Preventing Unintended Intraoperative Awareness

Intraoperative awareness, the condition that occurs when surgical patients under general anesthesia can recall sounds, events or even pain during their surgery, has been reported, but caution must be used when discussing this controversial trend. Anesthesiologists practicing in ambulatory surgery centers (ASCs) should be aware of this condition, as it is a reminder that patient safety and comfort is of utmost importance.

According to the Joint Commission, 48 percent of patients who experience awareness have it in the form of auditory recollections, 48 percent feel they cannot breathe and 28 percent experience pain. About half of patients experiencing intraoperative awareness end up suffering from mental distress following surgery.¹

“Unintended awareness is always an issue — and is something to be avoided — whenever and wherever general anesthesia is administered,” says Robert E. Johnstone, MD, vice president for professional affairs for the American Society of Anesthesiologists, and professor of anesthesiology at West Virginia University. “Unintended awareness appears to occur less often, though, in ambulatory surgery centers, perhaps because of the types of surgery done there. It’s been linked most closely with cardiac, obstetric and trauma surgery. It’s a rare occurrence, and ongoing studies as well as reports into the awareness data registry may clarify where and why it occurs.”

According to a paper, “Intraoperative Awareness in a Regional Medical System: A Review of Three Years’ Data,” published in the journal Anesthesiology in 2007, intraoperative awareness incidents may be as low as 1 in 14,000 surgeries.² Researchers reviewed data from more than 87,000 patients who underwent general anesthesia between 2002 and 2004 at facilities near Charlotte, N.C., including one ASC, an academic medical center and six community hospitals. Throughout the study, anesthesia was delivered by board-certified anesthesiologists and supervised certified registered nurse anesthetists. Brain function monitors were not used, and patients were interviewed twice during a 48-hour post-operative period under the qualifications of a modified Brice interview to determine awareness. The study concluded that “intraoperative awareness in patients undergoing general anesthesia is an infrequent but well-described adverse outcome. The reported incidence of this phenomenon is between 0.1 percent and 0.9 percent.”

While some clinicians say that more data is needed to fully understand the challenges of intraoperative awareness; many are glad the data has raised the profile of this issue. An alert issued by The Joint Commission notes, “Better understanding among healthcare professionals of this frightening phenomenon could reduce the risk of these events and assure appropriate support for patients when they do occur.” Another Joint Commission document, “Preventing and Managing the Impact of Anesthesia Awareness,” states that, “awareness is reported to be greater in patients in which the dose of general anesthetic must be smaller and carefully titrated to decrease significant side effects, for example, a patient who is hemodynamically unstable ... Factors contributing to the risk of anesthesia awareness include the increasing use of intravenous (IV) delivery of anesthesia, as opposed to inhalation, and the premature lightening of anesthesia at the end of procedures to facilitate operating room (OR) turnover.”

Incidences of awareness occur once or twice per 1,000 surgeries performed under general anesthesia, according to the American Society of Anesthesiologists (ASA). Not all incidences of recall during medical procedures involving anesthesia are considered cases of awareness. Patients who receive sedation, local anesthesia, regional blocks, spinal or epidural anesthesia are expected to be somewhat awake or aware of their surroundings and have some recall of the procedure. In addition at the very end of a surgical procedure, the anesthetic is reduced so that patients can awaken and therefore, there may be some awareness during this period.

The risk for anesthesia awareness is higher for unstable patients or for patients undergoing high-risk surgeries such as trauma, cardiac surgery or emergency Caesarean sections. In these high-risk cases, using a deep anesthetic may not be in the best interest for patient’s safety.

“Regardless of statistics, even one case of anesthesia awareness is too many,” says Roger A. Moore, MD, president of the ASA. “The ASA continues to study the occurrence of awareness to find effective ways to prevent the condition. The entire surgical team must be vigilant before, during and after surgery to ensure the safety, comfort and recovery of each patient.”

Specific steps can be taken by physicians and patients to reduce the risk of awareness. Patients and anesthesiologists should meet prior to surgery to discuss anesthesia options as well as the patient’s surgical, anesthetic and medication history. It may be helpful for patients to have a friend or family member advocate with them for this discussion. It is during this visit that patients should discuss any anxiety or concerns about their procedure with the anesthesiologist including possible awareness.

“The ASA has developed numerous standards, guidelines and advisories that describe safe and best practices,” Johnstone says. “Anesthesiologists should always consider these in their anesthetic plans and practices. Patients can check that an anesthesiologist is directly involved with their anesthesia care, and should review their concerns with their anesthesiologist preoperatively. Arriving at an ASC with a list of medicines, allergies and pertinent medical information is also wise.”

Following surgery, patients who believe they may have experienced anesthesia awareness are encouraged to contact their anesthesiologist regarding their experience. The first step in overcoming the adverse emotional consequences of an intra-operative awareness experience is acknowledgement that it may have occurred.

Seeking greater understanding why awareness occurs, ASA has sponsored the development of The Anesthesia Awareness Database, a voluntary registry of patients who have experienced awareness.

The Anesthesia Awareness Database was developed to understand why anesthesia awareness occurs, to prevent future occurrences of awareness, and to help anesthesiologists and other healthcare professionals better understand and assist patients who experience awareness.

The Joint Commission’s recommendations to help prevent intraoperative awareness include:

• Identify patients who are at proportionately higher risk for an awareness experience, and discuss the risks with them prior to surgery
• Use available anesthesia monitoring techniques
• Properly maintain anesthesia equipment
• Educate clinical staff about anesthesia awareness and how to handle patients who have experienced it
• Conduct post-operative follow-ups with all anesthesia patients, including children
• Facilitate access to support systems for patients who are experiencing mental distress.

References

1. The Joint Commission. Preventing and managing the impact of anesthesia awareness. Issue 32. Oct. 2004.
2. Pollard R, Coyle J, et al. Intraoperative awareness in a regional medical system: a review of 3 years’ data clinical investigations. Anesthesiology. February 2007.