Moshe Schein
No amount of postoperative antibiotics can compensate for intra-operative mishaps and faulty technique, or can abort postoperative suppuration necessitating drainage.
The Issue
Perhaps an issue as apparently banal as postoperative antibiotics does not deserve a separate chapter. Already in > Chap. 7 you read about pre-operative anti- biotics,and in > Chap.12 you were introduced to the concepts of contamination and infection and their therapeutic implications.Why not just administer postoperative antibiotics routinely for any emergency abdominal operation until the “patient is well”? In fact, this is a common practice in the surgical community in this country and around the world – patients receive postoperative antibiotics for many days, many of them are even discharged home on oral agents “just in case”.What is wrong with this approach? Our aim is to convince you that indiscriminate postopera- tive antimicrobial administration is wrong and to provide guidelines in order to approach this issue in a more rational way.
For a long time the topic of duration of administration has been easily dismissed by the “official” literature, with the common laconic recommendation that antibiotics should be continued until all signs of infection, including fever, leukocytosis, and even ileus subside, and the patient is “clinically well”. No evi- dence existed, however, to prove that indeed the continuation of antibiotics along these lines could abort an infection-in-evolution, or cure an existing one
(> Fig. 42.1).
During the last decade, we learned that fever and white cell response are part of the patient’s inflammatory response to a variety of infective and non-infective causes.We realized that sterile inflammation is common after any operation, mani- festing itself as a local inflammatory response syndrome (LIRS), or a systemic one (SIRS) (> Chap. 48). Is there a need to administer antibiotics after the bacteria are already dead?
The evolving policy of minimal antibiotic administration (strongly suppor- ted by the Surgical Infection Society – see Mazuski et al. 2002)1represents a trend away from the use of postoperative therapeutic courses of “fixed” and often long duration;rather, you should attempt to stratify the infective processes into grades of risks, and to tailor the duration of administration to the severity of infection.
Duration of Postoperative Administration
We recommend the policy summarized in > Table 42.1. It is based on the following arguments:
Conditions representing contaminationdo not require postoperative admin- istration since the infectious source has been dealt with at operation; bacteria and adjuvants of infection are effectively removed by the host’s defenses, supplemented by peritoneal toilet, and adequate tissue levels of pre- and intra-operative prophy- lactic antibiotics.By definition, prophylaxis should not be continued beyond the immediate operative phase.
In processes limited to an organ amenable to excision (“resectable infection”), the residual bacterial inoculum is low. A postoperative antimicrobial course of
Fig. 42.1. “This will cure your fever…”
1Mazuski JE, Sawyer RG, Nathens AB et al. (2002) The Surgical Infection Society Guidelines on antimicrobial therapy for intra-abdominal infections. Surg Infect 3:161–173.
24 hours should suffice to sterilize the surrounding inflammatory reaction and deal with gut bacteria, which may have escaped across the necrotic bowel wall by translocation.
“Non-resectable infections” with a significant spread beyond the confines of the involved organ should be stratified according to their severity. A therapeutic postoperative course of more than 5 days is usually not necessary. However, certain complex situations may need extended courses of postoperative antibiotics. A typ- ical example is infected pancreatic necrosis where the nidus of infection is not readily eradicated in a once-and-for-all surgical procedure. Similarly, patients with postoperative peritonitis, where the control of the source of infection is question- able, should be considered for prolonged antibiotic therapy.
It should be quite clear that the commonplace, blind, extended antibiotic administration, for as long as fever or leukocytosis are present, should be abandon- ed. Pyrexia and white cell response represent usually a sterile, peritoneal (LIRS) Table 42.1. Duration of postoperative antibiotic therapy
Contamination: no postoperative antibiotics
Gastroduodenal peptic perforations operated within 12 hours Traumatic enteric perforations operated with 12 hours
Peritoneal contamination with bowel contents during elective or emergency procedures
Appendectomy for early or phlegmonous appendicitis Cholecystectomy for early or phlegmonous cholecystitis
Resectable Infection: 24-hour postoperative antibiotic course Appendectomy for gangrenous appendicitis
Cholecystectomy for gangrenous cholecystitis
Bowel resection for ischemic or strangulated necrotic bowel without frank perforation
“Mild” Infection: 48-hour postoperative antibiotic course
Intra-abdominal infection from diverse sources with localized pus formation
“Late” (more than 12 hours) traumatic bowel lacerations and gastroduodenal perforation with no established intra-abdominal infection
“Moderate” Infection: up to 5 days of postoperative antibiotics Diffuse, established intra-abdominal infection from any source
“Severe” Infection: more than 5 days of postoperative antibiotics Severe intra-abdominal infection with a source not easily controllable
(e.g. infected pancreatic necrosis) Postoperative intra-abdominal infection
or systemic (SIRS), cytokine-mediated, inflammatory response; admittedly, less commonly, they may indicate the presence of a focus of persistent or recurrent infection. The former situation is self-limiting and resolves without antibiotics.
The latter usually represents suppurative infection, which should be treated by drainage of the intra-abdominal abscess (> Chap. 43) or the infected wound
(> Chap. 48). Antibiotic treatment can neither prevent nor treat suppurative infec-
tion; it may only succeed in masking it.
By now you should understand that the persistence of inflammation beyond the appropriate therapeutic course is not an indication to continue, re-start or change antibiotics. What should be avoided is complacent reliance on the advice of the average infectious disease (ID) specialist; this can only lead to an expensive and often unnecessary diagnostic work-up and,even more alarmingly,to the prescribing of the latest antibiotic agent on the market (e.g., dinnericillin, lunchicillin). What should instead be done is, first, to stop the antibiotics. The fever will subside spon- taneously in most patients, within a day or two, with little more than chest physio- therapy. At the same time, a directed search is undertaken for a treatable source of intra- or extra-peritoneal infection. Surgeons are best placed to anticipate com- plications in their patients, and this is what is meant by a directed search: a search that is conducted with the full knowledge of the patient’s initial disease process, the operative findings and the natural history of the surgical disease; in brief, a corpus of information that usually eludes the ID specialist.
We have nothing personal against the so-called medical ID specialists – who, at least on this side of the Atlantic, are considered the gurus on antibiotic therapy. But we have reasons to believe that many of them do not understand the concept of “surgical” infection and how it differs from “medical” infections (see > Table 42.2).
Table 42.2. Differences between “medical” and “surgical” infections
Medical infection Surgical infection
(e.g. pneumonia) (e.g. appendicitis)
Not amenableto surgical source Amenableto surgical source
control control
Antibiotics mainstay Antibiotics only adjunct to source
of treatment control
A host of potential causative Predictable causative organisms organisms
Prolonged formal course Antibiotics tailored to operative
of antibiotics findings
So when was the last time the ID “expert” asked you about your operative findings? And by the way, in a questionnaire study we asked ID specialists whether they would recommend obtaining peritoneal cultures during operation for a “fresh”
penetrating wound of the colon; 100% said yes – as if we do not already know the bacterial composition of s***!
We hope that you realize that unnecessary antibiotics are wrong because anything unnecessary in medicine is bad medicine. In addition, the price to be paid is high, not only financially.Antibiotics are associated with patient-specific adverse effects (the list is long, think of the gravity of C. difficile colitis) and ecological repercussions such as drug-resistant nosocomial infections in your hospital.
Are you convinced?
Start antibiotics prior to any emergency laparotomy; whether to continue administration after the operation depends on your findings. Know the target flora and use the cheapest and simplest regimen. The bacteria cannot be confused, nor should you be.
