Intra-abdominal infections Flashcards
When does primary peritonitis occur?
Primary peritonitis occurs without an evident source. Occurs in patients with ascites: Cirrhosis Chronic active and acute viral hepatitis Congestive heart failure Metastatic malignant disease Systemic lupus erythematosus Lymphedema
How is secondary peritonitis caused?
usually caused by spillage of GI or genitourinary microorganisms into the peritoneal cavity owing to loss of the integrity of the mucosal barrier.
What can cause secondary peritonitis?
Penetrating abdominal trauma Ruptured appendix Perforated peptic ulcer Perforated diverticular disease Perforated cholecystitis Postsurgical complications following abdominal procedures
What microorganisms are most likely to cause primary bacterial peritonitis?
Enterobacteriaceae 63% (Escherichia coli, Klebsiella spp., etc.)
S. pneumoniae 15%
Enterococci 6-10%
Anaerobes <1% (Bacteroides spp.)
If associated with peritoneal dialysis:
–Skin flora (S. epidermidis, S. aureus, Streptococci, Diphtheroids)
—Occasionally aerobic gram-negative bacilli
What microorganisms are most likely to cause secondary bacterial peritonitis?
Often polymicrobial (Enterobacteriaceae, Bacteroides sp., enterococci, P. aeruginosa (3-15%))
What are the most commonly isolated microorgranisms in intraabdominal infections?
Escherichia coli and Bacteroides species
What are the signs and symptoms for intra-abdominal infection?
Signs and symptoms Acute abdominal pain Faint or absent bowel sounds Fever- big sign of infectious process N/V Elevated WBCs, BUN Free air on abdominal X-ray = perforation Peritoneal fluid analysis, Gram-stain & culture --30-40% of pts have negative cultures
What does a negative culture mean?
That its inconclusive
What is done for the management of intraabdominal infections?
Removal or control of contamination
Physiological support
Antimicrobial therapy
What are the four things that should be considered when making the choice for antimicrobial therapy?
Consider severity
Community of hospital acquired
Previous antimicrobials
Patient immune status
What is the empiric treatment of primary peritonitis?
Cefotaxime
Ceftriaxone
Piperacillin/tazobactam (or Ticarcillin/clavulanic acid or amp/sulbactam)
If ESBL (extended spectrum bata lactamase) then imipenem or meropenem or ertapenem
What is used for prevention of primary peritonitis?
Cirrhosis & ascites: TMP/SMX DS or cipro
Cirrhosis & UGI bleed: Cipro
Are probiotics sufficient enough to prevent primary peritonitis?
No but they wont hurt the patient either
What is the treatment for secondary peritonitis
Empiric Therapy Usually Necessary
Select agents with aerobic and anaerobic coverage
Recognize potential resistance patterns
Consider adverse effects (eg, nephrotoxicity, coagulopathy, diarrhea)
Select dose and dose interval with particular regard to renal or hepatic dysfunction
Therapy must have activity against anaerobes even if they are not isolated
Anaerobic techniques are frequently inadequate
What are the antimicrobial regiments for secondary peritonitis- mild to moderate disease -> inpatient?
Ampicillin/sulbactam Pipericillin/tazo Ticarcillin/clauvulanate Ertapenem Cefoxitin Cefotetan Cipro + metronidazole
What are the antimicrobial regiments for secondary peritonitis- severe life threatening disease -> ICU patients?
Imipenem Meropenem Ampicillin + Metronidazole Gentamicin or tobramycin Ampicillin + metronidazole + cipro Ampicilin + gent or tobra
What should regimens cover when treating for secondary peritonitis?
Both gram-negative aerobes and anaerobes
When is enterococcal coverage recommended for secondary peritonitis?
Immunocompromised patients
Persistent or recurrent intra-abdominal infections
Shock
Clostridium difficle
Anaerobic, Gram-positive spore-forming rod shaped bacteria
Known cause of colitis and Pseudomembranous colitis
Overgrowth of C diff- normal flora, newly acquired
What are the risk factors for C. diff?
Antibiotic use (broad spectrum)
Manipulation of the GI tract (sgx, enemas, NG tubes)
Cytotoxic drugs
Age
What toxin is released with c. diff colitis?
Toxin A: enterotoxin which is responsible for most symptoms – hemorrhage/fluid secretion
Toxin B: cytotoxin
Ulcerations caused by toxins released
What are the complications of C. diff colitis?
Toxic megacolon
Colonic perforation
Death
What are the sx of C. diff?
Typically > 5 loose stools per day
Over minimally 2 days
Watery, green, foul smelling, small volume, mucus or blood
Presence of stool leukocytes in 50% of patients
Cramping, abdominal pain, dehydration
Presence of systemic signs of infection
Fever, leukocytosis
What is the antibiotic treatment for C. diff?
Metronidazole
Vancomycin- given orally
Bacitracin (Lack evidence, promising)
