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Critical Care (London, England) 2011Shock is defined as global tissue hypoxia secondary to an imbalance between systemic oxygen delivery and oxygen demand. Venous oxygen saturations represent this... (Review)
Review
Shock is defined as global tissue hypoxia secondary to an imbalance between systemic oxygen delivery and oxygen demand. Venous oxygen saturations represent this relationship between oxygen delivery and oxygen demand and can therefore be used as an additional parameter to detect an impaired cardiorespiratory reserve. Before appropriate use of venous oxygen saturations, however, one should be aware of the physiology. Although venous oxygen saturation has been the subject of research for many years, increasing interest arose especially in the past decade for its use as a therapeutic goal in critically ill patients and during the perioperative period. Also, there has been debate on differences between mixed and central venous oxygen saturation and their interchangeability. Both mixed and central venous oxygen saturation are clinically useful but both variables should be used with insightful knowledge and caution. In general, low values warn the clinician about cardiocirculatory or metabolic impairment and should urge further diagnostics and appropriate action, whereas normal or high values do not rule out persistent tissue hypoxia. The use of venous oxygen saturations seems especially useful in the early phase of disease or injury. Whether venous oxygen saturations should be measured continuously remains unclear. Especially, continuous measurement of central venous oxygen saturation as part of the treatment protocol has been shown a valuable strategy in the emergency department and in cardiac surgery. In clinical practice, venous oxygen saturations should always be used in combination with vital signs and other relevant endpoints.
Topics: Catheterization, Central Venous; Critical Care; Goals; Humans; Monitoring, Physiologic; Multicenter Studies as Topic; Oxygen; Perioperative Care; Shock; Veins
PubMed: 22047813
DOI: 10.1186/cc10351 -
Autonomic Neuroscience : Basic &... Jan 2020Our understanding of reflex regulation of veins lags behind that of the arterial system. While the cardiac sympathetic afferent reflex (CSAR) exerts control over...
Our understanding of reflex regulation of veins lags behind that of the arterial system. While the cardiac sympathetic afferent reflex (CSAR) exerts control over sympathetic outflow, its effect on venous tone is not known. We tested the hypothesis that activation of pericardial bradykinin sensitive afferents elicits systemic venoconstriction. Male and female Sprague Dawley rats were chronically instrumented for measurement of arterial pressure and mean circulatory filling pressure, an index of venous tone, and with an indwelling pericardial catheter. Mean arterial pressure, heart rate and mean circulatory filling pressure responses were assessed in conscious rats in response to graded pericardial injections of bradykinin (1.5-20 μg/kg) before and after ganglionic blockade, and to intravenous norepinephrine (0.05-0.8 μg/kg). Bradykinin B2 receptor was assessed by Western blot. Pericardial bradykinin injections caused graded increases in mean arterial pressure, heart rate and mean circulatory filling pressure. These responses were markedly attenuated after autonomic blockade. The increments in mean circulatory filling pressure were attenuated in female rats. There were no differences in the venoconstrictor responses to norepinephrine or ventricular bradykinin receptor expression between male and females. We interpret these findings to indicate that activation of bradykinin sensitive pericardial afferents elicits a sexually dimorphic, autonomically mediated systemic venoconstrictor response. Differences in venous smooth muscle responses to norepinephrine or ventricular bradykinin receptor expression do not account for the sexual dimorphism. We conclude that systemic venoconstriction contributes to the overall hemodynamic response to activation of the cardiac sympathetic afferent reflex and that this effect is sexually dimorphic.
