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Flashcards in Surgical Site Infections Deck (27):

What are SSIs?

+ Infections occurring in a wound created by an invasive surgical procedure

+ Responsible for ~20% of HCAIs

+ 5% of patients undergoing surgery develop an SSI

+ Can double length of hospital stay

+ Associated with high morbidity


What are some different types of SSIs?

+ Wound discharge
+ Dehiscence
+ Lymphadentitis
+ Abscesses
+ Necrosis (tissue or fat)
+ (Gas) gangrene
+ Sepsis
+ Induration
+ Purulent discharge


What are possible consequences of SSIs?

+ Microbial penetration of deeper tissue

+ Invasion of bloodstream (bacteraemia, sepsis)

+ Spread of bacteria to other sides (e.g heart valves, bones, peritoneum)


How, why and when do SSIs occur?

+ Contamination of incision by normal microbiota
+ Damage to tissues
+ Damage to blood vessels

+ Presence of foreign bodies (e.g sutures, implants)
+ Reduced efficacy of inflammatory response

+ Before, during and afer surgery


What are factors that infuence the development of SSIs?

+ Type of surgical wound (clean/dirty etc.)
+ Pre-, intra- and postoperative care
+ Surgical team
+ Age and general health of patient
+ Extent of tissue injury
+ Infection prevention procedures
+ Presence of prosthesis or foreign body
+ Presence or absence of drain
+ Duration of surgery
+ Place in operation list


What are the classifications of surgical wounds?

+ Clean (class I)
+ Clean/contaminated (class II)
+ Contaminated (class III)
+ Dirty (class IV)


What are the features of class I surgical wounds?

+ Elective surgery
+ No accute inflammation
+ Don't involve R, GI or GU tracts


What are the features of class II surgical wounds?

+ Urgent/emergency case
+ Clean wounds with higher risk of infection
+ Uncomplicated R, GI or GU surgery


What are the features of class III surgical wounds?

+ Outside object comes into contact with wound
+ Large amounts of spillage from GI tract into wound


What are the features of class IV surgical wounds?

+ Purulent inflammation
+ Foreign object lodged in wound
+ Traumatic or infected wounds


What is the incidence of SSIs without antibiotic prophylaxis?

Class I - 2%
Class II - 6-9%
Class III - 13-20%
Class IV - 40%


What is the incidence of SSis with antibiotic prophylaxis?

Class I - 2%
Class II - 3-4%
Class III - 6-7%
Class IV - 7-16%


What are microbial causes of SSIs of the skin?

+ Staphylococcus aureus
+ Streptococci spp.
+ Enterococci spp.


What are microbial causes of SSIs of the bowel?

+ Escherichia coli
+ Bacteriodes fragilis
+ Clostridium perfringens
+ Enterococci spp.
+ Anaerobic cocci


What are some forms of pre-operative care?

+ Pre-operative showering
+ Do not remove hair
+ Give antiobiotc prophylaxus before:
- clean surgery (prosthesis/implant only)
- clean-contaminated surgery
- contaminated surgey
+ Do not routinely use nasal decontamination
+ Do not routinely use mechanical bowel preparation


What are some forms of intra-operative care?

+ Surgical team hand decontamination
+ Do not use non-iodophor-impregnated incise drapes
+ Wear sterile fown and 2 pairs sterile gloves
+ Prepare skin at surgical site immediately before incision
+ Maintain patient homeostasis
+ Do not use wound irrigation or intracavity lavage
+ Do not use intra-operative disinfectant or topical antibiotics
+ Cover incisions with appropriate dressing at the end


What should be disinfected to minimise SSIs?

+ Hands of ward staff
- non-antimicrobial soap

+ Hands of surgical team
- scrub with aqueous antiseptic surgical solution before first op.
+ If not visibly soiled, subsequently use ABHR or antiseptic surgical solution

+ Patient's skin
- alcoholic chlorhexidine
- povidone iodine


What are the two types of dressings that can be used to prevent infection?

+ Conventional
+ Occlusive


What do conventional dressings include?

+ Gauze
+ Tulle gras
+ Non-adhesive fabrics


What do occlusive dressings include?

+ Hydrocolloids
+ Polyurethane films
+ Foams


What are examples of good post-operative care?

+ Use appropriate dressings
+ Use aseptic or non-touch technique to change/remove dressings
+ Use sterile saline for wound cleansing up to 48hrs after surgery
+ Do not use topical antimicrobial agents for wound healing by primary intention
+ Follow guidance regarding use of debriding agents


How can the risk of post-op infections be reduced?

+ Keep pre-op length of stay in hospital to minimum
+ Treat any current infections before surgery
+ Keep length of surgery as short as possible
+ Maintain good operative technique
+ Debridement of dead/necrotic skin
+ Establish good blood supply
+ Prevent pressure sores
+ Arrange active physiotherapy to minimise risk of URTIs and UTIs


What precautions can be taken to prevent catheter-related infections?

+ Always wash hands before procedure
+ Wear gloves when handling catheter
+ Use single use antiseptic wipe
+ Cover insertion site with dressing


What are early presentations of prosthetic joint infections?

Early < 1 month:
- fulminant with wound sepsis


What are delayed presentations of prosthetic joint infections?

Delayed < 1 year:
- indolent, low grade infection


What are late-onset presentations of prosthetic joint infections?

Late-onset > 2 years:
- septic arthritis


How can a prosthetic joint infection be diagnosed?

+ Blood culture
+ Collection of pus by needle aspiration
+ Bone biopsy
+ Raised ESR and CRP
+ Polymorphonuclear leucocytes
+ Radiological imaging