Anesthesia Update: Intraoperative Awareness

Anesthesia Update: Intraoperative Awareness
Intraoperative awareness incidents may be as low as 1 in 14,000 surgeries

By Michelle Beaver 

RECENT STUDIES SUGGEST that incidents of anesthesia awareness have been overestimated,¹ but the fact that any cases exist (and several do) motivates survivor Bonnie Mortillaro to share her story with the public. Mortillaro experienced anesthesia awareness in 2004 during a hysterectomy while she was intubated, and says that as a result, “a part of (her) did die that day.”

“I heard the conversation during surgery, the pumps, and suction,” Mortillaro says. “I felt the cutting and a hot poker burning, along with pulling and pushing. I could not breathe on my own. I was being tortured and thought I was dying. My mind screamed out in agony, fear, pain, and pleads.”

No healthcare professional wants people to experience such fright, but few agree entirely on how to prevent it. Anesthesia awareness occurs under general anesthesia when a patient can recall some or all of a procedure but since neuromuscular blocking agents are used during general anesthesia, patients are typically not able to express that they are aware.³ 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 awareness victims end up suffering from mental distress following surgery, a problem that sometimes manifests into post-traumatic stress disorder (PTSD).³ Fortunately, public understanding of this problem grows by the year, says David Shapiro, MD, CHC, CPHRM, LHRM, AAAHC, a board member for the American Association of Ambulatory Surgery Centers (AAASC).

“What’s been phenomenal about this topic is the awareness of the awareness,” Shapiro says. “It was something that was sort of recognized back when I was training, (but) in recent years it has risen to the level of absolute consciousness of any anesthesia provider in any setting.” He does not feel, however, that enough research has been done.

False Alarm?

According to a February 2007 paper published in the journal Anesthesiology, “Intraoperative Awareness in a Regional Medical System: A Review of Three Years’ Data,” intraoperative awareness incidents may be as low as 1 in 14,000 surgeries. 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 ambulatory surgery center (ASC), an academic medical center, and six community hospitals. The data represents a large cross section of the population.¹ Proper research was sorely lacking until this study was released, Shapiro says. “(Awareness) has risen up there now and that’s great even if the numbers were slightly inflated, that’s okay, it got our attention and I think now people are using it to make clinical decisions,” he says.

“I think (former data) were in a way overestimated, but in the end, going forward, the whole point isn’t how many — one is too many. I think a more realistic assessment and a quantification of how often these things occur (is necessary),” Shapiro adds.

According to the Joint Commission alert, “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.”

Dark Days

When patient Paul Monroe experienced anesthesia awareness in early 2007 he was surprised to discover that other people had been through it too. “Many people out there are unaware of this and when it happens many like me don’t know what to think or do about it, because it does haunt you and it does scar you forever,” Monroe says.

His experience happened in a hospital near Forth Worth, Texas, during a spinal surgery at a hospital in Mansfield. He says he was aware for about three minutes. “My first instinct was, ‘I’m awake and I can move my arms and can feel everything,” Monroe says. “After yelling and moving around they put me back out and even though I couldn’t move or speak, I could still feel everything. I knew it wasn’t a dream and this was very real. The only thing I could think was ‘My God what did I do to deserve this? Why are they doing this to me?’ My mind was racing and I was having one anxiety attack after another and I could still feel the pain and I was so helpless I just wanted to die.”

Monroe reported his case to the Joint Commission and was told that it would be investigated.

Highest Susceptibility

According to the Joint Commission alert, patients undergoing cardiac, obstetric, and major trauma surgeries are at a higher risk of anesthesia awareness.

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 OR turnover.”

One sensitive group — children — require special care, says Joseph Cravero, MD, the author of the paper, “New Thinking About Sedation Safety — You Snooze, You Don’t Lose.”

“Any discussion of sedation services must begin with the fact that no one has all the answers to the questions surrounding procedural sedation in general — and in particular sedation for children,” Cravero says.

“Each year millions of infants and children require sedation and pain control for medical procedures,” he adds. “We all recognize that hospitals and offices struggle with the logistical and medical difficulties associated with providing this service. There is often heavy demand for sedation services and these cases must be performed in a wide variety of locations involving many different services — radiology, dentistry, pediatric inpatient service, emergency department, nuclear medicine, etc.”