Topics: Afferent Pathways; Animals; Blood Pressure; Bradykinin; Female; Heart Rate; Hemodynamics; Male; Muscle, Smooth, Vascular; Norepinephrine; Pericardium; Rats; Rats, Sprague-Dawley; Receptors, Bradykinin; Reflex; Sex Characteristics; Sympathetic Nervous System; Vasoconstrictor Agents; Vasodilator Agents; Veins
PubMed: 31901785
DOI: 10.1016/j.autneu.2019.102624 -
The British Journal of Radiology Dec 2018Abnormal embryological development of the pulmonary veins can manifest as either partial or total anomalous drainage into the systemic venous circulation.... (Review)
Review
Abnormal embryological development of the pulmonary veins can manifest as either partial or total anomalous drainage into the systemic venous circulation. Echocardiography does not provide adequate information in all cases as the optimal visualization of anomalous structures is limited by the availability of acoustic window; also it is highly operator dependent. However, multidetector CT angiography, with its multiplanar reformatting and volume rendering techniques, offers precise information about the three-dimensional anatomy and spatial relationships of the cardiovascular structures. With advent of dual source CT scanners and use of advanced dose reduction techniques, this information can be obtained in a short time with minimal radiation dose. In this pictorial essay, we present the multidetector CT imaging findings of the spectrum of total and partial anomalous pulmonary venous connections, using a third-generation dual source CT scanner.
Topics: Computed Tomography Angiography; Humans; Multidetector Computed Tomography; Pulmonary Veins
PubMed: 30004806
DOI: 10.1259/bjr.20180298 -
Annals of the Royal College of Surgeons... Dec 1974The significance of congenital abnormalities in predisposing to portal hypertension and variceal haemorrhage needs to be remembered when these effects manifest in... (Review)
Review
The significance of congenital abnormalities in predisposing to portal hypertension and variceal haemorrhage needs to be remembered when these effects manifest in childhood, as portal venography will permit elucidation of the complicated congenital developmental abnormalities underlying the pathological condition and permit rational surgical amelioration.In the presence of portal hypertension the development of a collateral venous circulation may be represented by a hepatopetal or hepatofugal circulatory pattern and will closely parallel the developmental areas where portal and systemic venous circulations meet, being representative of the embryological anastomosis between the vitelloumbilical system and the posterior cardinal system of veins.
Topics: Angiography; Biliary Tract; Child; Collateral Circulation; Congenital Abnormalities; Duodenum; Esophageal and Gastric Varices; Humans; Hypertension, Portal; Infant; Infant, Newborn; Liver Circulation; Portal System; Portal Vein; Pulmonary Veins; Stomach Ulcer; Umbilical Veins
PubMed: 4614690
DOI: No ID Found -
Translational Research : the Journal of... Apr 2013Ischemic cardiovascular disease remains the leading cause of death worldwide. Despite advances in the medical management of atherosclerosis over the past several... (Review)
Review
Ischemic cardiovascular disease remains the leading cause of death worldwide. Despite advances in the medical management of atherosclerosis over the past several decades, many patients require arterial revascularization to reduce mortality and alleviate ischemic symptoms. Technological advancements have led to dramatic increases in the use of percutaneous and endovascular approaches, yet surgical revascularization (bypass surgery) with autologous vein grafts remains a mainstay of therapy for both coronary and peripheral artery disease. Although bypass surgery is highly efficacious in the short term, long-term outcomes are limited by relatively high failure rates as a result of intimal hyperplasia, which is a common feature of vein graft disease. The supply of native veins is limited, and many individuals require multiple grafts and repeat procedures. The need to prevent vein graft failure has led to great interest in gene therapy approaches to this problem. Bypass grafting presents an ideal opportunity for gene therapy, as surgically harvested vein grafts can be treated with gene delivery vectors ex vivo, thereby maximizing gene delivery while minimizing the potential for systemic toxicity and targeting the pathogenesis of vein graft disease at its onset. Here we will review the pathogenesis of vein graft disease and discuss vector delivery strategies and potential molecular targets for its prevention. We will summarize the preclinical and clinical literature on gene therapy in vein grafting and discuss additional considerations for future therapies to prevent vein graft disease.
Topics: Blood Vessel Prosthesis; Clinical Trials as Topic; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Veins
PubMed: 23274305
DOI: 10.1016/j.trsl.2012.12.003 -
BMJ Case Reports Dec 2018Inherited retinal venous beading is a rare retinal vascular disorder that is characterised by tortuosity and beading of the retinal veins. This can potentially lead to...
Inherited retinal venous beading is a rare retinal vascular disorder that is characterised by tortuosity and beading of the retinal veins. This can potentially lead to vision-threatening complications such as vitreous haemorrhage, macular hard exudation and ischaemia. We report a case of sporadic unilateral retinal venous beading in an 18-year-old white man who was referred by his optician following a routine eye examination. This malformation was unilateral and did not involve any other ocular structure. He had no associated ocular or systemic disorders. When last seen, he did not have any visual complications due to this vascular anomaly.
