Active clinical trials for "Hypotension"

The investigators thus propose to use an innovative randomized effectiveness trial design to test the theory that early automatic identification of a ¡ Low Systolic Blood Pressure¡± clinical condition and decision-support alerts will prompt earlier hemodynamic support and a consequently reduce the duration of such conditions. Specifically, the investigators will test the hypothesis that providing DSS alerts in regards to hypotension reduces the duration of hypotensive episodes. The core of the investigators study will be an existing electronic anesthesia record and smart-alarm decision-support system. All patients undergoing surgery at Hillcrest will be randomly assigned to routine care or to DSS support. In patients assigned to DSS support, a systolic blood pressure less than 80 mmHg will generate a warning within three minutes after detection. Clinicians will be free to act on the alert, ignore the alert, or to consider the provided information without acting on it. The randomization, complete anesthesia record, detailed record of hypotensive events, alerts provided, clinician responses, and SAP response, will be captured by the investigators electronic record-keeping system. The investigators primary outcome will be the duration of time the patient has a systolic blood pressure less than 80 mmHg. Secondary outcome will be duration of hospitalization. The investigators will assess the effect of the alert on the primary outcome of time to SBP returning to above 80 mmHg using survival analysis, with time to event censored (and considered a non-event) at either the end of surgery or end of monitoring if patient did not return to above 80 mmHg.

The purpose of this study is to determine whether midodrine administration decreases duration of intravenous vasopressors and intensive care unit length of stay for patients in septic shock.

It has been reported that corrected carotid flow time (FTc) may indicate the responsiveness of spontaneously breathing patients to fluid therapy. The primary objective of the study is to determine the effect of fluid preload applied to patients with preanesthetic FTc values below the cut-off value on the incidence of hypotension in cesarean section (C/S) surgery. Pregnant women who underwent cesarean section under spinal anesthesia were included in this prospective study. In the preoperative care unit, patients were assigned to two groups according to their baseline FTc values. Patients with baseline FTc < 327 ms were assigned to the first group, and Ringer Lactate (RL) preload fluid administration to these patients was continued until FTc > 327 ms. On the other hand, patients with baseline FTc > 327 ms were assigned to the second group, and preload fluid was not administered to these patients. Intraoperative hemodynamic data were recorded for each patient.

In order to evaluate the efficacy and necessity of continuous non-invasive arterial pressure (CNAP) by comparing it with non-invasive blood pressure (NIBP) in order to understand whether it has advantages over oscillometric technique for detection of hypotensive episodes in healthy pregnant women who underwent cesarean section (C/S) under neuraxial anesthesia. This prospective study will evaluate healthy pregnant women at term, who were scheduled for elective C/S under spinal anesthesia. Subjects were randomly assigned into 2 groups to receive either CNAP and NIBP or only NIBP. A thirty percent decrease in systolic blood pressure from either baseline or the measured values in the first two minutes, or if the systolic blood pressure was less than 90mmHg, is considered hypotension. Pre-, peri- and post-operative specifications, newborn characteristics, and complications were recorded and compared.

Postural hypotension is common in older people, leading to falls, decline in function, and dependence. Available treatments have limited efficacy and tolerability; novel approaches to treatment are therefore needed. Decreased vascular health, stiffening of the arteries and consequent decreased vascular reactivity are thought to contribute to postural hypotension and are therefore therapeutic targets. Recent trial evidence has suggested that vitamin K may exert beneficial effects on vascular health particularly in respect to inhibiting calcification. Calcification increases vascular stiffness, decreases compliance and thus decreases the ability of blood vessels to autoregulate blood pressure and flow - which could contribute to postural drops in blood pressure. Worsened vascular health could also impact adversely on baroceptor function, which is needed for blood pressure autoregulation and which is disrupted in patients with orthostatic hypotension. Vitamin K intake is below recommended daily intake in 60% of adults in the UK. In animals, vitamin K supplementation may be able to reverse calcification of arteries, and in humans Vitamin K has been shown to arrest decline in carotid artery elasticity compared to placebo. High levels of circulating vitamin K were also associated with lower levels of CRP in the Framingham cohort, suggesting a possible role in the suppression of chronic inflammation that is known to accompany vascular disease. The recent ECKO study suggested that vitamin K may reduce falls and fractures; an intriguing question that follows on from this is whether this could be due to beneficial effects on vascular health and postural hypotension, leading to less dizziness and reduced falls. This cross-sectional comparative study aims to find whether there is a difference in the vitamin K status of patients with postural hypotension compared to those without postural hypotension and whether differences in vitamin K status are associated with other markers of vascular function in patients with and without postural hypotension. This could potentially lead to new treatments for the condition for which there is currently little of proven benefit.

