Surgical site infections: Latest Approach on management

Surgical Site Infections

Dr. Suman PaulResident

Dept. of Orthopaedic SurgeryRMCH

Why this topic?

SSI is MOST COMMON hospital acquired infection in surgical patients.

3rd most common hospital acquired infection.

Preventable

Prolong the hospital stay (7.3 days)

Expenditure

Over one-third of postoperative deaths

Poor scar, persistent pain and itching, restriction of movement and a significant impact on emotional wellbeing

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Historyhas been documented for 4000–5000 years

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Egyptians• had some concepts about infection as

they were able to prevent putrefaction, testified by mummification skills. • Their medical papyruses also describe

the use of salves and antiseptics.

Norman S. Williams et al. Bailey & Love’s Short Practice of Surgery, 26th Edition. CRC Press, 2013.

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Hippocrates• His teachings described the use of

antimicrobials, such as wine and vinegar, • which were widely used to irrigate open,

infected wounds before delayed primary or secondary wound closure.


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Ignac Semmelweis• An Austrian obstetrician • showed that puerperal sepsis could be

reduced from >10% to <2% by the simple act of hand washing between cases, • particularly between post-mortem

examinations and the delivery suite. • He was ignored by his contemporaries.


Louis Pasteur• recognised through his germ theory that

microorganisms were responsible for infecting humans and causing disease.


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Joseph Lister• Applied this knowledge to the reduction of

colonising organisms in compound fractures by using antiseptics. • The principles of antiseptic surgery were

soon enhanced with aseptic surgery at the turn of the century. • As well as killing the bacteria on the skin

before surgical incision (antiseptic technique), the conditions under which the operation was performed were kept free of bacteria (aseptic technique). Norman S. Williams et al. Bailey & Love’s Short Practice of

Surgery, 26th Edition. CRC Press, 2013.

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Alexander Fleming• The discovery of the antibiotic penicillin

is attributed to Alexander Fleming in 1928, but it was not isolated for clinical use until 1941 by Florey and Chain. • Since then, there has been a proliferation

of antibiotics with broad-spectrum activity and antibiotics today remain the mainstay of antimicrobial therapy.


What is SSI?

Infections that occur in the wound created by an invasive surgical

procedure are generally referred to

as surgical site infections

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ClassificationAcute

a) Non-specifici. Generalized

• Bacteremia• Septicaemia• Pyaemia

ii. Localized• Abcess• Cellulitis• Carbuncle

b) Specifici. Generalized

• Tetanus• Gas gangrene

ii. Localized• Boil

Chronic

a) Non-specific– Ulcer– Sinus– Fistula

b) Specific– TB– Syphilis– Actinomycosis

Criteria for defining SSIs

Superficial incisional surgical site infections

Infection occur within 30 days of procedure

Involve skin or subcutaneous tissue • signs or symptoms of infection• purulent drainage +/-• organisms isolated• Diagnosis by experience

Stitch abscess, episiotomy, circumcision in infant, burn wound

Deep incisional surgical site infections

Infection occur within 30 days of procedure (or one year in the case of implants)

Involve deep soft tissues, such as the fascia and muscles.

• purulent drainage, signs of infection• spontaneously dehisces or opened by surgeon• an abscess or other evidence of infection

Involving both superficial and deep = DISSI

Space or organ ssi drain through Deep incision = DISSI

Organ or space Surgical site Infection

30 days no implant or 1 year with implant

Any part is involved which was opened or manipulated other than the incision• Purulent discharge from a drain• Isolated an organism• Abscess or other evidence of infection• Diagnosis by a surgeon

Early

•Infection presents within 30 days of procedure

Intermediate

•Occurs between one and three months

Late•Presents more than three months after surgery

Minor• Wound infection is

described as minor when there is discharge without cellulitis or deep tissue destruction

Major

• When there is pus discharge with tissue breakdown , Partial or total dehiscence of the deep fascial layers of wound or if systemic illness is present.

Severity

The risk is also related to the amount of contamination with microorganisms which is called “class” of the operation

Class Definition

Clean Operations in which no inflammation is encountered and the respiratory, alimentary or genitourinary tracts are not entered. There is no break in aseptic operating theatre technique.

Clean-contaminated Operations in which the respiratory, alimentary or genitourinary tracts are entered but without significant spillage.

Contaminated Operations where acute inflammation (without pus) is encountered, or where there is visible contamination of the wound. Examples include gross spillage from a hollow viscusduring the operation or compound/open injuries operated on within four hours

Dirty Operations in the presence of pus, where there is a previously perforated hollow viscus, or compound/open injuries more than four hours old.

