Hi fellow pumpheads,
This has been one of my major concerns since my surgery almost 9 years ago. I have noticed and still experience issues that I believe are tied to this. I have also brought this up to my doctors many times over the years. If nothing else, it documents my concerns and issue for whenever I may need to use this data for in the future.
I have done research on this in the past, and found many interesting articles. It will be good to see if anyone can add some "new" data regarding this issue.
I recall that Duke University has done many studies on this topic. Also, it was reported in the New England Journal of Medicine, a CBS news article, and the BBC.
If you "google" memory loss heart lung bipass... you will find more data.
Here is some of the info I have collected.
BBC
Last Updated: Saturday, 12 November 2005, 01:23 GMT
Heart-lung machine safety boosted
Heart-lung machines help keep people alive
Technology first used by the ancient Egyptians has been used to improve the safety of the heart-lung machine.
The machine is used during open-heart surgery to provide oxygen and circulate blood around the body while the heart is stopped.
A team at London's Hammersmith Hospital has found a way to clean the blood more effectively, and cut the risk of potentially serious side effects.
It involves using tiny carbon particles to reduce contaminants.
The technology was first used by the ancient Egyptians to filter water over 3,000 years ago.
Fat droplets, known as microemboli, can develop in the blood while a patient is connected to a heart-lung machine.
These droplets can become lodged in the small blood vessels in the brain, preventing blood flow and triggered small strokes known as transient ischaemic attacks.
In severe cases this can lead to brain damage and death.
Microemboli are thought to be created when a surgeon uses suction to remove blood from the chest cavity, which is then returned to the bloodstream via the heart-lung machine.
Significant problem
Lead researcher Professor Terry Gourlay said: "Microemboli blockages are responsible for a significant proportion of people suffering memory loss, minor personality changes and other brain dysfunctions.
"Over half of all patients who have been on heart-lung machines show some of these signs, so this is not an insignificant problem." A US study has shown that for each hour spent on the heart-lung machine the number of microemboli in the blood doubles.
The droplets have proved difficult to remove as they are so tiny.
But the Hammersmith team has achieved great success by using a form of activated carbon, which is highly sticky, or adsorbent.
Highly effective
Working with colleagues from the University of Brighton, they developed a short section of tubing that can be fitted into the heart-lung machine.
As blood passes through the tube, the fat droplets are adsorbed on to the surface of the carbon particles, completely removing all traces before the blood returns to the body.
The technique proved so effective that 100% of microemboli were removed with just a single passage of blood through the tubing. This is crucial , as any droplets that are returned to the body have the potential to cause great damage.
Professor Gourlay said: "With over five litres of blood passing through the machine every minute, finding a recipe for a tube that removes all traces of fat but does not damage the blood constituents was a major boost to our work."
Belinda Linden, of the British Heart Foundation said: "The development of the heart-lung machine has allowed cardiac surgeons to successfully carry out more complicated heart surgery.
"It is so important that we explore ways to lessen blot clot formation and these researchers may well be one step closer to a solution."
The technique could potentially be used in other forms of surgery, including liposuction and hip replacement operations.
Last year over 30,000 patients in the UK were placed on a heart-lung machine during surgery.
Hospital admissions for heart failure are projected to increase by over 50% over the next 25 years.
The New England Journal of Medicine -- February 8, 2001 -- Vol. 344, No. 6
Longitudinal Assessment of Neurocognitive Function after Coronary-Artery Bypass Surgery
Mark F. Newman, Jerry L. Kirchner, Barbara Phillips-Bute, Vincent Gaver, Hilary Grocott, Robert H. Jones, Daniel B. Mark, Joseph G. Reves, James A. Blumenthal, for the Neurological Outcome Research Group and the Cardiothoracic Anesthesiology Research Endeavors Investigators
Abstract
Background. Cognitive decline complicates early recovery after coronary-artery bypass grafting (CABG) and may be evident in as many as three quarters of patients at the time of discharge from the hospital and a third of patients after six months. We sought to determine the course of cognitive change during the five years after CABG and the effect of perioperative decline on long-term cognitive function.
Methods. In 261 patients who underwent CABG, neurocognitive tests were performed preoperatively (at base line), before discharge, and six weeks, six months, and five years after CABG surgery. Decline in postoperative function was defined as a drop of 1 SD or more in the scores on tests of any one of four domains of cognitive function. (A reduction of 1 SD represents a decline in function of approximately 20 percent.) Overall neurocognitive status was assessed with a composite cognitive index score representing the sum of the scores for the individual domains. Factors predicting long-term cognitive decline were determined by multivariable logistic and linear regression.
Results. Among the patients studied, the incidence of cognitive decline was 53 percent at discharge, 36 percent at six weeks, 24 percent at six months, and 42 percent at five years. We investigated predictors of cognitive decline at five years and found that cognitive function at discharge was a significant predictor of long-term function (P<0.001).
Conclusions. These results confirm the relatively high prevalence and persistence of cognitive decline after CABG and suggest a pattern of early improvement followed by a later decline that is predicted by the presence of early postoperative cognitive decline. Interventions to prevent or reduce short- and long-term cognitive decline after cardiac surgery are warranted. (N Engl J Med 2001;344:395-402.)
Source Information
From the Department of Anesthesiology (M.F.N., J.L.K., B.P.-B., V.G., H.G., J.G.R.), the Department of Surgery (R.H.J.), the Division of Cardiology (D.B.M.), and the Department of Psychiatry and Behavioral Science (J.A.B.), Duke University Medical Center, Durham, N.C. Address reprint requests to Dr. Newman at the Division of Cardiothoracic Anesthesia, Box 3094, Duke University Medical Center, Durham, NC 27710, or at
[email protected].
The members of the study groups are listed in the Appendix.
