View clinical trials related to Hypotension.
Filter by:The prophylactic use of small doses of ephedrine may be effective in obtunding of the hypotension responses to propofol with minimal hemodynamic and ST segment changes. The investigators aimed to evaluate the effects of small doses of ephedrine on hemodynamic responses of propofol anesthesia for valve surgery. There is widespread interest in the use of propofol for the induction and maintenance of anesthesia for fast track cardiac surgery. However, its use for induction of anesthesia is often associated with a significant rate related transient hypotension for 5-10 minutes. This is mainly mediated with decrease in sympathetic activity with minor contribution of its direct vascular smooth muscle relaxation and direct negative inotropic effects. Ephedrine has demonstrated as a vasopressor drug for the treatment of hypotension in association with spinal and general anesthesia. Prophylactic use of high doses of ephedrine [10-30 mg] was effective in obtunding the hypotensive response to propofol with associated marked tachycardia. However, the use of smaller doses (0.1-0.2 mg/kg) was successfully attenuated, but not abolished, the decrease in blood pressure with transient increase in heart rate. This vasopressor effect is mostly mediated by β-stimulation rather than α-stimulation and also indirectly by releasing endogenous norepinephrine from sympathetic nerves. Because the effect of decreasing the dose of ephedrine from 0.1 to 0.07 mg/kg may be clinically insignificant, the investigators postulated that the prophylactic use of small dose of ephedrine may prevent propofol-induced hypotension after induction of anesthesia for valve surgery with minimal in hemodynamic, ST segment, and troponin I changes. The aim of the present study was to investigate the effects of pre-induction administration of 0.07, 0.1, 0.15 mg/kg of ephedrine on heart rate (HR), mean arterial blood pressure (MAP), central venous and pulmonary artery occlusion pressures (CVP and PAOP, respectively), cardiac (CI), stroke volume (SVI), systemic and pulmonary vascular resistance (SVRI and PVRI, respectively), left and right ventricular stroke work (LVSWI and RVSWI, respectively) indices, ST segment, and cardiac troponin I (cTnI) changes in the patients anesthetized with propofol-fentanyl for valve surgery.
During Cesarean delivery, phenylephrine is used to maintain the patient's blood pressure. Low blood pressure is the most common side effect of the spinal medication used to anesthetize the patient prior to the start of surgery. This low blood pressure can also trigger unpleasant side effects such as nausea, vomiting and low Apgar scores for the baby. Currently there are 2 methods of phenylephrine administration during Cesarean section. One method is by intermittent bolus and the other is by continuous infusion. It is ideal to have a regimen for phenylephrine administration that maintains blood pressure without compromising cardiac output. In this study, cardiac output and blood pressure will be measured by transthoracic bioimpedance, which is a new technique of noninvasive continuous cardiac output monitoring. The hypothesis of this study is that the continuous infusion of phenylephrine will be equally effective in maintaining blood pressure as compared to the intermittent injection, and will induce less hemodynamic changes.
The aim of this study is to compare two different therapeutic approaches to blood pressure reduction: pharmacological vs. non-pharmacological. The setting is that of patients undergoing scheduled Cesarean section under spinal anesthesia and suffering from aorta-caval compression syndrome, which causes a sudden drop in blood pressure.
Intradialytic hypotension (IH) is a major complication during acute hemodialysis. The aim of this study was to evaluate the effects of dialysate temperature (DT) reduction with Na and ultrafiltration (UF) profiling on hemodynamics of critically ill acute kidney injury (AKI) patients submitted to sustained low-efficiency dialysis (SLED).
