BBI Contributing Writer
NEW ORLEANS, Louisiana – Reflecting the continued global unrest so apparent since the Sept. 11 terrorist attacks upon the United States, the attendance at the 2001 American Society of Anesthesiologists (ASA; Park Ridge, Illinois) meeting was dramatically affected. While more than 19,000 had registered, slightly more than 12,000 actually showed up in New Orleans. Interestingly, most of the no-shows were U.S. anesthesiologists, as most of the foreign physicians registered for the conference actually showed up and attended. This gave the meeting a very uncharacteristic slant towards non-U.S. markets, at least on the exhibit floor.
The meeting itself was replete with new technologies, products and more cost-effective therapies. The theme of the ASA meeting was the transition to evidence-based anesthesia practice, and the role that automated anesthesia systems could or should play in this transition. The vendors had picked up on this theme, introducing a variety of web-enabled products, and replacing mechanical devices with newer, electronic versions that support automated data capture. The anesthesia information management (AIM) vendors were also showing the newest versions of their systems. Much of this renewed interest in automation is being driven by three things. First, the Institute of Medicine's (Washington) report about medical deaths. Second, the Anesthesia Patient Safety Foundation's (ASPF) recommendations to implement anesthesia information management systems. Third, the increasing body of evidence that shows that with the correct protocols and tracking of information during and after surgery, patient length-of-stay and morbidity can be reduced.
Young, astute anesthesiologists and seasoned veterans are leading the way in research and adoption, but many others remain afraid of anything new that they don't perfectly understand or feel "in control" of, and are therefore finding reasons to resist change. Research presented at this year's meeting enhanced the awareness that data acquired by AIM systems is an enabling tool to practice less expensive medicine while actually enhancing, rather than compromising patient safety.
Aspect BIS reaches second milestone
Despite the relatively small percentage of patients undergoing surgical procedures who actually experience awareness, the fear of doing so is of concern to about 50% of patients. And of the few surgical patients who actually do experience intraoperative awareness, 70% continue to suffer from nightmares, sleep disturbance, flashbacks and anxiety following their surgical procedure. A study presented in a 2000 issue of The Lancet by Sandin, et al., cited the following incidence of intraoperative awareness; 0.4% for obstetric procedures, 1.1% to 1.5% in cardiac surgery, and between 11% and 43% in major traumas. Three companies at this year's ASA meeting were present to offer solutions to this problem. Aspect Medical (Newton, Massachusetts), the market leader; Physiometrix (Irvine, California), the market challenger; and newcomer Alaris Medical (San Diego, California), the first company to offer a fundamentally different, potential approach to measuring sedation.
Aspect Medical was the first company to introduce a technology for monitoring the level of consciousness with its bispectral index (BIS) monitor. BIS uses EEG processed with an advanced algorithm to assist in titration of optimal dosing of anesthetics. BIS monitoring has been studied extensively and used in more than 4.2 million surgeries as of October. BIS monitors were used on 1.2 million patients worldwide in more than 675 institutions as of March 2000. The data from this subset of cases shows that 41 of those cases have reported awareness while using BIS monitoring, a rate of 1 in 30,000 or 0.003%. While this is substantially better than the level of incidents that occur without BIS monitoring, it is still not perfect.
An investigation of the 41 cases has demonstrated that 46% of awareness occurred during stimulating portions of cardiovascular surgery. In eight cases, BIS monitoring was not being used during the time the awareness occurred. In 19 cases, BIS levels greater than 65 were observed in conjunction with the awareness. The remaining 14 cases did not have sufficient information to relate the awareness episode to a specific time or BIS value.
Aspect Medical is now implementing BIS as an OEM module with distribution by Philips Medical (Andover, Massachusetts), Datex-Ohmeda (Madison, Wisconsin), and GE Medical (Waukesha, Wisconsin), all of which were showing units at ASA, and also with Spacelabs (Redmond, Washington), North American Drager (Telford, Pennsylvania), and Nihon Kohden (Tokyo), none of whom are yet showing BIS modules. This is an impressive achievement for Aspect in a short period of time and one that effectively expands its sales distribution channels.
