Intra-abominal Infection - Block 2 Flashcards
What is an intraabdominal infection?
Infection of peritoneum within peritoneal cavity or retroperitoneal space
GI flora in stomach?
Streptococcus
Lactobacillus
GI flora in biliary tract?
Normally sterile (E. coli, Klebsiella, or enterococci)
GI flora in proximal small bowel?
Strep, Enterococci, E. coli, Kleb, Lactobacillus, diphtheroids
GI flora in distal ileum?
E. coli, Kleb, Enterobacter, enterococci, Bacterides, Clostridium, peptostrep
GI flora in colon?
- Enterobacteriaceae
- Enterococci
- anaerobes
- candida
What is uncomplicated IAI?
- Affects a single organ
- Doesn’t spread to peritoneum
- No anatomic disruption of the GIT
What is complicated IAI?
- Extension of infection into peritoneal space
- May be contained/localized or cause diffuse peritonitis
The most common
Differentiate the types of peritonitis?
Primary: Spontaneous bacterial peritonitis (SBP)
Secondary: disruption of GIT, involve in polymicrobial infection
Tertiary: persists or recurs at least 48hrs after apparently adequate management of primary and secondary
What is the most common cause of primary peritonitis?
Alcoholic
Cirrhosis or ascites
PD
Pathogen associated with cirrhosis?
E. coli
Pathogen associated with PD?
Staph spp.
Sterptococcus
E. coli
Klebsiella
Pseudomonas
What are the causes of secondary peritonitis?
Breach of GI mucosal membrane due to:
1. Abscess
2. Polymicrobial infection
RF of developing candida infection?
- Extensive broad ABX
- Immunosuppressed patients
What are the common causes of secondary bacterial peritonitis?
- Diverticulitis
- Appendicitis
- IBD
- Billiary tract infection
- Intestinal obstruction
- Perforation
- Trauma
Pathogens assocaited with 2nd peritonitis?
- Strep
- E. coli
- Kleb
- Enterococci
RF for primary peritonitis?
PPI use
RF for secondary peritonitis?
- Advanced age
- Obesity
- Smoking
- Lack fo exercise
- Low fiber
- Gallstones
- Cholangitis
- Biliary tract colonization
S/s of primary peritonitis?
GI upset
Bowel sounds hypoactive
PD: clouding dialysate fluid
Lab of primary peritonitis?
- Mild elevated WBC
- Elevated Procal
- Fever
- Ascites fluid leukocytes >250
- Bacterial growth in ascites or dialysate
- Protein <1 -> hepatic impairment
- Glucose >50
S/s of secondary peritonitis?
- Quick onset of ab pain
- 3rd spacing
- Abdominal tenderness and distension
- Faint bowel sounds that cease over time
Lab of secondary peritonitis?
- Elevated WBC
- Elevated BUN and lactate in hypovolemia
- Glucose <50
- Protein >1 -> protein leaking
- leukocytes >250
Imaging used for IAI diagnosis?
Ultrasound: abscess
CT of abdomen and pelvis: identify foci of the infection
* Ascites in SBP
* Free air -> perforation
Labs used to diagnosis IAI?
Microbio: culturing peritoneal fluid
CMP: WBC, Scr, liver enzyme, procalcitonin
What are the steps to manage IAI?
- Source control -> surgery
- Supportive care: hemodynamic stability, antipyretics, analgesics
- Empiric antimicrobial -> de-escaltaiton to target therapy
Nonpharm for peritonistis?
Surgical intervention
What is used for hemodynamic resuscitation?
- Fluids
- Albumin
When is empiric antimicrobials initiated?
ASA IAI is suspected
What ABX is B. fragillis resistant to?
Clindamycin and cefotetan
What ABX is Enterobacter resistant to?
Ampicillin-sulbactam and FQ
Tx for PD SBP? Pathogen?
Vancomycin + cefipine or Ceftazidime
Remove cath
Patho: staph, strep, pseudomonas
Tx for cirrhosis SBP? Pathogen?
Ceftriaxone, Cefotaxime
Patho: E. coli
When do you reassess SBP tx?
5 day duration, reassess if:
1. PMN count is <250 cells/microL, treatment is stopped
2. PMN count is greater than the pretreatment value
3. PMN count is elevated but less than the pretreatment value continue ABX for another 48h, repeating paracentesis
Prophylaxis agents for SBP?
- BActrim DS QD
- Ciprofloxacin QD
How are at risk for SBP recurrence?
- Cirrhosis and GI bleeding
- > 1 epidode of SBP
- Cirrhosis and ascites
Tx for Gastroduodenal secondary peritonitis?
Ceftriaxone
Tx for biliary tract secondary peritonitis?
Ceftriaxone
Tx for small or large bowel secondary peritonitis?
Ceftriaxone + Metronidazole
OR
Zosyn
Tx for appendicitis secondary peritonitis?
Ceftriaxone + Metronidazole
OR
Zosyn
Tx for abscesses secodnary peritonsisi?
Ceftriaxone + Metronidazole
OR
Zosyn
Tx for abscesses secodnary acute contamination from ab trauma?
Ceftriaxone + Metronidazole
OR
Zosyn
Pathogent for CA IAI?
Mild-mod: streptococci, non-resistant Enterobacteriaceae and anaerobes
High: above + pseudomonas
Pathogen for HA IAI?
MRSA + Pseudomonas and resistant strain of enterobacter
RF of CA IAI?
- > 70 YO
- Medical comorbidity
- Immunocompormised
- High severity of illness
- Extensive peritoneal or diffuse peritonitis
- Delay in initial intervention >24h
- Inability to achieve adequate debridement or drainage control
Tx for low risk (mild-mod) CA IAI?
Monotherapy:
* Zosyn
* Meropenem (ESBL)
* Moxifloxacin (anaerobic coverage)
Combo:
* Metronidazole +
* Ceftriaxone, Cefotaxime, Cefuroxime (IV/PO) OR
* Ciprofloxacin or Levofloxacin
Tx for high risk (severe) CA IAI?
Monotherapy: Zosyn
Combo: Metronidazole + cefepime or ceftazidime
What specific pathogen makes the difference of empiric abx between low risk vs. high risk?
PA
HA IAI 2 agent tx?
- Add Vanc to high risk CA (Zosyn or Metronidazole + Cefepime or Ceftazidime)
- Zosyn + Vanc
- Meropenem + Vanc (ESBL suspicion)
HA IAI 3 agent tx?
Cefepime + metronidazole + Vancomycin
Or
Ceftazidime + metronidazole + Vancomycin
What is the duration of IAI tx?
Peritonitis or IA abscess after adequate source control: 4 days
Defintive source not possible: 5-7 days
Acute IAI contamination: 24 hrs
Montioring IAI tx?
- De-escalation ABX
- Renal daily
- WBC, fever, GI, ab pain
- Improvement within 48-72 hrs
- 4-7 days (recent studies shows 3-5 days no difference vs. 7 days) -> 4 days
- Abscess, follow up CT