Pediatric sedation routines are inconsistent nationwide, according to Cravero.

“Some services require direct physician involvement while others rely on trained nursing personnel,” Cravero says. “Still others have developed the concept of a sedation room or a sedation team.

The jury is out, however, when it comes to evaluating and comparing these strategies.² “The major goals of procedural sedation are to provide anxiety relief, pain control, and reasonable movement control,” Cravero says. “The rate of failure to achieve these goals has been reported by various investigators to be as low as 2 percent to 3 percent and by others to be 10 percent to 20 percent — depending on the setting and the procedure that is being performed.

When sedation fails, procedures are carried out on children who are crying, struggling and requiring physical restraint … Similarly, inadequate preoperative sedation has clearly been linked to stress and PTSD-like symptoms in children and their families surrounding surgical procedures.

“Aside from psychological trauma, diagnostic procedure quality suffers when movement is not controlled, often requiring a procedure to be rescheduled with an anesthesiology team providing the sedation,” he adds. “Evaluating the safety of pediatric procedural sedation services has always been problematic. Sedation safety relates to how often a sedative drug produces an unwanted side effect, or toxicity. The most serious complication of pediatric procedural sedation — death — is most often due to the respiratory depressant side effect of sedative medications.”

Pinpointing who will be susceptible to awareness is difficult, according to Robert Goldstein, MD, executive vice president and chief medical officer for Somnia, Inc; a national provider of anesthesia services for hospitals, ASCs, and office-based surgical facilities.

“The effects of anesthesia awareness are very patient-dependent but underscore the need for patients to focus on who their surgeon is — as well as who their anesthesia service provider is scheduled to be,” Goldstein says. “Unlike a disease which may have very similar symptoms and outcomes among patients, anesthesia awareness is very idiosyncratic and can’t fit neatly into a few bullet points and how patients perceive it on both conscious and unconscious levels is not entirely certain. Certainly those patients who experience post traumatic stress disorder as the result of awareness while under anesthesia are a cause for great concern.”

Case Study

Information was collected between 2002 and 2004 for the study, “Intraoperative Awareness in a Regional Medical System: A Review of 3 Years’ Data Clinical Investigations,” and 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.”

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 postoperative period under the qualifications of a modified Brice interview to determine awareness.

Results were as follows: “data from 211,842 patients undergoing anesthesia were considered. Of these, the continuous quality improvement process followed up 177,468 (83.1 percent). Cases were not included in the study if the patient was younger than 18 years old, did not have a general anesthetic, or had a terminal event during the hospital course.

“By these criteria, a total of 87,361 patients followed by the continuous quality improvement process were at risk for awareness,” the study continues. “Six patients reported instances of recall. Conclusion: The incidence of intraoperative awareness in this large sample of patients from a regional medical center undergoing general anesthesia was 0.0068 percent, or 1 per 14,560 patients, substantially less than that reported in the recent literature.”

Regardless, the Joint Commission has issued recommendations in hopes of achieving a zero incidence rate. Authors of the recommendations urge hospital and surgery center decision makers to:

• 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 distress³

ASCs: Less Fallible in the Grand Scheme?

ASCs seem to have fewer instances of anesthesia awareness, and staffs there are certainly more likely to find out about cases of anesthesia awareness and assist the patient than the staffs at hospitals, according to Shapiro.

ASCs are typically smaller than hospitals, and when it comes to tracking down patients and problems, smaller is often better. Furthermore, since the ASC clientele is typically healthier than the patient load at hospitals, fewer people experience anesthesia problems in surgery centers.

“The patients that usually have their procedures done in an ambulatory surgery center have a very low incidence of the criteria which would predispose them to experience this unfortunate occurrence,” Shapiro says.

Many ASC patients do have a history of chronic pain, however, and because such pain is often treated with drugs that may lead to greater anesthesia awareness, these patients should be treated extra cautiously.

“One of the biggest predisposing factors to awareness is the use of long-acting muscle relaxers throughout the procedure,” Shapiro says. “On the whole our patients don’t usually come to us in a critical fashion or with so many concurrent illnesses and I think the surgeries we’re doing are for the most part of a non-emergency elective and much less invasive nature, and they’re mostly shorter.”

