Surgical Infections

1. SURGICAL INFECTIONSSURGICAL INFECTIONS
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ANTIBIOTICSANTIBIOTICS

2. SURGICAL INFECTIONSSURGICAL INFECTIONS
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ANTIBIOTICSANTIBIOTICS
DefinitionDefinition
PathogenesisPathogenesis
Clinical features & investigations (general)Clinical features & investigations (general)
Common pathogensCommon pathogens
Common infectionsCommon infections
Antibiotics useAntibiotics use
TherapeuticTherapeutic
ProphylacticProphylactic

3. 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

4. SURGICAL INFECTIONSSURGICAL INFECTIONS

A surgical infection is an infection A surgical infection is an infection
which requires surgical treatment and which requires surgical treatment and
has developed befor, or as a has developed befor, or as a
complication of surgical treatment.complication of surgical treatment.

5. Surgical InfectionSurgical Infection
A major challengeA major challenge
Accounts for 1/3 of surgical patientsAccounts for 1/3 of surgical patients
Increased cost to healthcare Increased cost to healthcare

6. Factors contributing to infectionsFactors contributing to infections

Adequate dose of microorganisms Adequate dose of microorganisms
Virulence of microorganismsVirulence of microorganisms
Suitable environment ( closed space )Suitable environment ( closed space )
Susceptible hostSusceptible host

7. 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

8. Host ResistanceHost Resistance

Intact skin / mucous membrane.Intact skin / mucous membrane.
(surgery/ trauma-break it )(surgery/ trauma-break it )
Immunity:Immunity:
Cellular (phagocytes )Cellular (phagocytes )
AntibodiesAntibodies

9. Prevention of surgical infectionPrevention of surgical infection
Patient in best general condition.Patient in best general condition.
(host defense)(host defense)
Minimize introduction of pathogens during Minimize introduction of pathogens during
surgery.surgery.
Good surgical technique.Good surgical technique.
Peri-operative care (support defense)Peri-operative care (support defense)

10. Clinical features Clinical features
Local-Local- pain, heat, redness, swelling, loss of functionpain, heat, redness, swelling, loss of function
(apparent in superficial infections)(apparent in superficial infections)
Systemic-Systemic- fever, tachycardia, chillsfever, tachycardia, chills
Investigations:Investigations:
Leukocytosis Leukocytosis
Exudates- Exudates- Gram stain, cultureGram stain, culture
Blood culture Blood culture ( chills & fever )( chills & fever )
Special investigations Special investigations ( radiology, biopsy )( radiology, biopsy )

11. Principles of surgical treatment Principles of surgical 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

12. STREPTOCOCCISTREPTOCOCCI
Gram positive Gram positive
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 feverinfections e.g.,lymphangitis, cellulitis, rheumatic fever
Strep. viridens-Strep. viridens- endocarditis, urinary infectionendocarditis, urinary infection
Strep. fecalis Strep. fecalis – – urinary infection, pyogenic infectionurinary infection, pyogenic infection
Strep. pneumonae Strep. pneumonae – – pneumonia, meningitispneumonia, meningitis

13. STREPTOCOCCAL INFECTIONSSTREPTOCOCCAL INFECTIONS
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 cheeksCommon site: around nose extending to both cheeks
Penicillin, ErythromycinPenicillin, Erythromycin

15. 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 )

17. NECROTIZING FASCIITISNECROTIZING FASCIITIS
Necrosis of superficial fascia, overlying skinNecrosis of superficial fascia, overlying skin
PolymicrobialPolymicrobial
strep,strep, staph, enterococci, bacteroides, enterobacteriaceae staph, enterococci, bacteroides, enterobacteriaceae
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

18. NECROTIZING FASCIITISNECROTIZING FASCIITIS
More in diabetic patientMore in diabetic patient
Starts as cellulitis, edema, systemic toxicityStarts as cellulitis, edema, systemic toxicity
Appears less extensive than actual necrosisAppears less extensive than actual necrosis
Treatment: Treatment:
Debridement , repeated dressings, skin grafting Debridement , repeated dressings, skin grafting
Broad spectrum antibioticsBroad spectrum antibiotics
ampicillin, clindamycin, aminoglycosidesampicillin, clindamycin, aminoglycosides

