1. Diverticulitis and intraabdominal infection
Michael J. Tan, MD, FACP, FIDSA
Associate Professor of Internal Medicine
NEOMED

2. Review common presentations of diverticular infection.
Objectives
Review common presentations of diverticular infection.
Understand pathogens of concern
Review approach to intra-abdominal infection
Select appropriate antimicrobial therapy for these processes
Summa Health Sample Preso

3. Ciprofloxacin + metronidazole Clindamycin Piperacillin-tazobactam
In a patient with acute intra-abdominal infection, which of the following would be the most appropriate initial treatment?
Ciprofloxacin + metronidazole
Clindamycin
Piperacillin-tazobactam
Ampicillin-sulbactam
Vancomycin
Summa Health Sample Preso

4. Case #1
A 68 year old female comes to your office complaining of acute onset LLQ pain. She had previous bouts similar to this that had relieved with time. Pain does not really have any exacerbating or alleviating factors. She has had no fever or chills. Which of the following would be the most appropriate choice?
A. Clear liquid diet
B. Ciprofloxacin and metronidazole
C. Hemicolectomy
D. Amoxicillin-clavulanate
E. Colonscopy
Summa Health Sample Preso

5. Diverticulitis Inflammation of diverticula Potential complications
Macroperforation
Bleeding
Obstruction
Fistula
Phlegmon
Abscess
Over 2 million cases reported every year
Nuts, corn, popcorn, berries have not been associated with an increased incidence of diverticulitis
Summa Health Sample Preso

6. Diagnosis
Usually older adults, acute onset of constant abdominal pain, predominantly LLQ
Fever, leukocytosis
History of diverticulosis
Complicated cases: peritonitis, hypotension, tachycardia
Imaging: CT scan, Plain films (free air)
Colonoscopy—after symptoms resolved
Differential: exclude other GI, GU, GYNconditions.
Summa Health Sample Preso

7. Diverticulosis/Diverticulitis
Am Fam Physician. 2013;87(9):
Summa Health Sample Preso

8. Am Fam Physician. 2013;87(9):612-620 Summa Health Sample Preso

9. Am Fam Physician. 2013;87(9):612-620 Summa Health Sample Preso

10. Abdominal Free Air
Brar AS, Gill RS, Gill SS, Wang H - J Clin Med Res (2011)
Summa Health Sample Preso

11. Inpatient or outpatient?
Most can be managed as outpatients.
Inpatient:
Peritonitis, inability to tolerate PO
Complicated diverticulitis
Summa Health Sample Preso

12. Outpatient management
Mild symptoms
Clear liquids for 2-3 days
Antimicrobials?
Reasonable to observe for 2-3 days and reassess need for antimicrobial
Summa Health Sample Preso

13. Antimicrobials
May not improve outcomes in patients with uncomplicated L diverticulitis
May not have significant differences in rates of complications (abscess or perforation), need for surgery or recurrence
IV abx for 24-48h may be as good as 7 days.
(Cochrane Database Syst Rev 2012 Nov 14;(11):CD009092)
Abx vs. no abx
Recurrent diverticulitis with readmission to hospital 15.8% vs. 16.2%
Complications 1% vs. 1.9%
Sigmoid resection 1.6% vs. 2.3%
Median hospital stay 3d vs. 3d.
None of the above differences are considered to be statistically significant
(Br J Surg 2012 Apr; 99(4):532)
Summa Health Sample Preso

14. Antimicrobial Recommendations
Significant pathogens, complicated disease: Gram negative, anaerobes
Mild/outpatient, antimicrobials may not be needed
Mild/persistent worsening, outpatient
First line agents
TMP-SMX DS PO q12h
Ciprofloxacin 750mg PO q12h + metronidazole 500mg PO q6h
Levofloxacin 750mg PO q24h + metronidazole 500mg PO q6h
-OR- amoxicillin-clavulante 875mg PO q12h
Second line agents
Amoxicillin-clavulante ER 2000/125mg PO q12h
Moxifloxacin 400mg PO q24h
Adapted from: Am Fam Physician. 2013;87(9):
Summa Health Sample Preso

