Wednesday, August 31, 2011

Surgeons vs. Pilots: There Is No Autopilot in the O.R.

We’ve all heard the comparison of surgeons to pilots.

Surgeons should be more like pilots.
Surgeons need more rest. They should have work hours restrictions like pilots do.
You wouldn’t want to fly with a pilot who had been awake for 24 hours.
Blah, blah blah.

A while back I blogged [see links below] that surgeons really cannot be compared to pilots because, unlike the boring, monotonous work that pilots do, surgeons perform tasks that are highly variable, both mentally and technically. I even said that the only time pilots really have to work is when the plane is taking off or landing. I had no idea how right I was.

Now comes proof. An article from the Associated Press entitled “Automation in the air dulls pilot skill,” discusses some recent plane crashes and notes that pilots increasingly seem to be making poor decisions when confronted with emergencies. Flying a plane is becoming more automated and the pilots’ skills are eroding. New air traffic control mandates are calling for GPS positioning rather than the use of radar. This will allow more accurate knowledge of a plane’s true location enabling planes to descend faster and closer together, possibly leading to more challenges for pilots.

The following statement sums up the current state of affairs:

Even when not using the new procedures, airlines direct their pilots to switch on the autopilot about a minute and a half after takeoff when the plane reaches about 1,000 feet, [Bob] Coffman [member of the FAA pilot training committee and an airline captain] said. The autopilot generally doesn't come off until about a minute and a half before landing, he said.

Do you get it? With the rare exception of the malfunctioning autopilot, pilots are actually hands-on flying their airplanes for 3 minutes per flight.

There is no autopilot in the operating room. Machines can’t perform surgery. Even the robot has to be guided by a surgeon every second.

So please tell me how can you compare what a surgeon does to what a pilot does? 

Thursday, August 25, 2011

Privacy and a Death in Labor and Delivery

In a beautifully written article the summer issue 2011 of The Pharos, the magazine for members of Alpha Omega Alpha, an anesthesiologist describes the emotional turmoil he experienced after the death of a patient to whom he gave a routine epidural anesthetic.

He has to deal with a very unhappy family. A healthy young woman who goes to the hospital to have a baby and dies is going to evoke some questions. He worries that he may have given her a total spinal anesthetic instead of an epidural. He anxiously awaits the autopsy results. She died of an amniotic fluid embolism. It wasn’t his fault. Years later, he still thinks about this case. [The story is not available online.]

We all have such cases, some our fault and some not. It is hard to forget about a patient who dies. No one has described this better than a surgeon-blogger named Bongi in a post he called “The Graveyard.”

I have another reason for telling you this. There has been a great deal of angst on Twitter about people tweeting and blogging about patients online. Everyone is concerned about patient privacy and HIPAA [often misstated as “HIPPA”]. A blogger was forced to close her blog after being browbeaten by another blogger even though the post in question was significantly altered to disguise the patient’s identity.

Yet, I hear very little outcry about privacy with stories like the one I described above in print media. What am I missing?

Wednesday, August 24, 2011

More on Patients and “Shared Decision Making”

About 10 days ago I tweeted this, "How can a patient, who does not know what meds she is on or why, seriously participate in 'Shared Decision Making'"

After receiving several negative comments about the tweet, I blogged in detail about patients not knowing what meds they were taking and finished with this:

“While I’m on shared decision making, I have this final comment. Physicians should not present three options with lengthy dissertations on the myriad side effects of treatment and no real advice as to what would be best for the patient. You cannot teach someone the anatomy, physiology or the nuances of medical care in a shared decision making discussion, especially if that patient can’t even remember what his meds are.”

Thanks to MedPage Today’s rather indirect mention of a poll involving patients and my superior internet research skills, I discovered this recent study from the Journal of Medical Ethics. Investigators at the University of Chicago surveyed 8308 hospitalized internal medicine patients and found that after hearing their options and being offered choices, 67% preferred to leave medical decisions to their doctor.

As I said before, I always review the options with a patient, listen to their concerns and answer their questions. But as the majority of patients themselves believe, I think I am in the best position to recommend the appropriate treatment. Maybe a better term than “shared decision making” would be “shared information.”

Tuesday, August 23, 2011

Fun with Statistics: Straw Man, Hawthorne Effect & Power Debunk Cholangiogram Study

Major bile duct injuries can be prevented by implementation of routine intraoperative cholangiography [an x-ray of the bile ducts] say the authors of a paper published in the August 2011 issue of the Journal of the American College of Surgeons. The Dutch researchers established a policy of routine intraoperative cholangiography during laparoscopic cholecystectomy and looked at the incidence of bile duct injuries three years before and three years after it was instituted. Selective [at the discretion of the surgeon] intraoperative cholangiography was performed in 421 patients and routine intraoperative cholangiography was to have been in 435. Bile duct injury occurred in 1.9% of patients before the routine use of intraoperative cholangiography and in no patients after. The difference was statistically significant, p = 0.004.

Therefore, everyone having a laparoscopic cholecystectomy should undergo routine intraoperative cholangiography, right?

