Tuesday, June 19, 2012

THE PUMPHEAD SYNDROME. A GENTLE REMINDER OF THE LONG TERM COGNITIVE EFFECTS OF THE HEART LUNG MACHINE IN PATIENTS POST BYPASS.

I was recently asked to comment on the long term cognitive effects of the heart lung machine on patients who have undergone on-pump coronary artery bypass surgery. I have chosen to reproduce the whole paper, so that I will not be wrongly accused of distorting the facts.

Longitudinal assessment of neurocognitive function after coronary-artery bypass surgery.

Source

Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA. newma005@mc.duke.edu

 N Engl J Med 2001 Jun 14;344(24):1876.

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.

Yes, the heart-lung machine allows the cardiac surgeons hours to work on the heart and bypass the problem causing stenosed coronary artery. However, this comes with a price. The heart lung machine itself also generates micro-bubbles, which can travel to the brain causing short term and long term cognitive impairment.
Maybe that is why years after bypass, some post CABG patients talk nonsense and should not be taken seriously. In fact, they should seek treatment, so that they can become  more responsible citizens and patients.

1 comment:

Nick Peterson said...

I offer a link to a paper regarding pump head. It dulls the 2001 Duke study.

http://ats.ctsnetjournals.org/cgi/content/abstract/88/2/445