The document discusses surgical site infections (SSI), their definitions, etiology, and prevention strategies, emphasizing the challenge they pose in surgical practice and their association with increased healthcare costs. It outlines types of SSIs based on depth and occurrence, as well as risk factors, important definitions, and recommended preoperative measures and antibiotic prophylaxis. The document also details treatment options and specific antibiotic regimens tailored to various types of surgeries and pathogens.

1. Surgical Site Infection
Dr. Utham Murali.M.S;M.B.A.
Asso.Prof.of Surgery
IMS / MSU / Malaysia.

2. Introduction
 Surgical infection is major problem in surgical practice.
 In 1992, the US Centers for Disease Control (CDC) revised its
definition of 'wound infection', creating the definition 'surgical site
infection' (SSI) to prevent confusion between the infection of a
surgical incision and the infection of a traumatic wound.
 Accounts for 15-25% of all surgical infections & increased cost to
healthcare.

3. Definition
 The infection of a wound can
be defined as the invasion of
organisms through tissues
following a breakdown of local
& systemic host defences
leading to local & systemic
presentation.

4. Micro-Organisms
S. aureus
S. epidermidis
Enterococcus
E. coli
Pseudomonas
klebsiella
Gr -ve
strept species
anaerobic
Gr +ve
19%
14%
12%8%8%
4%
15%
6% 3% 2%

5. Important Definitions
 SSI
 Is an infected incised wound or deep organ space.
 SIRS
 Is the body’s systemic response to an infected wound.
 MODS
 Is the effect that the infection produces systemically.
 MSOF
 Is the end-stage of uncontrolled MODS.

6. Important Definitions
 SIRS – Any 2
 Hyperthermia (> 38°C) or Hypothermia (< 36°C)
 Tachycardia (> 90/min) or Tachypnoea (> 20/min)
 WBC > 12 × 10 99 / l or < 4 × 10 9 / l
 SEPSIS
 Is SIRS with a documented infection.
 SEPSIS SYNDROME
 Is sepsis with evidence of one or more organ failures.

7. Pathogenesis
VirulenceBacterial dose
Impaired
host resistance

8. Risk factors
Malnutrition – Obesity
Metabolic disease – DM / Jaundice
Immunosuppression conditions
Colonoization of GIT
Poor perfusion – shock
FB material
Poor surgical technique

9. Factors - Determine
 Host response
 Virulence
 Vasculature & Health of tissue
 Presence of dead / foreign tissue
 Presence of antibiotic – “decisive

10. SSI – Assessment
 For surgical wound assessment several scoring systems are employed
 ASEPSIS wound score
 Southampton wound grading system
 These enable surgical wound healing to be graded according to specific
criteria, usually giving a numerical value, thus providing more objective
assessment of wound.

13. Types
Depth of wound infection
Etiology
Time of Occurrence
Severity

14. Depth - Superficial Incisional SSI
 Occurs < 30days
 Skin & sub.cut tissue
 Purulent discharge +/-
 1 sign – inflammation
 Incision – opened &
diagnosed - surgeon

16. Depth - Deep Incisional SSI
 Occurs - 30days – 1yr
 Deep soft tissue
 Purulent discharge – not from organ
 Spont.opened or delibe.opened
 Deep abscess – by re-op/histo/X-ray
 Opened & diagnosed - surgeon

18. Depth - Organ / Space SSI
 Occurs - 30days – 1yr
 Involves – any part [organ/space]
 Purulent discharge – drain
 Organisms – isolated
 Deep abscess – direct & re-op /
histology / X-ray
 Opened & diagnosed - surgeon

20. Further classification
Etiology
Time Severity
Primary:
Acquired from a community
or endogenous source (such as
that following a perforated peptic
ulcer).
Secondary or exogenous
(HCAI): Acquired from the OT
(such as inadequate air filtration)
or Ward (e.g. poor hand-washing
compliance) or from contam. at or
after surgery ( anastomotic leak ).
Early
Infection presents
within 30 days of
procedure.
Intermediate
Occurs between 1 –
3 months.
Late
Presents > 3
months after surgery.
Minor
Wound infections may discharge pus
or infected serous fluid but should not
be associated with excessive
discomfort, systemic signs or delay in
return home.
Major
A major SSI is defined as a wound
that either discharges significant
quantities of pus spontaneously or
needs a secondary procedure to drain it.

