Septic Arthritis Flashcards
What is bacterial arthritis?
Non-GC septic arthritis
What causes NON-GC septic (bacterial) arthritis?
Normal host: staph aureus
Immunocompromised people: Gram neg cocci, gram neg bacilli, fungi, or mycobacteria
What can happen to the patient if NON-GC septic (bacterial) arthritis goes untreated?
- Cause a destructive arthropathy (eats away at the cartilage)
- Development of osteomyelitis (goes into the bone)
- Lead in permanent joint damage
What are some risk factors for NON-GC septic (Bacterial) arthritis?
- Increasing age
- Presence of joint prostheses
- Rheumatoid arthritis
- Systemic steroid therapy
- Decubitus ulcer
What is the clinical presentation of NON-GC septic bacterial arthritis?
- Mono articular
- Fever
- Acute onset, pain, swelling, heat (progressively worsens)
If a patient comes in with NON-GC septic (bacterial) arthritis what will you find during the physical examination?
- Look for the cause (Wound, furuncle, abscess)
- Joint will be held in a comfortable position
- Severe pain with PROM
- Warmth
- Effusion (swelling)
What are the laboratory findings of NON-GC Septic (bacterial) arthritis?
- WBC count in blood and synovial fluid may be normal or abnormal (classically elevated)
*WBC usually >50,000/MCL and is often >100,000
*90% or more PMN cells (cells that are released during infection) - gram stain is usually positive as are cultures
- Blood culture positive 50%
- Antibiotics before culture decreases chance of a positive culture
What is the main treatment for NON-GC septic (bacterial) arthritis?
- Joint aspiration I&D
What is the treatment for NON-GC septic (bacterial) arthritis? (Gram positive staph)
Vancomycin to cover MRSA
What is the treatment for NON-GC septic (bacterial) arthritis? (Gram negative Cocci)
Pencillin G or cephalosporin
What is the treatment for NON-GC septic (bacterial) arthritis? (Gram negative bacilli)
Cephalosporin and gentamicin
What is the treatment for NON-GC septic (bacterial) arthritis? (Negative gram stain but infection still suspected)
Nafcillin with gentamicin or vancomycin with gentamicin
What is the general antibiotic treatment for NON-GC septic (bacterial arthritis)
- Vancomycin 1g Q12H WITH
- 3rd generation cephalosporin (ceftriaxone 1-2g IV daily most commonly sued)
*will provide broad spectrum coverage change when C&S results back
If a patient has NON- GC septic (bacterial) arthritis what are the necessary steps to take?
- Admit to hospital
- Consults orthopedics ASAP
- Unknown etiology- Broad spectrum IV antibiotics until C&S results
- Immobilization, elevation
- Therapy/ ROM (early, w/o therapy there will be contracture)
What can impact the prognosis of non GC Septic (bacterial) arthritis?
- Comorbidities
- Etiology (s. Aureus poor functional outcome)
- Timing of treatment
- 5-10% die of respiratory complications (sepsis)
- 30% mortality rate if polyarticular
What are the clinical features of Dissmeinate GC Septic arthritis ?
- Young sexual active individuals
- Often penicillin resistant
- Abrupt poly articular onset common
- May develop skin lesions
- Assume chlamydia
How to diagnose GC septic arthritis
- Will be difficult to culture the organism from skin lesions or the joint
*culture will most likely be positive at the vagina, rectum, or orally - Tenosynovitis is common (inflammation of the tendon sheath)
*If present with poluarticular disease, strongly consider GC septic arthritis
What are the lab tests of GC Septic arthritis ?
- Peripheral WBC smear increased in 1/3
- Synovial fluid WBC 30,000- 60,000
- Synovial fluid gram stain positive (1/4 of patients)
- Synovial culture positive (1/2 of patients)
- Blood culture positive is rare
- Urethral, throat, cervical, and rectal culture on all suspected patients more likely to be positive than above tests
What is the antibiotic treatment for GC septic arthritis
Assume PCN resistance
1. Azithromycin 1g orally and ceftriaxone 1g IV QD
2. Admission generally recommended (exclude endocarditis)
3. Drainage not frequently required
