Wednesday, December 10, 2008

Smoking and Surgery

We've known for a while that tobacco smoking deleteriously affects surgical outcomes. The theory is that knocking off the cancer sticks for even a few weeks pre-operatively will lead to an increase in oxygen delivery to healing tissues, therefore making it less likely that you'll have complications such as wound infections and anastomotic leaks and the like.

The Annals of Surgery just published another article from Sweden that further promulgates the wondrous benefits of smoking cessation prior to elective surgery. This one was a randomized controlled trial that compared 30 day outcomes of patients who had stopped smoking for 4 weeks prior to surgery versus a control group. Patients were given counselling and free Nicorette to facillitate the cold turkey stoppage.

Strangely, over the course of two years, at 4 different hospitals, only a total of 117 patients were enrolled in the study. Even stranger, the overall complication rate was 41% in the control group versus 21% in the intervention group. Now that's a ridiculously high complication rate. Especially given that the surgeries performed in the study were restricted to hernia repairs, laparoscopic cholecystectomy, and joint replacement surgery.

It seems the authors were rather generous in how they defined "complication". Routine post-operative developments such as fevers within 24 hours of surgery, urinary retention and ileus were included. Basically, anything that "necessitated treatment, investigation, or prolonged care" met the criteria. That's casting a rather wide net. Furthermore, even when there were legitimate complications, the article seemingly asks us to accept that the determining factor was whether or not the patient stopped toking up for a month. Are we really supposed to believe that one patient had a bile leak solely because she couldn't get off the Marlboro Lights? Or that another had a stroke because of an extra 28 days of Pall Malls?

We see these types of papers in the medical literature quite often. Little is gained from a scientific perspective (surely, it's clear by now that smoking is bad for you and compromises respiratory reserve and healing capacity). On the other hand, the propaganda value of such a "scientific article" is substantial. It gives you a peer reviewed paper to wave in the faces of patients. But is it necessary? Is it worth the cost and effort of enrolling patients, getting IRB approval, filling out all the forms, and crunching the numbers with complicated statistics equations just so we can have level one evidence that you're better off not smoking prior to elective surgery? What's next? A randomized controlled trial that "strongly suggests" infection rates are improved in surgeons who wear sterile gloves during an operation versus surgeons who dip their fingers in toilet bowls prior to a case and then operate gloveless?


Bianca Castafiore? said...

I'll bite. What would be the better definition of a post-op complication?

As an ex-smoker, I congratulate you on a most repulsive photo! Now *that* ought to hang on waiting room walls, in lieu of generic abstract geometric pastel washes...

Also -- we appreciated your thoracotomy entry. Is the survival rate improved if it's done in a proper operating theatre instead of the ED/ER (Would someone please pick one or the other. The trouble WhieCoat causes...)?

walt dandy said...

I agree. I think that there is significant pressure to publish in academic institutions (from a variety of sources) and it seems that some investigators become much more focused on getting papers out than they are on the process of posing and answering relevant questions. It has also been shown in a recent study (I don't have the reference handy at the moment) that there is an inherent bias in the peer review process, which I think also contributes to the publication of studies like this.

make mine trauma said...

I want to know who spent every waking and sleeping moment with these people to be absolutely certain that they were not sucking down smokes as soon as they were out of sight of the researchers. Guess it doesn't really matter because it does sound like a very bogus trial.