At our surgery center, we've found the key to lower PACU costs, efficient workflow, and satisfied patients. We've embraced the concept of "fast-tracking," which means that we transfer patients who are wide awake, oriented and practically pain- and nausea-free from the OR directly to private rooms instead of a Phase I PACU. Producing patients who are able to be fast-tracked, however, requires careful anesthesia technique - it's critical to administer just enough medication to ensure loss of consciousness, but not so much that the patient experiences post-op anesthesia side effects. We've found that Bispectral Index (BIS) monitors are crucial to achieving this delicate balance and vital to our fast-tracking ability.

By analyzing electroencephalogram (EEG) activity, the electrical activity of the brain, BIS monitors help determine a patient's level of consciousness. A BIS level of 100 means that the patient is wide awake, a reading of 70 indicates a light hypnotic state, 60 indicates unconsciousness, and zero is the absence of brain activity. Using BIS monitors helps us titrate anesthetic drugs more accurately, preventing us from putting the patient "too deep" and causing post-op drowsiness, nausea, and a slower recovery. BIS monitors have also enabled us to reduce our anesthetic drug costs by 30 percent and helped us eliminate incidences of intraoperative patient awareness.

We first tried BIS monitors for our cardiac surgery and trauma patients in our main hospital, Community Hospitals Indianapolis, in February 1997. In these cases, "fast-tracking" means that patients are extubated within six hours post-op instead of being ventilated overnight. Before BIS, we were fast-tracking almost 60 percent of our cardiac patients, but there was one unexpected side effect - some patients were experiencing awareness during surgery, possibly because the anesthesia was too "light." When we started using the monitors, my aim was not to enhance our fast-tracking capability, but to eliminate all such incidences of awareness.

The monitors helped us achieve that first goal, and intraoperative awareness episodes decreased to zero. As an unexpected bonus, I found that the monitors greatly enhanced my ability to administer just the right amount of anesthetic by telling me exactly when the patient became unconscious, or reached a BIS level of 60. I also observed that my patients were recovering more quickly and had less incidences of post-operative nausea and vomiting, since they had less anesthetic in their systems. Soon, we were fast-tracking almost 80 percent of our cardiac patients. Before long, we started using BIS monitors in all the ORs throughout the institution, including our multispecialty, six-OR Community Hospital East Surgery Center, which opened in April 1999.

Here's how I incorporate BIS monitoring into my anesthesia technique for outpatient surgery: I generally administer just enough medication to keep the patient's BIS reading between 50 and 65. Before I started using the BIS regularly, I probably would have given at least 20 to 30 percent more anesthetic before I was confident that the patient was sufficiently unconscious. In addition to the BIS number, I keep an eye on the EMG, or electromyographic activity, which indicates electrical activity due to muscle contractions in an unparalyzed patient. EMG activity can artificially inflate the BIS, making the patient seem more "awake" than he/she really is. Sometimes a patient who is actually deeply unconscious may experience a burst of electrical activity in the brain, which can also produce a false high reading, although a new algorithm, which is used in the newer BIS monitor models, has reduced this occurrence.

As long as you understand what to look for, however, I believe that tracking a BIS reading is far superior to simply monitoring a patient's vital signs. Taking a blood pressure, for example, is an inaccurate way to determine level of unconsciousness - a patient may experience a sudden increase in blood pressure not because of inadequate hypnosis, but due to an exacerbation of underlying hypertension, inadequate analgesia, or other cardiac abnormalities. This patient may require an antihypertensive or an analgesic rather than more anesthetic.

Conversely, a patient who experiences intraoperative hypotension may not be too "deep" and may need more fluid, vasopressor, etc., if the BIS reading is in normal range. A BIS monitor allows me to interpret vital signs more accurately and make more rational, informed decisions about which drug to administer.

Some physicians who have used the BIS monitor doubt its effectiveness because their patients move intraoperatively. However, intraoperative movement does not mean the patient is waking up, although it may mean that he/she is experiencing subconscious pain. The solution is to administer pre-emptive analgesia. I use a multi-modal pain therapy approach, combining moderate doses of opioids, local anesthetic infiltration at the surgery site, and non-steroidal anti-inflammatories (NSAIDs). This approach minimizes intraoperative movement and also helps prevent post-op pain.