15. Antimicrobial Recommendations
Mild-to-moderate symptoms/inpatient
First line agents
Piperacillin-tazobactam 3.375g IV q6h or 4.5g iv q8h
Ticarcillin-clavulante 3.1g IV q6h
Ertapenem 1g IV q24h
Moxifloxacin 400mg IV q24h
Second line agents
Ciprofloxacin 400mg IVq12h + metronidazole 500mg IV q6h
Levofloxacin 750mg IV q24h + metronidazole 500mg IV q6h
*Tigecycline 100mg IV x1 then 50mg IV q12h
Discouraged because of mortality data
Adapted from: Am Fam Physician. 2013;87(9):
Summa Health Sample Preso

16. Antimicrobial Recommendations
Severe/inpatient
First line agents
Imipenem-cilastatin 500mg IV q6h
Meropenem 1g IV q8h
Doripenem 500mg IV q8h
Should pip-tazo be here?
Second-line regimens
Ampicillin 2g IV q6h + metronidazole 500mg IV q6h + ciprofloxacin 400mg IV q12h or levofloxacin 750mg IV q24h
Ampicillin 2g IV q6h + metronidazole 500mg IV q6h + amikacin or gentamicin or tobramycin
Adapted from: Am Fam Physician. 2013;87(9):
Summa Health Sample Preso

17. Case #2
A 70 year old comes to the emergency department with acute onset of L lower quadrant abdominal pain. The patient had accompanying fevers, chills, and loss of appetite. CT scanning revealed a perisigmoid fluid collection. Which of the following would be the most appropriate antimicrobial therapy in addition pending drainage of the collection?
A. Piperacillin-tazobactam
B. Ciprofloxacin-metronidazole
C. Clindamycin
D. Vancomycin
E. Moxifloxacin
Summa Health Sample Preso

18. Diagnostic evaluation
History, PE, lab evaluation
For unreliable history or physical exam, consider intraabdominal infection if evidence of infection from an undermined source
If surgical intervention is to be performed, further diagnostic imaging is not necessary
If no immediate surgery is needed, CT scanning is modality of choice
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

19. Intervention Fluid resuscitation Antimicrobials
When intraabdominal infection is considered likely, septic shock
SOURCE CONTROL
Drain
Control peritoneal contamination by diversion or resection
Restore anatomic and physiological function feasible
Surgery if necessary even if resuscitation need be continued through procedure
Hemodynamically stable patients may be delayed up to 24h given appropriate antimicrobial therapy and clinical monitoring
Some patients with minimal physiological derangement and well-circumscribed focus of infection, such as periappendiceal or pericolonic phlegmon, may be treated with antimicrobial therapy alone without a source control procedure, provided close clinical follow-up is possible.
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

20. Evaluation Blood cultures if clinically toxic or immunecompromised
For health-care acquired infections, gram stain may help define presence of yeast
Cultures may not be necessarily in community acquired infections, but help define epidemiological changes in resistance and guiding therapy.
For significant resistance for particular pathogens (10-20%) culture and susceptibility should be obtained for perforated appendicitis and other community acquired- infections
Anaerobic cultures are not necessary for community acquired IAI if antimicrobial therapy for anaerobes is provided.
High risk patients should have cultures from the site
Cultures should be representative of material associated with the infection
Susceptibility testing for Pseudomonas, Proteus, Acinetobacter, S aureus, predominant enterobacteraciae should be performed.
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

21. Treatment regimens Clin Inf Dis 2010;50:133-64 Pathogens to consider
Consider Enteric aerobic, facultative bacilli, enteric GP streps.
Obligate anaerobes should be considered for distal small bowel, appendiceal, colon- derived infections, and proximal GI perf (if obstruction or paralytic ileus)
Mild-moderate community acquired infection (See table 2)
Ampicillin-sulbactam is not recommended for use because of high rates of resistance to this agent among community-acquired E coli.
same is not necessarily true of amox-clav as may be appropriate step-down/transition therapy
Cefotetan and clinda are not recommended for use because of increasing resistance among B frag group.
Enterococci empiric coverage not routinely needed for Community acquired IAI
Empiric antifungal coverage for Candida not recommended for patients with community- acquired IAI.
Agents outlined for higher-severity should be reserved for such to avoid toxicity and development of resistance
IAI->acute diverticulitis and some appendicitis without surgery, should draw from table 2, and have possibility of early oral therapy.
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

22. Antimicrobial Recommendations
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

23. Treatment Recommendations
High-Risk Community-Acquired Infection in Adults
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

