Circulation 76,548 • Volume 20, No. 4 • Winter 2005   Issue PDF

Scientific/Technical Exhibits Replete With Safety Themes

John H. Eichhorn, MD

Patient safety again was a prominent theme in the exhibit hall at the American Society of Anesthesiologists Annual Meeting October 22-26, even with the hurried translocation from hurricane-ravaged New Orleans to Atlanta. Both the Scientific/Educational Exhibits and also the Technical Exhibits from vendors of anesthesia-related equipment and supplies contained a few fresh concepts related to patient safety as well as many familiar themes with some new refinements.

In the Scientific/Educational Exhibits, 9 of the 48 exhibits in some way related to airway concerns. This simply reinforces the intriguing suggestion that airway management remains likely the greatest technical/mechanical challenge for anesthesia professionals. Indeed, it is the one central component of practice that has changed the least in the “modern era” of anesthesia, as defined by the widespread adoption nearly 20 years ago of electronic monitors such as oximeters and capnographs to extend the power of human senses and allow much earlier detection of dangerous intraoperative situations. The fact remains that general anesthesia continues to include induction of unconsciousness and then paralysis of a patient’s ventilatory musculature when there is no specific guarantee that intubation of the trachea or even positive pressure ventilation will be possible. Accordingly, virtually all anesthesia professionals still today experience “difficult airway” situations with a frequency that depends on their type of patients and practice. Thus, airway tools of a wide variety, airway models, airway simulators, airway educational efforts and the associated Scientific/Educational Exhibits, as well as airway-related products for sale in the Technical Exhibits continue to constitute a significant fraction of the displays. Frustratingly, there was no exhibit this year of any type of future “Star-Trek”-like computerized scanner that would fit over the patient’s head at the bedside or in an office setting and in seconds generate a detailed 3-D map of the airway and also a highly educated “smart algorithm” opinion of precisely how to manipulate and/or instrument the airway to facilitate successful airway management. Invention, testing, approval, and implementation of such devices or their (realistic) functional equivalent would revolutionize anesthesia care in somewhat the same manner as the introduction of electronic monitoring did in the mid-1980s.

In any case, a comprehensive plan for a departmental airway workshop was outlined by sponsors from the Medical College of Wisconsin, with reports of enhanced confidence in airway management gained by participants. Likewise, computerized video of airway management situations were presented from Rhode Island Hospital with the added intention of creating a detailed video archive of the difficult airways of specific patients for future pre-op reference by subsequent anesthesia personnel. Another related exhibit from the Cleveland Clinic featured a website for airway teaching material, particularly video. [Such a website could be a potential archive of actual difficult airways—with video of how to manage them—that could be accessed by any anesthesia provider anywhere when provided with the unlocking security code of the subject difficult airway patient who needs additional anesthesia care.] Specific airway management strategies for pregnant patients and for pediatric patients were featured in extensive exhibits. Strategies for topical anesthetization of the airway were featured as well as another exhibit devoted specifically to tools useful when extubating a patient (up to and including transtracheal jet ventilation and cricothyrotomy). An exhibit from Yale featured video through the LMA “C-Trach” device that is designed specifically to allow the anesthesia provider to see via a fiberoptic bundle down into the airway and guide placement of an endotracheal tube via the LMA under “direct vision” in circumstances where traditional views of the larynx are impossible. Further, the new concept of specific self-customization of the widely accepted “difficult airway algorithm” by different individual practitioners was recommended in an exhibit from Montefiore Medical Center in New York. Finally, the importance of these and all the airway related issues was specifically emphasized by the fact that “The Society for Airway Management” (founded in 1995 and pointedly billed as “apolitical”) had a booth in the exhibits and highlighted its promotion of airway education and research as well as its liaison with other anesthesia-related professional groups.

Other Scientific/Educational Exhibits with safety themes included one from the University of California at San Francisco with the intriguing title “How to Avoid Death for a Dollar,” which featured the implementation of (inexpensive) perioperative cardiac risk-reduction strategies employing proven beneficial medication: beta blockers and clonidine. A literature review as well as implementation protocols for medication administration were available. The American Sleep Apnea Association had a booth promoting its “A.W.A.K.E. Network” of apnea support groups. The use of ultrasound guidance for placement of arterial, central, and peripheral venous vascular catheters as well as for assisting with peripheral nerve blocks was again presented in 2 exhibits, but with more emphasis on the safety strategies of preventing errors and untoward patient outcomes. Finally, the evolution of molecular genetic testing for susceptibility to malignant hyperthermia and its obvious anesthesia patient safety implications was outlined in an exhibit presented by Henry Rosenberg, MD, from New Jersey. Note also that there was an exhibit from the University of Minnesota regarding “surgical errors” and a systems-based approach to help avoid them. The presentation cited the distribution of major errors as: wrong site (76%), wrong patient (13%), and wrong procedure (11%). While patient safety, not legal liability, was the exhibit’s emphasis, the implications were clear for anesthesia providers involved in such “surgical errors.”

