18 Clinical Trials for Various Conditions
To investigate the superior vena cava collapsibility index (SVC-CI), measured via transesophageal echocardiography (TEE), as a marker of fluid responsiveness. Two groups will be compared in this study. Groups will be identified by obtaining cardiac output (CO) by standard means using the TEE or pulmonary arterial catheter (PAC). Both of these monitors are considered standard for patient's undergoing coronary artery bypass grafting surgery (CABG) and recording initial CO readings. Based on CO, the patient's will be placed in study groups one or two. Participants with normal and mildly reduced left ventricular ejection fraction (LVEF \>40%) for group one and those with moderately to severely reduced LVEF (\<40%) in the second group. Following group separation, we will measure the SVC-CI and CO metric in both groups. The intervention will be an operating room table tilt test (head up and then head down) to artificially simulate giving the patient additional fluid. Before and after table tilt, the SVC-CI and CO will be obtained and measured. The SVC-CI is a mathematical equation determined by distance measurements taken via TEE to identify how much the superior vena cava has collapsed following table tilt. Participants will be considered responders if the CO increases by 12% following intervention. Non responders less than 12% change in CO following intervention. Our hypothesis is that the SVC-CI can differentiate responders vs non-responders with regards to fluid responsiveness with adequate sensitivity and specificity in participants with CAD undergoing isolated CABG. The SVC-CI numerical values for the two groups, responders and non-responders, will calculate a threshold of sensitivity and specificity percentages for future patients undergoing CABG.
Fluid administration is a commonly performed in the ICU for critically ill patients. However, it can lead to complications such as fluid overload, pulmonary edema, and increased mortality in some patients. Therefore, identifying patients who are likely to respond to fluid therapy is crucial for optimizing their management. Several methods have been used to assess fluid responsiveness, such as passive leg raising, stroke volume variation, and cardiac output monitoring. However, these methods have limitations and may not be feasible in all patients. In this study, the investigators aim to evaluate the use of velocity time integral (VTI) and Trendelenburg positioning in predicting fluid responsiveness in ICU patients.
In the critically ill population, fluid administration in an unstable patient is perhaps the most common intervention that is performed. Uncorrected hypovolemia with inappropriate vasopressors lead to organ hypoperfusion where as overzealous fluid administration especially in ARDS (Adult respiratory distress syndrome) can increase mortality. It has been estimated that only 50% of hemodynamically unstable critically ill patients are volume responsive, hence dynamic assessment of preload responsiveness has been proposed to better identify those individuals who would benefit from fluid bolus.
Predicting fluid responsiveness in critically ill patients is of paramount importance. It can help define an adequate fluid balance. Overzealous fluid administration is poorly tolerated and has been associated with poor outcomes but so has insufficient administration. Currently available predictors of fluid responsiveness rely on invasive monitors and require patients to be on mechanical ventilation. It is thus important to develop non invasive novel methods to assess fluid responsiveness to provide an accurate management for a favorable outcome. We propose a readily available non-invasive method that relies on improvement of the ventilation perfusion mismatch as recorded by end tidal CO2. Ventilation of physiologic dead space is part of a spectrum of mismatch between ventilation and perfusion of the lungs. The extent of pulmonary dead space varies depending on factors affecting pulmonary perfusion (e.g. pulmonary capillary hydrostatic pressure) and alveolar pressure (e.g. positive pressure ventilation). Compromised pulmonary capillary perfusion can lead to ventilation-perfusion mismatch in a patient with clear conductive airway and adequate alveolar oxygen pressure. Alveolar dead space results in decreased CO2 exchange that translates into lower levels of expired CO2. Stroke volume of the right ventricle is a major determinant of the pulmonary capillary perfusion. Right ventricular cardiac output can be increased by passive lower limb elevation maneuver, which ultimately results in improvement of the ventilation to perfusion ratio. This effect leads to a higher participation of perfused (and ventilated) alveolar units in gas exchange and narrowing of the gradient between arterial and expired CO2 concentration. Performing a passive leg raising (PLR) maneuver leads to stroke volume enhancement in both healthy patients and in those experiencing hemodynamic instability. Responsiveness to PLR can be assessed by different methods including echocardiography and pulse pressure variation. Left ventricular cardiac output (LVCO) can be easily measured by transthoracic echo and be used as a surrogate of right ventricular preload changes. LVCO can thus be used to assess the fluid responsiveness of PLR and the effects of on end tidal CO2 that ensue. We propose this study to test the hypothesis that expired CO2 is a reliable predictor of fluid responsiveness after performance of the PLR maneuver, based on the assumption that increasing right ventricular output causes a reduction of the ventilation to perfusion ratio, leading to increased levels of expired CO2. T
This is a prospective, nonrandomized, sequential data collection study to evaluate the ability of RPVi to predict fluid responsiveness in comparison with other dynamic parameters including stroke volume variation (SVV) and/or pulse pressure variation (PPV).
