Wednesday, May 22, 2013

Is it really best to take out a gallbladder in the daytime?

Under the headline "Best to take out gallbladder in daytime," MedPage Today reports on a study that says people who have laparoscopic cholecystectomies at night have more complications.

The work was presented at Digestive Disease Week in Orlando.

Ordinarily, I would not critique a paper that I had not read completely but I have to make an exception in this case.

There are some serious issues with both the research and the reporting. If the MedPage article is not read carefully, patients may receive inappropriate or delayed care.

According to the article, the paper comprised 549 patients who were mostly female (84%) with 65% having surgery in the daytime (defined as 7 a.m. to 7 p.m.), and 62% had surgery that was not elective—that is, urgent or emergent.

Those operated on at night had a longer median hospital length of stay, 3 days vs. 1 day and were more likely to have had non-elective surgery, p < 0.001 for both.

The article also says the nighttime patients "were more likely to have a discharge diagnosis." I'm only guessing, but I think they may have meant to say "a discharge diagnosis of acute cholecystitis."

"Bile leaks, bile duct injuries, retained stones, pneumonia, and readmission occurred at rates that did not differ significantly," says the report. The only complication that differed significantly was that of superficial wound infection, which occurred in 5% of the night and 2% of the day patients, p = 0.04.

Multivariate analysis showed that nighttime surgery increased the odds of complications by just over 3 times but with a wide confidence interval of 1.01-10.7 and a barely significant p value of 0.05.

So, what's the problem?

At the very end of the nearly 500-word article, we find that elective patients were excluded from the multivariate analysis with no explanation why. It could be that when the elective patients were included, there was no difference in outcomes.

The first part of the last sentence is even more revealing: "The authors also did not have data on postoperative length of stay and severity of gallbladder disease."

Perhaps some of the length of stay of 3 days for the nighttime patients was due to waiting for an available operating room, workup for possible common duct stones or stabilization of lab values.

But in my opinion, the factor that makes the entire study invalid is not knowing the severity of the gallbladder disease. A patient with a more severely inflamed gallbladder is obviously more likely to have a complication.

There is also no mention of co-morbidities like diabetes or heart disease which may have been more prevalent in the nighttime group.

I don't understand how this study ever saw the light of day, why it was selected as a featured paper by MedPage or why the misleading headline was used.

If you are a patient with a sick gallbladder, many recent studies have shown that you should have it removed as soon as possible—less time in the hospital, less cost better outcomes.

If your surgeon can do it at 8 p.m., please go ahead with the surgery. Don't wait until the next day.


artiger said...

Scalpel, since I have started reading your blog, I am continually amazed at the number of crap studies that get put out for the public to peruse. Maybe it's a conspiracy.

I can see delaying a surgery for up to 24 hours (due to late hour, lack of available crew, etc., especially in small rural hospitals, and of course surgeon convenience), but the old idea of "cooling it off a few days" has pretty well been debunked, hasn't it?

With that said, those elective, daytime surgeries are often "chip shot" lap chole's, the ones that take about 15-20 minutes. I don't know if that is significant or not.

Ryan Madanick, MD said...

I agree with you. If the analysis was restricted to elective procedures, this would make sense.

Skeptical Scalpel said...

Artiger, here's a link to a study that was presented at this year's ASA meeting.

Early surgery is better.

Ryan, I think because elective are much easier that emergency GBs, it would make no difference when elective ones are done. It's conceivable that there might be a difference for emergency GBs done at night, but this study clearly does not prove that.

Anonymous said...

Agree with all you've said. However, I'm a busy general surgeon and been in practice for >20 years, and I can say I've NEVER taken a GB out after 8PM! A few of my partners will but only if they themselves don't have time the next day, because, for instance, they are in clinic.
On the other hand I don't operate at night unless I absolutely have to. If an appy comes in after midnight I always do it the next morning unless it is a young child or peritonitis.

Skeptical Scalpel said...

Anon, thanks for commenting. I have done a few cholecystectomies after 8 pm in diabetics with air in the GB and impending sepsis. I never regretted doing so.

Moose said...

Yet again reinforcing my belief that doctors somehow manage to forget the basic rules of science with a disturbing frequency.

It's bad enough this stuff gets published, but when it's in an allegedly "peer reviewed" journal, one has to wonder if any of the "peers" remember how scientific studies are actually done.


Skeptical Scalpel said...

Moose, I must clarify that as stated in the post, this was a paper presented at a meeting. Although it's a pretty prestigious meeting, the paper was not peer reviewed in the strict sense of the term. The abstract was accepted by the program committee. The paper will likely be submitted to a journal at some point. Then it will be read by at least two peer reviewers.

RuggerMD said...

as an "acute care surgeon", who operates day and night, the only gallbladders you will see me take out at night are on sick patients with nasty acute cholecystitis. All the rest can wait until next day.
So, duh, those would be more difficult cases.
Again, I love common sense studies that are really just a waste of time for me to read.

peter43 said...

The reason the elective gallbladders were left out was to minimize the difference in the day and night groups. Including them would make the complications of the day cases even fewer. Can't tell yet if this is a flawed study. Actually this is important to look at. However, at our busy tertiary care center, add-on gallbladders are frequently on a wait list for 1-2 days and if not done at night will wait until the next night.

Skeptical Scalpel said...

Rugger, I agree. If the patient is so sick that you must do the case at night, there will be more complications.

Peter, you may be right about why they left out the elective cases. Also, the definition of elective, urgent and emergent for GB cases is often very fuzzy. I've had patients with biliary colic who have had a few attacks. They often want surgery as soon as possible because they don't want to have the pain again. When you operate on them, it's really more like an elective case.

orthopedic surgeon in nyc said...

I really love reading your blog to learn new things! Thank you so much for taking the time to write it

Skeptical Scalpel said...

Ortho, thank you for reading and the kind comment.

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