Characteristics of Postoperative Ileus

NOVEMBER 28, 2017
MD Magazine Staff

Raoul Concepcion, MD: So far, we’ve had a really nice global discussion about where we’ve come from. To me, without knowing the historical perspective of what we’ve done in the past, you really can’t appreciate where you need to go. As we evolve, I think it’s important to consider standardization—everybody, again, practicing evidence-based medicine. Hopefully, our outcomes and our metrics will be improved. Because, again, we know that as we talk about metrics, depending upon who you’re talking to, the metrics change. If you’re talking to an insurance company, it’s about how much money they’re putting out. If you’re talking to a surgical oncologist looking at the cancer standpoint, you’re looking at surgical margins, disease-free. When you’re talking to patients, it’s, “Hey, did I get back to work earlier?” “What was my quality of life?” And so, again, I think it’s important to incorporate that into all of the programs that we do—financial, outcomes based upon length-of-stay, outcomes based upon surgical margins, and those types of things. But, clearly, what we don’t do a good enough job of doing, and you had mentioned it, is addressing quality of life issues.

Clearly, one of the biggest complications that we see before ERAS (enhanced recovery after surgery), and especially with gastrointestinal surgery, is postoperative ileus. Traci, what is your impression of postoperative ileus? We know it’s a huge financial burden. I think the last data that I saw are over $1 billion is spent annually managing postoperative ileus, due to lengthening of stay and readmission rates. What is your overview of how you look at it, the characterization? Also, can you talk a little bit about the pathophysiology of postoperative ileus?

Traci Hedrick, MD, MS, FACS, FACRS: Sure. Ileus is a word that actually goes back to antiquity. It was originally used to describe what we now know as the modern-day volvulus. But in the 19th century, it really started to be associated with what is termed as a “functional obstruction.” There’s no mechanical kink to the bowel, but it just is not functioning properly. It used to be felt that that was an absolute unavoidable consequence of surgery. It was mainly related to the trauma of manipulation of the bowel. And what we now know is that while that is important, there is certainly many other factors that go into it, namely the administration of opioids.

And so, if you look at the literature, it can be a bit confusing because there are several different terms. There’s postoperative ileus, pathologic ileus, prolonged ileus. It can be defined differently, so the incidence will vary throughout the literature. There are those patients who get a little queasy on the first or second postoperative day. They may get a little burpy, or they may get bloated, but it quickly goes away. What most of us think as an ileus is those patients who develop complete intolerance of gastrointestinal function. They get very bloated, often times require an NG (nasogastric) tube, and that incidence is anywhere, on average, from 15% to 20% of patients. And while enhanced recovery certainly has reduced that, it’s important to know that it hasn’t completely eliminated it. So, it’s something that we all still need to be very familiar with knowing how to treat and prevent.

Raoul Concepcion, MD: And the thing about it is, you see it across every surgical subspecialty, right?

John Dalton, MD: Even if we’re not in the belly, we see it.

Traci Hedrick, MD, MS, FACS, FACRS: Yes. Spine surgery, particularly.

Raoul Concepcion, MD: When we look at postoperative ileus, again, one of the major contributing factors is obviously opioids. Declan, you had mentioned earlier, in one of the prior segments, about some of the localized inflammatory effects that go along with it. You casually dropped in a whole concept there—carbohydrate loading. Tell us a little bit about, again, how that plays a role, the carbohydrate loading?

Declan Fleming, MD: There are 2 components to that. There’s a sort of fed versus fasted state component. So, it’s a metabolic component. And then, there’s also a dehydration component. When we give a bowel prep of some sort, on whatever side of that you stand with your various operations, most people will come in not having had the absolute normal amount of eating and drinking up to the time of the surgery. And so, this carbohydrate load is a volume of fluid with, preferably, a complex, not a simple, carbohydrate. This is given to mitigate that dehydration and that low carbohydrate level in the bloodstream that alters body physiology and allows people to better tolerate the surgery, to diminish some of the metabolic response to surgery, and also to put a person at a more right fluid balance during the operation, which helps to hopefully diminish the need of intravenous fluid.

John, you’ll be able to speak to this better than I could, but we’ve always said that 2-thirds or 3-quarters of the amount of intravenous fluid that’s administered intraoperatively is not going to stay in the intravascular space. If that’s going out into something, part of what that’s going out into is the gut. That’s going to cause gut edema. And that is in addition to local neurotransmitters and neural stimulation, and the stimulation of the opioid receptors on the gut. I think edema plays a really significant role in the development of postoperative ileus.

Transcript edited for clarity.

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