22. Surgical site prevention
Antibiotics & Prophylaxis
appropriately
Operation Theatre
procedures
Maintain normal
BG / BT
Post- op care
Pre- operative measures

23. Pre-operative
 Staff should always wash their hands - pts.
 Length of patient stay should be kept to a min.
 Preop. shaving should be avoided if possible.
 Antiseptic skin prepn. should be standardized.
 Attention to theatre technique & discipline.
 Avoid hypothermia perioperatively & ensure
supplemental O2 in recovery.

24. Operation Theatre
 Ensure – sterile caps, masks,gowns &
gloves – used
 Skin cleaning – povidone iodine – used
 Drapes – dry & instruments – sterilized
 Avoid - Unimpregnated plastic drapes
 Table tips – gentle tissue handling /
absolute haemostasis, appropriate suture
materials, avoiding dead space.
 Severely contaminated – leave upon

25. Principles – Antibiotic therapy
 Antibiotics do not replace
surgical drainage of
infection.
 Only spreading infection or
signs of systemic infection
justifies the use of
antibiotics.

26. Antibiotic therapy - Approach
 A narrow-spectrum antibiotic may be
used to treat a known sensitive infection.
 Combinations of broad-spectrum
antibiotics can be used when the
organism is not known or when it is
suspected that several bacteria, acting in
synergy, may be responsible for the
infection.
 New antibiotics should be used with
caution & wherever possible, sensitivities
should first be obtained.

27. Prophylaxis – Choice of antibiotics
 Empirical cover against expected pathogens
with local hospital guidelines.
 Single-shot I. V administration at induction of
anaesthesia.
 Repeat only in prosthetic surgery, long
operations or if there is excessive blood loss.
 Continue as therapy if there is unexpected
contamination.
 Pts. with heart valve disease or a prosthesis
should be protected from bacteraemia caused by
dental work, urethral instrumentation or visceral
surgery.

28. Regimes – Operations
Type of Surgery Organisms involved Prophylactic regime
Vascular Staphylococcus epidermidis (or
MRCNS)
Staphylococcus aureus (or MRSA)
Aerobic Gram-negative bacilli (AGNB)
3 doses of flucloxacillin with or without
gentamicin, vancomycin or rifampicin
if MRCNS / MRSA a risk
Orthopedic Staphylococcus epidermidis / aureus 1 -3 doses of a broad-spectrum
cephalosporin or gentamicin
Oesophagogastric Enterobacteriaceae / Enterococci 1 3 doses of a second-generation
cephalosporin & metronidazole in
severe contamination
Biliary Enterobacteriaceae / Enterococci 1 dose of a second-generation
cephalosporin
Small bowel Enterobacteriaceae / Anaerobes 1 – 3 doses of a second-generation
cephalosporin with or without
metronidazole
Appendix / Colorectal Enterobacteriaceae / Anaerobes 3 doses of a second-generation
cephalosporin (or gentamicin)
with metronidazole

29. Treatment
 Mgt - depend on type of SSI
 Surgical debridement of wound
 Suture – removed – free drainage
 Fluid – C/S – Suitable antibiotics
 Signs of healing – sec. suturing

30. References

31. “Attack the problem, not the Person”
Penicillins- Penicillin G, Piperacillin
Penicillins with β-lactamase
inhibitors- Tazocin
Cephalosporins (I, II, III)-
Cephalexin, Cefuroxime, Ceftriaxone
Carbapenems- Imipenem, Meropenem
Aminoglycosides- Gentamycin,
Amikacin
Fluoroquinolones- Ciprofloxacin
Glycopeptides- Vancomycin
Macrolides- Erythromycin,
Clarithromycin
Tetracyclines- Minocycline,
Doxycycline