Volume 11, No. 2 • Summer 1996

Gravenstein Response on Anesthesia Machines

J.S. Gravenstein, M.D.


Editor”s Note: In the Winter issue of the Newsletter, a letter writer inquired, “Is there currently a consensus regarding when anesthesia machines become outdated, obsolete, or unsafe and, therefore, should be replaced?” Several readers responded and one of the long-time mainstay senior members of the Foundation offered these thoughts.

Parsimonious medical facility managers look askance at physicians who want to replace old equipment and at industry that balks at servicing it. Administrators ask why replace something that works as well as it is supposed to work? That raises the question of what equipment is obsolete and should be replaced.

It would be nice if we could develop clear guidelines to help clinicians and industry decide when a piece of equipment should be considered obsolete. Unfortunately, we cannot formulate such guidelines, perhaps in part because the definition of “obsolete” lies in the eye of the beholder. The Oxford English Dictionary (second edition) says obsolete is “what is no longer practiced,” what has “fallen into disuse,” what is “out of date, of a discarded type,” what is “worn out.” If it were just a matter of “worn out,” we might arrive at guidelines as we have for tires with a worn tread profile. But “what is no longer practiced” says something about what we do with the equipment. And that puts the definition back in our hands. In support of that perspective, primarily in North America, the word “obsolete” also serves as a transitive verb meaning “to render obsolete,” or “to discard.” I interpret that to mean something is obsolete when we say so, when we no longer want to use it, when we are ready to discard it.

The question to be asked then: When should we, that is anesthesiologists, or for that matter, industry obsolete1 and discard what has served well in the past? We must have done it many times because over the years we have obsoleted drugs and equipment without much discussion of the process. For example, diethyl ether was obsoleted when halothane arrived. The new drug smelled better, acted faster during induction and emergence, caused less nausea, and was not flammable. It also cost much more than ether. We obsoleted the McKesson apparatus, d-tubocurarine, red rubber endotracheal tubes, reusable i.v. needles, glass i.v. bottles, reusable catheters, hanging bellows, and a long list of other drugs, items, and procedures. In every instance, something better had come along and we let the old fall into disuse. Usually that something better was also more expensive.

In this process, industry played a decisive role. Many a new drug or device was not manufactured because we clamored for it, but because imaginative research and development in industry made it possible and then available. That industry rather than academe deserves credit for many innovations is not to denigrate the work carried out in universities; it is a question of scale and resources. Few academic departments can match the resources industry can tap when launching a new product development. Of course, industry takes sizable risks and suffers considerable financial losses when its offerings do not catch on in the marketplace. Take the clinical method of estimating blood volume with isotope-labeled protein; it came and went. More recent expensive types of products that did not achieve a sufficiently firm foothold in our practice to be considered commercial successes or routines of care include the automated anesthesia record keeper and the intra-arterial blood gas analysis system. Sometimes, systems that don’t make it in the marketplace are simply ahead of their time – costly to the company, but enormously important to the field by demonstrating possibilities and, of course, limitations.

I really don’t like to use “obsolete” as a verb, but it emphasizes a point. Thus, we have an interesting process of trial and error, of push and pull and the definition of obsolete assumes an additional meaning: “What can be replaced by something better, more functional, safer, or less expensive.” Industry itself can render the very product it manufactures obsolete by building or making something better. Little wonder then, that it does not want to repair and maintain what it deems obsolete, particularly if in the meantime the old equipment no longer meets newer currently effective safety and manufacturing standards and, as a result, becomes a potential legal liability to an industry targeted with lawsuits because of its deep pocket. Of course, there are financial incentives for industry to build and sell new things. Without financial successes it could not survive the occasional failures.

Patents on medications and their expiration introduce another consideration. A drug that becomes less expensive when the patent expires (due to the new availablility of generic formulations) will become obsolete only when a newer drug has well-defined advantages over the old, advantages that compensate for the often much higher price. Here the marketplace erects stiff challenges to the manufacturer, and our patients benefit when a new drug succeeds in rendering an older one obsolete. Finally, standard-setting agencies or authorities can render something obsolete by definition through the wording of their standards or, alternatively, refuse to obsolete what a user or a group of users want to discard. When a standard-setting agency declares something to be obsolete, administrators have little choice but to concur (because the medical-legal ramifications of not doing so are totally unacceptable). But, when administrators in central control refuse to replace what workers in the trenches (i.e. anesthesiologists) consider obsolete, difficult conflicts arise. Clinicians must not be expected to tolerate obsolescence when safety and quality of care are at stake. In either case, clinicians are challenged to explain how important they deem the new features of a new drug or a device; they must decide whether the new features are important enough to obsolete an older drug or device.

Usually no one can show with scientific rigor that this or that old feature affected the fate of patients in a measurable way. Here experts need to speak up. What a prominent expert in ergonomics recently testified still rings in my ears. Regarding a piece of equipment that was involved in a single bad outcome, he said: “Our knowledge of design and our experience with human failures is such that the manufacturer should have known that this particular arrangement makes possible the very type of error observed in this fatality.” He had no statistical evidence for the implication that the design was faulty; instead he based his statement on the body of knowledge represented by his scientific discipline within medicine. Anesthesiologists base their work on a body of knowledge and they must convey to the manufacturers, to standard-setting authorities, and to administrators their worries and expectations. Clinicians and manufacturers must identify and enumerate the types of failures a drug, a disposable item, an instrument, or whatever can facilitate or, at least, fail to prevent. All must strive to support the primary clinical mission, namely to care for patients compassionately, safely, efficiently, and thriftily. Neither anesthesiologists nor industry dares to halt or slow the progress that has done away with ether, has reduced the use of halothane, has introduced propofol, has changed the features of anesthesia equipment and monitors and will continue to enhance clinical practice. It will be up to all to obsolete what does not fulfill the highest expectations anesthesiologists have for the tools of their profession.

Dr.Gravenstein is Graduate Research Professor, Department of Anesthesiology, University of Florida at Gainesville.