Guidelines Summary
The World Society of Emergency Surgery (WSES) released guidelines in May 2017 on the management of intra-abdominal infections. [34] Strong recommendations are summarized below.
Evaluation
The term “intra-abdominal infections” (IAIs) describes a wide heterogeneity of clinical conditions. The anatomical extent of infection, the presumed pathogens involved, risk factors for major resistance patterns, and the patient's clinical condition should be assessed independently so as to classify patients.
Early clinical evaluation is essential for diagnosing IAIs. It helps to optimize diagnostic testing and can result in earlier implementation of a proper management plan. A step-up approach for diagnosis should be used and tailored to the clinical setting, resources, and patient’s age beginning with clinical and laboratory examination and progressing to imaging examinations.
Management
Source control
Highly selected patients with perforated diverticulitis (including those with an abscess < 4 cm in diameter), a peri-appendiceal mass, or a perforated peptic ulcer can be managed without definitive source control if they are responding satisfactorily to antimicrobial therapy and other supportive measures.
Laparoscopic appendectomy represents the first choice for most patients with acute appendicitis where appropriate resources and skills are available. There is no evidence of any significant advantages between laparoscopic and open repair of perforated peptic ulcer (PPU). However, laparoscopy has less postoperative pain and shorter hospital stay.
Early laparoscopic cholecystectomy is safe and feasible in acute cholecystitis and should be the preferred choice in absence of contraindications to pneumoperitoneum, even in high risk patients, where appropriate resources and skills are available.
Laparoscopic lavage is not recommended in Hinchey IV diverticulitis because it can not achieve adequate source control. Laparoscopic lavage is safe and not inferior to sigmoid resection in case of Hinchey III but it is not considered the preferred choice, given the lack of evidence of major benefits.
Planned relaparotomy is not recommended as a general strategy in patients with secondary peritonitis. There is insufficient evidence to advocate damage control surgery as general strategy in patients with secondary peritonitis.
Temporary abdominal closure using negative pressure therapy (NPT) can be useful to decrease the time to definitive abdominal closure. Prolonged NPT may increase the risk of enteric fistulae.
Antimicrobial therapy
Intraperitoneal specimens for microbiological evaluation from the site of infection are always recommended for patients with hospital-acquired (HA)-IAIs or with community-acquired (CA)-IAIs at risk for resistant pathogens (previous antimicrobial therapy) and in critically ill patients. Intraperitoneal specimens should be collected in every re-operation. Appropriate intraperitoneal specimen is peritoneal fluid/tissue collected from the site of infection.
Sufficient abdominal fluid/tissue volume (usually at least 1-2 mL of fluid) should be collected and transported to the microbiology laboratory using a transport system that properly handles and preserves the samples to avoid damage or compromise their integrity.
At the laboratory the intraperitoneal specimen should undergo Gram stain, aerobic and anaerobic culture, and antibiotic susceptibility testing.
Antimicrobial therapy
Empirical antimicrobial therapy should be based on local epidemiology, individual patient risk factors for difficult to treat pathogens, clinical severity of infection, and infection source. The patient should be reassessed when the results of microbiological testing are available. Antimicrobial de-escalation or withdrawal should be considered.
In the settings with a high incidence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, the extended use of cephalosporins should be discouraged and should be limited to pathogen-directed therapy because of its selective pressure resulting in emergence of resistance. Extended use of fluoroquinolones (FQ) should be discouraged because of its selective pressure (mainly ESBLs producing Entrobacteriaceae and methicillin-resistant Staphylococcus aureus [MRSA]). They should be generally used in patients with allergy to beta-lactams.
For patients with CA-IAIs, agents with a narrower spectrum of activity should be suggested. However, according to local ecology anti-ESBL-producer coverage may be warranted. By contrast, for patients with HA-IAIs, antimicrobial regimens with broader spectra of activity are preferred.
Carbapenem sparing treatment should be recommended particularly in the settings where there is a high incidence of carbapenem resistant Klebsiella pneumoniae.
Antimicrobial resistance among enterococcal isolates (ampicillin, gentamcin or vancomycin resistance) is mostly found in nosocomial (postoperative or tertiary) peritonitis. In vancomycin-resistant Enterococcus (VRE), treatment with linezolid (monomicrobial infection) or tigecycline (polymicrobial infection) is appropriate.
