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INFECTION Invasion of the body by pathogenic microorganisms and reaction of the host to organisms and their toxins Invasion of the body by pathogenic microorganisms and reaction of the host to organisms and their toxins
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SURGICAL INFECTIONSSURGICAL INFECTIONS&&
ANTIBIOTICSANTIBIOTICS
M K ALAMM K ALAM MS, FRCSMS, FRCS
Prof. & Consultant SurgeonProf. & Consultant SurgeonCollege of Medicine & RCHCollege of Medicine & RCH
OBJECTIVESOBJECTIVES
Definitions.Definitions. Pathogenesis .Pathogenesis . Clinical features .Clinical features . Surgical microbiology.Surgical microbiology. Common infections.Common infections. Antibiotics use.Antibiotics use.
INFECTIONINFECTION
Invasion of the body by pathogenic Invasion of the body by pathogenic microorganisms and reaction of the microorganisms and reaction of the host to organisms and their toxinshost to organisms and their toxins
SURGICAL INFECTIONSSURGICAL INFECTIONS
Infections that require surgical Infections that require surgical intervention as a treatment or develop intervention as a treatment or develop as a result of surgical procedure.as a result of surgical procedure.
Surgical InfectionSurgical Infection
A major challengeA major challenge
Accounts for 1/3 of surgical patientsAccounts for 1/3 of surgical patients
MorbidityMorbidity
MortalityMortality
Increased cost to healthcare Increased cost to healthcare
Factors contributing to infectionsFactors contributing to infections
Microorganism related factors:Microorganism related factors: -Adequate dose -Adequate dose -Virulence of microorganisms-Virulence of microorganisms
Host related factors:Host related factors: -Suitable environment ( closed space )-Suitable environment ( closed space ) -Susceptible host-Susceptible host
Pathogenicity of bacteriaPathogenicity of bacteria
Exotoxins:Exotoxins: specific, soluble proteins, remote cytotoxic effectspecific, soluble proteins, remote cytotoxic effect Cl.Tetani, Strep. pyogenesCl.Tetani, Strep. pyogenes
Endotoxins:Endotoxins: part of gram-negative bacterial wall, part of gram-negative bacterial wall, lipopolysaccharides e.g., E coli lipopolysaccharides e.g., E coli
Resist phagocytosisResist phagocytosis:: Protective capsule Protective capsule Klebsiela and Strep. pneumoniaeKlebsiela and Strep. pneumoniae
Host ResistanceHost Resistance
Intact skin / mucous membrane.Intact skin / mucous membrane. (surgery/ trauma- causes breach)(surgery/ trauma- causes breach)
Immunity:Immunity: Cellular (phagocytes )Cellular (phagocytes ) AntibodiesAntibodies
Clinical features Clinical features
Local- Local- pain, heat, redness, swelling, pain, heat, redness, swelling, loss of function.loss of function. (apparent in superficial infections)(apparent in superficial infections)
Systemic- Systemic- fever, tachycardia, chillsfever, tachycardia, chills
Principles of surgical Principles of surgical treatment treatment
Debridement-Debridement- necrotic, injured tissuenecrotic, injured tissue Drainage-Drainage- abscess, infected fluidabscess, infected fluid Removal-Removal- infection source, foreign bodyinfection source, foreign body Supportive measures:Supportive measures:
• immobilizationimmobilization• elevationelevation• antibioticsantibiotics
STREPTOCOCCISTREPTOCOCCI Gram positive, aerobe/anaerobeGram positive, aerobe/anaerobe
Flora of the mouth and pharynx, ( bowel )Flora of the mouth and pharynx, ( bowel )
Streptococcus pyogenes Streptococcus pyogenes –( –( β hemolytic)β hemolytic) 90% of 90% of infections e.g.,lymphangitis, cellulitis, rheumatic infections e.g.,lymphangitis, cellulitis, rheumatic feverfever
Strep. viridens-Strep. viridens- endocarditis, urinary infection endocarditis, urinary infection
Strep. fecalis – Strep. fecalis – urinary infection, pyogenic urinary infection, pyogenic infectioninfection
Strep. pneumonae – Strep. pneumonae – pneumonia, meningitispneumonia, meningitis
STAPHYLOCOCCISTAPHYLOCOCCI Inhabitants of skin, Gram positiveInhabitants of skin, Gram positive
