- Postperfusion syndrome
Postperfusion syndrome, also known as pumphead, is a constellation of neurocognitive impairments attributed to
cardiopulmonary bypass (CPB) duringcardiac surgery . Symptoms of postperfusion syndrome are subtle and include defects associated with attention, concentration, short term memory, fine motor function, and speed of mental and motor responses.cite journal | author = Jensen B, Hughes P, Rasmussen L, Pedersen P, Steinbrüchel D | title = Cognitive outcomes in elderly high-risk patients after off-pump versus conventional coronary artery bypass grafting: a randomized trial. | journal = Circulation | volume = 113 | issue = 24 | pages = 2790–5 | year = 2006 | pmid = 16769915 | doi = 10.1161/CIRCULATIONAHA.105.587931] Studies have shown a high incidence of neurocognitive deficit soon after surgery, but the deficits are transient with no permanent neurological impairment.cite journal | author = Jensen B, Hughes P, Rasmussen L, Pedersen P, Steinbrüchel D | title = Cognitive outcomes in elderly high-risk patients after off-pump versus conventional coronary artery bypass grafting: a randomized trial. | journal = Circulation | volume = 113 | issue = 24 | pages = 2790–5 | year = 2006 | pmid = 16769915 | doi = 10.1161/CIRCULATIONAHA.105.587931] cite journal | author = Van Dijk D, Jansen E, Hijman R, Nierich A, Diephuis J, Moons K, Lahpor J, Borst C, Keizer A, Nathoe H, Grobbee D, De Jaegere P, Kalkman C | title = Cognitive outcome after off-pump and on-pump coronary artery bypass graft surgery: a randomized trial. | journal = JAMA | volume = 287 | issue = 11 | pages = 1405–12 | year = 2002 | pmid = 11903027 | doi = 10.1001/jama.287.11.1405]Evidence for postperfusion syndrome
A study by Newman et al. at
Duke University Medical Center published in the "New England Journal of Medicine " (NEJM), showed an increased incidence of cognitive decline aftercoronary artery bypass surgery (CABG); both immediately (53 percent at discharge fromhospital ) and over time (36 percent six weeks , 24 percent at six months, and 42 percent at five years).cite journal | author = Newman M, Kirchner J, Phillips-Bute B, Gaver V, Grocott H, Jones R, Mark D, Reves J, Blumenthal J | title = Longitudinal assessment of neurocognitive function after coronary-artery bypass surgery. | journal = N Engl J Med | volume = 344 | issue = 6 | pages = 395–402 | year = 2001 | pmid = 11172175 | doi = 10.1056/NEJM200102083440601] This study shows an association of neurocognitive decline with CABG, but does not show causation; the study lacks acontrol group and is considered level II-3 evidence.Subsequent studies have compared "on-pump" CABG with
off-pump coronary artery bypass (OPCAB) - essentially establishing controls to compare of the incidence of neurocognitive decline in CABG with and without the use of CPB. A small study (60 patients total, 30 in each treatment arm) by Zamvar et al. demonstrated neurocognitive impairment at both 1 week and 10 weeks postoperatively.cite journal | author = Zamvar V, Williams D, Hall J, Payne N, Cann C, Young K, Karthikeyan S, Dunne J | title = Assessment of neurocognitive impairment after off-pump and on-pump techniques for coronary artery bypass graft surgery: prospective randomised controlled trial. | journal = BMJ | volume = 325 | issue = 7375 | pages = 1268 | year = 2002 | pmid = 12458242 | doi = 10.1136/bmj.325.7375.1268] A larger study (281 patients total) by Van Dijk et al. showed CABG surgery without cardiopulmonary bypass improved cognitive outcomes 3 months after the procedure, but the effects were limited and became negligible at 12 months.cite journal | author = Van Dijk D, Jansen E, Hijman R, Nierich A, Diephuis J, Moons K, Lahpor J, Borst C, Keizer A, Nathoe H, Grobbee D, De Jaegere P, Kalkman C | title = Cognitive outcome after off-pump and on-pump coronary artery bypass graft surgery: a randomized trial. | journal = JAMA | volume = 287 | issue = 11 | pages = 1405–12 | year = 2002 | pmid = 11903027 | doi = 10.1001/jama.287.11.1405] Furthermore, the Van Dijk study showed no difference between the on-pump and off-pump groups in quality of life,stroke rate, or all-cause mortality at 3 and 12 months. More recently OPCAB has been proposed to be beneficial in patients at high-risk of neurological injury; a study by Jenson et. al published in Circulation found no significant difference in the incidence of cognitive dysfunction 3 months after either OPCAB or conventional on-pump CABG.cite journal | author = Jensen B, Hughes P, Rasmussen L, Pedersen P, Steinbrüchel D | title = Cognitive outcomes in elderly high-risk patients after off-pump versus conventional coronary artery bypass grafting: a randomized trial. | journal = Circulation | volume = 113 | issue = 24 | pages = 2790–5 | year = 2006 | pmid = 16769915 | doi = 10.1161/CIRCULATIONAHA.105.587931]Given the above evidence, there is high incidence of neurocognitive deficit post bypass surgery, but the deficits are transient with no permanent neurological impairment. Controlled "on-pump" versus "off-pump" cardiac surgery has only been studied in the setting of CABG and is not necessarily generalizable to other types of cardiac surgery. Recent advancements in
