Hypobaric Oxygen during cardiopulmonary bypass to reduce gaseous Micro-Emboli during cardiac surgery: a randomised controlled trial
Sponsor: University Hospitals Bristol and Weston NHS Foundation Trust
After heart surgery, some people can experience mild problems which affect their brain. These can include short-term difficulties with thinking, attention, and memory. A recent study found about one in five people over 65 years of age who had heart surgery experienced these problems. In people over 80 years of age who had heart surgery, one in three people had these difficulties temporarily. Surgeons believe that the brain problems that are sometimes seen in patients after heart surgery are caused by tiny nitrogen-rich air bubbles getting into the blood when it is circulated in the heart and lung machine. These tiny air bubbles are also known as gaseous micro-emboli.
An artificial lung (part of the heart and lung machine) has been developed that limits the supply of oxygen entering the circulating blood and removes some of the nitrogen in the blood. This in turn helps the tiny air bubbles dissolve, as nitrogen in the air bubbles flows into the circulating blood and is removed from the heart-lung machine. Using this type of artificial lung is known as hypobaric oxygenation. We are doing this study to see if there are any differences in the number and type of air bubbles circulating in the bloodstream during heart surgery using the artificial lung that uses hypobaric oxygenation versus the standard, commonly used artificial lung in the heart and lung machine. The HOME Study will recruit 40 participants from the Bristol Heart Institute who are having either a coronary artery bypass graft (CABG), aortic valve replacement (AVR) or AVR and CABG at the same time.
Chief Investigator name: Professor Gianni Angelini
Trial Coordinator: Barbara Warnes