Exam 3 - Intraabdominal infections/C.Diff infections Flashcards
2 types of intraabdominal infections?
Peritonitis or abscess
definition of peritonitis
acute, inflammatory response of the PERITONEAL LINING in response to bacterial invasion, chemical irritation, irradiation, or foreign body injury
definition of abscess
- PURULENT collection of fluid separated from surrounding tissue by fibrinous capsule
- contains necrotic debris, bacteria, neutrophils
what part of the GI tract has a lot of anaerobes in their normal flora
colon
what is the etiology of secondary peritonitis
- results from a focal disease process within the abdomen
- bacteria usually enter the peritoneum as a result of disruption of the integrity of the GI tract by disease, injuries, surgery, or from local lesions of the female genital tract
Biliary tract or female genital tract:
has 0 normal flora?
has lots and lots normal flora?
biliary: 0
female genital: hella normal flora
in the STOMACH, bacterial counts increase up to 10^5-7 organisms/mL in what situations?
when LOW acid!
achlorhydria, H2 antagonists, PPIs, antacids, gastric cancer, gastric outlet
Super common bacterial species of intraabdominal infections?
E.Coli
Streptococcus
B.Fragilis/other bacteriodes
Clostridium
Intraabdominal infections have pseduomonas infections in what most situations?
in situations where the pt caught the infection in the hospital
Pathophys of intraabdomial infections:
NORMALLY peritoneal fluid is STERILE, ___ in protein and leukocytes, and contains no _______
LOW in protein/leukocytes
no fibrinogen
Pathophys of intraabdomial infections:
Serous fluid containing leukocytes/high protein concentration, and fibrinogen moves into peritoneum:
Fibrinogen polymerizes forming _____
adhesions (by forming plaques of fibrinous exudates on the inflamed peritoneal surface and begins to form adhesions)
What is “third spacing”
it is a fluid and protein shift – fluid moves to the peritoneal cavity
“Third spacing”: (decreased or increased)
_____ circulating blood volume
_____ cardiac output
_____ blood pressure
decreased
decreased
decreased…
Systemic GI responses to an intraabdominal infection?
initially diarrhea then bowel paralysis because of low perfusion –> distention b/c no poops
Systemic cardio responses to intraabdominal infections?
fluid going into peritoneal = decrease circulating blood volume/decrease venous return/decreased cardiac output/hypotension/
Systemic renal responses to intraabdominal infections?
decreased renal perfusion = acute renal failure
Systemic metabolic responses to intraabdominal infections?
increased energy demands deplete glycogen stores = catabolism of muscle/fat =weight loss
Role of facultative bacteria or anaerobes?
has virulence factors and are responsible for abscesses
anaerobes
Role of facultative bacteria or anaerobes?
produce extracellular enzymes to promote tissue invasion
and
provide environment conductive to growth for other bug
facultative
(these bugs use up the O2 which helps anaerobes grow)
(also they make enzymes to help anaerobes to get in)
Common symptoms of intraabdominal infections?
stomach pain (distension) Thirst (bc fluid in abdomen) Decreased urination (bc ^) cant pass gas/feces
Treatment of Secondary Peritonitis intraabdominal infections? (pharm and non-pharm)
collect cultures!! AEROBIC AND ANAEROBIC
empiric therapy to cover enterbacteriaceae and bacteriodes species
what two bugs are to cover empirically for Secondary Peritonitis intraabdominal infections?
enterbacteriaceae and bacteriodes species
what drugs typically cover anaerobes
we rarely have to do susceptibility testing for anaerobes
metronidazole
beta lactams + lactamase inhibitors
carbapenems
For intraabdominal infections: HEALTHCARE ASSOC.
want to have empiric therapy against _______ when..
[previous cephalosporin therapy,
pts who are immunocompromised,
if infection source is biliary tract,
pt has valvular hear disease or prosthetic intravascular material]
enterococci
Enterococci is typically covered by what 3 drugs?
ampicillin
pip/tazo
vanc
General Treatment guidelines for intraabdominal infections? (2 things)
1 – DRAIN IT – surgery
2 – Antimicrobial therapy (enterbacteriaceae and bacteriodes)
Examples of Primary Peritonitis?
Kids – nephrotic syndrome/post necrotic cirrhosis
Adults: hepatic failure/ascites
Alcoholic cirrhosis
CAPD (infection with peritoneal dialysis)
Primary Peritonitis:
if hepatic failure – what is the most common pathogen?
E.Coli
Primary Peritonitis:
if Peritoneal dialysis – what is the most common pathogen?
staphylococci (skin flora)
streptococci
Primary Peritonitis:
if kids – what is the most common pathogen?
Strep pneumoniae
Etiology of C.Diff bugs?
gram +
anaerobic
SPORE forming
what is BI/NAP1/027
- a type of _____
- a _____ strain
a type of C.Diff
virulent
BI/NAP1/027:
- hypo or hyper sporulating
- decreased or increased toxins A/B
hyper
increased
BI/NAP1/027:
has increased disease severity and has high resistance to _______
fluoroquinolones
Definition of CDI (C.Diff infection):
presence of unexplained new- onset diarrhea: ___ or more _____ stools in _____ hours
ALSO positive stool test for _______ or any histopathologic findings revealing pseudomembranous
3 or more
UNFORMED stools
24 hours
+ test for C. Diff toxins
what are the 4 critical components of C. Diff infection pathogenesis
disruption of colonic microflora
source of C.Diff (endogenous flora or exogenous source)
organism must have potential to produce toxin
multiple diff. individual risk factors
what are risk factors for C Diff infection
abx use (the longer the higher risk) duration of hospitalization advanced age physical proximity to a C Diff pt presence of a comorbidity use of PPIs or H2RAs chemo surgery immunosuppresion/HIV poor serum antibody response to c. diff toxins
what clinical markers indicate SEVERE C.Diff?
leukocytosis > 15,000
or SCr > 1.5
Treatment of CDI:
Initial episode - non-severe?
vanc fidoxamicin or metro (last line)
Treatment of CDI:
Initial episode - severe?
vanc
fidoxamicin
Treatment of CDI:
Initial episode - fulminant?
vanc + metronidazole
may give rectally
Treatment of CDI:
First recurrence
vanc (give vanc differently - tapered)
fidoxamicin (if vanc used 1st)
Treatment of CDI:
Second or subsequent recurrence
vanc tapered
vanc + rifampin or rifamixin?? (check ya notes)
or poop transplant
what is the monoclonal antibody for C.Diff and how does it work
Bezlotoxumab
binds to toxin B