The presence of Candida spp. in the peritoneal samples is a factor of poor prognosis.
In the setting of uncomplicated acute cholecystitis and acute appendicitis post-operative antimicrobial therapy is not necessary.
In patients with IAIs, when patients are not severely ill and when source control is complete, a short course (3–5 days) of post-operative therapy is suggested.
In patients with ongoing or persistent IAIs, the decision to continue, revise, or stop antimicrobial therapy should be made on the basis of clinician judgment and laboratory information.
Multifaceted interventions are more likely to improve antibiotic prescribing practices than simple, passive interventions. Didactic educational programs alone are generally ineffective.
As a single intervention, implementation of locally adapted, interdisciplinary evidence based guidelines that incorporate risk stratification (severity and CA-IAIs versus HA-IAIs) and local resistance data most consistently improves components of antibiotic prescribing for IAI.
Critically ill patients
The lack of source control and antibiotic adequacy are the only modifiable risk factors for mortality in patients with complicated IAIs admitted to the intensive care unit (ICU). Organ dysfunction is associated with worse outcomes.
If the patient is critically ill the treatment duration can be deferred until after a multi-disciplinary careful evaluation.
Principal determinants of antibiotic choice in critically ill patients are based on three parameters: 1) severity of illness, 2) local ecology, and 3) risk factors of the host. Previous antibiotic use is associated with a higher development of multidrug resistant organisms (MDROs). Broad-spectrum antibiotic therapy, including combination of different antibiotic classes should be recommended in patients with septic shock, settings with high rates of MDRO, and previous antibiotic administration.
Early identification of sepsis and prompt administration of intravenous fluids and vasopressors are always mandatory. Restoring a mean systemic arterial pressure of 65 to 70 mm Hg is a good initial goal during the hemodynamic support of patients with sepsis.
Fluid overload should be avoided in patients with generalized peritonitis.
Consideration should be given to draining ascites in the critically ill patient treated for peritonitis, especially if the ascites is associated with intra-abdominal hypertension (IAH).
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Peritonitis and abdominal sepsis. Diagnostic and therapeutic approach to peritonitis and peritoneal abscess.
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Peritonitis and abdominal sepsis. A 48-year-old man underwent suprapubic laparotomy, right hemicolectomy, and gastroduodenal resection for right colon cancer invading the first portion of the duodenum. After surgery, the patient developed abdominal pain and distention. Computed tomography (CT) scanning was used to confirm an anastomotic dehiscence. Figure A shows a contrast-enhanced scan of the abdomen and pelvis that reveals multiple fluid collections, perihepatic ascites, and mild periportal edema. A collection of fluid containing an air-fluid level is visible anterior to the left lobe of the liver. A second collection is anterior to the splenic flexure of the colon. In figure B, a third fluid collection is present in the inferior aspect of the lesser space and in the transverse mesocolon. Figure C shows the pelvis with a collection of free fluid in the rectovesical pouch.
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Peritonitis and abdominal sepsis. A 78-year-old man was admitted with a history of prior surgery for small bowel obstruction and worsening abdominal pain, distended abdomen, nausea, and obstipation. In figure A, a marked amount of portal venous gas within the liver, mesenteric venous gas, and pneumatosis intestinalis are consistent with ischemic small intestine. The superior mesenteric artery appears patent. The liver has a nodular contour consistent with cirrhosis. In figures B and C, markedly distended loops of small intestine containing fluid and air-fluid levels are consistent with a small bowel obstruction. No focal fluid collections are identified.
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Peritonitis and abdominal sepsis. A 35-year-old man with a history of Crohn disease presented with pain and swelling in the right abdomen. In figure A, a thickened loop of terminal ileum is evident adherent to the right anterior abdominal wall. In figure B, the right anterior abdominal wall is markedly thickened and edematous, with adjacent inflamed terminal ileum. In figure C, a right lower quadrant abdominal wall abscess and enteric fistula are observed and confirmed by the presence of enteral contrast in the abdominal wall.
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Peritonitis and abdominal sepsis. Gram-negative Escherichia coli.
