This document provides an overview of surgical site infections (SSIs). It defines SSIs and related terms like colonization and contamination. It discusses the historical context, epidemiology, classification, pathogenesis, clinical features, and factors that influence SSIs. The document also covers prevention strategies like proper patient preparation, aseptic technique, and antibiotic prophylaxis. It describes approaches for clinical assessment, wound scoring systems, and management of SSIs.

1. SURGICAL SITE INFECTIONS
By
Dr. Olofin. K E

2. OUTLINE
• INTRODUCTION
• DEFINITION OF TERMINOLOGIES
• HISTORICAL PERSPECTIVE
• EPIDEMIOLOGY
• CLASSIFICATION
• PATHOGENESIS AND SURGICAL MICROBIOLOGY
• CLINICAL FEATURES
• FACTORS INFLUENCING SSI’s
• CLINICAL ASSESSMENT
• MANAGEMENT
• PREVENTION
• CONCLUSION

3. introduction
• A surgical site infection (SSI)refers to the
presence of pain at a surgically created
wound, which is accompanied by erythema,
induration and local tenderness or presence
of purulent discharge at wound site.
• They refer to infections of the tissues,
organs, or spaces exposed by surgeons
during performance of an invasive
procedure

4. definitions
• Colonization
– Bacteria present in a wound with no signs or
symptoms of systemic inflammation
– Usually less than 105 cfu/gram of tissue
• Contamination
– Transient exposure of a wound to bacteria
– Varying concentrations of bacteria possible
– Time of exposure suggested to be < 6 hours
– SSI prophylaxis best strategy

5. • Infection
–Systemic and local signs of inflammation
–Bacterial counts ≥ 105 cfu/gram of tissue
–Purulent versus nonpurulent
• Surgical wound infection is SSI

6. Definition of SSI’s
• Infection occurring
– anywhere along the surgical tract after a
surgical procedure
– anytime from 0 – 30 days post op.
OR
– up to 1 year post op. if a foreign material
was used(prosthesis).

7. Historical perspective
• Before the late 19th Century, serious
infections among hospitalized patients were
rampant and the morbidity & mortality
were astounding.
• Nearly all traumatic & surgical wound
healing was accompanied by inflammation
& suppuration.
• Galen; 130 – 200 AD “Suppuration often
heralded recovery”

8. • Theodoric of Cervia, Pare & Guy de Chuliac
disagreed with Galen’s dictum.
• 1861, Ignac Semmelweis; Washing of hands
→↓maternal mortality!
• 1867, Louis Pasteur showed that infection is
caused by microbes foreign to the infected.
• 1867, Joseph Lister introduced antisepsis

9. Epidemiology
• Incidence of SSI varies depending on the type
of surgical procedure carried out and the class
of surgical wound and maybe as high as 20%.
• SS-Infections are the 2nd most common
nosocomial infections.
• It also represents the commonest nosocomial
infection amongst surgical patients accounting
for 38% of NI’s.

10. Epidemiology
• Causes substantial morbidity and mortality
viz:
- post-op length of hospital stay by 7-10days
- Increases hospital charges substantially in
affected patients
- Death is directly linked to SSI in >75% of
patients with SSI who die in the post-op
period.

11. Classification
Classification of SSI’s could be based on
• Depth of Tissue involved
• Etiology
• Time
• Severity

12. classification
Surgical Site
infection
Incisional SSI
Superficial
Incisional SSI
Deep
Incisional SSI
Organ/space
SSI

13. Classification contd

14. Classification contd
• Etiology
a) Primary
The wound is the primary site of infection.
b)Secondary
Infection arises following a complication
that is not directly related to the wound.

15. Classification contd
• Time
a) Early
Infection presents within 30 days of
procedure
b) Intermediate
Occurs between 1-3 mths
c) Late
Presents >3mths post-surgery

16. Classification contd
• Severity
a) Minor
- Discharge without cellulitis/deep tissue
destruction
b) Major
- Pus discharge + tissue breakdown ,
- Partial or total dehiscence of the deep
fascial layers
- Presence of Systemic illness

18. Pathogenesis
Bacterial dose Virulence
Impaired
host resistance

19. Microbiology

20. Clinical features
• Erythema
• Discharge
–Superficial
–From drain(s)
• Pain
• Fever
• Tenderness
• Delayed return of bowel sounds
• Other inflammatory changes

23. FACTORS INFLUENCING DEVELOPMENT OF SSI’S
Patient factors
Multiple Co-Morbidities (Diabetes ,CKD,
P.VasDx)
Nicotine use
Immunosuppression (Steroid use, Malignancy)
Malnutrition (Obesity, Undernutrition)
Hospital stay 
Nares colonization with S. aureus
Transfusion.