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Microbiology of SSIs

Staphylococcusaureus

17%

Coagulase neg.staphylococci

12%

Escherichiacoli10%

Enterococcusspp.8%

Pseudomonasaeruginosa

8%

Staphylococcusaureus

20%

Coagulase neg.staphylococci

14%

Escherichiacoli8%

Enterococcusspp.12%

Pseudomonasaeruginosa

8%

1986-1989(N=16,727)

1990-1996(N=17,671)

Michele L. Pearson. Prevention of Surgical Site Infections: Considerations in Measuring Effectiveness. CDC, 2005.

Pathogenesis of surgical site infection

Contamination• Endogenous

infection• Exogenous

infection• Haematogeno

us spread• Staph

aureus• Enterobacte

riaceae and anaerobes

Proliferation of bacteria

Induce inflammation – signs appear

Identified or unidentified

Self resolving -> resolve by treatment ->

sepsis and death

Risk Factors for Development of

Surgical Site Infections

Patient factor

Local factor

Microbial factor

• Older age - linear trend• Immunosuppression • Obesity • Diabetes mellitus • Chronic inflammatory process • Malnutrition • Peripheral vascular disease • Smoking• Anemia • Radiation • Steroid use

Patient factors

• Poor skin preparation • Contamination of instruments • Inadequate antibiotic prophylaxis • Prolonged procedure• Site and complexity of procedure• Local tissue necrosis • Hypoxia • Hypothermia

Local factors

•Wound Class•Prolonged hospitalization (leading to nosocomial organisms)

•Resistance

Microbial factors

PREVENTION OF

SURGICAL SITE

INFECTIONS

Pre operative Phase

• Pre op Shower– With soap or savlon– With in 8-12 hours

• Shaving• Patient Dress• Theatre staff Dress• Hand washing• Antibiotic prophylaxis

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Pre-operative Antiseptic Showers/Baths

• Most studies examine effects on skin colony counts antiseptic showering decreases colony counts

• Few studies examine effect on SSI rates

No ShowerShowerCruse 2.3% 1.3%

Ayliffe 4.9% 3.4%

Rooter 2.4% 2.1%

Pre operative Phase

• Shower• Shaving

– No need!– If needed:

• Limited to the area of surgery• Day of surgery

– Disposable razor Vs Clipping/Depilation cream

• Patient Dress• Theatre staff Dress• Hand washing• Antibiotic prophylaxis

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Pre-operative Shaving/Hair Removal

Method of hair removalRazor = 5.6% SSI ratesDepilatory = 0.6% SSI ratesNo hair removal = 0.6% SSI rates

Timing of hair removalShaving immediately before = 3.1% SSI

ratesShaving 24 hours before = 7.1% SSI ratesShaving >24 hours before = 20% SSI rates

Problems of Shaving

• Pain• Allergy• Infection risk!

Pre operative Phase

• Shower• Shaving• Patient Dress

– Don’t interfere with operation site/Venflon– Comfortable– Maintain dignity

• Theatre staff Dress• Hand washing• Antibiotic prophylaxis

Pre operative Phase

• Shower• Shaving• Patient Dress• Theatre staff Dress

– Non sterile, clean– Cap & Mask– Shoes– Goggles

• Hand washing• Antibiotic prophylaxis

Pre operative Phase

• Shower• Shaving• Patient Dress• Theatre staff Dress

• Hand washing– Betadine/Chlorhexidine– No need for soap/brush– 5 minute ritual– 2 minute between cases/hand scrub

• Antibiotic prophylaxis

Hand Wash 5 min ritual

Pre operative Phase• Shower• Shaving• Patient Dress• Theatre staff Dress• Hand washing

• Antibiotic prophylaxis– 1 hour before incision• Before induction!• Before tourniquet application!!

– 1 dose vs. 3 dose• Additional dose: –if prolonged operation–Excess blood loss:

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Antibiotic prophylaxis• Give antibiotic prophylaxis to patients before:

– clean surgery involving the placement of a prosthesis or implant – clean-contaminated surgery – contaminated surgery.

• Do not use antibiotic prophylaxis routinely for clean non-prosthetic uncomplicated surgery.

• Use the local antibiotic formulary and always consider potential adverse effects when choosing specific antibiotics for prophylaxis.

• Consider giving a single dose of antibiotic prophylaxis intravenously on starting anaesthesia.

• For operations in which a tourniquet is used give prophylaxis earlier

NICE Guideline on Prevention and treatment of surgical site infection, National Institute for Health and Clinical Excellence, 2008.

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Suggested prophylactic regimens for operations at risk.