In this research study we want to learn more about using non-invasive tools as a way to predict whether or not a child under general anesthesia will require and respond to fluid administration. It is important for an anesthesiologist to know if a child would respond to fluid administration so that they can provide the optimal intervention for low blood pressure and avoid unnecessary treatment.
The goal of this study is to identify in patients requiring active fluid resuscitation and mechanical ventilation for circulatory shock, can a controlled increase in intrathoracic pressure (either by positive-end expiratory pressure (PEEP) or tidal volume (TV)) predict responsiveness to additional fluid resuscitation. We hypothesize that a temporary, physiologically-safe increase in positive-end expiratory pressure (PEEP) and/or a temporary increase in tidal volume (from 6 cc/kg predicted body weight (PBW) to 8 cc/kg PBW) in patients requiring invasive mechanical ventilation will predict fluid responsiveness based upon an assessment of the change in pulse pressure and stroke volume variation.
Interventional data collection study to evaluate the ability of pleth variability index (PVI) to predict fluid responsiveness in comparison with other dynamic parameters including pulse pressure variation (PPV) and stroke volume variation (SVV).
Comparison of noninvasive cardiac output monitor (NICOM, Cheetah Medical) with Edwards FloTrac minimally-invasive cardiac output monitor in predicting fluid responsiveness in sepsis and septic shock.
This study assesses the mean difference in fluid balance at ICU discharge and associated patient outcomes, based on a dynamic assessment of fluid responsiveness in septic patients with refractory hypotension in an ICU setting.
Difficulties in the accurate assessment of intravascular volume in critically ill patients are frequently encountered. In addition to clinical evaluation, bedside echocardiographic measurements of fluid responsiveness can be technically difficult, especially in critically ill mechanically ventilated patients. The carotid artery is an easily accessible structure that is amenable to bedside ultrasonography performed by Intensivists. The investigators hypothesize that measurement of the carotid artery Corrected Flow Time (FTC) in response to a passive leg raise (PLR), which simulates a fluid bolus, can be used to predict fluid responsiveness.