Topics: Adolescent; Diagnosis, Differential; Genetic Predisposition to Disease; Humans; Male; Retinal Diseases; Retinal Vein; Tomography, Optical Coherence
PubMed: 30567160
DOI: 10.1136/bcr-2018-226116 -
Cells Jun 2019Portal hypertension is a common complication of liver disease, either acute or chronic. Consequently, in chronic liver disease, such as the hypertensive mesenteric... (Review)
Review
Portal hypertension is a common complication of liver disease, either acute or chronic. Consequently, in chronic liver disease, such as the hypertensive mesenteric venous pathology, the coexisting inflammatory response is classically characterized by the splanchnic blood circulation. However, a vascular lymphatic pathology is produced simultaneously with the splanchnic arterio-venous impairments. The pathological increase of the mesenteric venous pressure, by mechanotransduction of the venous endothelium hyperpressure, causes an inflammatory response involving the subendothelial mast cells and the lymphatic endothelium of the intestinal villi lacteal. In portal hypertension, the intestinal lymphatic inflammatory response through the development of mesenteric-systemic lymphatic collateral vessels favors the systemic diffusion of substances with a molecular pattern associated with damage and pathogens of intestinal origin. When the chronic hepatic insufficiency worsens the portal hypertensive inflammatory response, the splanchnic lymphatic system transports the hyperplasied intestinal mast cells to the mesenteric lymphatic complex. Then, an acquired immune response regulating a new hepato-intestinal metabolic scenario is activated. Therefore, reduction of the hepatic metabolism would reduce its key centralized functions, such as the metabolic, detoxifying and antioxidant functions which would try to be substituted by their peroxisome activity, among other functions of the mast cells.
Topics: Humans; Hypertension, Portal; Inflammation; Intestinal Mucosa; Lymphatic Vessels; Mast Cells; Mechanotransduction, Cellular; Mesenteric Veins; Mesentery; Splanchnic Circulation
PubMed: 31261968
DOI: 10.3390/cells8070658 -
American Journal of Physiology. Heart... Aug 2017The relevance of right atrial pressure (RAP) as the backpressure for venous return (Q) and mean systemic filling pressure as upstream pressure is controversial during...
The relevance of right atrial pressure (RAP) as the backpressure for venous return (Q) and mean systemic filling pressure as upstream pressure is controversial during dynamic changes of circulation. To examine the immediate response of Q (sum of caval vein flows) to changes in RAP and pump function, we used a closed-chest, central cannulation, heart bypass porcine preparation ( = 10) with venoarterial extracorporeal membrane oxygenation. Mean systemic filling pressure was determined by clamping extracorporeal membrane oxygenation tubing with open or closed arteriovenous shunt at euvolemia, volume expansion (9.75 ml/kg hydroxyethyl starch), and hypovolemia (bleeding 19.5 ml/kg after volume expansion). The responses of RAP and Q were studied using variable pump speed at constant airway pressure (P) and constant pump speed at variable P Within each volume state, the immediate changes in Q and RAP could be described with a single linear regression, regardless of whether RAP was altered by pump speed or P ( = 0.586-0.984). RAP was inversely proportional to pump speed from zero to maximum flow ( = 0.859-0.999). Changing P caused immediate, transient, directionally opposite changes in RAP and Q (RAP: ≤ 0.002 and Q: ≤ 0.001), where the initial response was proportional to the change in Q driving pressure. Changes in P generated volume shifts into and out of the right atrium, but their effect on upstream pressure was negligible. Our findings support the concept that RAP acts as backpressure to Q and that Guyton's model of circulatory equilibrium qualitatively predicts the dynamic response from changing RAP. Venous return responds immediately to changes in right atrial pressure. Concomitant volume shifts within the systemic circulation due to an imbalance between cardiac output and venous return have negligible effects on mean systemic filling pressure. Guyton's model of circulatory equilibrium can qualitatively predict the resulting changes in dynamic conditions with right atrial pressure as backpressure to venous return.