Infection characterized by suppurationInfection characterized by suppuration
Staph.aureus- Staph.aureus-
SSI, nosocomial ,superficial infections SSI, nosocomial ,superficial infections
Staph. epidermidis- Staph. epidermidis- opportunistic ( wound, endocarditis )opportunistic ( wound, endocarditis )
CLOSTRIDIACLOSTRIDIA
Gram positive, anaerobeGram positive, anaerobe Rod shaped microorganismsRod shaped microorganisms Live in bowel & soilLive in bowel & soil Produce exotoxin for pathogenicityProduce exotoxin for pathogenicity Important members:Important members: Cl. Perfringens, Cl. Septicum ( gas gangrene )Cl. Perfringens, Cl. Septicum ( gas gangrene ) Cl. Tetani ( tetanus )Cl. Tetani ( tetanus ) Cl. Difficile ( pseudomembranous colitis )Cl. Difficile ( pseudomembranous colitis )
GRAM NEGATIVE ORGANISMSGRAM NEGATIVE ORGANISMS( Enterobactericiae )( Enterobactericiae )
Escherichia coliEscherichia coli
Facultative anaerobe, Intestinal floraFacultative anaerobe, Intestinal floraProduce exotoxin & endotoxinProduce exotoxin & endotoxinEndotoxin produce Gram-negative shock Endotoxin produce Gram-negative shock
Wound infection, abdominal abscess,Wound infection, abdominal abscess,UTI, meningitis, endocarditisUTI, meningitis, endocarditis
Treatment-Treatment- ampicillin, cephalosporin, ampicillin, cephalosporin, aminoglycosideaminoglycoside
GRAM NEGATIVE GRAM NEGATIVE ORGANISMSORGANISMS
PseudomonasPseudomonas
aerobes, occurs on skin surfaceaerobes, occurs on skin surface opportunistic pathogenopportunistic pathogen may cause serious & lethal infectionmay cause serious & lethal infection colonize ventilators, iv catheters, urinary colonize ventilators, iv catheters, urinary
catheterscatheters Wound infection, burn, septicemiaWound infection, burn, septicemia Treatment:Treatment: aminoglycosides, piperacillin, ceftazidime aminoglycosides, piperacillin, ceftazidime
GRAM NEGATVE ANAEROBESGRAM NEGATVE ANAEROBES Bacteroides fragilis Bacteroides fragilis
Normal flora in oral cavity, colonNormal flora in oral cavity, colon Intra-abdominal & gynecologic infections ( 90% )Intra-abdominal & gynecologic infections ( 90% ) Foul smelling pus, gas in surrounding tissue, necrosisFoul smelling pus, gas in surrounding tissue, necrosis Spiking fever, jaundice, LeukocytosisSpiking fever, jaundice, Leukocytosis No growth on standard cultureNo growth on standard culture Needs anaerobe culture mediaNeeds anaerobe culture media Treatment:Treatment:
Surgical drainageSurgical drainageAntibiotics- clindamycin, metronidazoleAntibiotics- clindamycin, metronidazole
TYPES OF SURGICAL TYPES OF SURGICAL INFECTIONINFECTION
A. Surgical Site InfectionA. Surgical Site Infection B. Soft Tissue InfectionB. Soft Tissue Infection C. Body Cavity InfectionC. Body Cavity Infection D. Prosthetic Device related D. Prosthetic Device related
InfectionInfection E. MiscellaneousE. Miscellaneous
Surgical site infection Surgical site infection (SSI)(SSI)
38% of all surgical infections38% of all surgical infections Infection within 30 days of operationInfection within 30 days of operation Classification:Classification: Superficial: Superficial: Superficial SSI–infection in subcutaneous plane Superficial SSI–infection in subcutaneous plane
(47%)(47%)
Deep:Deep: Subfascial SSI-Subfascial SSI- muscle plane (23%)muscle plane (23%)
Organ/ space SSI-Organ/ space SSI- intra-abdominal, other spaces (30%)intra-abdominal, other spaces (30%) Staph. aureus-Staph. aureus- most common organism most common organism E coliE coli, Entercoccus ,other Entetobacteriaceae- deep , Entercoccus ,other Entetobacteriaceae- deep
infectionsinfections B fragilis – intrabd. abscessB fragilis – intrabd. abscess
Surgical site infection Surgical site infection (SSI)(SSI)
Risk factors: age, malnutrition, Risk factors: age, malnutrition, obesity, immunocompromised, poor obesity, immunocompromised, poor surg. tech, prolonged surgery, preop. surg. tech, prolonged surgery, preop. shaving and type of surgery.shaving and type of surgery.
