Archive for December, 2012

This one isn’t exactly “evolutionary medicine”, but it sure is a smart, cheap, and (in my experience) unheard of little tip for shortening hospital stay (and thus cutting the bill) for some surgery cases.

Surgery comes with innate risks. Bleeding and infection can occur with any surgery, but operations that affect the bowel come with additional risks and concerns. One frequent complication of abdominal operations is postoperative ileus- a temporary paralysis of the intestinal tract after surgery that is usually related to the degree of surgical trauma and bowel manipulation.

When you are part of the surgical team, an important part of post-surgical care is keeping track of the workings (or lack thereof) of the patients’ digestive system. A typical morning check-up on a patient might go something like this:

“Hello! How are you feeling this morning?” (This exchange usually takes place around 5:30 in the morning… Anyone who says “good” is obviously bluffing!

“Sleep well?” (I think I may be the only student that cares about this question.)

“Any pain?”

“And have you had a bowel movement? No? Ah- have you passed any gas? Above or below?”

Yes, when you enter the world of medicine, the taboos of normal conversation (indeed, many social graces) are quickly forgotten.  Gone are the tendencies to giggle when someone says “fart”. Instead, the return of a patient’s bowel function can become a celebrated event amongst the team.

Post operative ileus is likely caused by a number of factors, including increased sympathetic activity (the fight-or-flight side of our autonomic nervous system) which overpowers the parasympathic (the rest-and-digest) system, as well as inflammatory mediators.  Additionally, some of the drugs that are used before, during, and after surgery may also inhibit bowel motility [1].

Ileus can delay patient recovery and increase the length of patient hospitalization, which leads to greater healthcare care costs. So how can we decrease ileus?

There is some evidence to suggest that therapies such as early postoperative mobilization (getting up and walking) and early feeding may decrease post-operative ileus [1].  I’m particularly interested in early post-operative feeding, which seems to come with a host of benefits in comparison to “NPO” (nil by mouth) that is common after surgery.  In fact, in a meta-analysis of 11 studies including 837 patients, early post-operative feeding significantly reduced the risk of any type of infection and reduced the mean length of stay in the hospital.  It also reduced (though not statistically significantly) the risk of anastomotic dehiscence (the breakdown of the site where bowel was sewn together), wound infection, pneumonia, intra-abdominal abscesses, and mortality. The down-side of early post-operative feeding is that the patients have an increased risk of vomiting [2].

But is there a way to get the benefits of early feeding without the risk of vomiting? Is there a cheap and easy way to increase the rate at which bowel function returns?  It appears the answer is yes, and it is incredibly cheap and easy: Gum.

Gum chewing works as a type of sham-feeding that promotes intestinal motility. It seems that chewing gum causes our brain to pass the signal to our stomach that food is on the way. In normal volunteers, gum chewing stimulates gastric secretions. In patients, gum chewing appears to wake the GI tract up more quickly than if their mouth stays idle [1].

A meta-analysis of 9 trials including 437 patients showed a reduction in time to first flatus (the medical term for fart), time to first bowel movement, and reduction in hospital stay in patients in treatment groups versus controls. The treatment groups chewed sugarless gum at least three times a day for 5-45 minutes starting on the first post-operative day [1]. While early post-operative feeding seems to offer a number of benefits in comparison to fasting, it can be poorly tolerated and only taken in small amounts. Chewing gum is a method of sham-feeding that stimulates bowel activity, without the possibility of vomiting or the limited intake of food seen in some patients.

I have heard surgeons at our University talk about the data regarding early-feeding. I have not heard anyone talk about the benefits of gum chewing.  The data is out there, but unlike pharmaceutical interventions which have drug-reps proclaiming their benefits, simple interventions such as these are not widely promoted.  Who would benefit from promoting this information?  Even if every hospital ward in the country started stocking gum, I doubt the gum-makers would notice an uptick in their bottom line- this isn’t exactly a high dollar intervention. In fact, the meta analysis suggests that chewing gum can reduce the length of hospital stay by a mean of approximately 2 days at the average cost of $0.60 per patient [1].

It is important to mention that many of the studies included in the meta-analysis were conducted in Africa, where the risk of complication and the subsequent length of stay are much higher than in the US.  While on my surgery rotation, I saw some patients go home less than 24 hours after having their appendix removed. One paper from 2006 shows that the mean hospital stay after appendectomy at a teaching hospital in South Africa was 10.6 days [3]. Indeed, much of the primary data that I read about surgery in the developing world leaves me cold.

Laparoscopic surgery (performed through small incisions in the abdomen and visualized with a small camera), means that simple procedures such as the removal of an appendix or gallbladder can be done with minimal trauma and scarring. In developing countries, these operations are still done with open incisions, in operating rooms that lack many of the most basic tools necessary for good surgical care.

Angela’s recent guest post has inspired me to think more about the great disparities in health, disease, and medical care in the developed and the developing world.  As I read more about surgery and medical care in Africa, I realize that even the simplest of interventions can have a huge impact on health care, especially in developing areas. This was also brought through in Atul Gawande’s book The Checklist Manifesto, which I read recently.

It is unrealistic to think that hospitals in developing nations will be equipped with cutting edge technology to perform minimally invasive surgery any time in the near future. Such technology is expensive, and it requires surgeons who have been trained to use it (not to mention reliable sources of electricity to power the equipment).  Yet simple solutions, such as post-operative gum chewing, can offer serious benefits that should not be ignored [4].  And if I find myself on the other side of an early morning post-op check-in, I know I’ll be requesting something to chew on*!

