Wound & Device Infections

Question 1

What are 2 common causes of device related infections?

Answer 1

• Normal skin flora (ie. Staphylococcus epidermidis)

- Transient skin flora (ie. Staphylococcus aureus)

Question 2

What 3 devices increase risk for infection?

Answer 2

• Insertion of prostheses
• Pacemakers
• IV lines

Question 3

How do you treat infections with permanent pacemakers and defibrillators?

Answer 3

Removal of device + antibiotics

Question 4

What are 3 causes of infections of vascular grafts?

Answer 4

• Intraoperative contamination
• Extension from adjacent infected tissue
• Hematogenous seeding

Question 5

What is the most common bacterial cause of skin infections?

Answer 5

S. aureus

Question 6

What are 4 sources of infection with a IV catheter?

Answer 6

• Microbial contamination at insertion site
• Hub
• Contaminated infusate
• Hematogenous seeding from a distant site

Question 7

Describe dialysis

Answer 7

Removing toxic wastes from body in patients with renal failure

Question 8

What are 2 major methods for dialysis?

Answer 8

Hemodialysis/IV & Peritoneal dialysis

Question 9

Describe hemodialysis

Answer 9

• At the hospital
• Longer time commitment
• Filters blood through a machine

Question 10

Describe peritoneal dialysis

Answer 10

• At home
• Shorter time commitment
• Connects IV to peritoneal cavity

Question 11

What is peritonitis?

Answer 11

Inflammation of peritoneal membrane

Question 12

What is an infectious risk associated with hemodialysis?

Answer 12

Contamination of equipment with Hep B, C & HIV (blood borne pathogens)

Question 13

What is an infectious risk associated with peritoneal dialysis?

Answer 13

Contamination of abdominal cavity with bacteria from skin

Question 14

What are early symptoms of peritonitis?

Answer 14

Severe abdominal pain, nausea, vomiting, fever

Question 15

What is a complication of peritonitis?

Answer 15

Intra-peritoneal abscess

Question 16

What is an abscess?

Answer 16

A localized lesion accumulated with pus as a result of an external or internal infection

Question 17

Internal abscesses are often ____

Answer 17

polymicrobial

Question 18

Skin abscesses are often caused by:

Answer 18

S. aureus

Question 19

What is osteomyelitis?

Answer 19

Infection/abscess of the bone

Question 20

What is the most common cause of osteomyelitis from the blood?

Answer 20

S. aureus

Question 21

What is the most common cause of osteomyelitis from a nearby site?

Answer 21

Polymicrobial

Question 22

Osteomyelitis is difficult to treat, why?

Answer 22

Difficult to get antibiotics to bone, longer treatment periods

Question 23

Acute osteomyelitis often occurs in ____ bones and result in ____ lesions that are very painful

Answer 23

long, bone

Question 24

Chronic osteomyelitis often occurs in ____ bone fragments and can result in _____ to stop the spread

Answer 24

necrotic, amputation

Question 25

What is the normal flora of the upper body primarily composed of?

Answer 25

Staphylococcus sp.

Question 26

What is the normal flora of the lower body and abdomen primarily composed of?

Answer 26

Fecal flora (G-s and enterococci)

Question 27

When is it common to use antibiotic therapy for "dirty" surgery?

Answer 27

Before and during operation

Question 28

What are 3 consequences of wounds?

Answer 28

- Delayed healing - Formation of abscesses - Dissemination or spread of infection into nearby tissues or blood/lymph

Question 29

In snake bites, what causes tissue necrosis?

Answer 29

Venom

Question 30

What is the common cause of infections with snake bites?

Answer 30

Pseudomonas aeruginosa

Question 31

Human bites and "clenched fist" injuries occur ____ often than animal bites

Answer 31

more

Question 32

What is the common cause of infections with human bite injuries?

Answer 32

Eikonella corrodens

Question 33

What is cellulitis?

Answer 33

Acute spreading infection of the subcutaneous tissues

Question 34

What can cellulitis originate from?

Answer 34

Superficial skin lesions & trauma

Question 35

A majority of cases of cellulitis are caused by what 2 organisms?

Answer 35

S. aureus and S. pyogenes

Question 36

How do you treat cellulitis?

Answer 36

Immediately with IV antibiotics

Question 37

What can anaerobic cellulitis originate from?

Answer 37

Traumatized tissue or poor blood circulation

Question 38

How do you treat anaerobic cellulitis?

Answer 38

IV antibiotics and surgical debridement

Question 39

What is gas gangrene?

Answer 39

Organisms multiplying in subcutaneous tissues and invading deeper tissues

Question 40

What is classic gangrene caused by?

Answer 40

Clostridium perfringens

Question 41

Describe the morphology of C. perfringens

Answer 41

G+ anaerobic spore forming bacilli

Question 42

What is the pathogenicity of C. perfringens?

Answer 42

Alpha toxin, collagenase and hyaluronidase breaks down tissue and WBC

Question 43

What causes tetanus or "lockjaw"?

Answer 43

Clostridium tetani

Question 44

What are the symptoms of tetanus caused by

Answer 44

A neurotoxin, tetanospasmin, blocks release of inhibitory neurotransmitters, causing spasms

Question 45

>50% of tetanus cases are caused by:

Answer 45

Puncture wounds

Question 46

What type of vaccine is there for tetanus?

Answer 46

Toxoid vaccine

Question 47

What organism commonly infects burn wounds?

Answer 47

Pseudomonas aeruginosa

Question 48

Describe the morphology of P. aeruginosa

Answer 48

Motile G- bacteria that can grow aerobically or anaerobically

Question 49

What is the pathogenicity of P. aeruginosa?

Answer 49

Exotoxins damage cells + promote spread of infection and prevent healing