Aspect used this year's ASA gathering to introduced its new BIS XP monitor and sensor that is more resistant to artifact noise due to electrocautery devices, filters interference from EMG and other artifact conditions, and is dependable during cardiac and other deep anesthetic surgeries. It is also more expensive than current sensors, but will not replace them fully for another six to 12 months.
While this will help Aspect, it will do little for its OEM partners whose modules are all XP versions, and who receive none of the sensor revenues from Aspect, as Aspect does not share sensor revenues with its OEMs. Several significant holdouts regarding BIS include Welch Allyn/Protocol (Beaverton, Oregon), Invivo Research (Orlando, Florida), Datascope (Paramus, New Jersey) and some smaller companies. Aspect is hoping the XP and competitive pressure from companies who have adopted BIS will compel those who have yet to sign on. Aspect also has been successful in locking up several group purchasing organization contracts, including Premier (Chicago, Illinois).
The transition from direct sales of units by Aspect to OEM distribution of modules along with the declining growth in sensors has resulted in 2001 sales for Aspect projected to drop below 2000 sales of approximately $39 million, and end 2001 in the $35 million to $36 million range. That is almost $40 million short of the $76 million revenue levels at which the company would be profitable at current expense levels. As a result, Aspect has put in place a reduction of expenditures to reduce its capital burn rate from $5.6 million in 2Q01 to $2.8 million in 3Q01, and expects to continue at lower expenditure levels entering 2002. In spite of such reduced levels, a cash crisis could develop for the company in late 2002, particularly if the 20% to 40% revenue growth Aspect CEO Nassib Chamoun forecast for 2002 does not materialize.
Aspect is also facing class-action lawsuits based on alleged irregularities in its initial public offering disclosures. This makes 1Q02 and 2Q02 defining quarters for the company. If the unit sales take off, based on OEM and the new market/value proposition, then the potential to actually achieve the revenue growth by the end of 2002 is viable.
Physiometrix/Baxter remain non-factors, as the Physiometrix sensor has not found market acceptance, and the company is expediting projects to develop, test, collect clinical data and obtain FDA clearance on a newer type, more like the current Aspect sensor. Thus, Aspect has had the entire market to itself, yet has experienced a decline in sales and a decline in the use of sensors at existing accounts, indicating some fundamental problem with expanding the market for BIS from the "early adopters" to the "early majority" group of anesthesiologists. Aspect has responded by revamping its marketing message and value proposition to make it simpler and more understandable to this group of anesthesiologists.
In spite of Aspect's remarkable success, and the failure of Physiometrix to gain any real share with its competitive unit, there are other companies who have entered and are poised to enter the depth of anesthesia tracking market.
The newest company that will enter the market is Alaris Medical. It was present on the ASA exhibit floor, showing its Auditory Evoked Response (AER) monitor. This monitor is already available in Europe, but has not yet been introduced into the U.S. market, in spite of the fact that it has already received FDA marketing clearance. A company official who was demonstrating the product seemed uncertain when it might actually become available, what its price points would be, how it would overcome the OEM and GPO agreements that Aspect has already staked out, when an OEM module that was competitive to Aspect's might be available to potential OEM partners, or even which monitoring companies might be interested in the technology. The AER monitor is a relative monster – at 5" x7" and 7" deep, it has the volume of two to three Aspect monitors, and will be difficult to mount on an IV pole. It has a case design that seems somewhat European in character and out-of-date compared to competitive products.
Like Physiometrix, the AER product seems unlikely to represent any serious competition to Aspect. That is not to say that AER could not be a strong competitor, if its implementation were state-of-the-art, and it were offered by a company more attuned to the U.S. market. The whole approach of AER is itself mired in some confusion about intellectual property. Rather than attaching EEG electrodes to the patient's skull, and measuring left and right hemisphere response during sedation as does BIS, the AER introduces a series of rapid "clicks" into the patients' ears, which causes a response in the fast Fourier transform of the patients' EEG. This distinctive pattern then changes as the patient loses consciousness, and the brain is no longer able to process the response. Like BIS, the AER uses a 0-100 scale to indicate the level of consciousness, but unlike BIS, the optimal range – at least in the Alaris implementation – is 15-25. This may create confusion for physicians that have worked with BIS already, as the optimal range for BIS is between 50-60, substantially higher than AER.
