BB&T Contributing Editor

CHICAGO — Anesthesiology is a mature sector of the surgical spectrum, but that doesn't mean it can't grow. The field is replete with a number of issues that its practitioners continue to debate, and new technologies keep rolling out with the purpose of making the practice safer and its outcomes — a greater rate of successful surgeries — more predictable.

A close focus on the industry's issues and the evolution of its new technologies was obvious among the 19,000 attendees at the annual meeting of the American Society of Anesthesiologists (ASA; Park Ridge, Illinois/Washington) (5,000 of them ASA members) Oct. 14-18.

Clearly uppermost in the minds of attendees was the current battle being waged with the Centers for Medicare & Medicaid Services (CMS; Baltimore) over proposed cuts in Medicare reimbursements. The government is seeking a reduction of 6% in fees that anesthesiologists can charge for services, coupled with an already unveiled rollback in fees for all physicians of 5.1%. The ASA has submitted extensive comments to CMS and is encouraging its members to write letters of objection to the agency. ASA has also encouraged members to get their members of Congress involved.

Patient focus and surgical awareness

Orin Guidry, MD, outgoing president of the ASA, addressed the assembly, taking a strong stand against some recent occurrences that have shed a less-than-positive light on physicians and anesthesiologists in particular. Guidry cited a recent decision by a Missouri state judge ordering an anesthesiologist to oversee the administration of a lethal cocktail. Guidry asserted: "We cannot let patients see us as executioners … Remember, perception is reality."

He also highlighted the three caretakers (one physician and two nurses) who are accused of killing patients during Hurricane Katrina. Guidry urged all anesthesiologists to think of each individual patient encounter as an opportunity to demonstrate the positive and patient-centered focus of the profession. Guidry must also be given credit for helping to create a new atmosphere with some of the vendors and organizations focused on anesthesia.

At the 2005 ASA meeting, Aspect Medical (Newton, Massachusetts) and the ASA were at loggerheads over the issue of developing a standard of practice concerning depth of anesthesia monitoring to prevent surgical awareness — the occasional occurrence of a patient being awake during surgery but paralyzed and unable to respond. None of that animosity was apparent at the 2006 meeting, and Aspect says that it now has a working relationship with the ASA. Aspect personnel attributed the turnaround to better communication by both parties, and the need to study the issue further.

Carol Weihrer, president of the Anesthesia Awareness Campaign (Reston, Virginia), at odds with the ASA for many years concerning the frequency of surgical awareness, also reported a new willingness by the society to cooperate.

There are still some anesthesiologists believing that they do not need depth of consciousness as a parameter. but many are advocating its use in at least the most complicated cases. At the ASA, Aspect highlighted new research demonstrating the benefits of its BIS (bispectral index system) level-of-consciousness monitor with new research papers.

New focus on surgical pain

The newest research focus is the use of BIS to control pain during surgical procedures A second study correlated highly variable BIS readings and EMG (muscle) readings during surgery with increased pain for patients during their recovery period.

Aspect is now focusing its BIS as a "family of products" with an FDA 510(k) pending stand-alone monitor that has a compact design and simplified operations, as well as a 510(k) pending bilateral sensor which is designed for a four channel frontal electroencephalogram (EEG).

This sensor is intended for use with Aspect's BIS Vista monitor which allows the detection of hemispheric changes in the brain. The company says that this is useful in advanced applications, such as during surgery for epilepsy and other conditions. Aspect also reported that Spacelabs (Issaqua, Washington) and Datascope (Mahwah, New Jersey) have now incorporated BIS into their monitoring systems, a development meaning that all major monitoring vendors now offer BIS as an option in their systems.

The number of competitors in the field of anesthesia monitoring is growing, and they were all demonstrating products at the ASA.

Danmeter (Indianapolis) was showing the only wireless EEG monitor, which was very small, at 4 inches by 2 inches, making it a nice fit for the operating room (as long as the monitor is not lost in the changing of linen following a procedure). The sensors used by the Danmeter CSI (cerebral state index) monitor were only two, placed off to the side of the patient's forehead. The CSI uses fuzzy logic to quantify readings. The company also offers CSI monitoring in the form of a stand-alone monitor which was hard wired and larger than the wireless model.

