Friday, January 25, 2013

Choosing antibiotics for appendectomy and cholecystectomy: Are "big guns" needed?

An emergency medicine physician asked me to comment on the use of antibiotics in patients having surgery for acute appendicitis and acute cholecystitis. He said in hospitals where he has worked in three different areas—New York, Miami and San Francisco—surgeons are using Imipenem for cholecystitis and Zoysn for appendicitis.

He wondered why those drugs were chosen and offered a few theories. They are as follows:

1) Surgeons are trying to avoid resistant bugs, so they’re using bigger guns
2) There is more pressure to reduce post-op complication numbers, so they’re using bigger guns
3) It’s easier to give one antibiotic to cover multiple bacterial types, instead of, say, cipro/flagyl or cefoxitin/flagyl
4) Patients do better with these big gun antibiotics
5) Residents are being taught incorrectly, and are just developing bad habits

Yes, it is mandated that everyone needs a dose of prophylactic antibiotics within an hour of surgery for appendicitis and cholecystitis. Of course, there are nuances.
Appendicitis is a disease involving an inflamed, eventually infected appendix so the use of antibiotics is possibly therapeutic and not simply prophylactic.
For acute cholecystitis, a similar argument can be made. The problem here is that it is often difficult to tell acute cholecystitis (with possibly infected bile) from biliary colic (pain caused by a gallstone impacted in the neck of the GB) without infection. Sometimes the GB ultrasound says acute cholecystitis, the surgeon says acute cholecystitis and the path report says chronic cholecystitis. There are many other permutations of those three observations. (e.g., US-biliary colic, surgeon-biliary colic, path-acute cholecystitis, etc.)
Note: I do not routinely culture peritoneal fluid in appendicitis or bile in cholecystitis because by the time the culture report comes back, most patients have been home for two or three days. There is evidence to support not culturing either fluid.
Honestly, I’m not so sure that people with early acute appendicitis really need antibiotics. Unless the appendix is perforated, I use only one preop dose. There are also similar differences in the imaging reports, surgeon description and path reports for this disease too.

I doubt that patients with biliary colic benefit from antibiotics either. The problem is that one may not discover that acute cholecystitis is present until one is in the abdomen. The same issue occurs with appendicitis where an unsuspected perforation may be found at surgery.

At least for now, at least one pre-op dose of an appropriate antibiotic seems reasonable.
Where I practiced for the last few years, we did not use Imipenem for GBs and only occasionally is Zosyn used for appys. Most of us used Unasyn for both except in the penicillin-allergic patient. For that patient, we used Levaquin and Flagyl. The problem with the latter two drugs is that they each are supposed to be infused over an hour. This is not always possible because the surgery may be started within an hour in certain circumstances, such as when an operating room happens to be vacant and the patient is ready to go. It’s a rare event, but it does happen.
There is no evidence that patients with either disease, who usually present from home, have resistant bacteria, and postoperative complications, especially infections, are not common with either disease. There is no evidence that patients do better with “big gun” antibiotics. In fact, most of the evidence that prophylactic antibiotics are even needed in these two operations comes from the pre-laparoscopic era. Wound infections are extremely uncommon with laparoscopic appendectomies and cholecystectomies. This is probably due to the fact that the wounds are small and in most cases, the specimen is removed in a plastic bag so the infected organ does not touch the subcutaneous tissue.
If residents are being taught to use “big gun” antibiotics for these two diseases, I agree it’s incorrect. There is little hope of changing this.

It is similar to the unfounded practice of giving everyone who is NPO a proton pump inhibitor, which I wrote about here. There is no scientific rationale for it. Yet everyone does it, and no amount of discussion will convince people to stop.

[Note: A version of this post appeared on General Surgery News a few weeks ago. The version above is better because I thought about it more.]


artiger said...

Scalpel, good stuff here (as usual). I use a single preop dose of Mefoxin, and if something particulary nasty pops up, will go with Invanz postop (Flagyl/Cipro or Levaquin if need be). If it's a hernia or something along those lines, Ancef preop seems to work just fine.

I was trained in the 1990's, when we were still having reps feed us not just lunch but often a line of bull. I admit to some bias, but I almost welcome the powers that be looking at my costs for any given patient. We could all do a little more with regard to some accounting as far as how much is spent on a patient's care.

Skeptical Scalpel said...

Thanks for reading my blog. Your choices are fine. I agree we need to keep costs down. That's another reason not to use "big guns" for simple problems.

RuggerMD said...

simple appy- one pre-op dose of abx and no more. Cefepime or anything for G+ and G-.
perforated or gangrenous appy. Same and add anaerobic coverage (flagyl) or just use a big gun, cefoxitin or zosyn, etc. and treat until normal WBC, no fevers, and return of bowel function to decrease incidence of post op infections/abscess
I wrote a good paper on treating secondary peritonitis in this.

For chole any preop gram + and - coverage. I like levaquin, and no more abxs unless gangrenous or infected like above.

Really you should do this for most surgical management.
In other words, if its popped or dead, then treat post op with abxs until secondary peritonitis resolved, and if it doesn't look for infection.

Skeptical Scalpel said...

I agree with most of what you said except I don't consider cefoxitin a "big gun." And I don't know where treat until the WBC is normal comes from. Is that evidence-based?

Thanks for the link.

RuggerMD said...

No, more common sense based, so to say.
In other words, if your patient has a perforated or gangrenous appy (or anything else) they are at risk for post op infectious complications, ie. wound infection or intraabdominal abscess formation (for appy, but I think it applies to other surgical problems).
In our study it was 33% for just a perf or gangrenous appy. That is why some leave the skin open or treat longer with abxs.
Not every surgeon treated the same.
In any case, being the WBC is in indicator of inflammation (or infection), our thoughts were if you are developing an intrabdominal abscess you may have fevers, ileus (return of bowel function), or elevated WBC. So these were all used as markers for developing infection inside the belly. So we would treat those at risk w/ abxs post op until these criteria were met, then stop abxs. If not met, then we would continue abxs and on POD 5-7 look for an abscess.
We brought our infectious complications down significantly.
I still use this with everyone that I feel is at risk for post-op infections, ie., the organ we are treating perforated or died, and bacteria got into the belly.
IMHO, its a good rule to follow, as we should be treating secondary peritonitis, so to say.

Skeptical Scalpel said...

If it works for you, stay with it. Do you draw a CBC every day and obviously you must keep the patient in the hospital until the WBC is normal?

I've seen many patients with no fever and a normal WBC come back with abscesses. I honestly don't think you can prevent all of those abscesses with abx.

Jeffrey Parks MD FACS said...

I like zosyn for any/all appendicitis. If garden variety suppuratuve appy, I just give 24 hrs coverage (don't we do this for elective colon surgery?). Perfed ones I keep on zosyn until WBC trends down, clinically look well. For gallbladders we overuse abx. My preference is one preop dose unless in cases of obvious cholecystitis. The problem is that ER has already started a bag of zosyn/unasyn, even for symptomatic biliary colic, before i even get a call.

Skeptical Scalpel said...

Is the pseudomonas coverage of Zosyn worth the extra cost? Zosyn is about $30/dose and Unasyn is under $10/dose. I agree with the comments about GBs.

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