AER differs from BIS in that it is an active approach, one that introduces a known signal and then tracks the brain's inability to process it , as anesthetic agents make it "less aware." Its original developer is a matter of some dispute. Some patents for a similar evoked potential approach seem to have been issued to Dr. Galvin Kenny. However, a technician who worked with Kenny reportedly left his lab and went to work at Danmeter in Sweden. It is this company that developed the AER product that Alaris is showing. It is therefore uncertain whether the Danmeter work is original or a derivative and infringement of patents held by Kenny. Whatever the case, a second European company, AudioMedix (Glasgow, Scotland), is developing a similar approach, so there are likely to be at least two competitors at least offering this type of product to the U.S. market sometime in 2002 or early 2003, at which point the patent issues will probably be all sorted out. So Alaris may have a short window of opportunity during which it can offer AER exclusively.
Aortech (Bellshill, Scotland) showed its new truCCOMS rapid response continuous cardiac output (CO) device, which is of special interest to thoracic surgeons and anesthesiologists. TruCCOMS rapid response allows surgeons to follow and respond to CO changes in real time-especially important when a patient goes on and off bypass. True CO changes are also important in the thoracic ICU as patients' CO can change quickly during their recovery phase. TruCCOMS made its U.S. debut only a few months ago and is quickly finding enthusiastic users at several medical centers.
Compared to the Baxter (Deerfield, Illinois) Vigilant continuous cardiac output (CCO) catheter, the truCCOM monitors is much smaller, uses less power, uses less heat, and makes faster measurements. It has also been miniaturized and is available as an OEM board for other monitoring companies to incorporate into their systems. The first monitoring vendors to incorporate truCCOMS will differentiate themselves markedly from the competition who can only offer older, conventional Swan Ganz thermal dilution CO modules. TruCCOMS also has fewer complications than conventional CO, while offering the same catheter cost. TruCCOMS looks to be a winner in the invasive CO market, and we foresee early adoption by some U.S. monitoring equipment vendors serving the U.S. market. It will definitely have strong appeal to thoracic surgeons and the anesthesiologists and pump techs that assist them.
Philips is now offering the Pulsion Medical Systems (Munich, Germany) pulse contour cardiac output catheter as a module in its Agilent Technologies CMS 2001 acute care patient monitors. The Pulsion approach requires a standard central venous line for the thermodilution injectate and a thermistor-tipped arterial catheter to determine CO and arterial blood pressure. It was being shown in the Pulsion booth at the ASA, and now is available in the market. Philips is the exclusive worldwide distributor of this technology. While invasive, it is also less prone to complications than traditional CO approaches, but does not have the frequency of measurement or rapid response time of the Aortech truccoms technology.
Finally, there is LidCo (Vista, California), a company that uses Lithium dilution measurement every eight hours to calibrate a continuous, beat-to-beat, pulse contour cardiac output measurement. Continuous cardiac output, along with other derived hemodynamic values, are the parameters needed, along with O2 consumption and delivery to optimize patient care according to research by Shoemaker and others.
Lidco's technology is now FDA-cleared and the company is ramping up distribution of its device to deliver this data. The problem is that it is not looking to partner as an OEM with monitoring companies, but instead will depend on separate reps to place bedside monitoring screens and devices where this is used. This represents a far too expensive approach, and an entire paradigm change, which lacks integration with bedside data from conventional patient monitors in caring for patients. The approach is educationally intense, and the likelihood it can be scaled up beyond a few early adopters and clinical sites to the levels that would allow the company to reach critical mass is low. Poor market planning and execution could quickly kill what looks like good technology for a better, less risky invasive hemodynamic profile of major surgical patients.