24. Treatment Recommendations
High-Risk
FQ resistant E coli should not be used unless hospital surveys indicate >90% susceptibility
Aztreonam + metro is alternative, but need GPC agent
Use agents effective against enterococci
Avoid MRSA/yeast active agents if these organisms are not recovered
Optimize antimicrobial therapy
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

25. Treatment Recommendations
Health Care-Associated Infections in Adults
Consider local microbiology patterns
See table 3 for recommendations
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

26. Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

27. Other treatment considerations
Antifungal:
Use if Candida is grown from cultures
For critically ill, start with echinocandin over azole
Anti-Enterococcal therapy:
Use if enterococci are recovered from health care-associated infection
Empiric coverage for Health care-associated IAI
Especially patients who have had antimicrobials that select EC, immunecompromised, valvular disease or prosthetic intravascular material
Cover VRE if high risk for VRE.
Anti-MRSA Therapy:
Use if patient is colonized, health-care acquired colonized patient, or at risk because of prior treatment failure and excessive antimicrobial exposure
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

28. Case #3
Patient is a 50 year old female who presents to the emergency department with epigastric and right upper quadrant pain of several days duration. The pain is described as crampy and occasionally shoots to between the shoulder blades. The pain is especially noted when she eats fatty foods. She is noted to have a leukocytosis of about 15k and a temperature of 101F. Which of the following would be appropriate empiric antimicrobial therapy?
A. Ampicillin-sulbactam
B. Piperacillin-tazobactam
C. Ciprofloxacin + metronidazole
D. Metronidazole
E. Daptomycin
Summa Health Sample Preso

29. Cholecystitis and Cholangitis in Adults
Ultrasonography is the first imaging technique used
See table 4 for antimicrobial choices. Anaerobic therapy is not indicated unless a biliary-enteric anastomosis is present
Discontinue antimicrobial therapy within 24h unless there is evidence of infection outside the wall of the gallbladder
Community acquired biliary infections do not require enterococcal coverage (pathogenicity has not been demonstrated), unless immune compromised or hepatic transplant.
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

30. Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

31. Other considerations for therapy
Summa Health Sample Preso

32. Stewardship
Use micro to guide therapy, although for community-acquired infections, if patient is improving, alteration of therapy is not required even if unsuspected or untreated pathogens are later reported
Durations
4-7 days unless source control isn’t achieved. Longer courses have not been associated with improved outcomes.
Acute stomach and proximal jejunum perf, in absence of acid-reducing therapy or malignancy when source control is achieved within 24h, prophylactic anti-infective therapy directed at aerobic GPC for 24h is adequate.
Delayed operation for acute stomach and prox jejunum perf, gastric malignancy, acid reduction, cover mixed flora (complicated colonic infection)
Bowel injury attributable to penetrating, blunt, or iatrogenic trauma, repaired within 12h, any other intraop contamination of enteric contents. <=24h.
Acute appy without perf, abscess or local peritonitis, narrow spectrum regimens active against aerobic, anaerobic, stop without 24h.
Prophylactic abx to patient with severe necrotizing pancreatitis prior to the diagnosis is not recommended.
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

33. Oral therapy
No therapy required if signs and symptoms of infection are resolved
If susceptibility acceptable, and PO tolerable in stable and recovering patient, Po forms of moxi, ciproflox + metro, levoflox + metro, oral ceph with metro, or amox-clav
Use OPAT if IV is only option based on susceptibility
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

34. Suspected Treatment Failure
Persistent or recurrent evidence of IAI after 4-7 days of therapy, repeat imaging, continue antimicrobial
Look for extra abdominal sources
Repeat sampling and cultures.
Clin Inf Dis 2010;50:133-64
Summa Health Sample Preso

35. Take home points
For certain mild localized intraabdominal infection, antimicrobial therapy may not be necessary
Source control is usually required
Though recommended by guidelines and data, fluoroquinolones are falling out of favor for intraabdominal infections
E coli resistance, interactions, AEs
Amp-sulbactam is not recommended for empiric coverage due to E coli resistance
This is less of a concern for amox-clav.
Pip-tazo reasonable option for most hospitalized patients
Amox-clav is reasonable oral option/transitional therapy for IAI, diverticulitis
Guidelines and “new thinking” regarding antimicrobial selections may conflict
Guidelines for intraabdominal infection favor shorter courses, judicious use of antimicrobials.
Summa Health Sample Preso