Bone and Joint Infections Flashcards
Who should get pseudomonal coverage in a diabetic foot infection? [2]
- Exposure to water
- Clinical failure while receiving nonpseudomonal therapy
–> Pseudomonas is implicated only in a small percentage.
Labs to order in diabetic foot infection? [5]
- CBC
- CMP
- A1c
- ESR/CRP
- Blood cultures
Mgmt of foot ulcer in a patient with DM without redness, warm, swelling, drainage or order
Local wound care
No abx.
Length of abx therapy for diabetic foot infection?
4-6 weeks if no surgical debridement
Definition of a mild diabetic foot infection?
Do not extend deeper than skin and subcutaneous tissues, erythema is <2 cm from ulcer
Definition of a moderate diabetic foot infection?
Infection extends deeper than skin and subcutaneous tissues, erythema is >2 cm from ulcer
Definition of a sever diabetic foot infection?
There is associated systemic signs and symptoms.
Treatment of a mild diabetic foot infection? [3]
- Bactrim
- Clinda
- Doxy
–> MRSA/MSSA likely etiology
Treatment of a moderate diabetic foot infection? [2]
- Bactrim + Augmentin
2. Clinda + Fluoquinolone [Cipro, levo, moxi]
Three mechanisms of septic arthritis development? [3]
- Hematogenous spread from distant foci of infection [endovascuar, odontogenic]
- Contiguous spread [steroid injection, trauma]
- Extension from osteomyelitis
Most commonly involved joints in septic arthritis? [5]
- Knee [50%]
- Hip
- Shoulder
- Elbow
- Ankle
What joint involvement should prompt evaluation for IVUD? [2]
- SI joint
2. Sternoclavicular joint
Labs to obtain in evaluation of septic arthritis [4]
- CBC
- CMP
- ESR/CRP
- Blood cultures [positive in up to 50% of cases]
What joint fluid studies be sent
- Cell count and diff
- Gram stain and cultures [Aerobic, anaerobic, fungal AFB]
- Crystal analysis
Imaging studies to get?
- X-ray
- MRI [or CT if you cant get an MRI]
- Echo if endocarditis is suspected
How does disseminated gonococcal infection present?
Arthralgias [migratory], tenosynovitis [extensor] and rash [arthritis-dermatitis syndrome].
Purulent distal mono or oloigoarthritis can be seen in 1/3 of uncreated cases effecting the knees, wrists, and ankles.
Describe the cutaneous findings in a DGI
Maculopapular rash to pustular dermatosis of the palms and soles with 10-15 lesions on average.
Organisms to cause septic arthritis postpartum or in a recent history of GU tract manipularion
Mycoplasma hominis
Who gets GBS septic arthritis
Poorly controlled DM, cancer
Who gets strep pneumo septic arthritis
Those with splenic dysfunction
Describe the WBC count, PMN%, and appearance of the synovial fluid in non-inflammatory OA.
WBC: <200
PMN%: <25
Fluid: Transparent
Describe the WBC count, PMN%, and appearance of the synovial fluid in a normal patient
WBC: <200
PMN%: <25
Fluid: Transparent
Describe the WBC count, PMN%, and appearance of the synovial fluid in inflammatory arthritis [gout, pseudogout, RA]
WBC: >2,000
PMN: 50% or more
Fluid: Mildly opaque
Describe the WBC count, PMN%, and appearance of the synovial fluid in septic arthritis
WBC: >50,000
PMN: 75% or more
Fluid: Cloudy
Describe the WBC count, PMN%, and appearance of the synovial fluid in hemarthrosis
WBC: Variable, may be falsely elevated due to RBCs
PMN: 50-75%
Fluid: Bloody
Diagnosis of DGI?
NAAT of throat, rectum, urethra
NAAT of synovial fluid
Treatment of DGI?
- Ceftriaxone 1g IV q24 + Azithro 1g PO 1x.
2. May step down to doxycycline or cefixime if susceptible.
How does lyme arthritis present?
Monoarthritis in the knee most commonly
May not have systemic symptoms
Diagnosis of lyme arthritis
PCR for lyme in the synovial fluid
Treatment of lyme arthritis?
- Doxy
- Amoxicillin [alt]
- Cefuroxime [alt]
30 days of treatment
Most common nontuberculous mycobacteria that cause septic joints? [2]
- Chelonae
2. Fortuitum
Most common cause of fungal septic arthritis
Candida
–> Uncommon
Lab work up of septic arthritis? [5]
- CBC
- CMP
- CPK
- ESR/CRP
- Viral serologies?
Viruses that may cause inflammatory arthritis?
- HIV
- HBV
- HCV
- Parvo B19
- Alphaviruses [Chikungunya]