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Importance of Timing of Surgical Antimicrobial Prophylaxis (AP)

• Prospective study of 2,847 elective clean and clean-contaminated procedures

• Early AP (2-24 hrs before incision): 3.8% • Postop AP (3-24 hrs after incision): 3.3% • Periop AP (< 3 hrs after incision): 1.4% • Preop AP (<2 hrs before incision): 0.6%

Intra operative Phase

• Patient skin Preparation– Iodine/Chlorhexidine– Allow it to dry & avoid spillage to diathermy pad

• Incision drapes• Sterile Gown & Gloves• Patient Homeostasis• Theatre discipline• Wound dressing


• Patient skin Preparation• Incision drapes– No benefit– Use iodophor impregnated sticky drapes

• Sterile Gown & Gloves• Patient Homeostasis• Theatre discipline• Wound dressing


• Patient skin Preparation• Incision drapes• Sterile Gown & Gloves– Water resistant gowns– Double glove technique

• Patient Homeostasis• Theatre discipline• Wound dressing

Intra operative Phase• Patient skin Preparation• Incision drapes• Sterile Gown & Gloves• Patient Homeostasis

– Avoid Hypothermia• Warm fluids for infusion and for lavage• Warm blankets• Warm mattress• Monitor temperature every 30 min during surgery and post op

– Avoid Hypoxia• Post operative mask O2 / monitor Spo2

– Avoid hypotension• Infuse adequate fluids

• Theatre discipline• Wound dressing


• Patient skin Preparation• Incision drapes• Sterile Gown & Gloves• Patient Homeostasis• Theatre discipline– Sterile & Quiet environment– Avoid to & fro movement– Ensure sterility of equipments & Theatre– Laminar airflow/Filters

• Wound dressing

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Parameters for Operating Room Ventilation

• Temperature: 68o-73oF, depending on normal ambient temp

• Relative humidity: 30%-60%• Air movement: from “clean to less clean”

areas • Air changes: >15 total per hour

>3 outdoor air per hour American Institute of Architects, 1996

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Role of Laminar Air Flow (Ultraclean Air) in Preventing SSI

• Most studies involve only orthopedic operations

• Lidwell et al: 8,000 total hip and knee replacements

• ultraclean air: SSI rate 3.4% to 1.6% • antimicrobial prophylaxis (AP): SSI rate 3.4%

to 0.8% • ultraclean air + AP: SSI rate 3.4% to 0.7%

Laminar Air flow

Intra operative Phase• Patient skin Preparation• Incision drapes• Sterile Gown & Gloves• Patient Homeostasis• Theatre discipline

• Wound dressing– Sutured Wound:

• Primapore/ Tagaderm dressing with pad– Open wound: e.g: after debridement of necrotic ulcer

• Sofratulle/pad/Crepe

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Post-operative measures• Changing dressings

– Use an aseptic non-touch technique for changing or removing surgical wound dressings.

• Postoperative cleansing

– Use sterile saline for wound cleansing up to 48 hours after surgery.

– Advise patients that they may shower safely 48 hours after surgery.

– Use tap water for wound cleansing after 48 hours if the surgical wound has separated or has been surgically opened to drain pus.

NICE Guideline on Prevention and treatment of surgical site infection, National Institute for Health and Clinical Excellence, 2008.

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Post-operative measures

• Topical antimicrobial agents for wound healing by primary intention – Do not use topical antimicrobial agents for surgical wounds

that are healing by primary intention to reduce the risk of surgical site infection.

• Dressings for wound healing by secondary intention

– Do not use Eusol and gauze, or moist cotton gauze or mercuric

antiseptic solutions.– Use an appropriate interactive dressing.

Post-operative measures

• Antibiotic treatment of surgical site infection and treatment failure – When surgical site infection is suspected (i.e. cellulitis),

either de novo or because of treatment failure, – give the patient an antibiotic that covers the likely

causative organisms. – Consider local resistance patterns and the results of

microbiological tests in choosing an antibiotic.

• Debridement

Superficial Incisional

RednessPainSwellingHeatDischarging pus

Deep Incisional

Wound GappingFeverPainDischarge

Organ/Space SSI

FeverPainAnorexiaDischarge through drainImaging study

Treatment of SSI

• Surveillance• Drainage of pus– Culture and sensitivity• MRSA• VRE• ESBL strains

• Debridement• Antibiotics• Removal of Implant

Treatment

• Incisional: open surgical wound, antibiotics for cellulitis or sepsis

• Deep/Organ space: Source control, antibiotics for sepsis

Management of Incisional surgical site infection

• Removal of sutures with drainage of pus• Debridement and open wound care• delayed primary or secondary suture• Wound bed preparation

• Early closure in early post operative period• Mesh and biological implants• In a small dehiscence – secondary suturing

Reclosure of the wound

Tetanus Prevention• Prophylaxis with tetanus toxoid best

preventative treatment • In an established infection minor debridement

of the wound & antibiotic treatment with benzylpenicillin • Relaxants may also be required.• May require ventilation in severe forms, which

may be associated with a high mortality. • The use of antitoxin using human

immunoglobulin ought to be considered for both at-risk wounds and established infection.

