1、SURGICAL INFECTION AND ANTIBIOTICS,OUTLINE Introduction and overview Definitions and SIRS Risk factors for surgical infections Strategies for infection prevention Peritonitis and intraabdominal abscess Special infections Infection risk for the surgeon,SURGICAL INFECTION AND ANTIBIOTICS,InfectionThe
2、inflammatory response to the presence of microorganisms,SURGICAL INFECTION AND ANTIBIOTICS,Sepsis The systemic inflammatory response syndrome in response to infection,SURGICAL INFECTION AND ANTIBIOTICS,Severe Sepsis Sepsis associated with organ dysfunction, hypoperfusion or hypotension,SURGICAL INFE
3、CTION AND ANTIBIOTICS,Septic Shock Sepsis with hypotension, despite adequate fluid resuscitation, along with the presence of perfusion abnormalities that may include, but are not limited to, lactic acidosis, oliguria, or an acute alteration in mental state,SURGICAL INFECTION AND ANTIBIOTICS,The Syst
4、emic Inflammatory Response Syndrome Caused by the systemic effects of locally released cytokines Cytokine release can be triggered by both infectious and noninfectious insults Provides a conceptual framework for the understanding of ARDS and MODS in the absence of infection,SURGICAL INFECTION AND AN
5、TIBIOTICS,Systemic Inflammatory Response SyndromeManifested by two or more of the following: Temperature 38 C or 90 Respiratory rate 20 or PCO2 12 K 10% bands,SURGICAL INFECTION AND ANTIBIOTICS,Multiple Organ Dysfunction Syndrome The presence of altered organ function in an acutely ill patient such
6、that homeostasis cannot be maintained without intervention,SURGICAL INFECTION AND ANTIBIOTICS,Risk Factors for Surgical Infection Surgical wound class SENIC project NNISS,SURGICAL INFECTION AND ANTIBIOTICS,Surgical Wound ClassDeveloped by National Research Council in 1964 Classifies wounds into one
7、of four classes based on degree of contamination Clean Clean contaminated Contaminated Dirty,SURGICAL INFECTION AND ANTIBIOTICS,Study on the Efficacy of Nosocomial Infection Control Published by Haley in 1985 Utilizes four risk factors to stratify riskAbdominal operationOperation longer than 2 hours
8、Contaminated or dirty wound classHaving 3 or more medical diagnoses,SURGICAL INFECTION AND ANTIBIOTICS,National Nosocomial Infection Surveillance SystemDeveloped by Centers for Disease Control Uses 3 risk factorsASA score of 3 or greaterOperation classed as contaminated or dirtyOperation of longer t
9、han “T” hours with “T” being operation specific,SURGICAL INFECTION AND ANTIBIOTICS,Antibiotic prophylaxis Must be given pre-incision No justification for additional dosing Appropriate pharmacokinetics Benefits outweigh risks,SURGICAL INFECTION AND ANTIBIOTICS,Peritonitis and Intraabdominal AbscessCo
10、nventional Principles of Management Control source of contamination Irrigation of peritoneum with saline Closure of the abdomen Close monitoring,SURGICAL INFECTION AND ANTIBIOTICS,Peritonitis and Intraabdominal Abscess Antibiotic Therapy Usually empiric Rarely altered by culture data Should include
11、anaerobic coverage,SURGICAL INFECTION AND ANTIBIOTICS,Peritonitis and Intraabdominal Abscess Duration of Antibiotic Therapy Often empiric e.g. 5,7,10 or 14 days Often unnecessarily prolonged Usually not based on clinical parameters,SURGICAL INFECTION AND ANTIBIOTIC,Peritonitis and Intraabdominal Abs
12、cessDuration of Therapy Patients who are afebrile and with normal WBCs rarely develop further infection if antibiotics are stopped Approximately 30% of patients who are afebrile but with leukocytosis develop further infection when antibiotics are stopped Approximately 80% of patients who are still f
13、ebrile at the conclusion of antibiotics will develop further infection,SURGICAL INFECTION AND ANTIBIOTICS,Peritonitis and Intraabdominal AbscessDuration of TherapySummary Afebrile patients with normal WBC-stop antibiotics Afebrile patients with leukocytosis-either continue antibiotics or evaluate fo
14、r residual infection Febrile patients-evaluate for residual infection,SURGICAL INFECTION AND ANTIBIOTICS,Special Infections Fungal infections Diabetic foot infections Hand infections Invasive streptococcal infections C. dificile infection Tetanus,SURGICAL INFECTION AND ANTIBIOTICS,Fungal Infection F
15、ungal colonization common in ICU Fungal infection less common Risk factors for fungal infectionSeverity of illness (APACHE 20 or )Intensity of colonization,SURGICAL INFECTION AND ANTIBIOTICS,Fungal Infection Diagnosis depends on high index of suspicion Careful culture of blood, urine, sputum, and dr
16、ain material Eye examination important,SURGICAL INFECTION AND ANTIBIOTICS,Fungal InfectionTherapy Amphotericin B 0.5 mg/kg/day IV for 7-10 days Fluconazole 400 mg/day po for additional 7 days Remove central venous catheters,SURGICAL INFECTION AND ANTIBIOTICS,Diabetic Foot InfectionRisk Factors for F
17、oot Problems Neuropathy Vascular insufficiency Altered response to infection,SURGICAL INFECTION AND ANTIBIOTICS,Diabetic Foot InfectionsRole of Antibiotics Antibiotic therapy is an adjunct to overall surgical care Most infections polymicrobial 90% are gram + organisms 50% are gram - organisms 50% ar