Diagnosis: Diagnosis: Sup.SSISup.SSI- erythema, oedema, discharge and pain - erythema, oedema, discharge and pain Deep infections- Deep infections- no local signs, fever, pain, no local signs, fever, pain,
hypotension. need investigations.hypotension. need investigations. Treatment: Treatment: surgical / radiological interventionsurgical / radiological intervention. .
Prevention of SSIPrevention of SSI Pre-op:Pre-op: Treat pre-existing infection Treat pre-existing infection Improve general nutritionImprove general nutrition Shorter hospital stayShorter hospital stay Pre-op. showerPre-op. shower Hair removal timing?Hair removal timing? Intraoperative:Intraoperative: Antiseptic technique Antiseptic technique Surgical techniqueSurgical technique Post-operative:Post-operative: Hand hygiene Hand hygiene
STREPTOCOCCAL STREPTOCOCCAL INFECTIONSINFECTIONS
ErysipelasErysipelas Superficial spreading cellulitis & lymphangitisSuperficial spreading cellulitis & lymphangitis Area of redness, sharply defined irregular borderArea of redness, sharply defined irregular border Follows minor skin injuriesFollows minor skin injuries Strep pyogenesStrep pyogenes Common site: around nose extending to both Common site: around nose extending to both
cheekscheeks Penicillin, ErythromycinPenicillin, Erythromycin
SREPTOCOCCAL INFECTIONSREPTOCOCCAL INFECTION
CellulitisCellulitis
Inflammation of skin & subcutaneous tissueInflammation of skin & subcutaneous tissue Non-suppurativeNon-suppurative Strep. PyogenesStrep. Pyogenes Common sites- limbsCommon sites- limbs Affected area is red, hot & induratedAffected area is red, hot & indurated Treatment :Treatment : Rest, elevation of affected limb Rest, elevation of affected limb Penicillin, ErythromycinPenicillin, Erythromycin Fluocloxacillin ( staph. suspected )Fluocloxacillin ( staph. suspected )
NECROTIZING FASCIITISNECROTIZING FASCIITIS Necrosis of superficial fascia, overlying skinNecrosis of superficial fascia, overlying skin Polymicrobial : Polymicrobial : Streptococci (90%), Streptococci (90%), anaerobic Grampositive Cocci, aerobic Gram-negative anaerobic Grampositive Cocci, aerobic Gram-negative
Bacilli, and the Bacteroides spp.Bacilli, and the Bacteroides spp. Sites- Sites- abd.wall abd.wall (Meleny’s)(Meleny’s), , perineumperineum (Fournier’s)(Fournier’s), , limbs,limbs,
Usually follows abdominal surgery or traumaUsually follows abdominal surgery or trauma
NECROTIZING FASCIITISNECROTIZING FASCIITIS Diabetics more susceptibleDiabetics more susceptible Starts as cellulitis, edema, systemic toxicityStarts as cellulitis, edema, systemic toxicity Appears less extensive than actual necrosisAppears less extensive than actual necrosis Investigation: Aspiration, Gram’s stain, CT, MRIInvestigation: Aspiration, Gram’s stain, CT, MRI Treatment: IV fluid, IV antibioticsTreatment: IV fluid, IV antibiotics (ampicillin, clindamycin l metronidazole, aminoglycosides )(ampicillin, clindamycin l metronidazole, aminoglycosides )
Debridement , repeated dressings, skin grafting Debridement , repeated dressings, skin grafting
STAPHYLCOCCAL STAPHYLCOCCAL INFECTIONSINFECTIONS
Abscess-Abscess- localized pus collection localized pus collection Treatment- drainage, antibiotics Treatment- drainage, antibiotics
Furuncle- Furuncle- infection of hair follicle / sweat glandsinfection of hair follicle / sweat glands
Carbuncle- Carbuncle- extension of furuncle into subcut. tissueextension of furuncle into subcut. tissue common in diabeticscommon in diabetics common sites- back, back of neckcommon sites- back, back of neck Treatment: drainage, antibiotics, control diabetesTreatment: drainage, antibiotics, control diabetes
