Volume 10, No. 3 • Fall 1995

Anesthesia Safety: How Safe is “Safe”

J. S. Gravenstein, M.D.

Editor’s Note: J.S. Gravenstein, M.D., a much-respected leader of the APSF for the decade of its existence, is honored in an editorial on the following page. Dr. Gravenstein shares here some of his remarkably incisive current thoughts about and insight on anesthesia safety in our evolving practice environment.

Not a week passes without mention in one or the other medical publication of “cost containment,” not a day without reference in a hospital meeting about the economic vicissitudes of managed and capitated care. “Fewer resources, fewer personnel, longer hours, reduced income, do more with less” are the key words that ring in our ears. In the clamor for reducing costs we listen in vain for calls to invest in measures to increase or at least maintain safety in anesthesia.

How Safe is “Safe”?

Safety, of course, is relative. We all participate in activities that are not 100% safe. For example, we know that we face risks when we travel by air. Society’s concerns about safety in aviation can be judged by a recent cover story in Newsweek (April 24, 1995). The magazine introduced the story with a stirring: “How safe is this flight? Hundreds of Americans died in plane crashes in 1994, sounding a wake-up call for an industry lulled into complacency.”

How terribly unsafe is it to fly? Newsweek says that in the past decade with U.S. carriers the “death risk” (the probability that someone who randomly flew on one of the flights would be killed en route) ranged from zero deaths in 10 years of airline operation to 1 in 1 million flights. Imagine that: with some carriers in 10 years no death attributable to crashes!

But because other carriers had statistics with many deaths in the decade, the magazine published “Ten ways to make flying safer.” Among them:

  • Modernize now, (get billion dollar modernization program for the air-traffic-control back on track)
  • Speed up the flight-data program (upgrading of data recording equipment to analyze patterns and problems on all flights, not just crashes)
  • Set the highest standards for pilots (insist on rigorous and continuous training for pilots to insure that they know how to use the latest equipment)
  • Hire more air-traffic controllers (modernization may mean that the system can do with fewer people – but until then, hire more)
  • Install the terminal doppler weather radar (the FAA has bought 44 but has fully activated only 3)
  • Take fliers at their word (71% of respondents said they would pay higher airfares for safety 94% claimed they would put up with delays or flight cancellations)

In comparison to commercial aviation, how safe is anesthesia?

Relative Risk of Anesthesia Compared to Air Travel

Clearly, we cannot point to a record of no anesthesia related death in the last decade. Even a death rate of 1 in 1 million anesthetics would be far better than we can boast. The death risk is sometimes calculated as the deaths attributable to accidents in 100 million hours of exposure. Assuming a death risk of 1 in 10 million for commercial aviation and assuming an average of 2 hours per domestic flight, the death risk would be about 5 per 100 million hours of exposure. If we assume a preventable anesthetic mortality of 1 in 100,000 and assuming the average anesthetic to last about 2 hours, the anesthesia death risk would be 500 per 100 million hours of exposure. Feel free to play with the data. If you think the average anesthetic lasts longer or shorter, or if you believe anesthetic mortality to be higher or lower than these data used here just plug them into the formula. You won’t be able to get away from the fact that anesthesia is far less safe than flying as a passenger with one of the big commercial airline companies.

Of course, flying and undergoing anesthesia have nothing in common except that both are not entirely safe, that in both examples the victim does not contribute to a disaster, and that in both examples the passenger or patient has every right to expect that he or she will not be harmed by the trip – be it a flight or anesthetic. One might, therefore, reasonably ask, “What anesthetic death risk is acceptable?” And if the death risk in anesthesia is deemed to be unacceptable, what is society willing to invest in improving safety in anesthesia? Or, in other words, how much (in money and resources) should we commit to saving a life?