Background: - Omalizumab is an approved drug for the treatment of asthma by the Food and Drug Administration. - Researchers are now studying this drug in a double-blind placebo-controlled manner to assess efficacy in patients with idiopathic anaphylaxis (recurrent hypersensitive allergic episodes for which a cause is not identified). - The study will improve understanding of the mechanisms involved in anaphylactic reactions as a response to the downregulation (a decrease in the number of receptors on the surface of cells) in mast cell (a resident cell with several types of tissues) activation, and lead to the development of strategies to better prevent or treat anaphylaxis. Objectives: - To determine whether treatment with omalizumab will reduce or prevent episodes of unprovoked anaphylaxis (an acute allergic reaction) in subjects with a history of idiopathic anaphylaxis. - To assess pharmacodynamics (physiological effects of a drug) and identify patients with undiagnosed mastocytosis (rare disorders caused by too many mast cells). - To investigate cellular and molecular mechanisms of signaling and the effect of omalizumab on mast cells or basophils (a cell in the leukocyte family that releases histamine, which affects allergic response) and explore other regulatory pathways that may be involved with modulation of mast cell degranulation. Eligibility: - Patients between 18 and 70 years of age who have been diagnosed with idiopathic anaphylaxis, a diagnosis that is made only after other causes of anaphylaxis have been considered. - Patients with documented anaphylaxis episodes (mild to severe) at least six times within the past 1 year period, at least once within the last 4 months, and with at least one of the following: - Elevated serum tryptase above baseline within 2 hours of the event. - Emergency room visit with documented anaphylaxis without a known cause established by the acute onset of an illness (minutes to several hours) with involvement of the skin, mucosal tissue, or both (generalized hives, itching or flushing, swollen lips-tongue-throat) and at least one of the following: (1) respiratory compromise or gastrointestinal involvement (shortness of breath, wheeze-bronchospasm, throat tightness, low oxygen levels, nausea, vomiting, or abdominal pain); or (2) reduced blood pressure or associated symptoms of end-organ dysfunction (collapse, loss of consciousness, or loss of bladder or bowel control). - Hospitalization for anaphylaxis. - Patients must provide a letter of referral, with copies of pertinent medical history and laboratory tests, from the prospective participant s local physician, and have the ability to give informed consent. - Women with childbearing potential must have a negative pregnancy test, and must agree to practice abstinence or effective birth control from the start of the protocol and for 3 months following the last injection of the study drug. Design: - Participants will undergo a clinical evaluation, blood tests, and a bone marrow biopsy and aspirate. - Participants will be randomized to either drug or placebo and will receive two doses of omalizumab or a matched placebo while hospitalized, followed by continued outpatient therapy, every 2 to 4 weeks, for up to 6 months. - Participants will remain on the assigned regimen for 6 months or until they have experienced new onset of severe adverse event on one occasion within 24 hours of study medication that are related to the study drug, whichever comes first. At that time, the participant will be discontinued from drug administration.
The investigators designed this study to determine the predictive value for predicting fluid responsiveness of noninvasive evaluation of respiratory variation of peak velocity in brachial artery, in mechanically ventilated patients with acute circulatory failure.
A fall in blood pressure (hypotension) occurs in one third of spinal anesthetics administered to pregnant patients undergoing cesarean delivery. However, predicting which patients will experience hypotension following spinal anesthesia has proven difficult. Pulse wave analysis is a repeatable and reproducible method for investigation of cardiovascular function. A device called a SphygmacorTM can be used to measure pulse. The pulse measurement is called the Augmentation Index (AIx). AIx has been useful in detecting risks associated with blood pressure changes after complex surgery in patients with heart and blood vessel disease. In this study the investigators wish to see if it is possible to predict if a subject will experience hypotension based on her AIx measurement preoperatively.
This observational study collects information on the current incidence and management of hypotension in babies born at term or late preterm that are admitted to Neonatal Intensive Care Units (NICUs) within the Neonatal Research Network (NRN). Participants include all newborn infants born at 34 0/7 weeks gestation or greater who are admitted to NICU Network centers and intubated and mechanically ventilated at less than 72 hours of age. The information gathered will provide a framework for the design of a potential randomized controlled trial for the treatment of hypotension in neonates. This observational study is for a time-limited enrollment period of 4-6 months; NRN centers will continue to enroll until at least 50 patients are enrolled per center (for approximately 800-1,000 subjects total).
This trial tests the feasibility of enrolling 60 extremely preterm infants in a randomized, double-blinded study of blood pressure management within 12 months. Eligible infants will receive an infusion drug (dopamine or a dextrose placebo) and a syringe drug (hydrocortisone or a normal saline placebo). Enrolled infants will be randomized to receive one of the following drug pairs: - dopamine and hydrocortisone - dopamine and normal saline - dextrose and hydrocortisone - dextrose and normal saline. In addition to the intervention above, the NRN is conducting a 6-month time-limited prospective observational study of all infants born at an NRN center between 23 and 26 weeks gestational age. All clinical decisions made for these babies will be at the discretion of the attending neonatologist/infant care team according to standard practice at each institution. Data on blood pressure management in the first 24 postnatal hours collected for each infant.
Oxidative stress is associated with kidney damage in several different situations, including hypotension. In animal models it has been shown that the combination of n-acetylcysteine plus deferoxamine is superior to its isolate use in the treatment of several diseases. Thus the investigators aimed to determine if the administration of n-acetylcysteine plus deferoxamine could prevent renal failure in critical ill patients who develops hypotension.