Vasoconstriction

Medical and technological advancements allow increasingly complex invasive procedures to be performed on hospitalized patients, improving their survival rates and prognosis. However, these interventions impact physical, emotional, and psychological health. In this scenario, post-hospitalization syndrome (PHS) emerges as a concerning phenomenon characterized by functional, emotional, and social decline after discharge. Invasive procedures such as surgeries or prolonged use of catheters not only compromise physical integrity but also contribute to disorders like anxiety, depression, and post-traumatic stress. In fact, between 20% and 30% of patients admitted to the Intensive Care Unit (ICU) develop symptoms compatible with post-traumatic stress disorder. This underscores the need for a comprehensive approach focused on psychological and social well-being during and after the hospital stay. Despite humanization initiatives, few hospitals successfully implement them due to a lack of objective evaluations and clinical recommendations that justify their necessity. In this regard, venous catheterization (VC) is the most prevalent invasive procedure. The pain, anxiety, or fear caused by this technique triggers physiological and psychological alterations that can interfere with the successful insertion of the device. This stress response induces vasoconstriction, reducing the caliber of the vein, which increases technical difficulty, elevates the risk of complications, raises healthcare costs, and negatively impacts patient satisfaction. Natural outdoor environments have been shown to reduce stress, enhancing well-being and health in the general population. In this sense, the use of immersive virtual reality (IVR) to achieve immersion in virtual nature could help not only by diverting attention away from the painful or anxiety-inducing stimulus during invasive procedures but also by providing pleasant stimuli that could have a physiological impact. The objective of this study is to evaluate the impact of IVR on stress and anxiety during VC using validated clinical scales, measuring the caliber of the vessel to be punctured, and determining salivary biomarkers of stress, well-being, and pain. Confirming this hypothesis will provide the evidence to integrate virtual reality into the National Health System as a standard tool for more humanized and innovative care.

Right ventricular failure (RVF) is a common complication to cardiac surgery, which is associated to mortality, kidney failure, stroke, prolonged mechanical ventilation and ICU stay. The right ventricle is particularly vulnerable to an increased afterload. By increasing pulmonary vascular resistance (PVR), atelectasis might mitigate a negative effect on the right ventricle. Recruitment maneuvers have been shown to resolve atelectasis and improve hemodynamics by increasing cardiac output and lowering PVR. However these maneuvers transiently raise airway pressures, which in turn increases right ventricular afterload, a situation often poorly tolerated by patients with RVF. Prone position is used in patients with respiratory failure and has been shown to decrease mortality in patients with ARDS. Prone position decreases atelectasis and moves ventilation dorsally. In ARDS it also seems to mediate beneficial hemodynamic effects such as an increase in cardiac output and a decrease in PVR. The investigators hypothesis is that prone position early after cardiac surgery will increase cardiac output by recruitment of atelectasis and thereby decrease PVR.

The main purpose of this interventional study is to examine differences in resting blood pressure control between healthy males and females. The main questions it aims to answer are: 1. Are there sex differences in the communication between the sympathetic nervous system (also known as the "fight or flight" response) and peripheral blood vessels (which influence systemic blood pressure)? 2. What is the role of specific vascular receptors that respond to sympathetic signals, and is it different between males and females? Participants will complete one study visit of approximately 3 hours where they will: * Have a blood sample taken to measure circulating sex hormone and sympathetic transmitters. * Receive very small doses of medications commonly used to adjust blood pressure through an artery in their arm. The effects of these medications will be short-acting and localized to the forearm. * Have their sympathetic nervous activity directly measured through two very small needles (similar to acupuncture needles) in the side of their leg. * Have their blood pressure and heart rate recorded, and forearm blood flow measured using ultrasound.

In septic shock there is growing evidence of a state of hemodynamic "disconnection" with seemingly adequate macrocirculatory values despite actual microcirculation failing to meet cellular demand. Norepinephrine (NE) is recommended as first choice vasoactive agent for the treatment of septic shock. However, the dynamic effects of NE on macro- and microcirculation and perfusion parameters has not been described in detail in the context of septic shock, precluding rational individualized titration of NE and fluids, as recommended recently. In the present prospective observational multicenter study in adult septic shock patients, we intend to explore the effects of NE on preload dependency and tissue perfusion by evaluating the correlation and potential discrepancies between macro- and microcirculation both during titration of NE and after fluid resuscitation. The conclusions drawn from our study will contribute to the physiological knowledge necessary for establishing individualized evidence-based bedside management of hemodynamics in the setting of septic shock.