Not so fast. There are a few problems with the study. Let’s take the “Straw Man” issue first. A “Straw Man” is the establishing of a false premise and then defeating it with an argument. I have blogged about this before [here, here, and here]. The “Straw Man” in this case is the bile duct injury rate of 1.9% in the pre-routine intraoperative cholangiography cohort. Many  large series of laparoscopic cholecystectomies report rates of bile duct injury of well under 1%. An Egyptian study of 2,714 laparoscopic cholecystectomies found only 5 [0.18%] bile duct injuries. A Swiss study of 31,000 laparoscopic cholecystectomy patients noted a similar rate of bile duct injury of 0.3%. A third study reviewed 234,220 laparoscopic cholecystectomies done in Florida over a 10-year period and found that 0.25% resulted in a bile duct injury.

The next problem is called the “Hawthorne Effect,” which is the well-known finding that behavior improves when subjects know they are being watched. It is named for a factory near Chicago where several such experiments were done 80 years ago. Workers’ productivity increased no matter what changes were made in their environment. The surgeons in the routine intraoperative cholangiography study were given extra training in a skills laboratory and were aware that their performance was being monitored.

Despite the policy, only 59.8% of the patients in the routine intraoperative cholangiography group actually underwent routine intraoperative cholangiography. Even at the end of the three years, more than 23% of patients were still not undergoing routine intraoperative cholangiography. This suggests that the surgeons themselves were not totally convinced that the procedure was worth the extra time involved to complete the x-ray.

Another problem that is true of all so-called “before-and-after” studies is the fact that the “after” group has the benefit of the surgeons becoming more proficient simply because they have been performing the procedure longer.

The correct way to perform this investigation would be to randomize patients with one group having mandatory cholangiography and compare them to patients randomized to not have cholangiography. Such a study would be very difficult to do because the incidence of bile duct injury is so small. In order to achieve adequate statistical power, one would need more than 1000 patients in each group. 

Meanwhile, I will continue to perform selective intraoperative cholangiography.

Monday, August 22, 2011

Do Surgeons Suffer From "Decision Fatigue"?

What is “decision fatigue”? An article in yesterday’s NY Times Magazine describes “decision fatigue” as what happens when people are forced to make numerous decisions in short time periods. Israeli parole boards apparently grant parole to prison inmates much more frequently earlier in the day vs. later. It has something to do with overwhelming their ability to make choices, causing them to eventually opt to do nothing. Many social psychologists have experimented with this phenomenon and found it also affects willpower negatively. Repletion of glucose helps reverse the problem.

This prompted Paul Levy (@Paulflevy), who is an “Advocate for patient-driven care, eliminating preventable harm, transparency of clinical outcomes, and front-line driven process improvement,” to tweet, “Good article in Times: [NY times link] Query: Has anyone seen studies linking surgical error rate to the time of day?”

The answer is, “Yes.” But if the question had been, “Anyone seen any good studies linking surgical error rate to time of day?” the answer would have been, “No.”

Many studies on the purported effect of time of day on surgical outcomes have been published. The results are inconclusive. Some say there is no effect. Some say there is an effect on morbidity; i.e., surgery at night results in more complications and longer hospital lengths of stay. Some say there is an increase in early, but not long-term, mortality. In one study of critically ill non-surgical patients, those admitted at night actually fared better than those admitted in the daytime.

The studies are all retrospective, and there are many confounding variables. With or without emergency operations, it is not clear that time of day is an important cause of adverse outcomes. The impact of the number and complexity of surgeon decisions has not been addressed in any study.

I discussed surgeon fatigue and complications in high-risk surgery in a previous blog. (There is no difference in mortality rates by time of day of the procedure.) Besides fatigue, a very controversial subject, other potential confounders include system issues (number of physician staff, level of supervision, nurse experience and numbers, ancillary service availability, consultant availability), patient co-morbidities and whether a case is truly elective or urgent (not a raging emergency, but not a case that can wait until the next day).

In most instances, a surgeon does not have to make numerous complicated decisions in a short time. It is unlikely that decision fatigue plays an important role in the incidence of errors.

Here’s something that a lot of people do not understand. A bad outcome is not necessarily someone’s fault. There are times when, despite everyone’s best efforts, a patient suffers complications or even death.

References available upon request.

Friday, August 19, 2011

Here’s a Typical Story about Cancer Research

Yesterday, the BBC published a breathless report about a new study headlined “Modified ecstasy ‘attacks blood cancers.’” The research appeared in the journal Investigational New Drugs.

The modified ecstasy killed all leukemia, lymphoma and myeloma cells in vitro but the doses used “would have been fatal if given to people.”

According to the BBC, “A charity said the findings were a ‘significant step forward’” without actually naming the charity or explaining how a charity could speak.

The word “exciting” is used three times in the story, which is only 500 words long.

The investigators said that they were planning to modify the drug further. If the next iteration of the drug works in the test tube and if it works in animals, it could be available for clinical trials in humans in only 10 years.

The story ends with a quote from a Dr David Grant, scientific director of the charity Leukaemia and Lymphoma Research [possibly the earlier unnamed charity]. He said: "Further work is required but this research is a significant step forward in developing a potential new cancer drug."