Updated Guidelines for Managing Diabetic Foot Infections

Transcription

1 Updated Guidelines for Managing Diabetic Foot Infections Benjamin A. Lipsky, MD, FACP, FIDSA, FRCP Emeritus Professor, University of Washington Visiting Professor, University of Geneva Visiting Professor, University of Oxford

2 Doctor, your next patient is a diabetic with a foot infection...

3 Hospital Discharges for Diabetic LE Condition In Thousands, USA PAD Ulcer/ Infection Neuropathy Number of hospital d/c for diabetic patients with peripheral arterial disease (PAD), ulcer/inflammation/infection, or neuropathy as 1 st listed diagnosis CDC, 2013:

4 Guidelines for Managing Diabetic Foot Infections Many diabetic foot guidelines before 2004, but refer to infection only as present or absent 2004: Two groups empaneled expert committees to draft guidelines specifically for DFI International Working Group on the Diabetic Foot (IWGDF): now translated into >20 languages Infectious Diseases Society of America (IDSA): over 970 citations, >100,000 downloads/views

5 Web of Science: Diabetic Foot Infections Citations & Publications in Past Decade Published Items/year Citations/year ISI Web of Science January 2013

6 IWGDF DFI Guidelines: Revised (2012)

7 IDSA DFI Guidelines: Revised (2012) Clinical Infectious Diseases 2012;54(12): Published by Oxford University Press on behalf of the Infectious Diseases Society of America DOI: /cid/cis346

8 New IDSA Guidelines: The 10 Key Questions 1. When to suspect, how to classify a DFI 2. How to assess the wound, foot, patient 3. When & with whom to consult 4. When to hospitalize; to discharge 5. When & how to collect culture specimens 6. How to select/modify antibiotic regimen 7. When & which imaging studies to order 8. How to diagnose & treat osteomyelitis 9. When is surgery needed & what kind 10. What wound care & dressings to use

9 Clinical Classification Diabetic Foot Infection IDSA IWGDF Clinical Manifestations* Severity PEDIS No purulence or inflammation (erythema, pain, warmth tenderness, or induration) Infected ( 2 signs/sx inflamtn) but erythema 2 cm around ulcer, & infection limited to skin or the superficial subcutaneous tissues 1 of following: cellulitis >2 cm; lymphangitis; subq spread; deep abscess; gangrene; muscle, tendon, joint or bone involved Uninfected 1 Mild 2 Moderate 3 Severe 4 Systemic toxicity or metabolic instability *Severity worsened by ischemia

10 Epidemiology of Diabetic Foot Infections Population having diabetes: 8+% Develop a foot wound: 15-25% Wound infected at presentation: 40-70% Mild: 40+% Moderate: 30-50% :10-25% Lipsky et al, Clin Inf Dis 2012;54:132

11 Clinical Characteristics Suggesting a More Serious Diabetic Foot Infection (Table 3A) Systemic: SIRS, delirium, azotemia, etc Deep tissue abscess, gangrene, necrosis Courtesy: J. Aragon Sanchez

12 Factors Suggesting Hospitalization May be Necessary (Table 3B) Severe infection (Table 3A) Metabolic instability IV Rx needed (& not available/appropriate as outpt) Diagnostic tests needed not available as outpatient Critical foot ischemia present Surgical procedures (more than minor) required Failure of outpatient management Patient unable/unwilling to comply with outpt Rx Need for complex dressing changes

13 Microbiology of Diabetic Foot Infections

14 Obtaining a Specimen for Wound Culture Swab Curettage (Tissue Bx) Aspiration Biopsy

15 Bacteria Causing Diabetic Foot Infections Organisms % of Infections Aerobes Gram-positive S. aureus Streptococcus spp Enterococcus spp Coag-neg. staphs 7 12 Gram-negative Proteus spp. 5-6 Enterobacter spp. 2 3 E. coli 3 5 Klebsiella spp. 1-2 P. aeruginosa 2 7 Other GNRs 3 8 Anaerobes Gram- positive Finegoldia 8 27 Clostridium spp. 0 2 Gram-negative B. fragilis group 5 11 Other Bacteroides sp 3 6 Other anaerobes % are polymicrobial: Mean of organisms Based on data from multiple published studies