Topics: Adaptation, Physiological; Animals; Atrial Function, Right; Atrial Pressure; Blood Circulation; Cardiopulmonary Bypass; Extracorporeal Membrane Oxygenation; Ligation; Models, Animal; Models, Cardiovascular; Pulmonary Artery; Respiration, Artificial; Sus scrofa; Time Factors; Vena Cava, Inferior; Vena Cava, Superior
PubMed: 28550170
DOI: 10.1152/ajpheart.00081.2017 -
International Ophthalmology Oct 2023To review systemic associations of patients with dilated superior ophthalmic veins (SOV) in the absence of orbital, cavernous sinus, or neurological disease.
PURPOSE
To review systemic associations of patients with dilated superior ophthalmic veins (SOV) in the absence of orbital, cavernous sinus, or neurological disease.
METHODS
Retrospective review of patients who had dilated SOVs with a diameter of ≥ 5.0 mm. Patients with a dilated SOV secondary to orbital, cavernous sinus or neurological disease were excluded. Patient demographics, past medical history, and SOV diameters on initial and follow up scans were collected. The maximum diameter of the SOV was taken perpendicular to the long axis of the SOV.
RESULTS
Nine cases were identified. Patients ranged in age from 58 to 89 years and six out of nine were female. The dilated SOV involved both eyes in two cases, left eye in five cases and right eye in two cases. Three patients had dilated SOV likely secondary to raised venous pressures from decompensated right heart failure (n = 1), pericardial effusion (n = 1) and left ventricle dysfunction secondary to a myocardial infarction (n = 1). Five patients had a significant history of previous ischaemic heart or peripheral vascular disease. Two patients had risk factors for venous clotting disease whilst one patient had a history of giant cell arteritis and vertebral artery dissection.
CONCLUSION
A dilated SOV may raise concern for life threatening conditions such as a carotid cavernous fistula and may prompt additional investigations. A dilated SOV may be reversible and secondary to raised venous pressures due to cardiac failure. Other cases may be seen in patients with significant cardiovascular risk factors, possibly due to changes in vasculature.
Topics: Humans; Female; Middle Aged; Aged; Aged, 80 and over; Male; Cavernous Sinus; Embolization, Therapeutic; Eye; Veins; Peripheral Vascular Diseases
PubMed: 37392259
DOI: 10.1007/s10792-023-02782-3 -
Frontiers in Immunology 2022Systemic vasculitis are multisystem blood vessel disorders. However, Portal venous involvement is extremely rare, which represents a diagnostic and therapeutic challenge...
Systemic vasculitis are multisystem blood vessel disorders. However, Portal venous involvement is extremely rare, which represents a diagnostic and therapeutic challenge due to the heterogeneous nature, a lack of diagnostic criteria and limited effective therapy of vasculitis. We have reported a 48-year-old woman who was previously diagnosed with systemic vasculitis and was treated with prednisone, presented with gastrointestinal (GI) bleeding on admission. Further abdominal contrast-enhanced computed tomography (CT) with three-dimensional reconstruction suggested atrophic left hepatic lobe, enlarged spleen, and severe stenosis of main portal vein. Liver biopsy showed no evidence of fibrosis/cirrhosis. To prevent rebleeding, portal venous angioplasty by balloon dilation with collateral varices embolization was performed, and the GI hemorrhage was resolved completely. However, refractory ascites presented 8 months postoperatively. Abdominal CT angiography confirmed the recurrence of portal venous stenosis. Portal venous angioplasty by stent implantation was then performed to treat the portal hypertension (PHT)-related complications. After the intervention, the patient received anticoagulation therapy and continued immunosuppressive therapy. During the 5-year follow-up, the patient did not experience any onset of GI bleeding or ascites. Therefore, portal venous angioplasty with stent placement could be an effective treatment to prevent PHT-related complications when immunosuppression therapy failed.
Topics: Female; Humans; Middle Aged; Portal Vein; Constriction, Pathologic; Ascites; Hypertension, Portal; Gastrointestinal Hemorrhage; Systemic Vasculitis
PubMed: 36311772
DOI: 10.3389/fimmu.2022.1005300