venous physiology

PURPOSE OF REVIEW: Securing safe and effective intravenous (IV) access is of utmost importance for administering parenteral nutrition (PN). Sustaining this access can indeed pose challenges, especially when dealing with the risk of complications associated with long-term PN. This review emphasizes best practices to optimize intravenous access and reviews the current evidence-based recommendations and consensus guidelines. RECENT FINDINGS: An individualized approach when selecting central venous catheters (CVC) is recommended, considering the estimated duration of need for IV access and the number of lumens needed...

PURPOSE OF REVIEW: Venous pressure is an often-unrecognized cause of patient morbidity. However, bedside assessment of PV is challenging. We review the clinical significance of venous pressure measurement, existing techniques, and introduce the Venous Excess Ultrasound (VExUS) Score as a novel approach using doppler ultrasound to assess venous pressure. RECENT FINDINGS: Studies show clear associations between elevated venous pressure and adverse outcomes in critically ill patients...

PURPOSE OF REVIEW: Venous pressure is an often-unrecognized cause of patient morbidity. However, bedside assessment of PV is challenging. We review the clinical significance of venous pressure measurement, existing techniques, and introduce the Venous Excess Ultrasound (VExUS) Score as a novel approach using doppler ultrasound to assess venous pressure. RECENT FINDINGS: Studies show clear associations between elevated venous pressure and adverse outcomes in critically ill patients...

During surgery, various haemodynamic variables are monitored and optimised to maintain organ perfusion pressure and oxygen delivery - and to eventually improve outcomes. Important haemodynamic variables that provide an understanding of most pathophysiologic haemodynamic conditions during surgery include heart rate, arterial pressure, central venous pressure, pulse pressure variation/stroke volume variation, stroke volume, and cardiac output. A basic physiologic and pathophysiologic understanding of these haemodynamic variables and the corresponding monitoring methods is essential...

Primary hyperparathyroidism (PHPT) is characterized by elevated levels of calcium and parathyroid hormone (PTH). However, the interpretation of diagnostic tests, such as serum calcium and PTH levels, is complex in pregnant women. The aim of this report is to present a case of PHTP in a pregnant adolescent, with a special emphasis on an uncommon complication, as well as diagnostic and treatment strategies. A 17-year-old pregnant female presented with hyperemesis gravidarum and neurological symptoms, leading to the diagnosis of cerebral venous thrombosis...

OBJECTIVES: Robustness of radiomic features in physiological tissue is an important prerequisite for quantitative analysis of tumor biology and response assessment. In contrast to previous studies which focused on different tumors with mostly short scan-re-scan intervals, this study aimed to evaluate the robustness of radiomic features in cancer-free patients and over a clinically encountered inter-scan interval. MATERIALS AND METHODS: Patients without visible tumor burden who underwent at least two portal-venous phase dual energy CT examinations of the abdomen between May 2016 and January 2020 were included, while macroscopic tumor burden was excluded based upon follow-up imaging for all patients (≥3 months)...

Decompensated right ventricular failure (RVF) in pulmonary hypertension (PH) is fatal, with limited medical treatment options. Developing and testing novel therapeutics for PH requires a clinically relevant large animal model of increased pulmonary vascular resistance and RVF. This manuscript describes the method to induce an ovine PH-RVF model that utilizes left pulmonary artery (LPA) ligation, progressive main pulmonary artery (MPA) banding, and insertion of an RV pressure line for monitoring. The PA cuff and RV pressure tubing are connected to subcutaneous access ports...

An increased homocysteine level is a risk factor for cardiovascular disease, venous thromboembolism, cerebrovascular disease, and chronic kidney disease. In addition, vitamin D deficiency is associated with coronary artery disease and metabolic disorders. The present study included data from 1375 adults (895 men and 480 women) with a mean age of 52.62 ± 9.94 years who visited the Health Promotion Center of the University Hospital in Gyeonggi-do, Republic of Korea from January 2018 to December 2022 for routine checkups that included assessments of their homocysteine and vitamin D levels...

Inherited defects in the genes of blood coagulation essentially express the severity of the clinical phenotype that is directly correlated to the number of mutated alleles of the candidate leader gene (e.g., heterozygote vs. homozygote) and of possible additional coinherited traits. The F5 gene, which codes for coagulation factor V (FV), plays a two-faced role in the coagulation cascade, exhibiting both procoagulant and anticoagulant functions. Thus, defects in this gene can be predisposed to either bleeding or thrombosis...

AIM: As a medical condition, pregnancy mandates the simultaneous treatment of both the mother and the fetus, making it a distinctive aspect of clinical medicine. MATERIAL AND METHOD: We analyze the physiological changes occurring in the eyes and brain during pregnancy, as well as the neuro-ophthalmological manifestations that can occur during pregnancy. Studies published in both English and other languages, case reports, and reviews from 2011 to 2023 onwards were included...

One of the leading causes of maternal death in the United States is venous thromboembolism (VTE), which is influenced by acquired, genetic, and environmental factors. Pregnancy-associated physiological changes that exhibit the characteristics of Virchow's triad: reduced fibrinolysis, increased coagulation factors, trauma, and venous stasis all raise the risk of VTE. Furthermore, multiple gestations, advanced maternal age, cesarean delivery, and obesity are all pregnancy-associated risk factors that also increase the risk of VTE...