The Cost for a Life:

Captain O’Grady

Recently, one segment of our society heavily invested in the saving of a single life. The world and certainly all Americans heard about the brave rescue of a pilot shot down over Bosnia. Newsweek reported (June 19, 1995) that two CH-53 E Sea Stallions (cost: $26 million apiece), two AH-1W Sea-Cobra gunships ($12.5 million apiece), four AV-8B Sea Harriers ($24 million apiece), F/A-18 fighter bombers ($ 30 million apiece), F-16s ($20 million apiece), F-15Es (35 million apiece), EF-111s ($60 million), and AWACs ($ 250 million apiece) participated in the rescue, not to mention dozens of Marines and scouts. The investment of resources and funds to save one life was enormous and it was spectacularly successful. All participants realized the risks faced by rescuers and Captain O’Grady. After the widely hailed success, I have heard no administrator or bureaucrat suggest that to expend millions of dollars and risk many millions more to rescue Captain O’Grady was irresponsible.

Depending on Experience and Advice

Many factors and many uncertainties confronted the planners of the rescue. No scientific data guided them; no controlled experiment predicted the probability of failure. The military had to rely on the opinions of their experts.

When issuing safety related regulations, the Federal Aviation Agency also must deal with uncertainties and opinions based on experience rather than science, and rely on the advice of experts and make decisions without the benefit of controlled, prospective studies. It is similar in anesthesia; we, too, have not been able to and cannot hope to obtain scientific evidence that this or that safety strategy, behavior, or device will pay for itself. We also (like the military and the FAA) find ourselves forced to rely on the best advice we can garner. The comparisons among safety in aviation, safety in anesthetic, and the rescue of Captain O’Grady bring to light an important fact: The expectations of society – private or military – and the opinion of experts will be all we have to guide us.

Safety on Trial

Imagine what would happen if we were to demand scientific proof of measurable cost effectiveness for all safety measures we employ. The following (invented) lawsuit paints the picture:

Plaintiff’s Attorney (PA): Now, doctor, isn’t it a fact that you did not use any of the modern monitors, even though they are available in your hospital?”

Defendant (D) nods.

Judge: “Doctor, please speak up. The stenographer cannot catch a nod.”

D: “Yes.”

PA: “And you gave anesthesia with a Schimmelshrub mask.”

D: “With a Schimmelbusch mask, yes.”

PA: “And you used ether, correct?”

D: “Yes, diethyl ether. That is what I used.”

PA: “Doctor, is that anesthetic used routinely for anesthesia in your hospital?”

D: “By me, yes.”

PA: “But not by the other 18 anesthesiologists in your hospital?”

D: “I have not checked that recently, but I believe that I am the only one using ether.”

(A lengthy interrogation followed during which the PA established that the patient was a 70 year old man who had been in good health and who had been anesthetized by the defendant so that the surgeon could remove an inflamed gall bladder. During anesthesia the patient had suffered a cardiac arrest. Resuscitation had reestablished circulation but the patient had never regained consciousness and had died 4 weeks later. An autopsy had been performed. The pathologist had described extensive coronary as well as cerebral arterial atherosclerosis and the ravages of hypoxemic brain damage and recent as well as old myocardial infarctions.)

PA: “Doctor, you did keep an anesthesia record. Please explain to the jury how often you checked and recorded the vital signs of the patient.”

D: ” At all times did I keep my finger on the pulse and at all times did I watch the patient’s spontaneous ventilation and the color of his mucous membranes. It was necessary to keep anesthesia fairly deep because the patient was obese and it was not easy for the surgeon to dissect the gall bladder. I did not use muscle relaxants nor mechanical ventilation. I was able to check the blood pressure about every 10 minutes at which times I recorded the systolic pressure, the heart rate and the respiratory rate.”

PA: “Doctor, have you heard of pulse oximetry?”

D: “Yes, but…”

PA: “Just answer the question, please. Have you heard of capnography?”

D: “Of course, I…”

PA: “Please, doctor, just answer the question with yes or no.”

D: “Yes.”

PA: “Would you not agree that the use of these devices is by now well established, indeed pulse oximetry and capnography could now be called time honored standards of care, endorsed by your own profession, and adopted throughout the developed world?”

It was not a good day for the anesthesiologist.

Old “Proven” Ways: Just as Safe?