Accurate assessment of fluid responsiveness (FRes) is central to guiding fluid management in septic and critically ill patients. As evidence accumulates that both inadequate and excessive fluid resuscitation are associated with increased morbidity and mortality, it is simultaneously becoming increasingly clear that current widely used methods to predict FRes are of questionable accuracy. The optimal technique to predict FRes would be a non-invasive point-of-care test with not only a high degree of accuracy, but also one which requires minimal training to perform correctly and may be easily performed repeatedly for serial evaluation of FRes during the ongoing management of the critically ill patient. To date, three major ultrasonographic modalities have emerged as viable candidates for the bedside assessment of FRes: 1) measurement of dynamic changes in inferior vena caval diameter (IVC-CI), 2) measurement of dynamic changes in peripheral arterial waveform derived variables (PA Doppler), and 3) echocardiographic measurement of dynamic changes in left ventricular outflow tract waveform derived variables (LVOT Doppler). In this study, the investigators will perform the first direct comparison of techniques representing all three of the above modalities in the prediction of FRes against a non-invasive bioreactance cardiac output monitor (the Cheetah NICOM™), which has been extensively validated against gold-standard invasive methods of cardiac output measurement. The investigators will compare the accuracy of these modalities in both spontaneously breathing and mechanically ventilated patients using passive leg raise testing (PLR) as a surrogate for volume challenge. In addition, the investigators will also elicit information from the treating physician(s) on their clinical assessment of FRes. The investigators will recruit adult patients in the ED and ICU with sepsis, who have received an initial bolus of 20-30 cc/kg of IV fluid, and can tolerate the PLR and US procedures. Prior to US and NICOM measurement, investigators will ask the attending physician managing the patient regarding their assessment of the their fluid status. Then, separate investigators will perform US and NICOM measurements independently to ensure blinding. NICOM data, which has been well validated in septic patients, will be shared with the attending physician. They will then be asked if this new data will change management.
This study is designed to investigate the ability of pleth variability index (PVI) to non-invasively predict fluid responsiveness in mechanically ventilated children. Patients undergoing atrial septal defect (ASD) repair in the cardiac catheterization suite will be recruited for this study. These patients are ideal candidates because very few deviations will be made from standard clinical practice. All patients will already be under general anesthesia, mechanically ventilated, monitored with pulse oximetry, and provided with intravenous fluid to compensate for their nil per os (NPO) fluid deficit. The only deviation from clinical practice will include an abbreviated echocardiographic exam, application of the Masimo pulse oximeter, and measurement of CO via a thermodilution catheter by the interventional cardiologist.
The study aim is to examine point-of-care ultrasound findings, reliability, and ease of performance in association with fluid responsiveness for patients with severe sepsis and septic shock. The investigators propose a prospective observational research study of patients presenting to one of three Yale New Haven Hospital emergency departments, York Street Campus, St. Raphael's Campus, and Shoreline Medical Center who meet criteria for sepsis, severe sepsis or septic shock during their emergency department visit.
The objective of our study is to determine the correlation of transthoracic ultrasonographic indices of fluid responsiveness to changes in direct measures of cardiac output and to compare them to other established predictors of fluid responsiveness such as central venous pressure variation, systolic arterial pressure variation and pulse pressure variation in a broad population of patients. Hypothesis: There will be a significant difference in the inferior vena cava respiratory variation and subclavian vein respiratory variation between responders and non-responders to intravenous fluid challenge in a broad population of patients with shock.
This study aims to evaluate the effect of a novel hemodynamic management and monitoring strategy for reducing cardiac bio marker elevations and major adverse cardiac events.
Pregnancy is associated with a myriad of physiologic changes, including expansion of blood volume, decrease in oncotic pressure, and increased cardiac output. The obstetric population is associated with intrapartum hemorrhage. Accordingly, it is important to have an accurate method to assess fluid status in intrapartum patients. The use of standard volume assessment tools including arterial lines and central venous catheters is limited given the brevity of obstetric procedures and the morbidity of these techniques on the awake patients, and the costs. Non-invasive methods to assess volume status (carotid dopplers, direct measurement of blood loss, bio-impedance devices) are imperfect. Echocardiography is an attractive tool to measure fluid status in experienced operators such as anesthesiologists. IVC diameter and variation of aortic velocity time integral are two measures that can be obtained via echocardiography and been studied in spontaneously breathing patients. The purpose of this study is to determine whether these measurements can be used in the assessment of volume status in the laboring patient.
The aim of this study is to determine the effects of fluid alternations, hemodynamic changes, mechanical ventilation, pharmacologic agents, positional changes, and comorbidities on the Peripheral Intravenous waveform Analysis (PIVA) signal.