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.
Additional Background
American Society of Anesthesiologists
Practice Advisory for Intraoperative Awareness and Brain Function Monitoring
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.
From American Society of Anesthesiologists