View clinical trials related to Liver Circulation.
Filter by:Flow dynamics in the liver is altered in different hepatobiliary and cardiac pathologies, causing changes in hepatic vasculatures sizes and flow pattern changes which can be assessed by ultrasound (USG) study. Before one can use these measurements and observations to diagnose pathologies, a clear grasp of normality is crucial. In the field of pediatrics, this is particularly challenging as the normal range of measurements may change with age, weight, height, gender and race of children. Taking hepatic veno-occlusive disease as an example, current literature is conflicting regarding whether sonographic findings show consistent association with the disease. Sonographic findings therefore now have limited role in contributing to the diagnosis. This may be related to the lack of a robust age corrected normal range of measurement for reference. Existing literature shows that the normal portal vein diameter varies with age, weight and height and possibly gender. Literature for normal measurements of hepatic vein and hepatic artery in children is lacking. In this study, the investigators aim to conduct a prospective, cross-section observational study to establish the normal measurements ranges of hepatic vein, hepatic artery and portal vein in healthy children in the investigators' locality. Flow patterns, including qualitative assessment and quantitative measurements of resistive index and flow velocities will also be assessed. These age corrected normal measurements will be very helpful in the diagnosis and follow-up of hepatobiliary and cardiac pathologies associated with alterations in dynamics of hepatic circulation.
Recent occurrence of significant post-operative liver impairment at Nottingham University Hospitals NHS Trust has prompted investigation into whether interaction between general anaesthesia and prone positioning (lying face down) for surgery can influence liver function. Historical research has shown that the heart does not function as efficiently when an anaesthetised patient is placed in the prone position for surgery. The techniques used for anaesthetising and monitoring these patients have changed remarkably, since these studies were first performed. It is important to know accurately how the heart functions to enable better understanding of the changes in blood flow to the liver when in the prone position. Studies looking at blood flow to the liver when lying face down have been done before but are mainly reporting patients on the intensive care unit. These intensive care patients are different to those in theatre undergoing routine surgery. The intensive care patients are usually received in different types of drugs and monitored with several different types of monitor at the time. Perhaps most importantly is that they are placed face down on a soft air cushioned mattress and pillows rather than the rigid support used for surgical patients. This study will look at whether the function of the liver changes when a patient is anaesthetised and is then rolled onto their front. The function of the liver will be measured by looking how it clears a specific drug from the blood. Also this study will look at how accurate a particular type of heart monitor is when an anaesthetised patient is placed onto their front.