Plus, the surgeries during which anesthesia awareness would be most dangerous — such as trauma cases, cardiac procedures and C-sections — are done in hospitals, not ASCs. The average ASC employee is extremely aware of, well, awareness, Shapiro says.

“I think that the fabulous part for all practitioners is that it’s something that’s gotten so much publicity,” he says. “ASCs are typically incredibly diligent about following up on patients. We need to give patients every opportunity to tell any problem that they had during any party of their experience at the surgery center, so really that’s preop, intraop, and postoperative. If we’re calling them a day later or even two days later and this is something that’s occurred, there’s no doubt in my mind that this is something they’re going to mention.”

And if an anesthesia blunder does occur? Investigate it, Shapiro says. “Really, go back, talk to the practitioner, talk to the people in the room, see to what extent this may or may not have occurred, but also do a follow up and see all the parameters that are relevant,” Shapiro says.

“It’s great that people have an understanding that this is a potential problem so that we can be sensitive to it if it occurs,” he adds, “but also be concerned about it enough to learn how to prevent it.”

Rocky Road

The healthcare industry has a better understanding of anesthesia awareness than ever before, but that doesn’t mean the challenge is over, according to Goldstein.

“I am never sure we can say enough research has been done on anything involving how to provide better anesthesia service to patients, and anesthesia awareness is probably no exception,” Goldstein says.

“There is clearly a greater understanding throughout the anesthesia community as it relates to awareness under anesthesia,” he adds. “If you had asked me this same question even five years ago my answer may have been quite different. Through Somnia’s medical advisory board as well as with quarterly staff meetings we continuously provide anesthesia service professionals with resources to tackle these and other important anesthesia-related patient safety issues.”

Anesthesia providers certainly take the problem seriously, Goldstein says. “As a result of their greater understanding of the problem, I do believe most anesthesia service professionals understand what is necessary to prevent this poor outcome … In general, vigilance and preparation are really the keys to prevention of anesthesia awareness,” he adds. “These qualities can be hard to teach but most anesthesia service providers have a keen understanding of how to fashion an anesthesia technique that takes this into account.”

EEG Monitoring

A tool that is not being used to its full potential is the Bispectral Index (BIS)® monitor, says Mortillaro, who wishes that this device had been used during her hysterectomy.

“The use of BIS monitors to prevent anesthesia awareness is in no way downplaying the professionalism, nor mastery of the doctors,” Mortillaro says. “This technology advances the eye of the doctor, allowing him assisted levels of proficiency that is not possible by man.”

Mortillaro knows that the technology is not perfect, but she feels that it, combined with an attentive anesthesiologist, would decrease awareness incidents.

BIS monitoring (or EEG monitoring) is controversial, Shapiro says. “It’s a clinical decision,” Shapiro says. “Because of the typical anesthetics that we are delivering, we have a lot more signals available to us in terms of looking for purposeful or reflex movement in response to pain stimuli or in response to anything else that’s going on in the operating room environment in addition to the surgical procedure. If you don’t have those (EEG) monitors — and that’s the typical situation in the ASCs — that’s OK as long as you make sure you’re doing a good job with both the clinical as well as the conventional external monitors that you have available,” he adds.

According to the Joint Commission, properly monitoring patients to prevent anesthesia awareness can be challenging.

“Indicators of physiologic and motor response, such as high blood pressure, fast heart rate, or movement, or hemodynamic changes, are often masked by the use of paralytic agents to achieve necessary muscle relaxation during the procedure, as well as the concurrent administration of other drugs necessary to the patient’s management, such as beta-blockers or calcium channel blockers,” Joint Commission researchers state.

The authors believe that devices such as EEG, BIS, and spectral edge frequency (SEF) and median frequency (MF) monitors “may have a role in preventing and detecting anesthesia awareness in patients with the highest risk, thereby ameliorating the impact of anesthesia awareness.”

More evidence must be collected, however. The authors continue: “In its review of the Bispectral Index (BIS)® monitor, the Food and Drug Administration determined that, ‘Use of BIS monitoring to help guide anesthetic administration may be associated with the reduction of the incidence of awareness with recall in adults during general anesthesia and sedation.’”

EEG monitoring can be helpful, but is hardly the end-all-be-all, Goldstein says.

