Portal de Periódicos da CAPES

Too Much Technology?

2003; Lippincott Williams & Wilkins; Linguagem: Inglês

10.1213/01.ane.0000085795.50083.76

1526-7598

Steven J. Barker,

Anesthesia and Sedative Agents

“When technology is master, disaster comes faster.”—Piet Heim Although the quotation above seems to promote a fear of technology, its intent here is to stimulate a new examination of the role of technology in anesthesia care. The author of this editorial is a former engineer (PhD in Aeronautical Engineering, Caltech), who taught engineering at the university level for 7 years before changing careers into medicine. This author has always been a supporter and purveyor of technology in anesthesiology. He has served as President of the Society for Technology in Anesthesiology and is the current editor of the Anesthesia & Analgesia Section on Technology, Computing, and Simulation. Despite his documented admiration for “high-tech” devices, this author believes that anesthesiologists are moving too far toward a blind reliance on technology rather than on their own common sense. This trend can be seen in our training programs as well as our literature. (In both aspects, the author is one of the worst offenders.) The following is a recent actual case to illustrate the point. A 25-year-old healthy man was anesthetized for open reduction and internal fixation of a leg fracture. After a routine thiopental-succinylcholine induction of anesthesia, the trachea was intubated, and ventilation was mechanically controlled with sevoflurane, oxygen, and air. The preparation and drape period took longer than usual for unknown reasons. During this extended period of no stimulation, the arterial blood pressure gradually decreased into the 90 mm Hg-systolic range. The anesthesiology resident (an excellent resident) gradually decreased the sevoflurane inspired concentration in response to the decreasing blood pressure. Upon incision, the rather muscular patient sat up on the operating table and quickly removed his IV cannula. After a brief struggle, the patient was subdued and reanesthetized. The remainder of the case proceeded without incident, and the patient had no recall of the event. How does this case demonstrate too much reliance on technology? The reader may even infer the opposite; that is, the entire “rude awakening” might have been avoided by the use of still more technology, for example, a Bispectral Index (BIS) monitor. But BIS, like other neurophysiological monitors, measures level of hypnosis, not depth of anesthesia (1–3). BIS can display “surgical anesthesia” levels during normal sleep. The answer to the question above is simple: events of this kind are best avoided by the application of common sense, not more technology. Despite a low arterial blood pressure, heart rate, and even BIS value, our budding anesthesiologist should have known that 2% inspired sevoflurane is not likely to result in a 25-year-old man lying still for a surgical incision. We can observe this blind faith in technology in subtle ways every day. When asked how he knows that a patient is breathing after removal of an endotracheal tube, an anesthesiology resident may refer to the capnogram (absent during shallow breathing and high fresh gas flows), or the pulse oximeter (a very late sign of apnea). Some will point out chest wall movements (respiratory effort, not success) or fogging of the mask (one minimal expiration will do this). Occasionally, an unprompted resident will actually place a stethoscope on the patient’s chest and listen to breath sounds, thereby gratifying this author. Those who do so may feel they are catering to the eccentricities of the old fashioned (SJB) rather than doing something prudent. This is not the fault of the resident, whose custom-made earpiece probably resides in his locker. It is our fault—we instructors who have not properly balanced the Art of Anesthesiology with the Science of Anesthesiology in our training programs. Yes, this author believes that anesthesiology is part art and part science and that neither will lead to complete success without the other. Restoring the proper balance of art (i.e., common sense) and science into our training programs and the minds of our students does not imply teaching less technology. On the contrary, much of the problem is that we do not adequately teach the limitations of the technologies we have brought into the operating room. For example, residents learn early in their training that the pulse oximeter estimates arterial oxyhemoglobin saturation by using some sort of light absorbance measurement. That is a good start, but it is not sufficient knowledge to enable one to predict when the pulse oximeter may provide wrong or misleading information (4). The ease-of-use of our newer gadgets (pulse oximetry being a prime example) tempts us towards “black-box complacency.” That is, if a number appears on the instrument display, then it must be the correct value of whatever the instrument purports to measure. If the pulse oximeter displays 98%, then it is not possible for the patient to suffer from hypoxia. This is unfortunately not true, as numerous published papers have shown (5,6). Black-box complacency breeds an intellectual indolence, in which we do not seek alternative, confirming sources of the data we need. For example, if the automated sphygmomanometer displays flashing zeroes, we may stare at it in a hypnotic trance while it wastes 30 seconds of precious time attempting another blood pressure reading. In olden days, the anesthesiologist would palpate a radial pulse, pump up the manual cuff, and estimate a systolic pressure within 5 seconds. (How many readers remember the Ploss Valve?) This author has reviewed a case in which a 20-year-old man experienced an anaphylactic reaction to an IV antibiotic coincident with the induction of general anesthesia. At least 2 minutes passed before his cardiac status (pulseless electrical activity) was recognized. During this period, it was assumed that the automated sphygmomanometer was not working properly, and there was no pulse oximeter. The result was, of course, tragic. Perhaps the reader is now persuaded of a problem regarding the use of technology in the operating room, but no solution has been offered. The solution is not simply “less technology—more art,” but rather it is better education, including the following (1). Our residents must learn how the black boxes work and what artifacts can occur, so that they will know when to suspect erroneous values (2). We must teach them how to seek alternative data regarding circulation, oxygenation, ventilation, and depth of anesthesia. They must learn how to integrate these data together, using their knowledge of the physiology and pharmacology of anesthesia, to form a coherent picture of the patient’s status. Medical simulation is an outstanding training tool for developing this aspect of care. Anesthesiology should take its cue here from aviation. One of the key roles of aircraft simulator training is “partial panel” instrument flying. Without telling the student pilot, the instructor will cause one of the key flight instruments (for example, the artificial horizon) to fail. The failed instrument does not tell the student that it is no longer providing valid data. In fact, it may display data that seem reasonable at first, but will lead to disaster if the failure is not recognized. The student must quickly diagnose the instrument failure, and then integrate the other available data to maintain control of the aircraft. He has a few seconds to do this before loss of control occurs. In advanced pilot training, two or more of the aircraft’s critical flight instruments may “fail” simultaneously, yet the well-trained pilot will be able to maintain control. The same should be true for the well-trained anesthesiologist. Nearing the end of this editorial, we may seem to have contradicted the opening statement regarding too much technology, but we have not. Today’s problem is not simply too much reliance on technology. Our problem is not enough education in the basis of technology, its limitations, its relationship with physiology, and its integrated use in patient care. We leave the reader with the challenge of improving “techno-education” for the benefit of future anesthesiologists and the safety of our patients. We hope that Anesthesia & Analgesia’ s new Section on Technology, Computing, and Simulation will continue to make a significant contribution to this educational mission.