Wednesday, January 7, 2009

The Black Box: Aviation, Anesthesia, and the Debt We Owe Those Who Came Before Us

Excerpts of cockpit voice recorder transcript,
Air Florida Flight 90, January 13, 1982

Aircraft: Boeing 737-222B

Pilot: Captain Larry Wheaton, age 34
First Officer: Roger Alan Pettit, age 31

Initial complement: 74 passengers, 5 crew members
Weather: blizzard with severe icing

Portion of take-off checklist:
(Pettit): Air conditioning and pressurization?
(Wheaton): Set.
(Pettit): Engine anti-ice?
(Wheaton): Off.

15:59:24 (Control Tower): Palm 90 cleared for takeoff.
15:59:28 (Control Tower): No delay on departure if you will, traffic's two and a half out for the runway.
15:59:32 (Wheaton): Okay, your throttles.
15:59:35: [Sound of engine spool-up]
15:59:49 (Wheaton): Holler if you need the wipers.
15:59:51 (Wheaton): It's spooled. Real cold, real cold.
15:59:58 (Pettit): God, look at that thing. That don't seem right, does it? Uh, that's not right
16:00:09 (Wheaton): Yes it is, there's eighty
16:00:10 (Pettit): Naw, I don't think that's right. Ah, maybe it is.
16:00:21 (Wheaton): Hundred and twenty.
16:00:23 (Pettit): I don't know...
16:00:31 (Wheaton): Vee-one. Easy, vee-two
16:00:39: [Sound of stickshaker starts.]
16:00:41 (Control Tower): Palm 90 contact departure control.
16:00:45 (Wheaton):
Forward, forward, easy. We only want five hundred.
16:00:48 (Wheaton): Come on forward....forward, just barely climb.
16:00:59 (Wheaton): Stalling, we're falling!
16:01:00 (Pettit): Larry...We're going down, Larry....
16:01:01 (Wheaton): I know it.
16:01:01: [Sound of impact.]

The plane hit the 14th Street Bridge across the Potomac River and killed four motorists in addition to 74 on board. Only a minute and 37 seconds had passed from the time the tower cleared the plane for take-off to the time it crashed.


I don't like flying. I've been doing it almost all my life, since the age of four. But to this day as we take off in jets making that graceful upward angle I so love to watch from the ground, I think to myself, even though I can use physics to come up with the answer, "How on earth is this huge thing gonna get up and stay up?"

It's probably one of my life's greatest ironies, then, that I am an anesthesiologist by profession. Anesthesia owes a great deal to aviation for the safety measures that have now become the standard of practice, and there are several significant parallels between life in the cockpit and life behind the drape. [Click here for a great article on a play, Charlie Victor Romeo, that dramatizes this very subject and the impact it has had on medical professionals - hat tip to Transor Z for the link.]

Here are several that come to mind:

  • We (pilots and anesthesiologists) must function as part of high-performance teams with high stakes: if we mess up, people die.
  • We have to use technology with a great degree of skill and accuracy.
  • Our work environments are complex and potentially unpredictable.
  • High stress, dangerous work, fatigue, and potential disaster are ever-present issues in our line of work.
  • We value and use checklists, monitors, safety protocols known to the entire team, detailed plans, backup plans, closed-loop communication, and in-depth error analysis.
  • Take-off and landing are often considered most perilous times but we have to be prepared for turbulence in the middle as well.
As residents one of the most valuable educational experiences we had was training in a simulator. Practicing clinical responses to patient problems was useful but I think an even greater impact was made by the team-communication training we got in the sim. The "surgeon-as-captain-of-the-ship" model was rejected as outdated and, frankly, unsafe. Scrub techs, students, and circulating nurses were encouraged to ask questions and speak up in the name of patient safety, and all team members were expected to listen to one another, value each other's different skills, and combine them smoothly and efficiently.

One of the best tools we took from our simulator exercises was the "Advocacy/Inquiry" model of communication, which was held up as the paradigm for any person, from custodian to surgeon, who needed to express a strong concern. For example, if a surgeon noticed a drop in the patient's oxygen saturation and felt the need to confront the anesthesiologist, instead of saying, "What the heck are you doing to my patient?" he or she was taught to communicate concern for a shared patient with language like, "I'm noticing our patient's de-satting quite a bit (advocacy). What do you need me to do (inquiry)?" It may sound like touchy-feely psychobabble, but I'm telling you, it WORKS when used consistently to achieve coordinated and productive team efforts.