“Vigilance and preparation by anesthesia professionals to me are the critical steps to prevention of awareness under anesthesia,” he says. “EEG monitoring during anesthesia is not a replacement for these attributes but certainly has a role. For instance, while it is not practical nor indicated to use EEG monitoring on every patient under anesthesia, we can nonetheless define the higher risk groups (C-section, cardiac surgery, trauma surgery) and use EEG monitoring in those situations as another tool in our tool box.

“In today’s era of cost-containment, the cost for an EEG machine, and the disposable probes, creates a barrier for many facilities,” Goldstein adds. “Sadly, many insurance companies will not pay for the EEG machine nor supplies and nearly all are unlikely to pay a physician anesthesiologist or CRNA for monitoring the EEG on patients undergoing anesthesia.”

Mark Gan, the owner of an ASC in El Paso, Texas, agrees that a well trained anesthesiologist can thwart major problems. Gan has been in practice for 15 years and hasn’t had “any untoward events or catastrophes in that time,” he says.

“In El Paso I know of no ambulatory center using any sort of EEG monitoring,” he says. “If you know what you’re doing, awareness doesn’t seem to be a problem.”

Regardless, more education throughout the field may be in order, he says. “There needs to be an understanding on the part of all anesthesiologists that awareness in the OR just can’t happen,” he says.

Gan believes that some anesthesia challenges for the ASC industry involve finding economic drugs and gasses and keeping a healthy turnover all without “compromising patient safety or quality of care.”

A good combination of these topics, along with personalized care and a reduced use of unnecessary medications, will help ASCs continue to improve upon the hospital experience, he says.

Gadgets, Gizmos and Anesthesia Recommendations

Communicating about anesthesia awareness is important, but perhaps the scope of the conversation should change, Goldstein suggests.

“Awareness under anesthesia is usually studied only for patients receiving general anesthesia,” he says. “Patients receiving regional anesthesia or local anesthesia, MAC, or sedation are told prior to their care that recall or some level of awareness is expected with these types of anesthesia. So, if we limit the discussion to general anesthesia, we are looking for the type of general anesthetic that may limit risk of recall the most.

“Patients receiving neuromuscular blocking agents to prevent movement during anesthesia and surgery are at higher risk to experience recall while under anesthesia,” he says. “Recall can also be the result of faulty equipment (infusion pumps) so assuring the integrity of OR anesthesia equipment is very important.

“Finally, recall under general anesthesia can occur because of the need to limit the depth of anesthesia due to the health of the patient,” he adds. “Preparation for these types of anesthesia cases and an anesthesia plan that includes the use of benzodiazepines may do a lot to prevent anesthesia awareness for these patients.”

Since the organization of anesthesia services is such a big undertaking, hiring a manager is advisable, Goldstein believes.

Companies can analyze an ASC’s plans, facility size, case volume, etc., and supply a “road map” of suggestions including information about staff recruitment, revenue management, accountability, scheduling, supplies, etc.

Some helpful tools, according to Carlos Rosado, CEO of Lone Star Medical Equipment, include:

• LMA’s 
• Nerve stimulators 
• Fiber optic larygoscopes 
• Difficult intubations scope 
• Syringe pumps 
• Anesthesia supply storage cart with lock 
• Magill forceps 
• Vital signs monitor with anesthesia agent module 

The industry, as well as the tools involved, is changing, Rosado says. “For decades, (some companies) have dominated the anesthesia machine market,” he says, “(but) we are starting to see other manufacturers bringing high-quality, lower-cost machines into the market place. Also, the design of the ventilators has changed to accommodate high risk patients such as the morbidly obese.”

Proper research can mean big savings during the purchase or leasing of anesthesia equipment, Rosado believes.

“Anesthesia is one area where an ASC can save significant money by purchasing a refurbished anesthesia machine,” he says. “As always, the buyer should always ask for references. However, the most important factor is to ensure that the vendor can provide their refurbishing process and provide proof that the technicians working on the machines have had the appropriate training from the original equipment manufacturer. Finally, make sure that the refurbished anesthesia machine will have parts support from the manufacturer for a minimum of five years.” 

2. Cravero J. New thinking about sedation safety — you snooze, you don’t lose.

3. The Joint Commission. Preventing and managing the impact of anesthesia awareness. Issue 32. Oct. 2004.

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