Case 2. Case 3 - course. PE: uncomfortable, but NAD T 38.0 R 22 HR 120 BP130/60

Transcription

1 Case 2 42 y/o man c/o painful right arm and shoulder x 3 days. Hx of IDU ( skin popping heroin ). No other trauma or bite. PE: uncomfortable, but NAD T 38.0 R 22 HR 120 BP130/60 PMH: HCV, HBV, HIV negative, hx of multiple abscesses Differential: 12% bands 75% PMN Chemistries normal CXR: normal Case 3 - course Immediate antibioitics: Unasyn + clinda + vanco Immediate surgical consultation To OR 3 hrs after presentation, for suspicion necrotizing infection OR findings: massive subq edema; fat necrosis; muscle and fascia necrosis Pt died 2 hours post op from refractory shock 1

2 Necrotizing soft tissue infections (s) - definition Histologic findings: extensive tissue necrosis, thrombosed vessels, abundant bacteria with few inflammatory cells Clinical definition: rapidly progressive soft tissue infection, eventually associated with systemic toxicity, fatal without surgical therapy s - nomenclature Necrotizing cellulitis (fascia and muscle spared) Necrotizing fasciitis Type I: synergistic gangrene, gas gangrene, Fournier s gangrene, cervical nec. fasc. (Ludwig s angina), anaerobic myonecrosis Type 2: group A streptococcus (GAS)-associated (Step. toxic shock syndrome (TSS), flesh eating bacteria! ) s - bacteriology s - simplified pathophysiology 1/3-3/4 polymicrobial Staphylococcus - aureus (incl MRSA), epidermidus Nonclostridial anaerobes (oral anaerobes) Non group A Streptococcus Clostridium - perfringens and others Group A Streptococcus Most common monomicrobial culprit Gram negatives Devitalized tissue + Synergistic infection (Clostridium) Invasive GAS +/- host susceptibility Rapid bacterial growth & spread Nec fasc Myonecrosis Fournier's Strep TSS Exotoxins, cytokines s risk factors s epidemic in N. California IDUs IDU 30-56% of cases in urban series Typically, long hx of IDU / skin popping Diabetes Foot & lower extremity most common Post trauma and surgery Peripheral vascular disease Malnutrition & alcoholism Bosshardt. Arch Surg 1996 Davis, CA 107 cases presenting to ED 59 (55%) IDU Chen. Clin Inf Dis

3 s outbreaks in IDUs San Francisco, cases of Clostridial myonecrosis in IDUs in 5 weeks, 3 roommates Molecular linkage & Clostridia cultured from paraphernalia United Kingdom, spring cases; 45% mortality Mean WBC 64,000 C perfringens, Clostridium novyi Oakland CA, 2001 > 40 cases presenting to ED; ~20% mortality Clustered, assoc. w/ black tar heroin Case 3 36 y/o woman c/o 2d calf pain and swelling. Vague hx of recent minor trauma. No bite or wound. PMH: NIDDM Hab/Soc: no IDU MED: glyburide Afebrile BP 130/70 HR 95 R 20 WBC 12.2 Bangsberg. Arch Int Med 2002 MMWR 2000 Lonergan. J Emerg Med 2004 due to Group A Streptococcus Classic scenario: kids following varicella Usually: Adult victims without risk factors Community onset Portal of entry: none (50%) or trivial (blunt trauma) Clusters described GAS is spread among close contacts Consider post-exposure prophylaxis s presentation s presentation Average 3-4 d of sx prior to presentation Pain >> skin signs (common but not universal) Erythema (77%), induration (43%), swelling, warmth Classic signs frequently absent: Bullae Crepitus Cutaneus sensory deficit Skin necrosis Very characteristic in IDU s tense edema trunk WBC Fever: ~20-80% WBC: ~85% (WBC > 20 in over 50%) Shock or organ dysfunction: 0-40% 3