One of the hardest things to face, in real life certainly but even in the simulator, is error. There are so many different ways in which we err, and we all seem to err in some similar ways. We see signs of danger or doom, or get that nagging gut feeling, but we ignore the signs, or wish them away, or talk ourselves out of paying attention to them with wishful thoughts. We second-guess ourselves. We persist with a preconceived notion and try to fit all the evidence to that one idea at the risk of missing the real cause of a problem. We let an authority figure discourage us from taking a strong stand or "sticking to our guns." We see something bad on a monitor and do nothing, or do a lot without any real purpose. We fail to see what's right in front of us. We skip steps, either because we have not done a procedure often enough, or because we have done it so many times we could do it in our sleep. We forget or neglect to "follow the rules." Or, we fail to break the rules when needed.

Both novices AND experts commit the above types of errors. In addition to the use of checklists, safety protocols, and recognition of interdependent skills from different team members, one other fruitful legacy from the aviation industry is error analysis directed toward crisis management and disaster prevention rather than toward blame and punishment.

So what happened with Air Florida Flight 90?

  • The pilots failed to switch on the engines' internal anti-icing equipment - a skipped step / failure to adhere to established protocols, perhaps.
  • They used reverse thrust to leave the gate prior to take-off, which sucked large amounts of snow and ice into the engines in the setting of a failure to activate engine anti-ice.
  • They failed to abort takeoff per FAA regulations even though snow and ice build-up were visible on the wings and a power problem was detected while taxiing.
  • The first officer tried to express his misgivings, but then backed down, more than once; meanwhile, tragically, the captain failed to listen to and in-fact down-played his concerns, and insisted on "willing" his instrument readings to be heading in the right direction when in fact ice buildup on the probe measuring engine power was causing false readings.
One of the first videos we had to watch as anesthesia residents going into the simulator for the first time was a reenactment of an aviation disaster, with the actual cockpit voice recording in the background, impact-crunch and all. It was sobering. [See here for transcripts from various aviation disasters - even just reading them without hearing them can produce that pit in your stomach.] We take our jobs in our own cockpits very seriously because we have a healthy respect for the dark horror of that crunch and know well how what we do, or fail to do, can lead a patient down that fatal road. We're constantly judging ourselves, planning, double- and triple-planning, and de-briefing, trying to figure out how we could have avoided a particular problem or made some other thing better or smoother. And we have our colleagues in aviation to thank, in part, for that obsession with safety.

So when the de-icing team delayed our flight a bit to spray the wings of our tiny jet from Boston to DC with their de-icing stuff, and when the larger jet from Charlotte to San Francisco taxied BACK to the gate because the pilot heeded a warning light just after being told by the tower that he was number one for take-off, I was not annoyed in the least, as I might have been before my anesthesia days. Thanks for seeing the light, I wanted to say to him, and for paying attention. For listening to that nagging inner whisper, instead of brushing it off as "probably nothing anyway." It might just have been the tiny, meticulous move that made all the difference. It reminded me that even our smallest acts can hold unseen, great value - which is one of the things I love most about my work.
Addendum 1/16/09: In light of all the above thoughts, Captain Chesley B. "Sully" Sullenberger is my new hero. Read here how his training, experience, judgment, and skill saved lives - or better yet, listen here (while watching an animated recreation) to the actual conversation between the pilot and the air traffic controllers just before the plane went down.


Anonymous said...

As a professional airline pilot, this post resonates with me. There are many parallels between airline pilots and anesthesiologists. They both have a long training period, airline pilots typically have more than 5000 hours of flight time before being hired at major airlines and many more hours of training. They both use crew coordination concepts and adhere to checklists. In the cockpit we follow the established procedures religiously, failure to do so often means lives lost. One doctor who has done a lot of research about applying aviation safety procedures to the operating room is Dr. Richard Karl, chair of the department of surgery at the University of South Florida: I have attended one of his talks about this subject and he has some great ideas. This subject is also quite interesting to me because I am retiring from the airlines to attend medical school next year at the age of 30. It was a tough choice but I had always felt that I wanted to be a doctor but I chickened out the first time I was in college and I continued on my way to become a pilot. Who knows I may pursue this course of research in the future.

T. said...

Bozjet - thanks so much for stopping by. I had to smile when you wrote you "chickened out" of attending med school earlier but was brave enough to be an airline pilot! You have more courage than I can even imagine!