Because of the BIS monitor and our success in fast-tracking, we designed our surgery center with no Phase I PACU. Instead, we have 24 private rooms arranged around the perimeter of a nursing station, like the spokes of a wheel. Each room is used for pre-op as well as post-op care, and we can provide intensive care and 23-hour care, if needed. By eliminating a Phase I recovery area altogether, we've had to hire two fewer PACU nurses, and have reduced related PACU costs to a bare minimum. These savings have helped us achieve a strong bottom line - already we have realized a 50 percent profit margin.

I don't doubt that you can successfully fast-track patients without BIS monitors, but I guarantee that you will fast-track a higher percentage with them. More importantly, you can do it with the confidence that patients will not experience intraoperative awareness and will recover faster. These factors, I believe, make BIS monitors invaluable to any outpatient facility.

NO - You Can Fast-Track Patients Without One

Thomas Cutter, MD

The average operating room time at our multispecialty, five-OR ambulatory surgery center is about 45 to 60 minutes. More than half of our patients go directly to a step down unit (phase 2 post anesthesia care unit or PACU), but all of our patients are "fast-tracked." Bypassing a phase 1 PACU, the common definition of fast-tracking, is only a component of what fast-tracking means at our center. True fast-tracking is moving patients through the entire perioperative process as safely and quickly as possible. Accomplish-ing this takes careful pre-op preparation, good intraoperative anesthesia technique, and a streamlined post-op plan, but it does not, in my opinion, require a BIS monitor.

Here's how we ensure that patients move through our center as quickly and efficiently as possible: Several days before a procedure is scheduled, we evaluate patients at a perioperative medicine clinic where we assess their medical history and physical status. We also formulate a preliminary anesthetic plan, give pre-operative instructions, and answer any questions. The clinic is a key part of fast-tracking patients, avoiding any potential surprises (or cancellations), and making sure everything goes as smoothly as possible.

On the day of the procedure, we make sure everything is ready to go - the OR time is blocked out and the nursing staff and supplies are in place. Once the patient is in the OR, we try to avoid the whole issue of general anesthesia, and the inevitable recovery period associated with it, by administering a regional block whenever possible.

If general anesthesia is required, we try to use as many short-acting agents as we can. I avoid using pre-op anti-emetics - in my experience, they may not significantly reduce post-op vomiting, they typically come with their own undesired side effects (e.g. somnolence), and they are not inexpensive.

Our typical general anesthesia regimen involves induction with propofol and a short-acting muscle relaxant. We then maintain the anesthesia with desflurane or sevoflurane and nitrous oxide. About ten minutes before the end of the procedure, we stop mechanical ventilation and permit the patient to spontaneously breathe. We turn off the anes- thetic gases and administer fentanyl to maintain a ventilatory rate of 15. Fresh gas flows are varied to match the elimination of the residual anesthetic gases to the pace of the surgeon. An alternative is to coordinate the administration of a pure inhalational anesthetic with the surgeon?? ?s progress.

These protocols have served us well - the vast majority of our patients wake up quickly, with very little post-operative pain and nausea. Almost 60 percent go directly to a phase 2 PACU. I doubt that using BIS monitors would make a difference in our overall outcome and the total time that patients spend in our center. I've talked to colleagues who use the BIS monitors for every case, and none of them have consistently and significantly beat our 30- to 45-minute recovery period. Therefore, I am hard pressed to justify the cost of the monitor, plus the $10 to $15 for the disposable electrodes.

Even if it may contribute to patient recovery, the BIS may be more of a distraction than a benefit. It is one more piece of information to keep track of, and an inexperienced anesthesiologist may make the mistake of fixating on the BIS reading while paying less attention to everything else that is occurring. Also, the monitor may become a crutch rather than another source of information if the anesthesia provider depends more on its output than on his or her own clinical acumen.

Despite what one may infer from the marketing literature, there is no conclusive proof that using BIS monitors prevents intraoperative awareness. There simply have not been enough studies comparing the incidences of awareness in patients who received general anesthesia and were monitored by BIS devices vs. awareness episodes in patients who were given the same type of anesthesia and not monitored by BIS. If a doctor were sued by a patient alleging intraoperative awareness in a case where a BIS monitor was used, I wonder if Aspect (the company that manufactures BIS monitors) would be willing to defend the device in court alongside the anesthesiologist. I also believe that intraoperative awareness is so uncommon that using BIS monitors for every case is simply not cost effective.

If you feel that BIS monitors may help you improve your anesthetic technique, then by all means, you should give them a fair trial. But it's important to realize that fast-tracking patients requires that you keep all aspects of the perioperative process in mind, and BIS monitors alone may not make much difference.