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• The toxoid should be given in three separate doses to give protection for a five-year period, after which a single five-yearly booster confers immunity. • It should be given to all patients with open

traumatic wounds who are not immunised. • At-risk wounds those that present late, when

there is devitalisation of tissue or when there is soiling a booster of toxoid should be given.• If not immunised at all a three-dose course,

together with prophylactic benzylpenicillin.• The use of antitoxin is controversial because of

the risk of toxicity and allergy.

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Gas Gangrene

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Treatment• Maximum dose of penicillin• Blood transfusion• Long incision of muscle• Multiple subcutaneous drainage• Slough extraction• Anti gangrenous serum (polyvalent) 3

amp stat and 6 hrly later• Hyperbaric oxygen• Treat underlying DM, uraemia, etc.

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Prevention• Antibiotic prophylaxis should always be

considered in patients at risk, • especially when amputations are

performed for peripheral vascular disease with open necrotic ulceration.


ANTIBIOTICS

1. Bacteriostatic: prevent the growth of bacteria but do

not destroy them. Affects early stages of protein synthesis in the ribosome

2. Bactericidal: Agents that actively kill the bacteria It causes the ribosome to miscode and

consequently induced the manufacture of defective proteins and enzymes that poison the cell

Antibiotic Mode of ActionCellular site of

inhibitionBactericidal Bacteriostati

c

1. Cell wall synthesis

PenicillinCephalosphorinVancomysinBacitracin

2. Barrier function of cell membrane

Polymyxin BColistinAmphotericin B

Nystatin

Antibiotic Mode of ActionCellular site of

inhibitionBactericidal Bacteriostatic

3. Protein synthesis in the ribosome

Streptomycinaminoglycoside

TetracyclinChloramphenicolErythromycinClindamycin

4. DNA replication in chromosome

griseogulvin

Antibiotic Agents1. Penicillin

blocks the synthesis of the bacterial wall ---> osmotic instability & lysis

Active against most gram (+) bacteria

2. Cephalosphorin Bactericidal by inhibiting bacterial

cell wall synthesis Arranged into generation For gram (+) and (-) bacteria

Antibiotic Agents3.Erythromycin

Bacteriostatic ; bactericidal in higher dose

Inhibit bacterial protein synthesis

Treatment of choice in treating mycoplasm and Legionnaire’s disease, also for actinomycosis

Antibiotic Agents

4. Tetracyclines For gram (+) and (-) not sensitive

to penicillin Good for TB Bacteriostatic Interfere w/ protein synthesis For actinomycosis and nocardiosis Should be avoided in early

childhood causing yellow discoloration of the teeth

Antibiotic Agents

5. Chloramphenicol Broad spectrum and bacteriostatic Inhibits protein synthesis Well absorbed orally and

parenterally Drug of choice in typhoid fever

and other salmonella infection Good for meningitis and H.

influenzae

Antibiotic Agents

6. Aminoglycoside Bactericidal For gm(-) and (+) and

mycobacteria Toxic side effects:

Auditory branch damage nephrotoxic

Antibiotic Agents

7. Metronidazole Bactericidal Important for obligate anaerobic

bacteria

8. Amphotericin B Good for antifungal agents IV, intrathecally or instilled

directly to the site of infection

Antibiotic Agents9. Sulfonamides - Trimethoprim

Effective against community acquired gm (-)

Orally administered Has limited usefulnes in nosocomial

infection

10. 4-Fluoroquinolones Good for nosocomial infections Good activity against nearly all gram (-)

organism

Antibiotic Agents11. Carbapenems

Has the widest spectrum Highly effective against most

aerobic (S. aureus & P. aeruginosa) as well as anaerobic bacteria

Take Home Message

• Source Bailey & Love’s Short Practice of Surgery, 26th Edition.

– Schwartz’s Principles of surgery– Apley’s System of orthopaedics and fractures– Maingot’s operations– Surgical site infection (prevention and treatment of surgical site

infection) 2013– Internet

THANK YOU

Health & Medicine

Surgical site infections: Latest Approach on management