美國老年精神科協會(American Association for Geriatric Psychiatry (AAGP)) 2010年會：會議小組214。發表於2010年3月6日。
Cholinesterase Inhibitors Do Not Exacerbate Postoperative Complications in Patients With Dementia
By Pam Harrison
Medscape Medical News
March 9, 2010 — The risk of postoperative complications is not exacerbated by cholinesterase inhibitor therapy in elderly adults with dementia who receive general anesthesia during hip fracture surgery, suggesting the once-standard practice of discontinuing medication use in patients before surgery is not necessary.
Dallas Seitz, MD, Baycrest Centre, Toronto, Ontario, Canada, found no interaction between the muscle relaxants used in general anesthesia and cholinesterase inhibitor use in either community-dwelling or long-term care patients undergoing emergency hip fracture surgery.
Results from the member-in-training research award were presented during the American Association for Geriatric Psychiatry 2010 Annual Meeting. The study's primary composite outcome consisted of 30-day postoperative mortality, intensive care unit admissions, and the need for in-hospital resuscitation.
The investigators found the relative risk of community-based patients who were taking a cholinesterase inhibitor when they received general anesthesia was 0.89 compared with matched controls who were not taking cholinesterase inhibitors.
Similarly, the relative risk of long-term care patients who were receiving a cholinesterase inhibitor while undergoing general anesthesia was 0.78 compared with those who were not taking such medications. There was also no excess of adverse postoperative outcomes among either community or long-term care patients taking or not taking cholinesterase inhibitors who received regional anesthesia during hip fracture surgery.
"We do see patients who develop behavioral symptoms after withdrawal from the [cholinesterase inhibitors], so I think it’s fair to say that given standard anesthetic practice today, these medications do not appear to confer significant increased risk of postoperative complications, and I would recommend not discontinuing them," Dr. Seitz said.
Prevention Still the Best Medicine
The population-based cohort study linked administrative healthcare databases. The cohort consisted of patients 66 years and older with dementia who underwent hip fracture surgery between 2002 and 2007. The cohort was stratified into those who lived in the community before their fracture vs those who lived in long-term care facilities, as well as patients who received general vs regional anesthetic during surgery.
After carefully matching patients taking and not taking a cholinesterase inhibitor at the time of surgery, the team ended up with 624 matched community-dwelling pairs who received general anesthesia and 719 long-term care pairs who again received general anesthesia.
Both groups of pairs were well matched for sex, mean age, comorbidities, number of medications at the time of surgery, and duration of dementia, “so we had fairly comparable groups in terms of all the major covariates,” Dr. Seitz said.
Regardless of whether patients were taking a cholinesterase inhibitor, the prognosis after hip surgery for both matched pairs was poor. Even in "relatively healthy" community-dwelling pairs, the 30-day postoperative mortality rate was 10%, with an additional 5% requiring intensive care unit postoperative care. The postoperative prognosis for long-term care patients was even poorer, with a 30-day postoperative mortality rate of 12% to 15%.
"We still need to be vigilant about medication use in this population, but their outcome is so bad that by the time they have their hip fracture and come in for surgery, they are a very frail group to begin with and the marginal effect of the cholinesterase inhibitors is washed out in the rest of their comorbidities," Dr. Seitz said. "There is a definite need to prevent hip fractures and their complications in this population."
No Need to Withdraw Medication
Paul Newhouse, MD, University of Vermont, Burlington, told Medscape Psychiatry that in the early 1990s, patients taking cholinesterase inhibitors would routinely discontinue use of the medication before surgery, at which point, many would develop quite disturbing behavioral symptoms — and this was when physicians first recognized that these agents had positive effects on behavior.
The concern was that cholinesterase inhibitors might prolong the effects of muscle relaxants, themselves cholinergic drugs, used during general anesthesia, weakening respiratory muscles and increasing the risk of postoperative complications.
"Today, however, I think it is accepted wisdom that patients should generally be left on cholinesterase inhibitors because they can develop quite serious behavioral issues when the drug is withdrawn," said Dr. Newhouse.
Dr. Seitz and Dr. Newhouse have disclosed no relevant financial relationships.
American Association for Geriatric Psychiatry (AAGP) 2010 Annual Meeting: Session 214. Presented March 6, 2010.
