44 Infectious Arthritis and Osteomyelitis Flashcards
Frequently affected joint in septic arth
Knee and hip
Acute septic arth, duration
<2 weeks
Subacute septic arth,septic arth,, duration
2w-3m
Chronic osteomy, duration
> 3m
Usual sites of infection in reactive arth
Upper airway
GI
GU
Septic arth, MC pathogenic mechanism
Hematogenous
Joints with intraarticular metaphyses, giving increased risk for extension of infection from bone to joint space
Hips and shoulders
Conditions MC associated with hip septic arth
URTI with oral ulceration
Atopic derm with erosive skin infection
Varicella
Joints affected with septic arth, in IV drug users
SI joint
SC joints
Septic arth is MC caused by this organism
S. aureus
Organism implicated in septic arth in sickle cells dse
Salmonella
Organism that should be considered in young children with culture-neg skeletal infections
Kingella kingae
MC sites of septic arth
Joints of lower ext: knees > hips
Predisposes to multiple joint septic arth
Chronic granulomatous dse
AIDS
Recomm labs for septic arth
CBC, CRP, ESR, PCT
Very important test for synovial fluid since culture can be negative
GS
Protein and gluc content in septic arth
Protein >2.5g/dL, glucose low relative to plasma
Blood cultures are (+) in ___% of patients with septic arth
40
T/F No causative agent is ever identified in significant number of children with septic arth
T
Synovial fluid PCR remains diagnostic in up to ___ days after antibiotic initiation
6
T/F S. aureus is common even in culture neg MSK infections
T
Imaging modality of choice in children with septic arth
UTZ
T/F UTZ should be performed in all patients suspected to have septic arth
T
Common organisms in septic arth per age
Pg 588 box
MC organism in hematogenous nonneonatal septc arth
S. aureus
1st-line for S. aureus in previously healthy children in communities with low (<10%) rate of CA-MRSA
1st- or 2nd-gen cephalosporin (Cefaz, Cefu)
Drug of choice for S. aureus in previously healthy children in communities with>10% rate of MRSA and resistance to Clinda is low (<10%)
Clinda
REgionally common causative agent of septic arth in children <4y
Kingella kingae
Drug of choice for Kingella kingae septic arth
Cephalosporins
Drug of choice for Salmonella septic arth
Ceftriaxone
Duration of septic arth treatment
IV: 2-4 days with clinical recovery and CRP decreasing
Oral: 10d-2w in previously healthy nonneonatal children if with clinical recovery and CRP decreasing
Target vanco trough level
15-20 ug/mL
Duration of septic arth treatment for CA-MRSA
IV: 1-2 weeks
Total IV + oral: 4-6 weeks
T/F Salmonella requires longer duration treatment than salmonella septic arth
T
Flowchart for workup and treatment of septic arth in children
Pg 591
Recommended empiric abx for septic arth: Child <3m
Cefotax + nafcillin/oxacillin (if >1week in NICU, consider Vanco)
Recommended empiric abx for septic arth: Child >3m
CA-MRSA <10%: Nafcillin/oxacillin or cefazolin
CA-MRSA >10%: Clinda or vanco
Surgery for septic arth is reserved for
Cases unresponsive to abx or have delayed presentation
T/F Intraarticular administration of abx may be necessary in some cases of septic arth
F, abx penetrate joints fluid readily
Excellent lab measure for recovery in septic arth
Serial CRP
T/F Decreasing CRP indicates clinical recovery even if fever persists
T
Duration of monitoring of septic arth patients
At least 1 year
Cause neonatal septic arth through seeding from birth canal
S. aureus, GBS, G- (e. coli, neisseria)
REcommended treatment for neonatal septic arth
Anti staph penicillin + aminoglycoside
Predisposing factors for septic arth in neonates
Umbi cath
Prematurity
Septicemia
Pathognomonic findings for neonatal septic arth
Motionless hip joint that is flexed, abducted, and externally rotated
Hip septic arth MC affects what age group
Infants and young children
Organism that may cause purulent arthritis in several joints
N. gonorrhea
MC mechanism of spread of mycobacterial arthritis
Hematogenous