GAS GANGRENEGAS GANGRENE Cl. Perfringens, Cl. SepticumCl. Perfringens, Cl. Septicum Exotoxins: Exotoxins: lecithinase, collagenase, hyaluridaselecithinase, collagenase, hyaluridase Large wounds of muscle Large wounds of muscle ( contaminated by soil, foreign body )( contaminated by soil, foreign body ) Rapid myonecrosis, crepitus in subcutaneous tissueRapid myonecrosis, crepitus in subcutaneous tissue Seropurulent discharge, foul smell, swollenSeropurulent discharge, foul smell, swollen Toxemia, tachycardia, ill lookingToxemia, tachycardia, ill looking X-ray: gas in muscle and under skinX-ray: gas in muscle and under skin Penicillin, clindamycin, metronidazolePenicillin, clindamycin, metronidazole Wound exposure, debridement , drainage, Wound exposure, debridement , drainage,
amputationamputation Hyperbaric oxygenHyperbaric oxygen
TETANUSTETANUS Cl. Tetani, produce neurotoxinCl. Tetani, produce neurotoxin Penetrating wound Penetrating wound ( rusty nail, thorn )( rusty nail, thorn ) Usually wound healed when symptoms appearUsually wound healed when symptoms appear Incubation period: 7-10 daysIncubation period: 7-10 days Trismus- first symptom, stiffness in neck & backTrismus- first symptom, stiffness in neck & back Anxious look with mouth drawn up Anxious look with mouth drawn up ( risus sardonicus)( risus sardonicus) Respiration & swallowing progressively difficultRespiration & swallowing progressively difficult Reflex convulsions along with tonic spasm Reflex convulsions along with tonic spasm Death by exhaustion, aspiration or asphyxiationDeath by exhaustion, aspiration or asphyxiation
TETANUSTETANUS Treatment:Treatment:
wound debridement, penicillinwound debridement, penicillin Muscle relaxants, ventilatory supportMuscle relaxants, ventilatory support Nutritional support Nutritional support
Prophylaxis:Prophylaxis: wound care, antibioticswound care, antibiotics
Human TIG in high risk ( un-immunized )Human TIG in high risk ( un-immunized ) Commence active immunization ( T toxoid) Commence active immunization ( T toxoid)
Previously immunized Previously immunized-- booster >10 years needs a booster booster >10 years needs a booster dosedose
booster <10 years- no treatment in low risk booster <10 years- no treatment in low risk woundswounds
PSEUDOMEMBRANOUS COLITISPSEUDOMEMBRANOUS COLITIS Cl. DifficileCl. Difficile Overtakes normal flora in patients on antibioticsOvertakes normal flora in patients on antibiotics Watery diarrhea, abdominal pain, feverWatery diarrhea, abdominal pain, fever Sigmoidoscopy: Sigmoidoscopy: membrane of exudates membrane of exudates
(pseudomembranes)(pseudomembranes) Stool- culture and toxin assayStool- culture and toxin assay Treatment :Treatment : stop offending antibioticstop offending antibiotic oral vancomycin/ metronidazoleoral vancomycin/ metronidazole rehydration, isolate patient rehydration, isolate patient
Body Cavity InfectionBody Cavity Infection Primary peritonitis: Primary peritonitis: SpontaneousSpontaneous Children, AsciticChildren, Ascitic Haematogenous/ lymphatic routeHaematogenous/ lymphatic route AntibioticAntibiotic
Secondary peritonitis: Secondary peritonitis: Inflam./ rupture of visceraInflam./ rupture of viscera PolymicrobialPolymicrobial Investigations: blood, radiologicalInvestigations: blood, radiological Treatment of original causeTreatment of original cause
Prosthetic Device Prosthetic Device Related InfectionRelated Infection
Artificial valves and jointsArtificial valves and joints Peritoneal and haemodialysis catheters Peritoneal and haemodialysis catheters Vascular graftsVascular grafts Staphylococcus aureusStaphylococcus aureus Antibiotics, washing of prosthesis or Antibiotics, washing of prosthesis or
removalremoval
Hospital Acquired Hospital Acquired InfectionInfection
Occurring within 48 h of hospital admission, three Occurring within 48 h of hospital admission, three days of discharge or 30 days following an operationdays of discharge or 30 days following an operation
10% of patients admitted to hospitals10% of patients admitted to hospitals Spent 2.5-times longer in hospital - UKSpent 2.5-times longer in hospital - UK Highest prevalence in ICU- Highest prevalence in ICU- Enterococcus, Pseudomonas spp.,E coli, Staph. Enterococcus, Pseudomonas spp.,E coli, Staph.