In this edition of the journal, the Perioperative Quality Initiative (POQI) present three manuscripts describing the physiology, assessment, and management of right ventricular dysfunction (RVD) as pertains to the perioperative setting. This narrative review seeks to provide context for these manuscripts, discussing the epidemiology of perioperative RVD focussing on definition, risk factors, and clinical implications. Throughout the perioperative period, there are many potential risk factors/insults predisposing to perioperative RVD including pre-existing RVD, fluid overload, myocardial ischaemia, pulmonary embolism, lung injury, mechanical ventilation, hypoxia and hypercarbia, lung resection, medullary reaming and cement implantation, cardiac surgery, cardiopulmonary bypass, heart and lung transplantation, and left ventricular assist device implantation...

OBJECTIVE: To evaluate mortality outcomes by varying degrees of reduced calf muscle pump (CMP) ejection fraction (EF). PATIENTS AND METHODS: Consecutive adult patients who underwent venous air plethysmography testing at the Mayo Clinic Gonda Vascular Laboratory (January 1, 2012, through December 31, 2022) were divided into groups based on CMP EF for the assessment of all-cause mortality. Other venous physiology included measures of valvular incompetence and clinical venous disease (CEAP [clinical presentation, etiology, anatomy, and pathophysiology] score)...

This study tested the hypothesis that acute moderate normobaric hypoxia augments circulating thyroid hormone concentrations during and following one hour of cold head out water immersion (HOWI), compared to when cold HOWI is completed during normobaric normoxia. In a randomized crossover single blind design, 12 healthy adults (27 ± 2 y, 2 women) completed one hour of cold (22.0±0.1⁰C) HOWI breathing either normobaric normoxia (FiO2 = 0.21) or normobaric hypoxia (FiO2 = 0.14). Free and total thyroxine (T3) and triiodothyronine (T4), and thyroid stimulating hormone (TSH) concentrations were measured in venous blood samples obtained before (baseline), during (15-, 30-, and 60-min), and 15 min following HOWI (post-), and were corrected for changes in plasma volume...

During veno-venous extracorporeal membrane oxygenation (V-V ECMO), blood is drained from the central venous circulation to be oxygenated and decarbonated by an artificial lung. It is then reinfused into the right heart and pulmonary circulation where further gas-exchange occurs. Each of these steps is characterized by a peculiar physiology that this manuscript analyses, with the aim of providing bedside tools for clinical care: we begin by describing the factors that affect the efficiency of blood drainage, such as patient and cannulae position, fluid status, cardiac output and ventilatory strategies...

Lymphatic flow abnormalities are central to the development of protein losing enteropathy, plastic bronchitis, ascites and pleural effusions in patients palliated to the Fontan circulation. These complications can occur in isolation or multicompartmental (two or more). The treatment of multicompartmental lymphatic failure aims at improving thoracic duct drainage. Re-routing the innominate vein to the pulmonary venous atrium decompresses the thoracic duct, as atrial pressure is lower than systemic venous pressure in Fontan circulation...

BACKGROUND: The impact of mechanical ventilation on the survival of patients supported with veno-venous extracorporeal membrane oxygenation (V-V ECMO) due to severe acute respiratory distress syndrome (ARDS) remains still a focus of research. METHODS: Recent guidelines, randomized trials, and registry data underscore the importance of lung-protective ventilation during respiratory and cardiac support on ECMO. RESULTS: This approach includes decreasing mechanical power delivery by reducing tidal volume and driving pressure as much as possible, using low or very low respiratory rate, and a personalized approach to positive-end expiratory pressure (PEEP) setting...

BACKGROUND: Brexpiprazole is a second-generation antipsychotic approved in Japan in 2018; however, information on placental passage and breast milk transfer remains limited. In this report, the patient, a 30-year-old pregnant woman with schizophrenia, was medicated with brexpiprazole, risperidone, and quetiapine. METHODS: The study used high-performance liquid chromatography-tandem mass spectrometry to determine the concentrations of brexpiprazole, quetiapine, risperidone, and its active metabolite (paliperidone) in maternal and neonatal plasma, cord venous plasma, and breast milk...

Aqueous humor (AQH) is a transparent fluid with characteristics similar to those of the interstitial fluid, which fills the eyeball posterior and anterior chambers and circulates in them from the sites of production to those of drainage. The AQH volume and pressure homeostasis is essential for the trophism of the ocular avascular tissues and their normal structure and function. Different AQH outflow pathways exist, including a main pathway, quite well defined anatomically and referred to as the conventional pathway, and some accessory pathways, more recently described and still not fully morphofunctionally understood, generically referred to as unconventional pathways...

BACKGROUND: It is unclear whether muscle blood flow (MBF) is altered in long-term Hodgkin Lymphoma (HL) survivors. We test the hypothesis that: 1) MBF response during mental stress (MS) is impaired in long-term HL survivors; 2) Aerobic exercise training combined with local strength exercise (ET) restores MBF responses during MS in these survivors. METHODS: Eighteen 5-year HL survivors and 10 aged-paired healthy subjects (HC) were studied. Twenty HL survivors were randomly divided into two groups: Exercise-trained (HLT, n=10) and untrained (HLUT, n=10)...