflammatory signaling molecule that plays diverse roles in maintaining vascular homeostasis. Nitric oxide produced by endothelial cells is a critical regulator of this balance, such that endothelial dysfunction is defined as a reduced capacity for nitric oxide production and decreased nitric oxide sensitivity. ⋯ Endothelial dysfunction is central in numerous pathophysiologic processes. This article reviews mechanisms governing nitric oxide production and downstream effects, highlighting the role of nitric oxide signaling in organ system pathologies.
-
Critical care clinics · Apr 2020
ReviewThe Inflammatory and Hemostatic Response in Sepsis and Meningococcemia.
Meningococcemia is notorious for evasion of the host immune system and its rapid progression to fulminant disease, and serves as a unique model for pediatric sepsis. Illness severity is determined by complex interplays among host, pathogen, and environment. ⋯ This leads to endothelial dysfunction and activation of the hemostatic response, which may lead to disseminated intravascular coagulation. This article reviews the pathogenesis of sepsis, in particular the inflammatory and hemostatic response in meningococcal sepsis.