24. • Pre-Op factors
• Preoperative antiseptic showering
• Preoperative hair removal
• Patient skin preparation in the operating room
• Preoperative hand/forearm antisepsis
• Antimicrobial prophylaxis

25. Pre-Op factors
 Preoperative hair
removal
  Shaving:
– immediately before the
operation: SSI rates 3.1%
– shaving within 24 hours
preoperatively: 7.1%
– having performed >24
hours: SSI rate > 20%.
 Hair removing creams:
– lower SSI risk than
shaving or clipping
– hypersensitivity
reactions
0
5
10
15
20
>24 Hr 24 Hr On table
SSI (%)

26. Prophylactic antibiotics
• Class 1 = Clean
• Class 2 = Clean contaminated (Prophylactic
antibiotics indicated)
• Class 3 = Contaminated(Prophylactic
antibiotics indicated)
• Class 4 = Dirty infected ( Therapeutic
antibiotics indicated)

27. ABX
Once the incision is made,
antibiotic delivery to the
wound is impaired.
Must give before incision!

29. Intra-Op factors
• Operating room environment
• Surgical attire and drapes
• Asepsis and surgical technique

30. Intra-Op factors
 Operating room environment
 Ventilation
- Positive pressure with respect to corridors and
adjacent areas.
 Environmental surfaces
- Rarely implicated as the sources of pathogens
important in the development of SSIs.
- Important to perform routine cleaning of these surfaces
 Conventional sterilization of surgical instruments
- Inadequate sterilization of surgical instruments has
resulted in SSI outbreaks

31. Intra-Op factors
 Surgical attire and drapes
 The use of barriers:
- patient: minimize exposure to the skin, mucous
membranes, or hair of surgical team members
- surgical team members: protect from exposure to
blood and blood-borne pathogens.
 Asepsis and surgical technique
 Rigorous adherence to the principles of asepsis by all scrubbed
personnel
 Excellent surgical technique: reduce the risk of SSI.
 Drains: increase incisional SSI risk.

32. Post-Op factors
• Incision care
Primary Closure, Delayed Primary Closure,
wound left open to heal by second intention.
• Haematoma/Seroma formation
• Foreign body
• Presence of non-viable tissue

33. Wound assessment
• The most common Surgical wound assessment
scores used include:
ASEPSIS SCORE
SOUTHAMPTON SCORE

34. ASEPSIS SCORE
• ADDitional Treatment
– Antibiotics
– Drainage under L.A.
– Debridement under G.A.
• Serous Discharge
• Erythema
• Purulent exudate
• Separation of wound
• Isolation of pathogen
• Stay in hospital > 2 weeks

35. ASEPSIS SCORE

36. Southampton Score

37. Management of SSI’s
• Source control
• Incision and Drainage
–Percutaneous
–Surgical
• Frequent wound dressing
• Débridement and delayed primary closure
• Antibiotic therapy.

38. Prevention
–Antisepsis
–Asepsis
–Antibiotics
–Manipulation of host factors to
minimize infection.

39. Pre-op precautions
• Pre op warming
• Cessation of smoking
• Adequate nutrition
• Plasma glucose control throughout
• Supplemental oxygen

40. Intra-op precautions
• Strict maintenance of asepsis
–Double gloving, strategic positioning
• Minimal handling of tissue
–Avoid desiccation, keep tissue warm...
–Ensure adequate tissue perfusion
–Ensure sufficient haemostasis

42. Intra-op precautions contd
• Avoid dead space
• Remove all necrotic/devitalized tissue
completely
• Justified drain use
• Delayed primary closure when indicated

43. Post-op Precautions
• Keep surgical incision(s) protected
• Continue effective antibiotic therapy
• Remove all drains as soon as practicable!
• Resume enteral nutrition as soon as
permissible
• Supplemental O2
• Keep patient warm

44. Conclusion

45. • THANKS FOR LISTENING!