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 )