Objectives Review basic categories of intra-abdominal infection and their
respective treatments Community acquired intra-abdominal infection Mild/Moderate Severe
Acute biliary tract infections Nosocomial intra-abdominal infection
Consider other abdominal processes associated with antibiotic use
Spontaneous bacterial peritonitis Pancreatitis with and without necrosis Infectious diarrhea
Mention of prevention of surgical infections during colorectal surgery
Useful guidelines1. IDSA complicated intra-abdominal infection guideline1
2. IDSA infectious diarrhea guideline2
3. AASLD ascites guidelines3
4. ACG pancreatitis guideline4
5. IDSA SHEA surgical prophylaxis guideline5
6. ISPD peritoneal dialysis infection guideline6
7. AGA diverticulitis guidelines11,12
Intra-abdominal infection Enteric contents enter the peritoneal cavity leading to abscess or
peritonitis
Obtaining adequate early source control is the rule
Localized- Appendicitis, diverticulitis, cholecystitis with or without perforation Contained perforation without hemodynamic instability Carefully selected patients with appendiceal perforation OCCASIONALLY
treated medically without an open or percutaneous source control procedure Trend to non-operative management of perforated diverticulitis utilizing
percutaneous drainage only Trend to percutaneous transhepatic cholecystostomy (PTC) in severe
cholecystitis with delayed >72h duration of symptoms or unacceptable surgical risk32-33
Diffuse peritonitis- after perforation THESE PATIENTS ARE SICK AND NEED TO GO TO THE OR
“High risk” infection1
Treatment Mild-moderate severity: perforated appendicitis, diverticulitis,
intra-abdominal abscess. Cefazolin 1-2g iv q8h plus metronidazole 500mg iv q8h
If local cefazolin E. coli susceptibility <90% consider ceftriaxone 2g
High-risk severity: hemodynamic instability, advanced age, immune-compromised state (Table 1 on prior slide) Piperacillin/tazobactam 3.375g iv q8h over 4h, or
Cefepime 1g iv q6h plus metronidazole 500mg iv q8h
Healthcare-associated Use high-risk regimen
Can consider empiric addition of vancomycin but RARELY NEEDED
Metronidazole dosing T1/2 = 8h (similar to ceftriaxone)
Concentration dependent killing
Some institutions use q24h dosing when using IV 1g – 1.5g IV q24h in adults1,7
30 mg/kg/day IV q24h in children8
When given PO, nausea is limiting so q8h dosing more appropriate
Basic points Cultures not mandatory for mild-moderate infections
Do not use ampicillin/sulbactam, clindamycin, aminoglycosides, or cephamycins Suboptimal E. coli and/or B. fragilis activity
Empiric enterococcus therapy not needed for mild-moderateinfections but favored for severe infections If recovered in culture in severe or healthcare-associated infection
then treat
Empiric antifungal therapy is not recommended Give fluconazole if recovered in culture until identified
Patients to be treated non-operatively for low-risk infections should typically be on a low-risk regimen with plans for early PO conversion
Biliary infections These are UPPER GI flora No anaerobic coverage required for non-severe disease
unless pre-existing biliary-enteric anastomosis is present
Mild-moderate Cefazolin (or ceftriaxone if E. coli susceptibility <90%)
Severe Piperacillin-tazobactam, or Cefepime plus metronidazole
De-escalation and alteration of initial regimen
Low-risk patients with adequate source control who are improving DON’T have to be broadened if untreated pathogens are later reported in culture
In high risk or persistently ill patients, try to optimize regimen to predominant flora and generally avoid narrowing
Duration of therapy Stomach or proximal jejunal perforation repaired within 24h and with
adequate source control Cefazolin prophylaxis x24h then discontinue If on PPI or malignancy, give high-risk regimen x4-7d
Penetrating/blunt or iatrogenic perforation repaired within 12 hours Treat for ≤24h
Acute appendicitis without perforation Treat ≤24h
Acute cholecystitis without perforation Treat ≤24h after cholecystectomy Treat ≤7 days if treated non-operatively with percutaneous cholecystostomy31
Complicated established infection with adequate source control 4 – 7 days
Recent duration-of-therapy literature
Acute grade II cholecystitis9
WBC >18, Mass in RUQ, >72h symptoms, or gangrenous/pericholecystic abscess/emphysematous/local peritonitis
≤4 days of therapy after surgery as effective as >4 days Rx
STOP-IT trial10
NEJM 2015 518 patients with complicated intra-abdominal infection Randomized to fixed 4 day Rx vs. 10 days or “clinical
resolution” Results: intervention group got 4 days, control 8 days Equivalent 21% recurrence rates
Acute uncomplicated diverticulitis Antibiotics may not be needed after all!? If no perforation or sepsis
AGA guidelines allow for “selective” use11,12
Several new studies show no difference in acute resolution, possible reduced recurrence with antibiotics13-
16
Too early to know what to recommend, but argues for less-aggressive trend to current approach
