Strategies in Mitigating Postoperative Ileus
NOVEMBER 30, 2017
MD Magazine Staff
Raoul Concepcion, MD: The traditional program that we used for urology was full blown bowel prep, antibiotic prep, nothing past midnight. I’m assuming that’s all by the wayside now?
Sanjay Patel, MD: Yes. There’s still a lot of places that do that, and it took us a while to kind of step away from that dogma. But with bowel prep, there’s evidence that shows that it’s not really beneficial. Having patients take clear liquids up to 2 hours until the time of surgery and carbohydrate loading are all part of the pathway. I think that those are things that used to be dogma. They’re pretty well studied now, and they show that those things are beneficial.
From a urologic standpoint, with ileus, we do a lot of these urinary diversions. Often, we will have urine and all of this stuff mixing in the abdomen. Certainly, an inflammatory mediator can contribute to that. But also, we have electrolyte abnormalities. You’re now taking urine and you’re putting in something that absorbs nutrients. And so, we often, in urology, see a lot of these fluid shifts. We try to pay attention to it. We also see electrolyte shifts. There’s always a characteristic classic hypochloremic, hypokalemic metabolic acidosis, that occurs with the urinary diversion. So, certainly, all of those things play into the whole ileus picture and certainly contribute to it.
Raoul Concepcion, MD: John, what about anesthetic agents used intraoperatively? Are there some that have a more deleterious effect on the gastrointestinal tract than others, especially gastric motility and those types of things?
John Dalton, MD: Well, clearly, and Traci brought it up earlier, we’ve talked about narcotics. If we don’t use narcotics, we contribute greatly to preventing this problem. As far as the other anesthetic agents, I don’t think there’s a contribution that I know of. But fluid management is a big thing. The buzz word is “goal-directed fluid therapy.” When we were doing bowel preps and preparing patients like you described a number of years ago, we would have a patient in the operating room who was fluid deficit. They were dehydrated, and we would have to give them a lot of fluid just to basically resuscitate them during the early part of the procedure. For cystectomies or radical prostatectomies, we’d give 7 liters, 8 liters of crystalloid during a procedure. Now, with goal-directed fluid therapy, following noninvasive ways to measure stroke volume or its effect, we can get volume with crystalloid down to 1300 ccs, or less, in some of our surgeries. That addresses the concern that Declan was talking about, the edema of the bowel. If we can decrease that, I think we decrease the ileus and function of the bowel.
Traci Hedrick, MD, MS, FACS, FACRS: I just want to make one point. I look at bowel prep a lot, and the literature is confusing to look at. But when you look at the literature that shows it’s not effective, there is evidence of its use for a hyperosmotic bowel prep, like Fleets Phospho-Soda, and also in the absence of oral antibiotics, which is what they primarily do in Europe. When you look at the data where they’re using an iso-osmotic bowel prep like a PEG [polyethylene glycol] solution in the combination of oral antibiotics, it actually has been shown to reduce the incidence of ileus and surgical site infection. That is in colorectal surgery.
Declan Fleming, MD: In colorectal, yes.
Traci Hedrick, MD, MS, FACS, FACRS: Now, in urology, where you’re doing primarily small bowel anastomoses, I don’t think that it has quite the same effect. But in our enhanced recovery program, we do bowel preps on all patients. Because it’s iso-osmotic, they don’t get dehydrated. They get an average of 1100 cc’s of intravenous fluids a case, and that’s even for open surgery. I think that there’s still some question about the equivalence of that, but I just wanted it to be shown that you still can do enhanced recovery in the setting of a bowel prep.
Raoul Concepcion, MD: John, you talked about goal-directed fluid management. Can you expand on that a little bit? How is that calculated? Obviously, different surgical procedures, again, are sort of ...
John Dalton, MD: Well, it’s a $25 phrase for a fairly simple concept. We’re just trying to keep vascular volume euvolemic as defined by the effect of stroke volume. We can give fluid challenges if we don’t have fancy equipment. And, if the pressure comes up or the fluid challenge, maybe you’re a little behind. If it doesn’t come up, then it’s probably something else. Maybe you’re euvolemic. There are monitors where we can measure volume, or its variation, noninvasively. Those are being used a lot in the ERAS [enhanced recovery after surgery] program. Those are very useful. It gives the providers a little more comfort, maybe, in limiting fluids to an enormous extent based on what we used to do. I was trained to give a lot of fluid, say 7 liters, 8 liters, 10 liters of fluid for a prostatectomy. Now, we’re giving, as Traci said, a fraction of that.
Declan Fleming, MD: In our hospital, working with our anesthesiologist, as we began to use, at first, the intra-arterial monitor, and also, now, some noninvasive monitors, looking at stroke volume variation and using that as the guide, it dramatically diminished the amount of fluids our anesthesiologists were giving, even for large cases. And the interesting side effect of that was it began to cause those anesthesiologists to rethink their whole paradigm around fluid administration. And so, we’ve now routinely seen less fluid administration across the board. We’ve become more comfortable with it as a group, surgeons and anesthesiologists, together.
John Dalton, MD: And to expand on that just a little bit, I appreciated Traci’s comments about isotonic bowel preps. But if you’re using the hyperosmotic bowel prep and they’re NPO (nil per os) for 8 hours, you can’t do goal-directed fluid therapy. You’ve got to resuscitate them when they get to the operating room. On the other hand, if, by protocol, we’re doing all this and we’re collaborating well, we can dramatically limit the amount of fluid they get in the operating room. There is a physiologic difference in how you handle fluids when you’re awake versus when you’re under general anesthesia, and that’s what we see with this. You can get a lot of fluids preoperatively. You’ll handle things a lot differently. You’ll create a lot less edema than you will if I give you 5 liters while you’re under general anesthesia.
Declan Fleming, MD: I think that’s a great point. It is important to remember that the relatively small-volume carbohydrate load that you get is a small volume of fluid. You’re not going to make up for hours and hours of dehydration by taking a drink of the carbohydrate load immediately before the surgery, a couple hours before the surgery.
Transcript edited for clarity.