Lecture 28 - Peritonitis & Intra-Abdominal Infection

Question 1

Peritonitis presentation?

Answer 1

fever, tachycardia, RR increase, vomiting, abdominal pain, tenderness and rigidity, increased blood leukocytes; fluid build up in CT/US

Question 2

Primary peritonitis?

Answer 2

diffuse bacterial infection from loss of GI integrity, rare, associated w liver disease

Question 3

Secondary?

Answer 3

acute infection resulting from loss of GI integrity or infected viscera, most common, related to visceral pathology or post surgical infection

Question 4

Tertiary?

Answer 4

recurrent infection following adequate initial therapy, often due to defective immunity

Question 5

Microbial causative agents?

Answer 5

polymicrobial, or bacterial: E. Coli, anaerobes, enterococci

Question 6

Route of transmission?

Answer 6

most commonly Appendicitis and diverticulitis

Question 7

Risk factors?

Answer 7

liver disease (primary), app. and divert., surgery (secondary), prior peritonitis (tertiary)1

Question 8

Pathophysiology?

Answer 8

usually infected bacteria phagocytosed or maintained in fibrin clump, clearance not effective in presence of nutrients and necrotic tissue -> proliferation -> inflammation -> fluid exudate & dilution of antimicrobial factors

Question 9

Abcess formation?

Answer 9

fibrin deposited traps bacteria, may block phagocytosis -> proliferation -> protease etc. damage tissue

Question 10

Diagnositc microbiology?

Answer 10

aspirate pus, gram negative rods (combination possible), anaerobic culture

Question 11

Collecting anaerobes & bacteroides?

Answer 11

difficult, requires aseptic aspiration, transportation and cultivation, gram negative rods

Question 12

Polymicrobial infection?

Answer 12

typically B. fragilis w antiphagocytic capsule, complement degradation and reduced oxygen toxicity, and E.coli which has its Haem binding factor intercepted by B. fragilis

Question 13

Treatment?

Answer 13

of symptoms (fluids, pain relief, drainage), of source (origin location, dead tissue removal and leak repair), and of microbial cause (empiric antimicrobial therapy, triple or single for liver/kidney impaired)

Question 14

C. Difficile?

Answer 14

infection resistant to empirical treatment, normal flora killed allows it to flourish

Question 15

Metronidazole?

Answer 15

kills anaerobic gram negative bacilli and positive cocci, and protozoa, inneffective against aerobic and facultatively anaerobic bacteria

Question 16

Prevention?

Answer 16

prompt diagnosis and treatment of predisposing conditions