16 Microbiology of the Diabetic Foot: An Overview Microbial complexity Microbial burden Anaerobes Gram rods Chronicity Gram + cocci Depth Necrosis Prior Abx PEDIS classification of infection Lipsky BA, Berendt A, The Diabetic Foot: Essentials of Managing Infectious Complications. CMG/Springer 2008

17 Factors that may Influence Choices of Antibiotic Therapy for Diabetic Foot Infections (Table 4) Infection related - Clinical severity of the infection - H/O antibiotic therapy w/n 3 mos - Bone infection (presumed/ proven) Pathogen related - Likelihood of non-gpc pathogen(s) - H/O MDROs colonization/ infection - Local rates of antibiotic resistance Patient related - Allergies to antibiotics - Impaired immunological status - Patient treatment preferences - Renal or hepatic insufficiency - Impaired gastrointestinal absorption - Arterial insufficiency in affected limb Drug related - Safety profile (frequency & severity of AEs) - Drug interaction potential - Frequency of dosing - Formulary availability/ restrictions - Cost considerations (acquisit n & administ n) - Approval for indication - Likelihood of inducing C. difficile disease or antibiotic resistance - Published efficacy data

18 Antibiotics for DFI: Revised IDSA Guidelines Route & Agent Mild Mod erate /Severe Comments Table 8 Dicloxacillin (po) [* = 1 DFI trial] Requires QID dosing, inexpensive Cephalexin (po)* [Ital=FDA aprvd] Requires QID dosing, inexpensive Clindamycin (po,iv)* t [ t =covers MRSA] GP aer/ana-robes; ±MRSA; D-test Trimeth/Sulfa (po,iv) t [Bold=common] GPC (± streps), GNR, C-A MRSA Amoxicillin/clav(po)* Relatively broad-spectrum Levofloxacin (po,iv)* QD dosing; suboptimal S. aureus Moxifloxacin (po,iv)* QD dosing; better for anaerobes Cefoxitin (IV)* 2 nd gen cephalosporin- for anaerobes Ceftriaxone (IV,IM) 3 rd gen cephalosporin; QD dosing Ampicillin/sulb (IV)* Rel. broad-spectrum, not Ps aerug. Linezolid (po,iv)* t GPs & MRSA; $$; toxicity >2 weeks Daptomycin (IV)* t GPs & MRSA; $$; QD; monitor CK Vancomycin (IV)* t Cheap; MIC creep; monitor for creat Ertapenem (IV)* QD; rel. broad-spect, not Ps aerug. Tigecycline (IV)* t Broad-spect. & MRSA;N/V; efficacy Piperacillin/tazo(IV)* TID/QID; broad-spect. & Ps aerug. Imipenem-cilast (IV)* Broad-spect. & ESBLs; not MRSA

19 Diagnosing DFO: Current Methods Clinical History: long wound duration, recurrent infection Exam: deep/large (>2 cm 2 ) ulcer; over bony prominence; visible bone/joint; sausage toe Probe-to-bone: useful if done/interpreted correctly Dinh et al Clin Inf Dis 2008;47:519; Butalia et al JAMA 2008;299:806 Berendt et al. Diabetes Metab Res Rev 2008;24 Suppl 1:S145

20 The Probe-to-Bone Test in DF Osteomyelitis Method (Grayson, JAMA 1995): 14 F blunt metal probe Bone: gritty, hard feel Interpretation: Key issue is pre-test probability Helps R/O DFO when low Helps confirm when high Lipsky BA, Berendt AR, Osteomyelitis, Am Coll Phys Medicine 2010

21 Diagnosing DFO: Current Methods Clinical History: long wound duration, recurrent infection Exam: deep/large (>2 cm 2 ) ulcer, bony prominence visible bone/joint, sausage toe Probe-to-bone: useful if done/interpreted correctly Blood tests: WBC, ESR, C-RP, PCT,? biomarkers Imaging Plain x-ray: limited sensi (early) & specif (late) Radionuclide scans: WBC>bone; non-specific MRI: best current test; marrow edema, soft tissue SPECT/CT, PET/CT, PET/MRI quite promising Bone biopsy: for culture & histology (gold standard) Dinh et al Clin Inf Dis 2008;47:519; Butalia et al JAMA 2008;299:806 Berendt et al. Diabetes Metab Res Rev 2008;24 Suppl 1:S145

