Active clinical trials for "Hypotension, Orthostatic"

Neurogenic orthostatic hypotension occurs in a significant number of people and has no effective treatment. Neurogenic orthostatic hypotension is associated with intermittent episodes of fainting which can be debilitating for the patients. Using sinusoidal galvanic vestibular stimulation, an oscillating current between the two ears, collaborators have discovered an effective technique to habituate anesthetized rats that develop vasovagal responses. The investigators propose to determine whether a similar use of sinusoidal galvanic vestibular stimulation can eliminate or alleviate neurogenic orthostatic hypotension and the associated syncope in susceptible human subjects. If so, then sinusoidal galvanic vestibular stimulation, which is safe and widely used to study muscle sympathetic nerve activity, can be used in humans, who have a history of syncope and a positive tilt test to habituate vasovagal responses. Habituation will be accomplished using repetitive periods of sinusoidal galvanic vestibular stimulation in two 30min sessions three times/week for 2 weeks. Similar 1 hour sessions are routinely used by others when activating muscle sympathetic nerve activity with sinusoidal galvanic vestibular stimulation without harm to the subjects. The 30 min periods were chosen because this was effective in producing habituation of vasovagal responses. The habituating stimulus will be given by applying paste electrodes over the mastoid processes and plugging the leads into a battery driven-stimulus box, which when activated by a switch, will provide a very low frequency bipolar, ± 2 mA, 0.025 Hz oscillating current sinusoidal galvanic vestibular stimulation between the mastoids. Subjects will be seated during the stimulation. The onset and end of the stimulation period will be denoted by tones, and the subjects will be free to watch television, read, or listen to music while they are being stimulated. The effectiveness of the habituation will be determined in several ways: 1) Subjects will keep a history of the number of episodes of syncope in the inter-test intervals. 2) They will have tilt tests at the beginning and end of habituation. 3) Their blood pressure and heart rate will be recorded and the investigators will determine if there is a loss of low frequency (0.025 Hz) oscillations, which the investigators have found in animal models to disappear when the animals are habituated. 4) Habituation should be accompanied by an increase in heart rate to counteract the fall in blood pressure.

The aim of this study is to examine the efficacy of 5 mg Midodrine (Gutron) vs. placebo on reducing the incidence of orthostatic hypotension during mobilization 6 h after a total hip arthroplasty.

Orthostatic hypotension is a highly prevalent deficit in the aging population especially when coupled with stroke, frailty, diabetes, Parkinson's disease or spinal cord injuries. This population has difficulty with the autonomic regulation of blood pressure and experiences elevated risks of falls. The fall risk is greatest when the person transitions from supine or sitting to standing as this is when blood has a tendency to pool in the legs preventing adequate blood circulation to vital organs. This is a safety concern and limiting factor for rehabilitation of patients with orthostatic hypotension in the inpatient rehabilitation setting. There is low-quality evidence that compression garments such as abdominal binders and compression stockings can be helpful to manage orthostatic hypotension and the associated fall risk. However, many people with orthostatic hypotension perceive the treatment approach with compression stockings to be largely unacceptable. Aquatic immersion may provide better advantages to compression garments because hydrostatic pressure exerts a little over 22 mmHg pressure for every foot of water. Therefore, an individual standing in 4 ft depth water will have roughly 90 mmHg pressure on their feet and about 56 mmHg at their knees. These amounts of pressure are more than those induced by typical compression stockings, which provide 30-40 mm Hg pressure. In addition, immersion at level of xiphoid process or higher is known to translocate blood from the lower to the center of the body and act to increase cerebral blood flow which may be beneficial for preventing orthostatic hypotension symptoms. No studies have looked at the physiologic response to immersion and aquatic exercise for people with orthostatic hypotension. Since this population is known to have difficulty with autonomic regulation of blood pressure, it is unclear if they will experience a similar hemodynamic response during immersion than the healthy population during or after aquatic therapy due to orthostatic hypotension. Anecdotal evidence suggests that patients with orthostatic hypotension do not exhibit adverse effects due to orthostatic hypotension when standing in water or participating in aquatic exercise independent of compression garments use. They often have improved standing tolerance in the pool compared with prolonged standing on land. Steps to manage orthostatic hypotension when out of the pool, such as hydration during pool session, placing compressive garments prior to exit of pool and slow transitions out of pool setting has been adequate to prevent symptoms of orthostatic hypotension in the post exercise period in this population. The primary aim of this study is to look at heart rate and blood pressure response when going from sit to stand during physical therapy sessions on land compared to in the pool for people who have orthostatic hypotension (defined as a drop in systolic blood pressure of at least 15 mmHg or 7 mmHg drop in diastolic blood pressure from sitting to standing). The secondary aim of this study is to evaluate tolerance for physical activity during physical therapy sessions in the pool compared to on land for people with orthostatic hypotension. The third aim of the study is to investigate heart rate and blood pressure response for 3 hours following the physical therapy sessions. We hypothesize that orthostatic hypotension will be reduced and standing exercise tolerance will be increased when in the pool compared to on land. In addition, we hypothesized that there will not be a significant difference in heart rate or blood pressure response in the 3-hour post exercise period of aquatic vs. land exercise.

