View clinical trials related to Cardiac Output.
Filter by:This study is to test the usefulness of ultrasound dilution measurements in patients on extracorporeal membrane oxygenation. Measurements may include; efficiency of support (recirculation), amount of clotting in the oxygenator (oxygenator blood volume), and how well the heart is working (cardiac output). At the present time there are no devices available to perform these functions.
The ability to measure cardiac output (CO) accurately and reproducibly at frequent intervals remains elusive to the clinician caring for critically ill pediatric patients even though a large proportion of these children are known to have hemodynamic compromise as a result of their illness. Current techniques used in adults to measure CO are not suitable for routine use with pediatric patients. A new ultrasound dilution approach provides an opportunity to measure cardiac output and blood volumes in pediatric patients. The main aim of this study is to compare CO measured by the new method with the clinician's estimate and implied CO from the measurement of the arteriovenous oxygen content difference.
A novel method to measure cardiac index based on ultrasound indicator dilution technology (UIDT) has been developed by Transonic Systems Inc. (Ithaca, NY, USA). The method overcomes many of the limitations that have plagued the existing techniques used to measure cardiac index in critically ill children. In the proposed investigation, the investigators hope to validate a novel application of an existing technology in critically ill infants and children. The primary aim of this study is to determine the accuracy of cardiac index measured by UIDT when compared to the gold-standard Fick technique. The primary hypothesis is that the average of three consecutive measurements of cardiac index by UIDT will be accurate when compared to the Fick technique. Secondary aims will be to determine the precision of the measurement, the feasibility of the technique with regards to time required and any complications encountered. An exploratory secondary aim of this study is to determine whether central blood volume (CBV) derived from indicator transit time (ITT) correlates with central venous pressure (CVP) and echocardiography derived measures of preload.
Cardiac Output (amount of blood pumped by the heart in one minute) will be measured using the new COstatus(R) system and these values will be compared with cardiac output values measured by other methods such as thermodilution. Blood volumes measured by the COstatus(R) system will also be recorded.
Accurate cardiac output determination is a commonly used and important index of myocardial performance. The thermodilution method using a pulmonary artery catheter is the most common approach to cardiac output determination; however, placement of the pulmonary artery catheter is not without risk and at times can be problematic. Ultrasound dilution measurement has been shown to correlate with measured cardiac output in animal models and adults, but it has not been validated in pediatric patients. This study will validate the accuracy of ultrasound dilution measurements of cardiac output to thermodilution measurements of cardiac output in pediatric patients.
The purpose of this study is to test the accuracy of a new noninvasive way to measure how much blood our heart pumps per minute. This new way measures the heart's pumping activity from outside the body, instead of breaking the skin and measuring it from the inside. Subjects will breathe normally through a mask while we record how fast and how much air they are breathing. We will have them "re-breathe" some of the air they breathed out by adjusting the ventilator. During this time, we will use the air breathed out to calculate how much blood per minute the subject's heart is pumping. We will also measure how much blood the heart is pumping at this time by injecting fluid into the catheter in the neck and then drawing about 1 teaspoon of blood from the catheters in the neck and arm. We will compare the calculated and measured values of the amount of blood pumped out of the heart for accuracy. After we complete this procedure, we will remove the mask and allow you to rest for 10-30min. Following the rest period, we will repeat the process and collect a second set of measurements. We will draw a total of 4 teaspoons of blood for the study. If you cannot comfortably breathe along with the ventilator, we will withdraw you from the study. If you want to stop taking part in the study at any time, let the study doctor know that you wish to withdraw. We will take off the mask, and your time in the study will end. This decision will not affect your regular medical care.