Best of luck with your career change (I was a bit of a latecomer to med school too), and please consider the wonderful field of anesthesiology, for which I think your aviation experience will prove so immeasurably valuable. And thanks for letting me know about Dr. Karl - I've seen some of the literature by Gaba, Sexton, and Helmreich and am always interested in learning more.

Please drop me a line and let me know, if you think of it, what you end up choosing in medicine, and also accept my deepest thanks for your service as a professional pilot. I'm grateful and relieved every time a plane I'm in touches the ground smoothly, in one piece.

Anonymous said...

I loved this post. I am afraid of flying, too. It reminded me of the play "Charlie Victor Romeo," which I have made it a point to NEVER see. Here's a link to a Newshour story on the same subject from a while back:

gelci72 said...

Transor Z - the link is terrific. Thanks!

Unknown said...

Loved this post and conversation with the pilot-turning med student! I'm phobic about both flying and anesthesia!! I do fly as much as I can, as I love to travel. I can watch my palms sweat as we take off! A recent 'return to airport' venture turned out well, but I was so grateful that I managed to stay in my seat and not climb over the seats to 'help the crew!' One of my fears is that I will act cracy if something goes amiss. As for anesthesia, I've avoided it entirely since I was a child, but have to face it for a mitral valve repair. Yikes! Your blog reassures me a bit. I just hope I get somebody as careful as you are, and as willing to 'stay by my side.' It's is oddly reassuring to me to know that an anesthesiologist shares my fear of flying! I'll be praying for safe journey for you.

Unknown said...

The anesthesia/aviation metaphor is apt as I posted in The Pilot of the Soul.

Anonymous said...

I am constantly fascinated by the interface and similarities between aviation and anaesthetics. I loved your post Bozjet. The irony is, of course, that I always wanted to be a pilot and my eyesight initially restricted me from military aviation - which was where I wanted to learn to be a SAR helicopter pilot. Now I am an anaesthetics registrar (resident, for all my North American friends) with an interest in aeromedical retrieval. I now often flirt with the idea of dropping medicine to learn to be a pilot. I guess the grass is always greener on the other side!

There are, indeed, many interesting parallels between aviation and anaesthetics and we do owe aviation a great deal for the safety lessons that many have tried to apply to anaesthetics. Unfortunately there remains a reluctance amongst many of my seniors and colleagues to fully embrace the checklist, aviation approach to their anaesthetic practise. Often, it seems to me, that they reject it as 'cookbook' anaesthesia and therefore somehow 'beneath' them and their egos.

Observationally, I believe that this reluctance is tolerated and common in medicine for two reasons - 1. there is not the same commercial imperative as there is in aviation and, most importantly, 2. When my 'plane' crashes I never die. In my cockpit, I am ALWAYS safe.

I wish you the best of success Bozjet, think of doing anaesthesia - you will be joining it at a time when the culture is significantly shifting for the better and the safer.

D. Patrick Caldwell said...

I enjoyed the parallel here. I actually wrote a blog post about a mistake I made because I got distracted and I didn't use my pre-landing checklist.The thing is, 99 percent of the time, you can remember what you're supposed to do without the checklist. It's that 1 percent that makes me nervous. Now, I always use my checklists and I always verify that what I say is right.

The pilot in this case used his checklists and called out the correct response, but it didn't cross his mind that "off" was a bad thing. Almost every time he takes off, that's how the checklist goes.

A checklist like that whether you're flying an airplane, sedating a patient, or packing for vacation shouldn't be passively recited; they should be actively executed.

Anonymous said...

I have spent most of my career flying commercial airliners; I agree that there are indeed some similarities between the work done by an airline pilot and an anesthesiologist. There is one significant difference: on the flight deck we always have at least 2 rated and experienced pilots at the controls. In too many operating rooms, I see multiple CRNA's providing anesthesia with one anesthesiologist (at best) "supervising" and in the worst scenerio there is no anesthesiologist at all. It's nice to talk about safety and checklists, but I don't allow anyone but a rated pilot fly my airplane. I respectfully submit that anesthesia should be provided by anesthesiologists not by CRNA (nurses); supervised or not. I recently cancelled my surgery at the last minute when the CRNA told me that "she was equal to an anesthesiologist" and that she didn't need to be supervised by anyone (there was no anesthesiologist in the building and 4 surgeries we taking place). This is unsafe IMHO.