20. 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- opportunisticopportunistic ( wound, endocarditis )( wound, endocarditis )
Antibiotics:Antibiotics: Penicillin, Cephalosporin, VancomycinPenicillin, Cephalosporin, Vancomycin
MRSA:MRSA: VancomycinVancomycin

21. STAPHYLCOCCAL INFECTIONSSTAPHYLCOCCAL INFECTIONS
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

23. Surgical site infection (SSI)Surgical site infection (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 (47%)Superficial SSI–infection in subcutaneous plane (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 infections, Entercoccus ,other Entetobacteriaceae- deep infections
B fragilis – intrabd. abscessB fragilis – intrabd. abscess

24. Surgical site infection (SSI)Surgical site infection (SSI)
Risk factors: Risk factors: age, malnutrition, obesity, age, malnutrition, obesity,
immunocompromised, poor surg. tech, immunocompromised, poor surg. tech,
prolonged surgery, preop. shaving and prolonged surgery, preop. shaving and
type of surgery.type of surgery.
Diagnosis:Diagnosis:
Sup.SSI- erythema, oedema, discharge and pain Sup.SSI- erythema, oedema, discharge and pain
Deep infections- no local signs, fever, pain, hypotension. Deep infections- no local signs, fever, pain, hypotension.
need investigations. need investigations.
Treatment:Treatment: surgical / radiological interventionsurgical / radiological intervention. .

26. Surgical site infection (SSI)Surgical site infection (SSI)
Intra-abdominal infectionsIntra-abdominal infections
GeneralizedGeneralized
LocalizedLocalized
Prevention- good tech., avoid bowel Prevention- good tech., avoid bowel
injury, good anastomosis.injury, good anastomosis.
Diagnosis- History, exam., investigations.Diagnosis- History, exam., investigations.
Treatment- surgery/ interventionTreatment- surgery/ intervention
Antibiotics Antibiotics (aerobe+ anaerobe)(aerobe+ anaerobe)

27. GRAM NEGATIVE ORGANISMSGRAM NEGATIVE ORGANISMS
( Enterobactericiae )( Enterobactericiae )
Escherichia coliEscherichia coli
Facultative anaerobe, Intestinal floraFacultative anaerobe, Intestinal flora
Produce exotoxin & endotoxinProduce exotoxin & endotoxin
Endotoxin 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, aminoglycosideampicillin, cephalosporin, aminoglycoside

28. GRAM NEGATIVE ORGANISMSGRAM NEGATIVE ORGANISMS
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 catheterscolonize ventilators, iv catheters, urinary catheters
Wound infection, burn, septicemiaWound infection, burn, septicemia
Treatment:Treatment: aminoglycosides, piperacillin, ceftazidime aminoglycosides, piperacillin, ceftazidime

29. 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 )

30. 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, amputationWound exposure, debridement , drainage, amputation
Hyperbaric oxygenHyperbaric oxygen

31. 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

32. 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 dose booster >10 years needs a booster dose
booster <10 years- no treatment in low risk woundsbooster <10 years- no treatment in low risk wounds

33. 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 (pseudomembranes)membrane of exudates (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

35. 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 drainage
Antibiotics- clindamycin, metronidazoleAntibiotics- clindamycin, metronidazole

36. ANTIBIOTICSANTIBIOTICS
Chemotherapeutic agents that act on organismsChemotherapeutic agents that act on organisms
Bacteriocidal:Bacteriocidal: Penicillin, Cephalosporin, Vancomycin Penicillin, Cephalosporin, Vancomycin
AminoglycosidesAminoglycosides
Bacteriostatic:Bacteriostatic: Erythromycin, Clindamycin, Erythromycin, Clindamycin,
Tetracycline Tetracycline