Approach to perforated diverticular abscess
Patients with diffuse fecal peritonitis require emergent surgery
Localized small abscesses <4-6cm may be amenable to antimicrobial therapy alone17,18
Larger abscesses are generally drained by CT guidance percutaneously
Failure to improve with medical or CT drainage after 3 days suggests need for surgery
Patients with successful drainage may require delayed elective sigmoid resection due to high recurrence rates19-22
Spontaneous bacterial peritonitis3
Defined as PMN ≥250 cells/mm3 in ascitic fluid of cirrhotic patient with signs or symptoms suggestive of ascitic fluid infection
Tap and treat if PMN criteria reached
Ceftriaxone 1g iv q12h x5 days Narrow if a single pathogen is isolated in culture Cefotaxime option offers no benefit, limited availability Total daily dose 2g vs. 1g associated with improved outcomes29
Give SBP prophylaxis in patients with GI bleeding Ceftriaxone 1g IV q24h x 7 days
Secondary prophylaxis after 1st SBP episode30 if ascites protein <1 Trimethoprim/sulfamethoxazole DS 1 tab daily Ciprofloxacin 500mg PO daily if tmp/smx not feasible
Acute pancreatitis These patients have high WBC, fever, and tachycardia;
they look septic
Patients with shock need blood cultures and antibiotics4
Without shock, treat as pancreatitis with fluids, NPO etc If antibiotics started, when blood cultures negative and no
other source found abx should be discontinued
Necrotic pancreatitis is not an indication for antibiotics Earlier trials of PROPHYLACTIC antibiotics23,24 have been
disproven25-27
No decrease in infections or sugery, but more RESISTANT organisms when infection develops25
Infected pancreatic necrosis Patients failing to improve or worsening after 7-10 days of
conservative management
CT guided fine needle aspiration (FNA) can be used to diagnose Preferred from stewardship standpoint over empiric abx
Prolonged IV antibiotics if infected Surgery can be avoided in ~3/4 of patients and only ~1/3
required percutaneous drainage28
Cephalosporin plus metronidazole or carbapenem
Infectious Diarrhea2
Fever and blood = dysentery Shigella, campylobacter, sometimes salmonella Await stool culture if stable
If using rapid diagnostics, be sure to submit culture prior to treatment
If septic can give azithromycin 500mg or ciprofloxacin 500mg
Traveler’s diarrhea Entero-toxigenic E. coli (ETEC), shigella, salmonella Empiric ciprofloxacin 500 bid x3d or 750 x1; azithromycin 500 x3d
Blood and NO fever Enterohemorrhagic E. coli (EHEC): NO ANTIBIOTICS
Recent hospitalization, ED visit, or antibiotics CDIFF, CDIFF, CDIFF (which is another talk entirely)
Peri-operative prophylaxis for colorectal surgery
Our protocols mimic our treatment guidelines
Cefazolin 2g (3g if >120kg) plus metronidazole 500mg Immediately prior to incision Can be mixed and given in same bag as “cefanidazole” Cefazolin redosing interval 4h; metronidazole not redosed
Levofloxacin 750mg plus metronidazole if anaphylactic penicillin allergy No redosing
If known MRSA colonized can consider adding vancomycinthough literature supports primarily for orthopedic and cardiac surgery
If already on antibiotics and going to OR
Re-dose based on published intra-operative re-dosing interval5
4h for cefazolin 2h for piperacillin/tazobactam
Using cefazolin/metronidazole is effective, easy, and logistically simple vs. alternative regimens
We do NOT endorse use of ertapenem for prophylaxis Extremely broad , ESBL coverage
If surgeons insist on q24h regimen can use daily dosed ceftriaxone plus metronidazole 1g
References1. Clinical Infectious Diseases 2010; 50:133–64
2. Clinical Infectious Diseases 2001; 32:331–50
3. Hepatology 2009;49:2087-107).
4. Am J Gastroenterol 2013; 108:1400–1415;
5. Am J Health-Syst Pharm. 2013; 70:195-283
6. Peritoneal Dialysis International, Vol. 25, pp. 107–131
7. J Chemother. 2007 Aug;19(4):410-6
8. J Pediatr Surg . 2008 June ; 43(6): 981–985
9. J Gastrointest Surg (2013) 17:1947–1952
10. N Engl J Med 2015;372:1996-2005.
11. Gastroenterology 2015;149:1944–1949
12. Gastroenterology 2015;149:1950–1976
13. Colorectal Dis. 2016 Apr 18
14. Gastroenterology 2015;149:1650–1651
15. Br J Surg 2012;99:532–539.
16. United European Gastroenterol J 2014;2(1S):A2
17. Tech Coloproctol. 2015 Feb;19(2):97-103
18. Dis Colon Rectum. 2006 Oct;49(10):1533-8
19. Dis Colon Rectum. 2016 Mar;59(3):208-15
20. ANZ J Surg. 2016 Apr 8.
21. Ann Surg. 2015 Dec;262(6):1046-53
22. Dis Colon Rectum. 2014 Dec;57(12):1430-40
References23. Surg Gynecol Obstet 1993 ; 176 : 480 – 3
24. Lancet 1995 ; 346 : 663 – 7
25. Ann Surg 2007 ; 245 : 674 – 83
26. Cochrane Database Syst Rev : CD002941
27. Am J Surg 2009 ; 197 : 806 – 13
28. Gastroenterology 2013 ; 144 : 333 – 40
29. F1000Research 2014, 3:57
30. Ann Pharmacother. 2010 Dec;44(12):1946-54
31. World J Surg (2017) 41:1239–1245
32. The American Journal of Surgery (2013) 206, 935-941
33. Hepatobiliary Pancreat Dis Int2014;13:316-322
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