ABSITE Review - Infection

Question 1

What is the MC immune deficiency?

Answer 1

Malnutrition

Question 2

What is the microflora in the stomach?

Answer 2

Virtually sterile; some GPCs, some yeast

Question 3

What is the microflora in the proximal small bowel?

Answer 3

10^5 bacteria, mostly GPCs

Question 4

What is the microflora in the distal small bowel?

Answer 4

10^7 bacteria, GPCs, GPRs, GNRs

Question 5

What is the microflora in the colon?

Answer 5

10^11 bacteria, almost all anaerobes, some GNRs, GPCs

Question 6

What is the MC organisms in the GI tract?

Answer 6

Anaerobes

Question 7

What is the MC anaerobe in the colon?

Answer 7

Bacteroides fragilis

Question 8

What is the MC aerobic bacteria in the colon?

Answer 8

Escherichia coli

Question 9

What is the MC organism in gram-negative sepsis?

Answer 9

Escherichia coli

Question 10

What is the endotoxin of gram-negative organisms? What it triggers?

Answer 10

Lipopolysaccharide lipid A

Triggers the release of TNF-alpha (from macrophages), activates complement and coagulation cascade

Question 11

How clostridium difficile can be diagnosed? What is the treatment?

Answer 11

Dx - Fecal leukocytes in stool, C.difficile toxin

Tx - oral or IV flagyl, oral vancomycin, lactobacillus

Question 12

How you classify the wound of an elective colon resection with prepped bowel?

Answer 12

Clean-contaminated = 3-5% risk of wound infection

Question 13

How you classify the wound of GSW to colon with repair?

Answer 13

Contaminated = 5-10% risk of wound infection

Question 14

How many bacteria are needed for a wound infection?

Answer 14

10^5 bacteria

Question 15

Mention some risk factors for wound infection.

Answer 15

Long operations, hematoma or seroma formation, advanced age, chronic disease (COPD, renal failure, liver failure, DM), malnutrition, immunosuppressive drugs

Question 16

Which are the agents involve with invasive soft tissue infection?

Answer 16

Clostridium perfringens and beta-hemolytic strep

Question 17

What are the MC agents in ICU pneumonia?

Answer 17

#1 - Staph aureus
#2 - Pseudomonas

Question 18

What are the MC agents in ICU pneumonia?

Answer 18

#1 - Staph epidermidis
#2 - Staph aureus
#3 - yeast

Question 19

What are the MC agents in necrotizing soft tissue infection?

Answer 19

Beta-hemolytic, Streptococcus (group A), C.perfringens and mixed organism

Question 20

Mention signs and symptoms of necrotizing soft tissue infection.

Answer 20

WBC 20, thin gray drainage, marked induration, edema of entire limb, hypoNa (<135), skin blistering/slougihng, skin necrosis, crepitus/soft tissue gas on x-ray, pain out of proportion, sepsis

Question 21

What is the treatment for necrotizing fasciitis?

Answer 21

Early debridement, high-dose penicillin or broad spectrum abx if polyorganismal

Question 22

What is the toxin of C.perfringens?

Answer 22

Alpha-toxin

Question 23

What is the MC presentation of C. perfringens? Describe the gram stain.

Answer 23

Myonecrosis and gas gangrene

Gram stain - GPRs without WBCs

Question 24

C. perfringens is common in __________ injuries.

Answer 24

Farming

Question 25

What is Fournier's gangrene? Mention some risk factors.

Answer 25

Severe infection in perineal and scrotal region | RFs - DM, immunocopromised state

Question 26

What are common symptoms of Actinomyces? What is the treatment?

Answer 26

MC - Pulmonary symptoms, tortous abscesses in cervical, thoracic, ad abdominal areas Tx - drainage and penicillin G

Question 27

What are common symptoms of Nocardia? What is the treatment?

Answer 27

Pulmonary and CNS symptoms | Tx - drainage and sulfonamides (Bactrim)

Question 28

What are common symptoms of Histoplasmosis? What is the treatment?

Answer 28

Pulmonary symptoms, Mississippi and Ohio River valleys | Tx - amphotericin for severe infections

Question 29

What are common symptoms of Cryptococcus? What is the treatment?

Answer 29

CNS symptoms | Tx - amphotericin for severe infections

Question 30

What are common symptoms of Coccidiodomycosis? What is the treatment?

Answer 30

Pulmonary symptoms, Southwest | Tx - amphotericin for severe infections

Question 31

What is a risk factor for SBP?

Answer 31

Protein < 1g/dLin peritoneal fluid

Question 32

How is SBP diagnosed?

Answer 32

PMNs > 500 in peritoneal fluid is diagnostic

Question 33

What is the treatment of SBP? Short-term prophylaxis?

Answer 33

Ceftriaxone, prophylaxis with fluoroquinolones

Question 34

What are the 2 MCCs of laparotomy in HIV patients?

Answer 34

``` #1 - CMV infection #2 - neoplastic disease ```

Question 35

Is upper or lower GI bleeding more common in HIV patients?

Answer 35

Lower GI bleeding is more common Upper GI bleeds - Kaposi, lymphoma Lower GI bleeds - CMV, bacterial, HSV

Question 36

What is the bacteria in cat and dog bites?

Answer 36

Pausterella multocida

Question 37

What is the bacteria in human bites?

Answer 37

Eikenella