4 : diagnostic tests of foot soft tissue gas on plain x-ray Plain x-ray for gas: ~ 30% sensitive CT scan for gas: more sensitive than plane film MRI Ultrasound Strep. rapid antigen test Bedside fascia inspection CPK in myonecrosis WBC > 14 + Na <135 Necrotizing fasciitis ultrasound findings Necrotizing fasciitis MRI findings Fascial enhancement Thickening Adjacent fluid Lacks specificity diagnostic approach risk factors for poor outcome (15-30% mortality) INDEX OF SUSPICION is the key IMMEDIATE surgical consultation EARLY exploration and debridement Time to OR is only correlate of survival that is modifiable Low threshold for operation (analogous to traditional approach to appendicitis) Systemically ill patient still goes to OR Be forceful with inexperienced surgical consultants Age > 60, # of organ system failure, extent of infection, elevated Cr Delay to operation >12-24 hrs appears to quadruple mortality Admission to a nonsurgical service Negative bedside FNA 4

5 s pattern recognition 1. IDUs: beginning at injection site on extremities trunk; marked edema; WBC; case clusters 2. Feet lower extremities, in diabetics 3. Perineum lower abd, usually in men (Fournier s) 4. Head & neck, dental source (Lugwig s) 5. GAS-associated: normal host w/ unexplained severe soft tissue pain; leukocytosis or fever; case clusters antibiotic therapy Non IDU, type 1 (diabetic foot, Fournier s): Pipercillin/tazobactam + clindamycin + vanc* IDU (resistant GNRs rare): Clindamycin + vanc* +/- pipercillin/tazobactam GAS infection: Clindamycin + PCN G * If MRSA a local problem, add vancomycin Worried about a? Worried about a? Skin & soft tissue infections take home messages Think like a surgeon Look for pus (ED ultrasound) & drain it! Consider, which requires immediate surgery Bonus Slides CA-MRSA Wherever you are CA-MRSA is there When in doubt, culture SSTIs 5

6 Cellulitis ddx Infectious Deep abscess Tenosynovitis Necrotizing soft tissue infection Gout & pseudogout DVT Insect bite allergic reaction (esp. bee stings) Drug allergy (esp fixed drug eruption) Other: pyoderma gangrenosa, Sweet s syndrome, Kawasaki s disease Run of the mill Erysipelas Periorbital Buccal IDU-related Liposuction-related Cellulitis pathogens Setting Post surgical (mastectomy, saph vein harvest, etc) GAS Pathogens group A strep. (GAS), S. aureus (community-acquired MRSA?) S. aureus, GAS, pneumococcus Hemophilus influenzae S. aureus (MRSA), Strep (group A,C,F,G) Non-group A hemolytic strep. GAS, peptostreptococcus Bottom line: Strep. & Staph. coverage required (+/- community-acquired MRSA) Recommended therapy: Penicillin alone Erysipelas Special cellulitis pathogens Setting Diabetic foot ulcer Human bite Cat, dog bite Salt water + wound Fresh water + wound Fish handler, butcher Salt water (fish tank) Vibrio vulnificus Aeromonas sp Erysipelothrix Pathogen GNR s incl P. aeruginoa, GAS, S. aureus, anaerobes incl B. fragilis Eikenella corrodens, oral anaerobes, Strep., S. aureus Pasteurella multocida, S. aureus Mycobacterium marinarum PIP/TZ or clinda + FQ or Imipenim; +/- Vanc Amox/clav Amox/clav Cipro or Ceftazadime Doxy antibiotic Cipro or cefotax. Clarithro or doxy or others SSTIs assoc. w/ water exposure Careful micro eval Gram & acid fast stains Cx & AFB Empiric ceftazidime + quinolone ID consult recommended Cellulitis evaluation & treatment Blood cultures (in febrile cellulitis): + in 3-30%; rarely change management Generally recommended prior to admission Needle aspirates and punch biopsies Vibrio vulnificus Fish tank granuloma mycobacterium marinum Admission criteria: fever, failure of outpt tx Antibiotics*: IV: cefazolin, nafcillin, ceftriaxone Oral: cephalexin, dicloxacillin Elevation *If local MRSA prevalence is : add IV vanco, clinda or linezolid or po clinda,tmp/smx, or linezolid 6