37. 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, CeftriaxoneCephalexin, Cefuroxime, Ceftriaxone
CarbapenemsCarbapenems- - Imipenem, MeropenemImipenem, Meropenem
AminoglycosidesAminoglycosides- - Gentamycin, AmikacinGentamycin, Amikacin
FluoroquinolonesFluoroquinolones- - CiprofloxacinCiprofloxacin
GlycopeptidesGlycopeptides- - VancomycinVancomycin
MacrolidesMacrolides- - Erythromycin, ClarithromycinErythromycin, Clarithromycin
TetracyclinesTetracyclines- - Minocycline, DoxycyclineMinocycline, Doxycycline

38. 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

39. ANTIBIOTIC THERAPYANTIBIOTIC THERAPY
( Guideline for surgical infections )( Guideline for surgical infections )
Pseudomembranous colitis-Pseudomembranous colitis- oral vancomycin/ metronidazole oral vancomycin/ metronidazole
Biliary-tract infection-Biliary-tract infection- cephalosporin or gentamycincephalosporin or gentamycin
Peritonitis-Peritonitis- cephalosporin/ gentamycin + metronidazole/ clindamycin cephalosporin/ gentamycin + metronidazole/ clindamycin
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/ vancomycin Flucloxacillin/ vancomycin
or Cefuroxime or Cefuroxime
Cellulitis-Cellulitis- penicillin, erythromycin penicillin, erythromycin
( flucloxacillin if Staphylococcus infection. Suspected ) ( flucloxacillin if Staphylococcus infection. Suspected )

40. ANTIBIOTIC PROPHYLAXISANTIBIOTIC PROPHYLAXIS

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 )

41. ANTIBIOTIC PROPHYLAXISANTIBIOTIC PROPHYLAXIS
BASED ON SURGICAL WOUND CLASSIFICATIONBASED ON SURGICAL WOUND CLASSIFICATION
A. Clean : CLASS IA. Clean : CLASS I e.g. surgeries on thyroid gland, e.g. surgeries on thyroid gland,
breast, hernia,breast, hernia,
• • No need for prophylaxis in clean surgeries, except for :No need for prophylaxis in clean surgeries, except for :
o Immunucompromised patients, e.g. diabetics, patients o Immunucompromised patients, e.g. diabetics, patients
using corticosteroids.using corticosteroids.
o If the surgery include inserting foreign materials such as o If the surgery include inserting foreign materials such as
artificial valves.artificial valves.
o High risk patients like those with infective endocarditis.o High risk patients like those with infective endocarditis.
The risk of postoperative wound infection is around The risk of postoperative wound infection is around
2%.2%.

42. ANTIBIOTIC PROPHYLAXISANTIBIOTIC PROPHYLAXIS
B. Clean/Contaminated (minimal B. Clean/Contaminated (minimal
contamination) : CLASS IIcontamination) : CLASS II
e.g., biliary,urinary, GI tract surgerye.g., biliary,urinary, GI tract surgery
Prophylaxis is advisable, and the risk of Prophylaxis is advisable, and the risk of
infection is about 5-10%.infection is about 5-10%.

43. ANTIBIOTIC PROPHYLAXISANTIBIOTIC PROPHYLAXIS
C. Contaminated (gross contamination) : C. Contaminated (gross contamination) :
CLASS III CLASS III e.g. during bowel surgerye.g. during bowel surgery
Prophylaxis is advisable and the risk of infection Prophylaxis is advisable and the risk of infection
is up to 20%.is up to 20%.

44. ANTIBIOTIC PROPHYLAXISANTIBIOTIC PROPHYLAXIS
D. Dirty : CLASS IV D. Dirty : CLASS IV through established through established
infection infection
e.g., peritonitis ( up to 50% )e.g., peritonitis ( up to 50% )
The use of antibiotic is considered to be of The use of antibiotic is considered to be of
therapeutic nature (not prophylactic).therapeutic nature (not prophylactic).
The risk of infec@on is up to 5CD.The risk of infec@on is up to 5CD.