When the time came for D’s attorney to summarize the position of the defense, he said:

“Instead of standing here accused of negligence, my client should be praised for having saved many lives. In his practice he uses only what can be defended by prospective, controlled, and scientifically valid studies. There are no studies that can document with scientific rigor that pulse oximetry or capnography will improve the chances of a patient to make it through anesthesia without suffering harm. There are no studies to show that ether anesthesia is less safe than any of the newer drugs in use today. There are no scientific, controlled studies establishing that the surgeon will do a better job when muscle relaxants are used during a cholecystectomy. Indeed, we can show you reports by distinguished experts that we lack scientific evidence that anesthesia is safer when the newer drugs and methods are used than was true in years gone by, before these new and expensive drugs and devices had been available. Well, you might say, but if the profession accepts these new drugs and devices and they are established as the standard of care, should my client not have used what every one else is using?

“I tell you, no, no, and a thousand times no. The history of medicine is replete with ‘time honored’ procedures that were accepted as dogma not just for years, not just for decades, but for centuries until scientific, and I stress scientific, insight proved them to be utterly without merit. I imagine that someday a man like my client will be able to demonstrate that the use of fancy muscle relaxants – which have their own morbidity and mortality rates – and the use of capnography and pulse oximetry, etc. is not justified. Indeed, these elaborate monitors may be harmful; they may distract and confuse the clinician, may present deceptive artifacts, and may give rise to misinterpretations leading to unnecessary and even injurious interventions.

“No, my client has not been blinded by the deceptive concepts of ‘standard of care’ and ‘time honored’ usage. Instead, he has searched for the evidence to defend the use of these new devices and drugs. When he could find neither evidence that such drugs and devices improved or worsened the outcome of anesthesia, he asked the second, essential question: `Can I defend the use of something that has no proven benefit but causes no measurable harm?’ `Not’, he concluded, `if it costs money. The sums squandered on useless devices and drugs in anesthesia could save lives elsewhere, for example, they could be used to lower the unacceptable high infant mortality in the United States.’

“We deeply regret the loss of the life of this elderly patient. But instead of focusing on his death, focus instead on the lives of the children that could be saved if throughout anesthesia, my client’s practice patterns were adopted and many millions of dollars were saved and invested in prenatal care!”

And so ended the closing statement of defense counsel.

Cost Pressures on Safety

Even ardent defenders of the need to show scientific proof and favorable cost/benefit ratios for everything we do will not urge us to adopt the practice here caricatured. But I sense an attitude among some administrators that would push us in the direction of reducing rather than enhancing the steps designed to increase safety in anesthesia. Imagine we were to go before the public and say: “We are now satisfied with our accomplishments in anesthesia. We have made enormous progress. In the study by Beecher and Todd, anesthetic deaths were about 1 in 2000 or, assuming again a 2 hour average duration, about 25,000 deaths per 100 million hours of exposure.1 To have wrestled 25,000 down to the vicinity of 500 or less is a great accomplishment. True, the mortality in anesthesia is still 10 or 100 times as great than that of flying in a commercial jet, but we think it is pretty good. Certainly, there is no need to spend more money on safety for anesthesia. Our administrators remind us that we cannot increase our expenditures for safety unless we can show that it raises income or measurably improves outcome. With an anesthetic mortality as low as 500 or maybe even only 250 per 100 million hours of exposure, we would need millions of comparable cases in a balanced, prospective study to show an effect on mortality. It cannot be done. So, we are going to keep the status quo, more or less. Perhaps we can even squeeze out some savings. We are sure you won’t mind.”

Safety as Top Priority

Of course, we won’t say that. Instead we should raise our voices in support of safety. If we don’t, safety will take a backseat to economy, and our mortality statistics will eventually show our patients doing worse rather than better.

In the magazine of Delta Airlines (June 1995), the ruddy face of Delta’s CEO appeared with an article: “Safety is Delta’s top priority every hour of every day.”We should say no less. Not only in publications such as this Newsletter devoted to safety, but also in speaking with our patients. They deserve to hear how we work to make anesthesia safe for them. Even safer than it is today. We have a long way to go to make anesthesia as safe as possible.

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

Reference

1. Beecher HK, Todd DP: A study of the deaths associated with anesthesia and surgery. Annals of Surgery 1954;140:2-34.