*It should go without saying that this post is not meant as specific medical advice, but as an exploration of a potentially useful therapy that doctors should consider. If you find yourself on the wrong side of the operating table, work with your medical team to get yourself on the road to recovery ASAP.


1.            Noble, E.J., R. Harris, K.B. Hosie, S. Thomas, and S.J. Lewis, Gum chewing reduces postoperative ileus? A systematic review and meta-analysis. Int J Surg, 2009. 7(2): p. 100-5.

2.            Lewis, S.J., M. Egger, P.A. Sylvester, and S. Thomas, Early enteral feeding versus “nil by mouth” after gastrointestinal surgery: systematic review and meta-analysis of controlled trials. BMJ, 2001. 323(7316): p. 773-6.

3.            Ayoade, B.A., O.A. Olawoye, B.A. Salami, and A.A. Banjo, Acute appendicitis in Olabisi Onabanjo University Teaching Hospital Sagamu, a three year review. Niger J Clin Pract, 2006. 9(1): p. 52-6.

4.            Ngowe, M.N., V.C. Eyenga, B.H. Kengne, J. Bahebeck, and A.M. Sosso, Chewing gum reduces postoperative ileus after open appendectomy. Acta Chir Belg, 2010. 110(2): p. 195-9.

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I’m on Pathology elective. This means that I get to see interesting “gross” specimens and I spend a lot of time sitting at a multi-headed microscope looking at slides with attending physicians, residents, and fellow med students. It also means that I have a bit of a breather.  I do have to give a presentation later this week (I’ve opted to talk briefly about pathology of the appendix because I am oh so fond of it!), but there is no exam at the end of the elective and the final grade is pass/fail. When I’m not in the hospital, I’m using this two week period to go to the gym, catch up on clinic visits, and refresh my social life. So far I’m doing well on all fronts!

If you haven’t caught on by now, I’m a bit of a nerd. Therefore it should come as no surprise that I’m a fan of things such as ‘The Rap Guide to Evolution’.


I was first introduced to Baba Brinkman’s work two years ago on the now (sadly) defunct Evolvify forum. Last year I saw that he was performing the Rap Guide to Evolution in NYC and couldn’t resist the train ride in to see the show.  When I heard he was back with a new show this winter I made plans to catch his new production: Ingenious Nature:

Everyone’s looking for love, or sex, occasionally even both. Evolutionary psychology claims to explain why, and how this state of affairs came about. But can it help us find the right one? A young man decides to take the “science of mating” seriously in his quest for a happy ending. Will the theory work in practice? It turns out, ovulation studies can make for awkward first date conversation.

I should admit that my first foray into internet shenanigans (by which I mean getting somewhat involved in the paleosphere) came not because of diet, but because I wanted to talk about evolutionary psychology on the previously mentioned Evolvify forum. There I found bright minds that not only embraced an evolutionary appropriate approach to diet, but who also liked thinking about why humans act the way we do- especially when it comes to sex and behavior (no neck down Darwinists there).  Curious for more? Read this as an example. (Or I highly recommend the book The Mating Mind.)

So anyway- Ingenious Nature!

After a delicious dinner at Takashi, a Yakiniku restaurant with a mind-expanding menu  (Thanks Melissa McEwan for the recommendation!), my friend and I headed over to Soho Playhouse to catch the show.  I’ve been a fan of Baba Brinkman since the first time I saw one of his videos (maybe it was his “[Darwin-] Very gradual change we can believe in” T-shirt), and this show certainly didn’t disappoint. It was interactive, witty, smart, and entertaining, and that was before he even started rapping.

It appears Baba is a generous man, as you can listen to all his tracks in one place online for free (though donations are of course appreciated).  I highly recommend you go take a listen to his work. The tracks are fun, and the information is backed up by scientific principles and peer-reviewed research. Heck, he even has some of the heavy hitters in the field weighing in on his tracks (at the end of the show there was a message from Steven Pinker, though that track doesn’t appear to be available online*).  Here’s a personal favorite: She’s Ovulating (and yes, lap dancers do make more money while ovulating and men find the scent of fertile women more alluring).

The show is a complete package, with an amusing story line interwoven with raps and sketches that bring scientific theories and data to life. If you have a sense of humor and are interest in the mating game (~99% of humans I suspect!), I expect you will enjoy this show.  If you’re someone with a long-standing interest in evolutionary psychology, you’ll recognize that Brinkman is very knowledgeable on the subject. Even the most well-read evolutionary psychologist will get something out of this show- even if it’s just some laughs and a refreshing new way to look at the data.

Speaking of data… The show is interactive. At times you can use your phone to text responses that are compiled into graphs as the show goes on- it’s kind of fun, though I didn’t always have time to get my answer in before the next question came up. It would be interesting to know if he gets any reliable trends with some of his questions!

Brinkman is accompanied by Jamie (Mr. Simmonds) on the turntables. I’ll admit that I’m ignorant about DJing and remixing, but whatever they’re doing is working. The final package is fantastic.  If you’re in the New York area and can get in to see his show, I highly recommend it. Actually, I’ve heard enough first-date horror stories in the last few days to think I should be giving away tickets as Christmas presents!

OK, if you haven’t already listened to “She’s Ovulating”, do it now!

I love this. You can read the story here. Profits from sales go to NCSE.

I love this. You can read the story here. Profits from sales go to NCSE.

It looks like you can get tickets half price here. Also- if you’re interested in the mating game, cruise around some of the older posts on Evolvify or check out this awesome old blog with conclusions drawn from online dating profiles. There are also LOTS of good books, papers, and blogs exploring evolutionary psychology, a fascinating field.

* UPDATE! You can hear the messages from the Peer-Reviewed panel here.

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