Everest Biomedical Instruments (Chesterfield, Massachusetts) also had a depth-of-consciousness monitor called SNAP that was portable (most clinicians hang the unit on an IV pole) but not wireless. SNAP utilizes both high and low frequency EEG to evaluate the state of consciousness, which the company stated allowed a faster response time. Everest had a few research studies that compared SNAP clinically favorably to BIS. While the Everest technology is also comparable to BIS in price ($27 per sensor use), Danmeter said that its sensors cost from $15-$18. Everest is introducing SNAP regionally through a distributor in the Ohio/Indiana area.

Aspect has far and away the most research papers supporting its technology, and the other companies will have to produce more documentation to convert the skeptics. But with a soon-to-be-released Hollywood movie due out on the subject of awareness during a surgical procedure — titled "Awake" — the stock of depth-of-consciousness monitoring may increase considerably. The Aspect personnel, as well as ASA personnel, are gearing up for a public reaction to the movie and the condition.

Blood sugar a surgical risk

Some of the other clinical issues brought to the attention of the conference attendees included a study performed at Thomas Jefferson University (Philadelphia) by Boris Mraovic, MD, demonstrating that an increased preoperative blood sugar level in patients can leave them vulnerable to deep vein thrombosis and possible pulmonary embolus post-operatively. About 10% of the patients who went in to surgery with blood sugars over 250 mg/dl on the day of surgery developed significant pulmonary emboli after surgery, which is 6.2 times that of the general population.

This study emphasizes the importance of better blood sugar control and, by implication, the search for a medical device to monitor patients' glucose levels indirectly and continuously.

Masimo (Irvine, California) and many other companies, have been researching noninvasive blood glucose measurement for some time. Masimo's research focuses on the use of distinct wavelengths of light to determine parts of the hemoglobin (blood) molecule. Masimo won't say how close it is to being able to indirectly detect the glucose component of hemoglobin, but at this year's ASA, Masimo introduced the hospital version of its Rainbow Technology (Radical-7), which indirectly measures carboxyhemoglobin (COHb) and methhemoglobin as well as SpO2, pulse and perfusion index.

Masimo clinicians were addressing the under-evaluated condition of carbon monoxide (abnormal carboxyhemoglobin measurements) in hospitalized patients and the need to get this message out to them. Especially affected by carbon monoxide may be those patients undergoing surgical procedures as studies are now linking the use of many of the "caines" (local anesthetics) to the condition.

The routine spraying of patients' throats with Benzocaine prior to intubation performed by anesthesiologists is one practice that has already received government warnings based on research. Masimo executives have a daunting task bringing this new knowledge to clinicians, but then they know the way to achieve that success is the task they accomplished when they introduced their SET pulse oximetry technology in 1995.

Masimo SET is the pulse oximetry technology that produced lawsuits against Nellcor (Pleasanton, California), Masimo claiming that Nellcor was infringing its signal extraction technology (SET) patents. The lawsuits are mostly settled now, and last year Nellcor had to cease use of the infringing technology. At the ASA, Nellcor demonstrated its N600 oximeter as its "new" (replacement) technology with studies to support its efficacy.

However, the studies, still currently in early stages, only tested the oximeter under stable conditions and found the N-600 without much variation from Masimo's oximeter. (The Nellcor studies will be completed shortly and the company hopes to present the results at next year's conference of the Society of Critical Care Medicine).

At the Masimo booth, a demonstration comparison of the Masimo SET oximeter to the Nellcor N-600, as well as the N-595, showed different results once motion and temperature variation were introduced. With the three sensors on different digits of one hand, the demonstrator held a glass of ice water and then added movement. While the Masimo SET continued readings uninterrupted, the N-595 display froze, and the N-600 simply stopped displaying at all, setting off alarms.

End tidal carbon dioxide another metric

The other blood component measurement that is receiving increasing clinician focus is that of end tidal carbon dioxide (etCO2), a technology allowing the global evaluation of three main body functions: metabolism, circulation and ventilation. If two of these parameters are held constant, the changes in etCO2 signal a difference in the third. etCO2 is used as a monitoring device in various clinical settings as a noninvasive indicator for the evaluation of therapeutic efforts during low-flow states and especially during cardiopulmonary resuscitation.

Oridion (Needham, Massachusetts) was demonstrating its plug-and-play etCO2 for use in pain management. With pain management increasingly being a focus for anesthesiologists, the measurement of end tidal carbon dioxide as an indicator of respiratory depression is increasing. And, like Masimo, Oridion has an educational challenge as pain management is routinely performed on the hospital general ward.