The Technical Exhibits at the ASA meeting were nearly as numerous and elaborate as in a normal year, albeit rearranged from the original printed floor plan. The ASA-associated foundations were prominently located directly by the main entrance door with the APSF booth directly in the entry path. Attendee interest in the APSF patient safety exhibits was significantly increased this year.

In the large exhibit hall, continuing the theme from the Scientific/Educational Exhibits, there were no fewer than 29 technical/commercial exhibits exclusively or largely devoted to equipment and supplies for airway management, again dramatically emphasizing the major role of improving airway handling as an ongoing component of the evolution of anesthesia patient safety. Several very large displays exhibited a panoply of all manner of airway tools and equipment, possibly raising the question that there may be too many competing technologies and varieties of equipment available for there to be adequate investigation of their applications, risks, and benefits. As is frequently characteristic of the commercial marketplace in medical equipment, it appears that several manufacturers have rushed into production of new tools or technologies that have only been “tested” by their inventor and have never been the subject of peer-reviewed publications or multi-center clinical trials. While this approach may be entrepreneurially understandable, it makes for a bewildering array of choices for average anesthesia practitioners. For many, it may seem much easier to stick with the familiar Mac 3 or Miller 2 rather than try to figure out what may be better, either in general or in “difficult airway” scenarios.

There were several updates and variations on the fiberoptic and video-assisted laryngoscopes, several of which were intended for routine every-day use. Some featured eyepieces and some other displays offered miniature cameras that projected either to very small (1.7 inch diagonal and attached directly to the laryngoscope handle) or very large video monitors. Several were battery powered from rechargeable battery packs. Some systems featured blades containing integral optics that would fit onto a traditional C battery-powered handle, claiming to give a view around the base of the tongue without the need to displace it as in traditional direct line-of-sight laryngoscopy. One flexible optical stylet powered by 4 AA batteries claimed the ability to turn difficult intubations into routine ones with “success on the first attempt every time.”

Patient warming was another very common commercial theme in the Technical Exhibits. Several new brands and variations of warming blankets or equivalents were displayed. Actively warmed wraps for the patient’s arms as the sole source of warming were offered as a new solution, particularly for procedures in which traditional blankets could not be used. One genuinely new technology involved a flexible heating fabric containing very thin low-voltage heating wires that make the slightly stiff fabric become toasty warm. This single-use system was touted as simpler, less bulky and cumbersome, and much less expensive than the commonly employed forced-air/plastic blanket system. Further, and apparently the subject of intense interest at the exhibit booth from many meeting attendees, was the additional new product that is a vest or jacket of the same heating material for the anesthesia provider who is chilly (or “freezing”) in the OR. The material gets fairly warm, but not hot, and can be turned on and off by connecting or disconnecting a power cord to the same electric power supply that is connected to the patient’s warming blanket.

Infusion pump displays touted patient safety with an increased emphasis and volume that has not been seen before. Apparent sensitivity to case reports of patient injuries from infusion pump accidents and subsequent regulatory and government inquiries seemed to be motivating some of the sales discussions from representatives of these companies. Likewise, new features and variations of rapid infusion devices stressed safety issues, particularly improved ability to detect air in infusion lines and then prevent entry of that air into the patient’s blood stream.

Ventilation monitoring during MAC and sedation seemed to reemerge as a targeted safety issue this year. Several companies heavily promoted the potential safety benefits of qualitative or near-quantitative assessment of expired CO2 during sedated spontaneous ventilation. There was no specific reference to reported hypoventilation accidents with “deep sedation,” such as in plastic surgeons’ offices or even endoscopy or imaging suites, but the implications were unmistakable.

Finally, an intriguing new product that could have safety implications was featured. A mechanical device inserted in the breathing circuit in place of the Y-connector is intended to speed up emergence from the effects of inhalation anesthetics and, for example, reduce the time in stage 2 delirium and reduce time to extubation at the end of a general anesthetic. It functions in 2 ways, by causing some rebreathing and resulting deliberate mild hypercapnia intended to stimulate increased minute ventilation and, thus, the faster exhalation of volatile anesthetics, and also by a second internal component that is an “anesthetic absorber” that captures the exhaled volatile anesthetic and prevents any return into the patient via the semi-closed circuit, thus increasing the excretion gradient and speeding emergence. Three abstracts with 45 total patients were cited as supporting clinical trials.

Overall, patient safety remains a central focus of the exhibits at the ASA Annual Meeting. This recognizes both the current success in improving safety and also the significant challenges still remaining, such as, for example, in making genuine changes in practice, leading to lower risk of patient injury associated with issues in airway management.

Dr. John Eichhorn, Professor of Anesthesiology at the University of Kentucky, founded the APSF Newsletter in 1985 and was its editor until 2002. He remains on the Editorial Board and serves as a senior consultant to the APSF Executive Committee.