transcatheter andpercutaneous valve replacement may soon allow comparison of other types of cardiac surgery with and without CPB.Neurocognitive deficit as a consequence of vascular disease
A study by McKhann et al.cite journal | author = McKhann G, Grega M, Borowicz L, Bailey M, Barry S, Zeger S, Baumgartner W, Selnes O | title = Is there cognitive decline 1 year after CABG? Comparison with surgical and nonsurgical controls. | journal = Neurology | volume = 65 | issue = 7 | pages = 991–9 | year = 2005 | pmid = 16107605 | doi = 10.1212/01.wnl.0000175220.78475.99] compared the neurocognitive outcome of people with
coronary artery disease (CAD) to heart-healthy controls (people with no cardiac risk factors). People with CAD were subdivided into treatment with CABG, OPCAB and non-surgical medical management. The three groups with CAD all performed significantly lower at baseline than the heart-healthy controls. All groups improved by 3 months, and there were minimal intrasubject changes from 3 to 12 months. No consistent difference between the CABG and off-pump patients was observed. The authors concluded patients with long-standing coronary artery disease have some degree of cognitive dysfunction secondary tocerebrovascular disease before surgery; there is no evidence the cognitive test performance of bypass surgery patients differed from similar control groups with coronary artery disease over a 12 month follow-up period. A related study by Selnes et al.cite journal | author = Selnes O, Grega M, Borowicz L, Barry S, Zeger S, Baumgartner W, McKhann G | title = Cognitive outcomes three years after coronary artery bypass surgery: a comparison of on-pump coronary artery bypass graft surgery and nonsurgical controls. | journal = Ann Thorac Surg | volume = 79 | issue = 4 | pages = 1201–9 | year = 2005 | pmid = 15797050 | doi = 10.1016/j.athoracsur.2004.10.011] concluded patients with coronary artery bypass grafting did not differ from a comparable nonsurgical control group with coronary artery disease 1 or 3 years after baseline examination. This finding suggests that late cognitive decline after coronary artery bypass grafting previously reported by Newman et al.cite journal | author = Newman M, Kirchner J, Phillips-Bute B, Gaver V, Grocott H, Jones R, Mark D, Reves J, Blumenthal J | title = Longitudinal assessment of neurocognitive function after coronary-artery bypass surgery. | journal = N Engl J Med | volume = 344 | issue = 6 | pages = 395–402 | year = 2001 | pmid = 11172175 | doi = 10.1056/NEJM200102083440601] may not be specific to the use of cardiopulmonary bypass, but may also occur in patients with similar risk factors for cardiovascular and cerebrovascular disease.Proposed mechanism of injury
Physicians have theorized that the syndrome is caused by tiny debris and air bubbles (microemboli) that enter the brain via cardiopulmonary bypass. Surgeons attempt to minimize time spent on bypass to decrease postoperative deficits; studies have shown increased bypass time is associated with increased incidence and severity of postperfusion syndromeFact|date=February 2007 and mortality.Fact|date=February 2007
Postperfusion syndrome in the press
Postperfusion syndrome has attracted some public notoriety following the coronary bypasses of former U.S. President
Bill Clinton and Vice-PresidentDick Cheney .The National Enquirer speculated that Clinton experienced permanent debilitating brain damage; [cite web| url = http://www.nationalenquirer.com/politics/62632| title = Clinton's Secret Health Crisis| author = Brenna, Tony and Peter Davidson| accessdate = 2006-11-08| year = 2004| month = October] using the NEJM articlecite journal | author = Newman M, Kirchner J, Phillips-Bute B, Gaver V, Grocott H, Jones R, Mark D, Reves J, Blumenthal J | title = Longitudinal assessment of neurocognitive function after coronary-artery bypass surgery. | journal = N Engl J Med | volume = 344 | issue = 6 | pages = 395-402 | year = 2001 | id = PMID 11172175] discussed above to provide credibility to the claim.See also
*
Heparin-coated blood oxygenator
*Postoperative cognitive dysfunction
*Post-chemotherapy cognitive impairment (aka "chemo brain")References
Further reading
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