As anesthesiologists go up the learning curve of this newer parameter, so must general ward nurses. Oridion employs a simple user interface for its monitoring device to assist nurses in this new role. For patient comfort, the company has made the nasal cannula a bit softer while having reinforced the rest of the tubing to make it useable for the two to three days necessary for many patients undergoing PCA (pain controlled analgesia).

Other ASA releases

Spacelabs Healthcare (Issaquah, Washington) introduced its new anesthesia system, representing a collaboration between the technology Spacelabs acquired from Blease (Buckinghamshire, UK) and Spacelabs' Sirius perioperative monitoring suite. The system, trade-named BleaseSirius, offers precision pressure-controlled ventilation, a method that actively controls airflow throughout the respiratory cycle. Spacelabs personnel explained the advantage by comparing the system to an automobile's braking system. With BleaseSirius, the anesthesiologist controls gas delivery on both inspiration and expiration — akin to letting the foot off the gas in a car and using the brake to slow down.

Other systems control airflow just on expiration. Spacelabs made 29 physical changes (such as a swivel-arm on the ambu bag) from the original Blease system, which make it U.S. anesthesiologist-friendly. BleaseSirius also enables clinicians to set up the ventilator to match clinical and patient needs rapidly and easily, much like ventilator systems only available in intensive care units.

Spacelabs also introduced its Ultraview Perioperative Monitoring Suite at the meeting. Newest additions to the Ultraview include a multi-gas analyzer that measures O2, CO2, N2O plus five anesthetic agents with the ability to identify mixed agents. In addition, two additional slots are located in the front of the Ultraview — ideal for the new BIS monitoring offering by Spacelabs (in the ooperating room) or etC0? monitoring in the poast-anesthesia care unit. The new software offered in this release includes a start/end case feature that provides an easy transition between setup, start and the end of a procedure using one-button commands for each. Spacelabs has emphasized the idea of workflow throughout the perioperative setting with these introductions.

New telemetry

Draeger Medical (Telford, Pennsylvania) was showing its soon to be introduced — via 510 (k) submission — patient-worn telemetry system called Infinity TeleSmart. It banners TeleSmart as the only type of telemetry system built on WiFi technology and having a lightweight transceiver that will monitor ECG and SpO2 in both pediatric and adult patients. Draeger built TeleSmart after it spent many hours listening to clinicians explain what they wanted in their telemetry.

TeleSmart incorporates features such as a much-reduced number of wires attached to the patient, a central charger where the telemetry units are stored when not in use — including an "auto-discharge" of patient data so that the unit is ready for the next patient. The central charger not only charges the battery for the next patient but keeps the units centrally located rather than "lost" in a drawer or elsewhere. While the units are on a patient, they can be docked when the patient is in bed so that the battery is being recharged, and the battery status is displayed on the top of the unit with "bars" much like a cell phone display. When Draeger receives final FDA approval for TeleSmart, it should open many opportunities in hospitals for them.

In addition to the coming WiFi telemetry, Draeger recently introduced a new web-based solution in its Infinity Symphony Suite that makes patient information available anywhere using the hospital intranet. This will empower clinician access to patient data, giving them a more complete picture of patient status as well as the results of medical interventions monitored from their home or office.

Also shown at the ASA was the Innovian Anesthesia System, Draeger's next-generation peri-anesthesia information solution. Draeger was referring to Innovian Solutions as "fully integrated into anesthesia workstations or can be independent of gas machines and monitors."

Innovian can run on a web-based application server providing input into and access to patient data. Innovian's touchscreen can be used to document patient information with a drop-down menu with access to information from the anesthesia workstation to the patient charting data. The flexible workstation platform in Draeger monitoring can support Dicom (image) applications as well as lab applications and other IT applications. Innovian can be either wireless or PC-based and provides, for example, an overview of a patient's medical history, enables patient-centric care, and improves staff and patient satisfaction because it is workflow focused.

The monitoring and IT solutions in the booth demonstrated how information is accessible at the OR workstation and throughout the perioperative continuum of care as well as beyond the perioperative setting.

