Osteomyelitis Flashcards
Methicillin-resistant Staphylococcus Aureus (MRSA)
Predisposing Factors:
Hospitals, prisons, nursing homes, close living quarters, military, athletes, weakened immune systems.
MRSA
Incubation period
Highly variable; typically 4-10 days, but asymptomatic (years)
Any strain of S. aureus that has developed multiple drug resistance(s) to _______________
beta-lactam antibiotics
CA-MRSA definition
Community-acquired MRSA seen in outpatient settings
HA-MRSA definition
Hospital-acquired MRSA, typically nosocomial
MSSA Definition
Any strain of S. aureus susceptible (abled to be killed by) beta-lactam antibiotics
What issue?
SSTIs, specifically furuncles, carbuncles, and abscesses, are the most
frequently reported clinical manifestations.
(a) Patient’s c/c of “spider bite”
(b) Areas of fluctuance and purulent drainage are commonly present
MRSA
What is the mainstay of therapy for any fluctuant lesion secondary to MRSA.
Incision & drainage (I&D)
I&D is followed by
proper packing of the wound, daily dressing changes, and oral antibiotics
What are the antibiotics used to treat a MRSA infection?
(a) TMP-SMX (160mg/800mg)
-1) PO bid x 5-10 days
(b) Clindamycin 300 – 600mg
-1) PO bid x 5-10 days
(c) Doxycycline 100mg
-1) PO bid x 10 days
MRSA – Disposition
Unless complications develop, most cases of MRSA should be
retained onboard and treated by the IDC.
What would these issues necessitate?
(a) SSTI on the face, neck, or head that may require I&D.
(b) Any case of orbital cellulitis, regardless of suspected etiology
(c) Any SSTI unresponsive after 48 hrs. to antibiotics therapy
with activity against MRSA.
(d) Any SSTI with suspicion of transition to osteomyelitis.
(e) Any Necrotizing Soft Tissue Infection consistent with
Necrotizing Fasciitis
An MO should be consulted
MRSA – Disposition
Patients with recurring infections should be
referred to a MO
-May be colonized with MRSA and require decolonization or referral to Dermatology.
What is the 3rd most common bite wound pattern after dog & cat bites?
Human bites
Human bites occur in two basic categories:
a) ____________________
-1) Similar to dog or cat bites; teeth closing over and
breaking the skin
b) _________________________
-1) Skin surface strikes a tooth resulting in damage to skin & underlying structures
(a) Occlusive wounds
(b) Clenched-fist or “fight bites”
Likelihood of infection secondary to human bite determined by depth
& location of wound:
(a) Approximately 2% for ______
(b) <10% for _______
(c) >25% for ____________ or _____________________
a) superficial wounds
b) occlusal bites
c) clenched-fist wounds or other wounds on the hand
What issue?
(1) MOI:
-(a) Often occurs secondary to moderate-to-high speed kinetic impact of clenched-fist with teeth of other individual.
-(b) Occur most commonly in adolescent boys and adult men
(2) Location:
-(a) Typically dorsal aspect of 3rd, 4th or 5th MCP joint
(3) Patho-anatomy:
-(a) Teeth lacerate overlying skin and penetrate capsule of MCP joint during kinetic impact
–i. Mouth flora (bacteria) enter joint.
–ii. Bacteria are trapped under extensor tendon and/or joint capsule as fist is released from clenched position
Clenched Fist Injury (Fight Bite)
Clenched Fist Injury (Fight Bite) Management
– No signs/symptoms of infection
Hand wounds are examined with fingers extended & in the _________ position; wounds can often ‘disappear’ with fingers in extension.
clenched fist
Clenched Fist Injury (Fight Bite) Management
What is the primary factor in preventing infection?
Initial wound care
Initial wound care steps
(a) Control bleeding, clean wound with soap & water, povidone iodine, or CHX.
(b) Assess for tendon injury & assess neurovascular integrity.
(c) Local anesthesia, irrigation with sterile saline & removal of grossly visible debris.
(d) Careful re-examination of cleaned & anesthetized wound
(e) Determine whether wound closure is appropriate.
(f) Dress/bandage wound to prevent secondary infection or injury. Follow-up in 24hrs.
True/False
Human bites are considered tetanus-prone wounds
True
Clenched Fist Injury (Fight Bite)
Management – No signs/symptoms of infection
(1) Hand wounds are examined with fingers extended & in the clenched fist position
(2) Initial wound care
(3) Assessment of TDAP/HBV/HIV immunization/testing status.
(4) Evaluation for ABx prophylaxis & follow-up/re-evaluation Q24 hrs.
until healed,
True/false
Clinically uninfected bite wounds should not be cultured; results not
predictive of subsequent infection.
True
True/False
In general, human bite wounds can be closed due to the
high risk for the development of infection.
False
SHOULD NOT
Patients who undergo primary closure warrant what?
antibiotic prophylaxis.
What is the exception for closing a bite wound and why?
Facial lacerations where cosmesis is a concern