There are always major developments in pulse oximetry at the ASA meetings, new clinical studies on the accuracy of various vendors, and interesting new implementations of existing technologies. This was true again this year. Anesthesiology, like other fields of medicine, is seeing an influx of consumer electronics into what used to be "proprietary" medical device space. Palm and Compaq personal digital assistants (PDAs) are everywhere, as is consumer wireless networking. The cleaver companies take advantage of this, realizing they cannot compete with such devices by offering proprietary packages, RF and hand-held computing platforms, when they manufacture such devices in the thousands, while companies like Palm (Santa Clara, California), Compaq (Houston, Texas), Symbol Technologies (Holtsville, New York) and others manufacturer them in the hundreds of thousands, or in some cases millions of units.
Dolphin (West Allis, Wisconsin) – formerly OSI and TFT prior to that – is one company that has adopted a consumer (Compaq) PDA platform for its new, motion-tolerant, DD3000 pulse oximeter. This oximeter is even smaller than the latest Siemens Micro O2 Plus (with its Masimo technology) and also offers more capabilities, some of which it has designed in, and others of which it gets essentially for free from its host device. Indeed, Compaq just recently introduced the Ipaq Model 3875 with built-in Bluetooth 2.4 GHz wireless networking. By creating an oximeter card that simply slides into the 3875, Dolphin gets networking for free, with minimal application software change to its code set. Because a number of other vendors, including Symbol Technologies, also make "holsters" for the Ipaq family, Dolphin's pulse oximetry customers can also select IEEE-802.11b communications (if more speed is needed, and power can be traded off), as well as enhanced battery operating time and faster data speeds. This is simply a "holster" option in the Ipaq family, which users can even switch back and forth from, as their communications needs change.
Moreover, given the Compaq Ipaq platform, the Dolphin DD2000 oximeter becomes a chameleon of sorts, in that it doubles as a web browser, contact management, 2-D bar code scanning (of patient ID bracelet or drug bags) and application platform for recording patient notes on rounds or writing/renewing patient prescriptions, things that the Siemens Micro O2 Plus could never do. So the Dolphin DD3300 is cost-effective, flexible and scalable – and that is its advantage. Given the low cost, incredible flexibility of the platform and adaptability and accuracy of the measurement engine, why other major oximetry suppliers continue to overlook such benefits is hard to understand. If Dolphin can find a viable marketing partner to help present this new device to large numbers of physicians, it will suddenly make its presence felt in the market, way out of proportion to its small size. Should this same approach be emulated by a better-known competitor, it could be an instant success, opening up new market niches where other vendors' devices simply are not presently successful.
Dolphin also was showing its next-generation portable pulse oximetry monitor, the 2100, which it says is comparable in motion tolerance to the Masimo Radical and the Nellcor N395. Dolphin is claiming the new monitor as being able to work through motion artifact, much as the Radical does. For its part, Masimo claims that the 2100 also violates its patents. However, Masimo has not had much success in court proceedings thus far in proving that anyone violates its patents, and until it prevails in court, other vendors may be able to get away with using approaches that they may not have invented.
Dolphin's claims about its noise immunity and low perfusion sensitivity, like Nellcor's, are based largely on tests performed in their own labs, rather than by independent researchers. In such tests, as one might expect, they show better performance than either the Masimo Radical or Nellcor N-395, but this won't be particularly impressive until these same tests are validated by independent clinical studies. Dolphin said it submitted a unit for evaluation to Dr. Stephen Barker of the University of Arizona (Tucson, Arizona), a researcher well known for his evaluations of pulse oximeters, but the company said Barker refused to test the unit. Whether he will include the Dolphin unit in subsequent tests is unknown, but the company is meanwhile looking for other, independent researchers who are open to evaluating its oximeters along with others currently being tested.
Nonin (North Plymouth, Minnesota) was showing its new 2500 PalmSAT digital hand-held pulse oximetry device at ASA. This oximeter uses rechargeable batteries and provides up to 72 hours of trend information that can be dumped via a serial port onto a standard PC. It is ideal for sleep apnea investigations, allowing the patient or doctor to see the number, depth and duration of desaturations during the night as a patient sleeps. It is an inexpensive screening device to qualify whether patients need to undergo a more intensive and expensive sleep apnea evaluation in a hospital, a procedure that now costs patients' insurance companies more than $2,000.