Tables
Source Regions |
Causes |
Esophagus |
Boerhaave syndrome Malignancy Trauma (mostly penetrating) Iatrogenic* |
Stomach |
Peptic ulcer perforation Malignancy (eg, adenocarcinoma, lymphoma, gastrointestinal stromal tumor) Trauma (mostly penetrating) Iatrogenic* |
Duodenum |
Peptic ulcer perforation Trauma (blunt and penetrating) Iatrogenic* |
Biliary tract |
Cholecystitis Stone perforation from gallbladder (ie, gallstone ileus) or common duct Malignancy Choledochal cyst (rare) Trauma (mostly penetrating) Iatrogenic* |
Pancreas |
Pancreatitis (eg, alcohol, drugs, gallstones) Trauma (blunt and penetrating) Iatrogenic* |
Small bowel |
Ischemic bowel Incarcerated hernia (internal and external) Closed loop obstruction Crohn disease Malignancy (rare) Meckel diverticulum Trauma (mostly penetrating) |
Large bowel and appendix |
Ischemic bowel Diverticulitis Malignancy Ulcerative colitis and Crohn disease Appendicitis Colonic volvulus Trauma (mostly penetrating) Iatrogenic |
Uterus, salpinx, and ovaries |
Pelvic inflammatory disease (eg, salpingo-oophoritis, tubo-ovarian abscess, ovarian cyst) Malignancy (rare) Trauma (uncommon) |
*Iatrogenic trauma to the upper GI tract, including the pancreas and biliary tract and colon, often results from endoscopic procedures; anastomotic dehiscence and inadvertent bowel injury (eg, mechanical, thermal) are common causes of leak in the postoperative period. |
|
Type |
Organism |
Percentage |
Aerobic |
|
|
Gram negative |
Escherichia coli |
60% |
|
Enterobacter/Klebsiella |
26% |
|
Proteus |
22% |
|
Pseudomonas |
8% |
Gram positive |
Streptococci |
28% |
|
Enterococci |
17% |
|
Staphylococci |
7% |
Anaerobic |
Bacteroides |
72% |
|
Eubacteria |
24% |
|
Clostridia |
17% |
|
Peptostreptococci |
14% |
|
Peptococci |
11% |
Fungi |
Candida |
2% |
Peritonitis (Type) |
Etiologic Organisms |
Antibiotic Therapy (Suggested) |
|
Class |
Type of Organism |
||
Primary |
Gram-negative |
E coli (40%) K pneumoniae (7%) Pseudomonas species (5%) Proteus species (5%) Streptococcus species (15%) Staphylococcus species (3%) Anaerobic species (< 5%) |
Third-generation cephalosporin |
Secondary |
Gram-negative |
E coli Enterobacter species Klebsiella species Proteus species |
Second-generation cephalosporin Third-generation cephalosporin Penicillins with anaerobic activity Quinolones with anaerobic activity Quinolone and metronidazole Aminoglycoside and metronidazole |
Gram-positive |
Streptococcus species Enterococcus species |
||
Anaerobic |
Bacteroides fragilis Other Bacteroides species Eubacterium species Clostridium species Anaerobic Streptococcus species |
||
Tertiary |
Gram-negative |
Enterobacter species Pseudomonas species Enterococcus species |
Second-generation cephalosporin Third-generation cephalosporin Penicillins with anaerobic activity Quinolones with anaerobic activity Quinolone and metronidazole Aminoglycoside and metronidazole Carbapenems Triazoles or amphotericin (considered in fungal etiology) (Alter therapy based on culture results.) |
Gram-positive |
Staphylococcus species |
||
Fungal |
Candida species |
||
Routine |
Optional |
Unusual |
Less Helpful |
Cell count |
Obtain culture in blood culture (BC) bottles. |
Tuberculosis (TB) smear and culture |
pH |
Albumin |
Glucose |
Cytology |
Lactate |
Total protein |
Lactate dehydrogenase (LDH) |
Triglyceride |
Cholesterol |
|
Amylase |
Bilirubin |
Fibronectin |
|
Gram stain |
|
Alpha 1-antitrypsin |
|
|
|
Glycosaminoglycans |
