View clinical trials related to Hypotension.
Filter by:Comparison of the incidence of hypotension under remimazolam and propofol-based anesthesia in patients undergoing breast surgery under general anesthesia
Cirrhosis is an end stage in liver disease leading to replacement of normal liver tissue with regenerative nodules surrounded by fibrous bands in response to chronic liver injury. It is the eighth leading cause of death in the United States and the thirteenth leading cause of death globally. Patients with cirrhosis have decreased spontaneous vascular resistance leading to hypotension. The mechanism of hypotension in cirrhosis is thought to be a complex result of the presence of increased level of circulating vasodilators such a nitric oxide coupled with reduced resistance to vasoconstrictors and increased sensitivity to vasodilators.
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.
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.
Intrathoracic pressure regulation (IPR) therapy, delivered by impedance threshold devices (ITDs) or intrathoracic pressure regulators (ITPRs), increases venous return, preload, cardiac output, blood pressure, and cerebral perfusion pressure by intermittently creating negative intrathoracic pressure, which improves circulation in hypotensive animals and humans. By increasing systemic pressure and cerebral perfusion as well as promoting venous return, IPR therapy potentially improves cerebral oxygenation. The lower intrathoracic pressures may also reduce pulmonary artery pressure, although there is currently little evidence one way or the other. Use of an ITPR can counteract the multifactorial intraoperative hypotension common during surgeries under general anesthesia, and reduce the need for other measures to treat such hypotension; however, they might simultaneously promote pulmonary complications. The investigators will therefore assess whether the use of intrathoracic pressure regulation in adults having shoulder surgery under general anesthesia in the sitting position reduces vasoactive medication requirements compared with routine clinical practice. Simultaneously, the investigators will assess the effect of intrathoracic pressure regulation on pulmonary circulation, cerebral oxygenation, and postoperative atelectasis.
Hyperoxygenation for resuscitation of abnormal fetal heart rate tracings has been routine obstetric practice. However, there have not been any studies to support this practice. Recent literature have either found no associated benefit to intrapartum maternal oxygen administration, or in a number of studies demonstrated higher risk of neonatal complications. Despite these studies, the evidences have not been adequate to change the clinical practice because the majority of these studies either focused on biological differences rather than clinical outcomes data or were retrospective rather than randomized trials. Therefore, the investigators propose a large single center randomized clinical trial to determine the effects of maternal hyperoxygenation therapy for the treatment of fetal heart rate tracing abnormalities.
This is a pilot study to determine the hemodynamic effects when hydroxocobalamin vs methylene blue is administered during cardiopulmonary bypass in patients at risk of vasoplegia by measuring mean arterial pressure (MAP), systemic vascular resistance (SVR) and vasopressor requirement.
In this study investigator's aim to determine the impact of insulin therapy on hypotension and sarcopenia
Robot assisted urological procedures are often long surgical cases that can potentially result in complicated postoperative hospital course. The amount of intravenous (IV) fluids administered to patients during these operations fluctuates based on the length of the case, surgical blood loss, hemodynamic monitors, and the discretion of the anesthesiologist. The goal of intraoperative fluid therapy is to maintain optimal tissue perfusion without causing fluid overload. We plan to use a goal directed fluid therapy protocol to optimize fluid status and analyze post-operative outcomes.
Undifferentiated hypotension is a medical emergency where a patient's blood pressure drops to critical levels due to several possible reasons. The medical staff treating the patient will need to find out the reason for your drop in blood pressure as soon as possible. When treating low blood pressure, the medical staff typically performs a procedure called central venous cannulation (CVC). CVC involves accessing a large vein (usually the subclavian under the collarbone) by inserting a needle into the vein. By doing this, the medical staff can measure the pressures in the patient's veins or give medicine to the patient while they are in the hospital. The purpose of this study is to compare the time needed to complete CVC using the AxoTrack device to CVC guided by landmarks on a patient's body. The investigators expect that there will be a maximum of 30 patients enrolled in this study.