Surgical Site Infection

This PPT is mainly for the Final - Yr MBBS - Students. It is purely based on Bailey & Love - Short Practice of Surgery.

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
Virulence
Bacterial 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
period”

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