aureus.aureus. Sites: Urinary, surg. Wounds, resp., skin, blood, GITSites: Urinary, surg. Wounds, resp., skin, blood, GIT
ANTIBIOTICSANTIBIOTICS
Chemotherapeutic agents that act on organismsChemotherapeutic agents that act on organisms
Bacteriocidal:Bacteriocidal: Penicillin, Cephalosporin, Penicillin, Cephalosporin, VancomycinVancomycin
AminoglycosidesAminoglycosides
Bacteriostatic:Bacteriostatic: Erythromycin, Clindamycin, Erythromycin, Clindamycin, Tetracycline Tetracycline
ANTIBIOTICSANTIBIOTICS PenicillinsPenicillins- - Penicillin G, PiperacillinPenicillin G, Piperacillin
Penicillins with Penicillins with ββ-lactamase inhibitors-lactamase inhibitors- - TazocinTazocin
Cephalosporins (I, II, III)Cephalosporins (I, II, III)- - Cephalexin, Cefuroxime, Cephalexin, Cefuroxime, CeftriaxoneCeftriaxone
CarbapenemsCarbapenems- - Imipenem, MeropenemImipenem, Meropenem
AminoglycosidesAminoglycosides- - Gentamycin, AmikacinGentamycin, Amikacin
FluoroquinolonesFluoroquinolones- - CiprofloxacinCiprofloxacin
GlycopeptidesGlycopeptides- - VancomycinVancomycin
MacrolidesMacrolides- - Erythromycin, ClarithromycinErythromycin, Clarithromycin
TetracyclinesTetracyclines- - Minocycline, DoxycyclineMinocycline, Doxycycline
ROLE OF ANTIBIOTICSROLE OF ANTIBIOTICS
Therapeutic:Therapeutic: To treat existing infectionTo treat existing infection
Prophylactic:Prophylactic: To reduce the risk of wound To reduce the risk of wound infectioninfection
ANTIBIOTIC THERAPYANTIBIOTIC THERAPY
Pseudomembranous colitis-Pseudomembranous colitis- oral vancomycin/ oral vancomycin/ metronidazolemetronidazole
Biliary-tract infection-Biliary-tract infection- cephalosporin or gentamycincephalosporin or gentamycin
Peritonitis-Peritonitis- cephalosporin/ gentamycin + metronidazole/ cephalosporin/ gentamycin + metronidazole/ clindamycinclindamycin
Septicemia-Septicemia- aminoglycoside + ceftazidime, Tazocin or imipenem, aminoglycoside + ceftazidime, Tazocin or imipenem, ( may add metronidazole ) ( may add metronidazole )
Septicemia due to vascular catheter-Septicemia due to vascular catheter- Flucloxacillin/ Flucloxacillin/ vancomycin vancomycin or Cefuroxime or Cefuroxime
Cellulitis-Cellulitis- penicillin, erythromycin penicillin, erythromycin ( flucloxacillin if Staphylococcus infection. Suspected ) ( flucloxacillin if Staphylococcus infection. Suspected )
ANTIBIOTIC PROPHYLAXISANTIBIOTIC PROPHYLAXIS BASED ON SURGICAL WOUND BASED ON SURGICAL WOUND
CLASSIFICATIONCLASSIFICATION Clean wound Clean wound -- e.g., thyroid surgery ( 2% )e.g., thyroid surgery ( 2% )
Clean-contaminatedClean-contaminated-- minimal contamination minimal contamination e.g., biliary, urinary, GI tract surgery ( 5-10% )e.g., biliary, urinary, GI tract surgery ( 5-10% )
ContaminatedContaminated-gross contamination -gross contamination e.g., during bowel surgery- (up to e.g., during bowel surgery- (up to 20% )20% )
Dirty-Dirty- surgery through established infection surgery through established infection e.g., peritonitis ( up to 50% ) e.g., peritonitis ( up to 50% )
ANTIBIOTIC ANTIBIOTIC PROPHYLAXISPROPHYLAXIS
Prophylaxis in clean-contaminated/ Prophylaxis in clean-contaminated/ high risk clean woundshigh risk clean wounds
Antibiotic is given just before patient Antibiotic is given just before patient sent for surgerysent for surgery
Duration of antibiotic is controversial Duration of antibiotic is controversial ( one dose- 24 hour regimen )( one dose- 24 hour regimen )