22 Bone Biopsy for Diabetic Foot Osteomyelitis Courtesy: E. Senneville, MD

23 In Which Situations Is Diagnostic Bone Biopsy Most Recommended? Uncertainty regarding the diagnosis of osteomyelitis despite clinical and imaging evaluations Absence (or confusing mix) of culture data from soft tissue specimens Failure to respond to empiric antibiotic therapy Plan to insert metalware in bone at affected site Desire to use antibiotic agents that may be especially effective for osteomyelitis but have a high potential for selecting resistant bacteria (eg, rifampin, FQs)

24 Treating DFO: Suggested Approach Resecting infected, necrotic bone usually recommended, but Consider nonsurgical approach if: No persisting sepsis (after if on antibiotics) Pt can receive and tolerate appropriate antibiotic Bone loss has not irretrievable foot compromise Surgical risk high due to patient comorbidities Patient prefers to avoid surgery Surgery not required for bone or soft tissue issues Consider bone resection if: Patient/MD prefer to avoid long-term antibiotics Needed for manageable soft tissue wound/closure IDSA DFI Guidelines Table 10

25 Surgical Intervention in Diabetic Foot Infections Most infected wounds require some debridement, many require I & D Seek surgical consultation for infection with gas in deeper tissues, abscess, substantial nonviable tissue, necrotizing fasciitis, extensive bone or joint involvement, bullae, neurologic loss, new anesthesia 4 central The surgeon should have spaces knowledge of foot anatomy & experience in dealing DFIs Evaluate limb arterial supply; consider revascularization

26 Adjunctive Therapies for Diabetic Foot Infection Hyperbaric oxygen therapy May hasten recalcitrant wound healing No evidence that helps cure bone/st infection Granulocyte colony stimulating factors May reduce need for surgery (including LEA) Does not hasten cure of infection Maggot (larvae) biotherapy : some benefit for both debridment and antibiotherapy Rx with no proven value for curing infection Advanced dressings Silver based treatments Negative pressure therapy Peters et al, Diab Met Res Rev 2102; Feb;28 Suppl 1:142

27 Outcome of Treatment Mild infections: 90% resolve with appropriate Rx Moderate/Severe infections: Many require surgical debridement (soft tissue ± bone) or LE amputation (usually partial/minor) With extensive infection LEA rates up to 50-60% (most foot-sparing), but infection cure in ~80% Recurrence of foot infection in 20-35% ( w/ osteo) Evidence of cure of infection Resolution of signs/symptoms of infection Normalization of inflammatory markers Signs of bone healing on x-ray Multidisciplinary teams: improve outcomes

28 Amputation Rate/100,000 UW/UG/GTC/UO The Value of a Diabetic Foot Service General Population, Ipswich Hospital, UK Change amputation rates Total 40% Major 62% Minor 22% Foot service introduced Reduced service Service returned Krishnan et al, Diabetes Care 2008;31:99

29 Validation of IDSA DFI Severity Classification Severe DFI defined as 2 findings SIRS criteria (T>38 /<36 C; HR>90; RR>20; WBC>12K/<4K) 119 pts: 54 with severe vs 65 with moderate DFI 2.5 X risk any amputation 7.1 X risk major amputation (same for minor) 7.8 X presentation with gangrene 5 X anorexia, chills, nausea/vomiting 4 days mean length of stay - re-admissions, organisms on wound culture Wukich et al, Foot Ankle Int 2013; 34:351 Wukich et al, Diab Care 2013:36:3706

30 Have DFI Guidelines Been Found to be Useful? Benefits of Implementing DFI Guidelines in France 2003 audit of microbiological assessment of DFI Many clinically uninfected wounds cultured Most cultures collected by suboptimal techniques Frequently isolated MDROs (especially MRSA) Isolated many low-virulence (likely colonizing) species Developed & implemented IDSA-based guidelines emphasizing appropriate wound culture methods Re-audited clinical & micro data on 405 pts Improved compliance with guidelines associated with Savings: 20,555 lab workload; 210,585 treatment Sotto et al, Diabetologia 2010 ;53:2249

31 Diabetic Foot Infections: Summary Common, complex and costly problem Classification: based on severity (± ischemia) Causative organisms: GPC >> GNR > Anaerobes Antibiotic therapy: choosing empiric, definitive Often need debridement, I&D; ± revascularization Osteomyelitis: difficult to diagnosis & to treat Adjunctive measures occasionally helpful Multidisciplinary teams improve outcomes Guidelines have been tested for validity, usefulness How do we improve implement, audit, study

32 축하해요 Chugha haeyo

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