October 25, 2005
FOR IMMEDIATE RELEASE
Tuesday, October 25, 2005
Contact:
ASA Annual Meeting Press Office
Georgia World Congress Center
(404) 222-5612, 5613, 5614,
5615
Or after October 26:
Gina Steiner
ASA Communications Department
(847) 825-5586
REPORT ON AWARENESS UNDER GENERAL ANESTHESIA SAYS ANESTHESIOLOGISTS
HAVE MULTIPLE TOOLS AND APPROACHES FOR MINIMIZING RISKS
ATLANTA—At its annual meeting today, the House
of Delegates of the American Society of Anesthesiologists
(ASA) approved the final report of ASA’s Task Force
on Intraoperative Awareness. The report, “Practice
Advisory for Intraoperative Awareness and Brain Function
Monitoring,” represents
the most thorough document to date to assist anesthesiologists
and hospitals in minimizing the risks of awareness under
general anesthesia.
The purpose of a practice advisory is to provide ASA members
with the most up-to-date information possible to assist
them in making treatment decisions for individual patients.
A practice advisory is not a standard or guideline, and
does not serve to identify a particular treatment or approach
as a standard of care.
Unintended awareness under general anesthesia is rare,
and involves the patient having some recollection of events
during his or her surgery, including possibly hearing sounds
and feeling sensations or pain. It is more likely to occur
in patients whose condition is unstable, or in emergency
or trauma situations.
The incidence of intraoperative awareness has been reported
as 1 to 2 cases per 1,000 surgeries under general anesthesia.
Although many cases are brief, some are more significant
or traumatic for the patient. It is not possible to eliminate
episodes of awareness in all cases, as anesthesiologists
must sometimes opt for lighter anesthesia to keep the patient
safe.
Though cases of unintended awareness are unusual and sometimes
unavoidable, this phenomenon has been highly publicized
in recent years.
The report reviews several processes, approaches and tools
that anesthesiologists can consider in their treatment
plans for individual patients, with the goal of reducing
the incidence of unintended awareness under general anesthesia.
In the report, the task force makes several recommendations
and statements related to monitoring of patients for intraoperative
awareness.
First, it states that physicians should rely on “multiple
modalities, including clinical techniques (e.g., checking
for clinical signs such as purposeful or reflex movement)
and conventional monitoring systems (e.g., electrocardiograms,
blood pressure monitors, heart-rate monitors, end-tidal
anesthetic analyzers and capnographs).”
Second, the report states that “the decision to
use a brain function monitor should be made on a case-by-case
basis by the individual practitioner for selected patients.” This
group may include patients undergoing trauma surgery
or cesarean section who cannot tolerate a deep anesthetic.
Providing a lighter than normal anesthetic to at-risk
patients may be a necessary step taken by anesthesiologists,
the possibility of which is generally discussed with
the patient in advance of surgery, if circumstances permit.
“The most important monitor in the operating room
is the anesthesiologist, who has 12 years of medical training
and a wealth of experience to draw on when deciding what
is appropriate for each individual patient,” said
Orin Guidry, M.D., newly installed ASA president.
In a separate but related action, the ASA House of Delegates
passed a recommendation that ASA study funding further
research into the usefulness of brain function monitoring
technology in minimizing the risk of intraoperative awareness.
The American Society of Anesthesiologists has been educating
its members about awareness for more than a decade through
its NEWSLETTER and educational meetings. Its Practice Advisory
on Intraoperative Awareness and Brain Function Monitoring
represents the most comprehensive examination of the subject
to be undertaken in the health care arena.
ASA encourages patients to discuss any concerns about
awareness under general anesthesia with their anesthesiologist.
It also advises that anesthesiologists continue to treat
any patient who reports awareness with compassion and
respect, and to refer them for counseling as appropriate.
More information for patients is available at: http://www.asahq.org/patientEducation/Awarenessbrochure.pdf.
“We spend our entire career working to make sure
that every patient is kept safe, and is protected from
pain and fear. This is what we do,” Dr. Guidry
said.
The Task Force and its Report
ASA’s Task Force on Intraoperative Awareness,
appointed in 2004, was charged with producing a practice
advisory that would identify risk factors associated
with intraoperative awareness, provide decision tools
to enable the clinician to reduce the frequency of unintended
intraoperative awareness, stimulate the pursuit and evaluation
of strategies to prevent or reduce the frequency of intraoperative
awareness, and provide guidance for the intraoperative
use of brain function monitors as they relate to this
phenomenon.
As part of its work, the Task Force reviewed more than
150 studies. The group sought comments on several preliminary
drafts of the report from ASA members and other interested
parties earlier this year. Members, technical experts
and manufacturers of brain function monitors (devices
marketed to measure the depth of a patient’s sedation)
submitted comments.
The final report examines the latest medical and scientific
information on intraoperative awareness, including
factors that increase a patient’s risk. It summarizes
the research on brain function monitoring, reports on
multiple approaches for minimizing risks, and recommends
appropriate followup for patients who report awareness
during surgery. It also reports on the opinions of members
and consultants about the usefulness of brain function
monitoring in minimizing the risk of intraoperative awareness.
Brain Function Monitoring
Brain function monitoring devices, made by a handful
of companies, use processed electroencephalographic data
to assign a numeric value to a patient’s depth
of sedation. One application for which they are marketed
is to help minimize the risk of intraoperative awareness.
The report recognizes the devices as a possible tool for
monitoring selected patients, but concludes that the decision
to use this emerging technology should be made on a case-by-case
basis by the individual practitioner.
“There is still much to be discovered about how
these devices work, and in which situations they are best
applied,” Dr. Guidry said. “We are interested
in following their continued evolution and to conducting
further research in this area. Meanwhile, brain function
monitors are an option to be used when the anesthesiologist
deems it appropriate, just as he or she makes choices
about specific drugs, dosages, warming devices, and other
types of monitors depending on the individual patient.”
From an historical perspective, ASA’s approach to
these monitors is consistent with its approach to other
types of equipment used by anesthesiologists. For example,
capnographs and pulse oximeters are widely used today to
monitor surgical patients’ breathing and blood oxygen
levels. Yet language encouraging their use in ASA standards
and guidelines did not happen overnight; it was strengthened
gradually as the devices’ usefulness, reported
by anesthesiologists and researchers, became more evident.