prosthetic joint infection-original

Prosthetic Joint Infections

Introduction to the Infectious Patient

Susanne Barnett, PharmD, BCPS

[email protected]

Objectives

Understand the pathophysiology of prosthetic joint infections (PJIs)

List bacterial pathogens commonly implicated in PJIs

Identify first-line therapy for PJIs

Evidence-Based Resources

Osmon DR, et al. Diagnosis and management of prosthetic joint infection: Clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2012;56:e1-25.

Prosthetic Joints

Images accessed 3/17/13 at: http://www.scripps.org/articles/2029-knee-joint-replacement; http://www.antimicrobe.org/new/printout/e3printout/e3treat.htm

Epidemiology

Patients receiving total hip (THA) and knee (TKA) arthroplasties in U.S. annually is ~1,000,000

Risk of infection is ~ 1-2%

Prosthesis removal is usually necessary to treat these infections

Annual U.S. healthcare costs up to $700 million

Osmon DR, et al. Clin Infect Dis. 2012;56:e1-25.Brause BD. Chptr 104 in Mandell et al. Principles and practice of infectious diseases. 7th ed. 2010.

Pathophysiology

Route of infection Local (contiguous) Hematogenous – 20-40% (e.g. bacteremia)

Infection often occurs in osseous tissue adjacent to a foreign body (bone-cement interface)

Clinical Presentation

Joint pain (95%)

Fever (43%)

Periarticular swelling (38%)

Drainage (32%)

Early, Delayed, or Chronic Infections

Causative Pathogen(s)

Pathogens Frequency (%)Coagulase-negative staphylococci 22Staphylococcus aureus 22Viridans Streptococci 9ß-Hemolytic streptococci groups A,B, G

5

Enterococci 7Gram negative aerobic bacilli 25Anaerobes 10

Brause BD. Chptr 104 in Mandell et al. Principles and practice of infectious diseases. 7th ed. 2010.

Diagnostics

Pre-operative Radiographic studies CRP and ESR Arthocentesis (cultures)

Intra-operative Histopathological examination 3-6 peri-prosthetic tissue samples/explanted prosthesis for

culture

Osmon DR, et al. Clin Infect Dis. 2012;56:e1-25.; Images accessed 3/18/13 at: http://www.hss.edu/conditions_revision-total-hip-replacement-overview.asp

Prosthetic Joint Infections Assessment Q #1

Which of the following is FALSE regarding prosthetic joint infections?

A) Local or contiguous infection is more common than hematogenous infection

B) Incidence of PJIs is declining

C) Patients w/ PJIs often present with a cc of joint pain

D) Staphylococcus species are a common cause of PJIs

Prosthetic Joint Infections…defined

Definitive definition Presence of a sinus tract communicating to the prosthesis Purulence without another known etiology surrounding the

prosthesis ≥2 intraoperative cultures yielding the same organism Combination of intraoperative cultures and preoperative aspiration

yielding the same organism

Highly suggestive Acute inflammation seen on histopathologic examination at time of

prosthesis removal Growth of virulent organism in single sample

Osmon DR, et al. Clin Infect Dis. 2012;56:e1-25.

Treatment of Choice

Debridement and retention of prosthesis Staphylococcus aureus: Nafcillin, cefazolin, ceftriaxone

Alt: Vancomycin, daptomycin, or linezolid 2-6 weeks pathogen specific IV antimicrobials + po rifampin bid Followed by po levo/cipro + rifampin Alternative: TMP/SMX, minocycline/doxycycline, cephalexin,

dicloxacillin Total DOT: 3 months (hip) or 6 months (knee)

Other organisms 4-6 weeks pathogen specific IV or highly bioavailable oral abx

Consider chronic, long-term suppression if device removal not possible Cephalexin, dicloxacillin, TMP/SMX, minocycline


Antimicrobial Therapy

Resection +/- staged reimplantation (2-stage) 4-6 wks pathogen specific IV or highly bioavailable oral abx

Following 1-stage exchange (uncommon) Staphylococcus aureus

2-6 weeks pathogen specific IV antimicrobials + po rifampin bid Followed by po levo/cipro + rifampin Alternative: TMP/SMX, minocycline/doxycycline, cephalexin,

dicloxacillin Total DOT: 3 months (hip or knee)

Other organisms 4-6 weeks pathogen specific IV or highly bioavailable oral abx

Can consider chronic oral suppression in select cases


Antimicrobial Therapy

Following amputation Removal of all infected bone/tissue AND no

sepsis/bacteremia Pathogen specific IV abx 24-48 h post procedure

Residual infected bone and/or soft tissue 4-6 weeks pathogen specific IV or highly bioavailable oral

therapy


PJIs: Pathogen Specific Antimicrobials


Attachment and growth of bacterial communities

Common in staphylococci, Pseudomonas spp.

Biofilm microbes are 10–1000 times less susceptible to antimicrobials

Rifampin has high activity against biofilm organisms

Esposito S. Int J Antimicrob Agents. 2008 Oct;32(4):287-93.; Osmon DR, et al. Clin Infect Dis. 2012;56:e1-25. Images accessed 3/18/13 at: http://hardinmd.lib.uiowa.edu/cdc/staph/sem3.html.

Biofilms in Prosthetic Devices

PJI Assessment Q #2

Which of the following regimens is the best initial choice for a patient undergoing a 2-stage reimplantation for methicillin-susceptible S. aureus?

A) Cefazolin IV + PO rifampin

B) Ciprofloxacin IV + PO rifampin

C) Levofloxacin PO + nafcillin IV

D) Cefazolin IV

Role of the Pharmacist

Monitor culture results and susceptibilities

Monitoring of patient response ESR, CRP, pain, swelling, tenderness

Monitoring for adverse events to long term IV antimicrobial therapy Long-term oral therapy for those with chronic suppressive

therapy

Key Points

Prosthetic joint infections can occur via hematogenousor contiguous spread

Treatment of PJIs involves surgery and antibiotic therapy

Staphylococcus spp. are the most common organisms associated with PJIs

Nafcillin, cefazolin, or ceftriaxone are often first-line therapy

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