Monitoring never sleeps

Philips Medical Systems (Andover, Massachusetts) showed an expanded range of anesthetic and respiratory gas monitoring options with its IntelliVue G5 module, which offers automatic agent identification and mixed-agent monitoring capabilities. The new Philips Spirometry module provides lung mechanics information displayed on Philips' IntelliVue patient monitors.

Philips also showed a new Multi-Measurement Server (MMS) with Masimo SETSpO2 (availability pending 510(k) clearance in the U.S.)

Philips was showing two high-definition imaging ultrasound systems for anesthesiology with good image quality, user-focused ergonomics and one-button image optimization. The Philips EnVisor HD and HD11 XE systems assist in ultrasound-guided nerve block procedures, and the large screens and adjustable monitors offer the anesthesiologist an easy view of the image during the procedure. Regional anesthesia is becoming an increasingly popular anesthetic choice among anesthesiologists (and patients) because of shortened recovery times, effective pain control and a low incidence of nausea as compared with general anesthesia.

Ultrasound guidance allows the anesthesiologist to visualize the nerves, the surrounding vasculature and anatomy, the needle and the spread of local anesthetic, facilitating quick, accurate administration of the anesthetic agent. Physicians also report that ultrasound guidance shortens procedure times, thereby improving patient throughput.

Nihon Kohden America (NK; Foothill Ranch, California) unveiled an agreement with Masimo to integrate Masimo SET into its line of bedside and patient monitoring products. NK was also touting a new use for its existing wireless telemetry solution — NK has bundled its telemetry into a "padded black container" for quick accessibility in disaster situations.

NK telemetry offers eight channels with a central station, using its NTX transmitter. The NTX Transmitter is capable of monitoring ECG, Sp02, respiration and non-invasive blood pressure and operates in the WMTS frequency band using three alkaline AA batteries.

And networking continues to grow

Medrad (Indianola, Pennsylvania) was showing a new wireless network called the Certo MR for use in MRI areas. The system allows Medrad's Veris MR monitor (introduced in 2005) to freely travel with a patient from the prep room to the scanner room to the recovery area, all the while maintaining communication with the remote display on the network. In June of this year, Medrad received FDA clearance for use of its Continuum MR Infusion System in MRI environments. Continuum was first introduced in 2002 as a MR-compatible infusion system but with the advent of higher strength magnets, Medrad had to test for attraction, artifact and homogeneity.

Hospira (Lake Forest, Illinois) was showing a novel non-magnetic imaging infusion system called Symbiq, which featured safety software that assists clinicians in preventing medication errors. This software assures total compliance with any hospital's dosing and clinical safety guidelines — with some alarms allowing the clinician to override the warning and others blocking them from administering the medication.

The system also features a simple-to-use large LCD screen with touch activated buttons and the screen was easily seen from up to 12 feet away. The system offered an automatic medication loading slot and was able to be quickly clamped onto an IV pole or a patient bedrail.

Trianim (Slymar, California) a company that offers specialty solutions for healthcare, was showing an innovative product from Advanced Circulatory Systems (Eden Prairie, Minnesota), called ResQPod, an impedance threshold device that improves pressures in the chest and increases the return of spontaneous blood circulation of patients during cardiac arrest.

ResQPod prevents unnecessary air from entering the chest of a patient during CPR, which increases the negative pressure in the patient's chest which causes more blood to return to the heart. Studies have shown that ResQPod increases cardiac output, blood pressure and survival rates. ResQPod connects to the patient face mask and includes a light that assists responders in timing of CPR technique. It is the only device that has received a Class IIa recommendation from the American Heart Association (Dallas).

Final notes

The Center for Integration of Medicine and Innovative Technology Interoperability Program (CIMIT; Boston), an organization with a mission to improve patient care by bringing scientists, engineers, and clinicians together to catalyze development of new technologies, was demonstrating interoperability at the ASA.

The Medical Device Plug-and-Play (MD PnP) (http://www.mdpnp.org) program is a multi-institutional, multidisciplinary program sponsored by CIMIT, Partners HealthCare Information Systems, and the Telemedicine & Advanced Technology Research Center (TATRC) of the U.S. Department of Defense. At this year's ASA, the interoperability demonstration stressed the need for open standards to be supported, the definition of a safe, least burdensome regulatory pathway for a proposed system to clear regulatory agencies, and use of the "sandbox" (opened May 2006) that allows vendors to evaluate a device for interoperability.

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