Infectious Disease in the ER: 2 infections you can't miss!

Question 1

What is the classic-triad of bacterial meningitis sx?

Answer 1

1. fever
2. neck stiffness
3. altered mental status (<50% cases)

*headache as well

• if all 3 absent, not meningitis
• 2/4 present in 95% px

Question 2

What are all of the sx of bacterial meningitis?

Answer 2

• headache
• fever
• meningismus
• altered sensorium
• vomiting
• seizure
• focal findings
• papilledema

Question 3

What two signs are seen in meningitis?

Answer 3

1. Brudzinski’s sign

2. Kernig’s sign

Question 4

When do you proceed to LP with suspected BM?

Answer 4

• if CT indicates absence of SOL (inc ICP)

* needle b/w L3/4

Question 5

What is the CSF in lumbar puncture used to investigate in BM?

Answer 5

tube 1: cell count and ddx

tube 2: glucose, protein

tube 3: gram stain, culture, special ID studies (viruses etc)

tube 4: cell count, ddx (xanthrochromia)–ensure blood not from puncturing

Question 6

What are the values for the following in BM?

cell count
glucose
protein
gram stain

Answer 6

• cell count: elevated WBC, elevated neutrophils (100-10,000x10^6/L)
• glucose: 1g/L
• gram stain: may be negative in 60% cases

Question 7

What is the rx of BM?

Answer 7

-dexamethasone (blunt inflammation and edema/^ICP) - IV before/with AB, every 6 hrs for 48-96 hrs

Question 8

What is necrotizing fasciitis?

Answer 8

deep infx of subcutaneous tissues–> destruction of subcutaneous tissue, fascia, vasculature, nerves

25% mortality

RF: drug use, DM, obesity, immunosuppression, PVD

Question 9

what are the systemic findings of NF?

Answer 9

• fever
• tachycardia
• hypotension

Question 10

What are the signs/sx of NF?

Answer 10

• tense edema outside involved skin
• disproportionate pain
• blisters/bullae
• crepitus
• subcutaneous gas
• necrosis

Question 11

What are the 2 types of NF (describe)?

Answer 11

type 1: Polymicrobial NF:

• mixed aerobic/anaerobic infx
• most commonly after surgery, in px w DM/PVD

type 2: Monomicrobial NF

• usually Strep pyogenes (GAS)
• must consider CA-MRSA if common in community

Question 12

What bacteria are often causal of NF type 1?

Answer 12

anaerobic: bacteroides sp., clostridium sp., peptostretococcus sp., strep sp. (not grp A), e.coli, enterobacter, klebsiella, proteus

Question 13

What oral anaerobes usually cause head/neck NF type 1?

Answer 13

-fusobacteria, anaerobic strep, bacteroides, spirochetes

Question 14

What is Fournier’s gangrene? what bacteria are commonly involved?

Answer 14

-gangrene of groin (type 1 NF)

facultative organisms:
-e. coli, klebsiella, enterococci

anaerobes:
-bacteroides, fusobacterium, clostridium, anaerobic or microaerophilic streptococci

Question 15

What are 3 types of type 1 NF?

Answer 15

• Fournier’s gangrene
• Traumatic fresh water lesions-aeromonas hydrophila (Georgia)
• Traumatic salt-water lesions (gulf coast, SE US seaboard)- vibrio vulnificus

Question 16

What causes type II NF (hemolytic streptococcal gangrene)?

Answer 16

• group A strep (GAS) or other beta-hemolytic strep** in combo with or alone:
• S aureus
• ca-MRSA if in community

Question 17

Rx for NF?

Answer 17

• antimicrobial therapy: clindamycin, penicillin G Na, IVIG

- EARLY COMPLETE SURGICAL DEBRIDEMENT