18、e anaerobes,SURGICAL INFECTION AND ANTIBIOTICS,Hand Infections Commonly seen ER condition 60% trauma 30% human bites 10% animal bites Most infections result from neglected injury Antibiotics given early prevent many complications Reaction to infection determined by anatomic compartments of hand,SURG
19、ICAL INFECTION AND ANTIBIOTICS,Microbiology of Hand Infections Microbiology depends on type of injury Staph aureus in 35% Anaerobes in 35% 50% of human bites infections are predominantly anaerobic,SURGICAL INFECTION AND ANTIBIOTICS,Antibiotics in Hand InfectionsCoverage should be directed by culture
20、 data In the absence of culture material use broad spectrum penicillin plus B-lactamase inhibitor (e.g. amoxicillin/clavunanate) Erythromycin a good alternative in penicillin allergic patients,SURGICAL INFECTION AND ANTIBIOTICS,Hand InfectionsManagement Principles Immobilization Splinting Rest Eleva
21、tion Surgical drainage Appropriate antibiotics,SURGICAL INFECTION AND ANTIBIOTICS,Invasive Streptococcal Infections Include puerperal sepsis, scarlatina maligna, septic scarlet fever, bacteremia, erysipelas, necrotizing soft tissue and fascia infection, gangrene, and myositis Recent increase in the
22、number and virulence of these infections Occur mainly in healthy, immunocompetent patients,SURGICAL INFECTION AND ANTIBIOTICS,Necrotizing Soft Tissue and Fascial InfectionFirst described by Meleney in 1924 Preantibiotic era mortality rate 20% Modern era mortality rate 50% Increase in virulence? Decr
23、ease in specific immunity?,SURGICAL INFECTION AND ANTIBIOTICS,Necrotizing Soft Tissue and Fascial Infection Presentation 80% follow minor trauma 20% post operative Initial lesion frequently mild erythema Swelling, heat, erythema occur rapidly and spread from initial lesion Systemic toxicity early an
24、d severe,SURGICAL INFECTION AND ANTIBIOTICS,Necrotizing Soft Tissue and Fascial Infection Microbiology Group A hemolytic strep Staph Aureus Enteric organisms including Clostridia species,SURGICAL INFECTION AND ANTIBIOTICS,Necrotizing Soft Tissue and Fascial InfectionTreatment Aggressive surgical deb
25、ridement Initial empiric antibiotic coverage for Staph, Strep, Enterics including Clostridia Tailor antibiotic coverage to culture results,SURGICAL INFECTION AND ANTIBIOTICS,Clostridium Dificile Associated Diarrhea Most common cause of nosocomial diarrhea on surgical units Variable manifestations in
26、cluding No symptoms Peritonitis, toxic megacolon, perforation, death,SURGICAL INFECTION AND ANTIBIOTICS,Clostridium Dificile Associated Diarrhea Clinical Criteria for Diagnosis 3 or more loose stools per day for 2 days without an obvious cause Previous antibiotic or antineoplastic administration wit
27、hin 6 weeks Response of the diarrhea to oral vancomycin or metronidazole,SURGICAL INFECTION AND ANTIBIOTICS,Clostridium Dificile Associated DiarrheaLaboratory Criteria for Diagnosis C. dificile culture-most sensitive test C. dificile toxin assay-most specific test Clinical diagnosis plus positive cu
28、lture adequate to confirm diagnosis,SURGICAL INFECTION AND ANTIBIOTICS,Clostridium Dificile Associated DiarrheaEndoscopic Diagnosis Scope optionsRigid proctosigmoidoscope (25 cm)Flexible sigmoidoscope (60 cm)Colonoscopy If patients do not have pseudomembranes on limited exam, then colonoscopy indica
29、ted Lack of pseudomembranes DO NOT rule out disease,SURGICAL INFECTION AND ANTIBIOTICS,SURGICAL INFECTION AND ANTIBIOTICS,Tetanus Preventable disease 100 new cases reported per year in USA,SURGICAL INFECTION AND ANTIBIOTICS,Tetanus Prophylaxis GuidelinesACS Committee on TraumaGeneral Principles Guid
30、elines for both general and specific preventive measures are available Prevention depends uponAdequate immunization of general populationGood surgical wound carePassive immunization with tetanus immune globulin-human as indicated,SURGICAL INFECTION AND ANTIBIOTICS,Infection Risk for the Surgeon HIV
31、Hepatitis B Hepatitis C,SURGICAL INFECTION AND ANTIBIOTICS,HIV Risk of infection relatively low (0.3-0.1%) Universal precautions for all cases Additional precautions in known or strongly suspected cases,SURGICAL INFECTION AND ANTIBIOTICS,HIVPostexposure Prophylaxis Recommended for exposure to known
32、HIV infected patients or high risk patients Therapy within 1-2 hours postexposure and continued for 4 weeks 2 drug therapy in all cases, 3 drug for “high risk” exposure Drugs: zidovudine, lamivudine, and indinavir,SURGICAL INFECTION AND ANTIBIOTICS,HIV No clearly documented case of surgeon to patien
33、t transmission reported Universal precautions important No justification for restriction of HIV+ surgeons privileges,SURGICAL INFECTION AND ANTIBIOTICS,Hepatitis 12,000 infections with 250 deaths in HCWs per year Much more dangerous than HIV Cases equally divided between B & C,SURGICAL INFECTION AND ANTIBIOTICS,HepatitisPrevention Vaccination for hepatitis B Universal precautions,SURGICAL INFECTION AND ANTIBIOTICS,HepatitisTransmission by Surgeons Transmission documented in 18 cases All HBe Ag positive Risk if HBe Ag negative is very low,SURGICAL INFECTION AND ANTIBIOTICS,Questions?,