Induction of general anesthesia to the patient could be a challenging period of anesthesia management. Due to autonomic system suppression, hemodynamic fluctuation, such as hypotension or hypertension, is commonly seen during this period. Furthermore, it has been observed that a fraction of patients who develop hypotension may be refractory to vasoactive medications to attempt to restore the systemic arterial blood pressure back to an acceptable level. Previous studies have shown that patients chronically taking angiotensin converting enzyme (ACE) inhibitors have a higher incidence of developing hypotension under general anesthesia as well as being refractory to adrenergic vasoconstrictor medications given to help restore systemic blood pressure. Interestingly, not all patients taking ACE inhibitors have shown the described hemodynamic response after induction of general anesthesia. Therefore, investigators are attempting to identify what changes in vascular physiology in those patients may contribute to acute refractory systemic hypotension. Specifically, investigators wish to explore whether differences in baseline levels of arterial stiffness potentially contribute to this phenomenon. Arterial applanation tonometry is a non-invasive technique that has been shown to reliably provide indices of arterial stiffness. In the proposed project, applanation tonometry will be performed on the right carotid and femoral arteries to assess carotid-femoral pulse wave velocity, a surrogate for aortic stiffness. (SphygmoCor system, AtCor Medical, Sydney, Australia) The measurement will be obtained before induction of general anesthesia in the pre-surgical area. During induction of general anesthesia with standard induction agents, brachial blood pressure will be measured by a cuff every minute up to 10 minutes after tracheal intubation. A hypotensive response to anesthesia will be defined by a systolic arterial blood pressure below 90mmHg upon induction. Hypotensive patients that do not respond to vasoconstrictor medications (i.e. requires more than 200 mcg phenylephrine to maintain systolic arterial blood pressure above 90 mmHg) will be classified as 'refractory hypotensive." Using non-invasive applanation tonometry, we will be able to examine if aortic stiffness has a propensity to become refractory hypotension after induction of general anesthesia. This information will potentially help identify future patients that might be at greater risk of developing refractory hypotension in response to induction of general anesthesia.

The study evaluates the potential beneficial effects on hemodynamics when hypobaric bupivacaine is used instead of isobaric bupivacaine in continuous spinal anesthesia for surgical repair of hip fracture in elderly patients. Half of the patients will receive hypobaric bupivacaine and the over half will reveive isobaric bupivacaine and hemodynamic data will be compared.

BACKGROUND: Hypotension occurs commonly during spinal anaesthesia for caesarean section and may result in detrimental effects to the mother and foetus. A previous pilot study where images of the pulse oximeter waveform study were taken, found that the dicrotic wave moved away from the systolic wave during the onset of hypotension. AIMS: The investigators wish to download electronic data which describe the pulse oximeter pulse wave to more accurately assess movement of the diastolic wave relative to the systolic wave during spinal anaesthesia for caesarean section. METHODOLOGY: 20 women undergoing caesarean section under spinal anaesthesia will be recruited by informed consent for this observational study. Data downloaded from the pulse oximeter will be analysed to identify movement of the dicrotic wave relative to the systolic wave and this will be related to changes in blood pressure. EXPECTED OUTCOMES: The investigators will establish best way to analyse changes in the pulse oximeter waveform and the relationship between changes in pulse oximeter waveform morphology and the onset of hypotension during spinal anaesthesia for caesarean section. IMPLICATIONS: Analysis of movement of the dicrotic wave could be used to anticipate and thus avoid severe hypotension during spinal anaesthesia for caesarean section.

The study will determine the 90% effective seated time after intrathecal injection of hyperbaric bupivacaine to avoid hypotension in patients undergoing cesarean delivery.

Suspension syndrome refers to a potentially life-threatening condition that can occur in unconscious persons after prolonged suspension in a harness. To date, our understanding of the pathophysiology and appropriate treatment is based primarily on case reports and expert opinion. The main pathophysiological hypothesis implicates blood pooling in the lower extremity and lack of return via muscle pumping. However, a recent French study could not support this hypothesis. Other mechanisms, such as a central vagal reflex may play a role in the pathophysiology of suspension syndrome. The aim of this study is to better understand the pathophysiological basis of suspension syndrome and to develop practical recommendations for prevention and treatment.