Nonin also was showing its popular Model 9500 Onyx, the only self-contained finger oximeter. Powered by two AAA batteries, the 9500 can operate continuously for 18 hours, providing measurements every 30 seconds, or if used intermittently, can take up to 1,600 measurements before requiring a battery replacement. This unit is private-labeled to Respironics (Pittsburgh, Pennsylvania), and is available in a consumer version for private pilots to use during flights, to track and monitor the drop in their oxygen saturations as a function of altitude. At 8,000 feet, desaturation can be considerable, and by 12,500 feet, pilots can lose consciousness if unaccustomed to the altitude. This device allows a pilot to recognize when he need to begin breathing richer O2 mixtures, or decrease altitude to improve O2 saturation if supplemental O2 is not available.
On the clinical accuracy front, several new papers were presented at ASA. One, by Stefanie Kroeber, et al., compared the effects of IABP and cardiac arrhythmias on three pulse oximeters – a Nellcor N-3000, a Masimo and an HP/Philips CMS. A total of 42 patients were studied.
The paper, "Effects of IABP and Cardiac Arrhythmia on Pulse Oximetry," summarized the results by stating, "In all patients, the overall dropout time during a total measuring time of 50 hours, in which no data was available for technical reasons, was shortest with the Masimo SET (1% with IABP and 1.8% with arrhythmia respectively) and considerably longer with the HP Viridia CMS (6.7% with IABP and 5.1% with arrhythmia), and the Nellcor N-3000 (7.9% with IABP and 6.7% with arrhythmia). With respect to motion and low perfusion, false alarms were detected in only 33.4% of patients, but the majority of false positive alarms can be rated as a result of the interference of cardiac arrhythmias (47.1%) or IABP (76.2%). With IABP, the reliability of SpO2 and pulse rate determination by third generation pulse oximeters is significantly decreased, but is less compromised in patients with cardiac arrhythmia particularly when a N-3000 is used.
In a second paper by Nitin Shah, MD, et al., of the University of California (Berkeley, California), seven ASA volunteers were studied on two different Masimo oximeters, a Novametrix MARS oximeter, an HP Viridia 24C oximeter, an HP CMS Rev B oximeter, and Nellcor's new N-395. After a total of 91 motion tests, of which 63 were normoxemia and 28 were hypoxemia, the results showed that the Masimo SET oximeters tested had the fastest recovery times and the smallest percentage failures compared to the other two oximeters. Of the remaining two, HP's (now Philips) appeared to be lower in failures than Nellcor's N-395, but took substantially longer to recover after a failure. The oximeter with the worst performance was the Novametrix MARS, failing from 74% to 80% of the time for saturation and pulse rate, respectively. The researchers' conclusion was: "Among the pulse oximeters studied it appears that Masimo Radical may serve better for monitoring, as it has the shortest recovery time and lowest failure rate for both SpO2 as well as pulse rate."
The third paper presented by the University of Arizona's Barker studied 30 volunteers. It compared Masimo's Signal Extraction Technology against two other oximeters in each series of tests, recording the performance index during motion, its dropouts, its sensitivity and specificity.
Barker commented, " ... the Masimo SET pulse oximeter showed the best performance of all units during motion, in terms of both accuracy and reliability. A key difference between this and other volunteer studies is the fact that we maintained skin temperature below normal to reduce perfusion and better represent patients in critical care settings."
As in Shah's tests, the Novametrix MARS unit seems more equivalent to older, non-motion tolerant oximeters than to any of the other, newer oximeters designed to be motion tolerant.
In the final new study on oximeters, performed by Sara Clack, et al., of the University of California, seven patients were studied, comparing the Masimo SET, HP Viridia 24C and CMS Rev B, Nellcor's N-395 and Novametrix's MARS.
The researchers concluded, "While no pulse oximeter withstood 100% of this vigorous test schedule, Masimo SET performed the best and has the highest sensitivity, specificity with the fewest false alarm rates. HP CMS, Nellcor N-395, HP Viridia 24C and Novametrix MARS performed in decreasing order based on the sensitivity, specificity and false alarm rate." (The HP units now are under the Philips Medical banner.)
Accurate pulse oximetry is definitely a parameter that should be automatically acquired and included in any anesthesia information management system used to manage perioperative patient care.