The purpose of this study is to determine the cause of low blood pressure in selective patients who have problems with their involuntary (autonomic) nervous system. These patients frequently have had symptoms throughout their life, and their disorder might have a genetic basis. The biochemical, physiological and pharmacological procedures in this study should help us define the problem and perhaps lead to more effective treatment.

The purpose of this study is to evaluate the effect of low dose versus high dose steroids vital signs of patients currently on steroids or recently treated with steroids undergoing major colorectal surgery. The investigators hypothesize that there will be no statistically significant difference in orthostatic hypotension (blood pressure measured on lying, sitting, and standing), blood pressure, temperature or heart rate in the standard and low dose groups.

Clinical and biological assessments of volemia are challenging in older patients as they are more likely to present non-typical signs. Point of care ultrasonography (POCUS) using heart and lung exploration is a relevant tool to assess volemia in adults with little data in older adults. The primary objective of the study is to evaluate feasibility of positional POCUS in aging patients. The secondary objectives are to assess the variability of measurements between decubitus and sitting position.

The investigators will test whether breathing through an inspiratory resistance device will improve the ability to be upright and decrease blood pressure drops on standing in patients with orthostatic hypotension.

Older persons with diabetes have a harder time maintaining blood pressure when standing up. When blood pressure drops when standing up, fainting may occur. This study will see how regular exercise can improve the ability of the body to keep blood pressure up when standing. We want to see how this improvement varies with a home-based walking program.

The pilot study aims to evaluate a prototype system that enables military pilots to train under conditions of orthostatic hypotension and ischemic hypoxia. Both of these phenomena are experienced by aircraft crews of mainly highly maneuverable aircraft, and their syndromes include loss of color vision, loss of peripheral vision, blackout and finally G-induced loss of consciousness (G-LOC). A motorized tilt table to generate orthostatic (ORTHO) stress combined with an automatically controlled lower body negative pressure (LBNP) chamber to extort pooling of blood in the lower extremities has been developed in order to obtain new knowledge on counteracting the above-mentioned effects and minimizing the risk of their occurrence. This will help optimize the selection procedures of candidates with the best physiological predispositions to work as military pilots. The system is equipped with modules for monitoring biomedical parameters of a subject, including cerebral oxygenation, which ensures their safety and provides a source of data for performing advanced analyses. The ORTHO-LBNP system has been subjected to comprehensive laboratory tests and after a successful testing is ready for a pilot study involving pilots and/or cadets of the Polish Air Force Academy (PAFA). It is anticipated that new indicators will be proposed to enable an objective assessment of the predispositions to pursue a military pilot career. The prototype system can be easily adaptable to the needs of clinical and sports medicine as well as rehabilitation.

Orthostatic hypotension (OH), which consists in a significant reduction in blood pressure levels upon standing from a seated position, may affect approximately one in three patients with Parkinson's disease (PD). It usually presents as dizziness, lightheadedness, feeling faint, or feeling like you might black out while standing. This can significantly impact the quality of life (QoL) of PD patients, resulting in difficulties with balance, walking, and increased risk of falls. The main aim of this study is to evaluate whether the use of technological devices (a computerized system for analyzing abnormalities in walking in clinical settings and a wearable sensor to detect changes in postural unsteadiness in the home environment) may improve the detection of complications and the response to medical therapies for OH in patients with PD.