Definition, Epidemiology, Types, Risk factors, Etiology, Pathophysiology, Clinical presentation, Complications, Diagnosis and Treatment of Surgical Site Infections

1. V. S.Swathi
Assistant
Professor
VIPT, Duvvada
SURGICAL SITE INFECTIONS

2. Definition
 According to Centers for Disease Control and
Prevention (CDC), A surgical site infection is an
infection that occurs after surgery in the part of
the body where the surgery took place.
 Surgical site infections can sometimes be
superficial infections involving the skin only. Other
surgical site infections are more serious and can
involve tissues under the skin, organs, or
implanted material

3. Epidemiology (World and India)
 Globally SSIs estimation is 0.5%-15% and in
India it is in higher rates ranging from 23%-38%.

4. Types
According to CDC
Superficial incisional
 Affects skin and
subcutaneous tissue
Deep incisional
 Affects fascial and
muscle layers
Organ/ space infection
 Affects any part of the
body other than incision
that is opened/
manipulated during the
surgical procedure

5. Classification of surgical
procedures based on risk of
infection
Clean
 Atraumatic
 No inflammation encountered
 No break in technique
 Gastro intestinal, genitourinary and respiratory
tracts not entered
 Wound infection rate is 1.5-4.2%
 Need for prophylaxis not usually required
 Example: Inguinal hernia repair

6. Classification of surgical
procedures based on risk of
infection
Contaminated
 Gastro intestinal tract/ respiratory tract entered
but without spillage
 Minor break in technique
 Wound infection rate is less than 10%
 Prophylaxis is usually required
 Example: Cholecystectomy

7. Classification of surgical
procedures based on risk of
infection
 Clean- Contaminated
 Acute inflammation
 Infected bile or urine
 Gross spillage from gastro intestinal tract
 Major lapse in technique
 Fresh traumatic wound (12-24h)
 Wound infection rate is 10-20%
 Prophylaxis is usually required
 Example: Appendicectomy

8. Classification of surgical
procedures based on risk of
infection
 Dirty and infected established infection
 Transaction of clean tissue to enable collection of
pus
 Traumatic wound with retained lifeless tissue
 Faecal contamination
 Delayed treatment
 Wound infection rate is 20-40%
 Prophylaxis is compulsorily required
 Example: Sigmoid colectomy

9. Risk factors
Patient related risk factors
 Advanced age
 Malnutrition
 Obesity
 Concurrent infection
 Diabetes mellitus
 Liver impairment
 Renal impairment
 Immune deficiency status
 Prolonged preoperative stay
 Blood transfusion

10. Risk factors
Operative risk factors
 Tissue ischemia
 Lack of haemostasis
 Tissue damage
 Presence of necrotic tissue
 Presence of foreign body including surgical
material

11. Etiology
 Methicillin resistant Staphylococcus aureus-24%
 Methicillin sensitive Staphylococcus aureus-14%
 Enterobacteriaceae-21%
 Coagulase negative Staphylococci-10%
 Enterococcus-10%
 Pseudomonas-5%
 Streptococcus-3%
 Anaerobic bacilli-2%
 Anaerobic cocci-2%
 Candida-1%
 Acenobactor-1%

12. Pathogenesis
Any surgery
↓
Breaching of protective barrier of any organ (epithelial
tissue) and mucosa
↓
Entry of endogenous and exogenous micro organisms
to that organ
↓
Inflammation
↓
Surgical site infection

13. Clinical Presentation
Superficial incisional
 Affects skin and subcutaneous tissue
 Clinical presentation include redness, pain, heat/
swelling at site of incision and presence of pus
within 30 days

14. Clinical Presentation
Deep incisional
 Affects fascial and muscle layers
 Clinical presentation include presence of pus/ an
abscess, fever with tenderness of wound,
separation of the edges of the incision exposing
the deeper tissues within 30 days and 1 year if
implant is used

15. Clinical Presentation
Organ/ space infection
 Affects any part of the body other than incision
that is opened/ manipulated during the surgical
procedure
 Clinical presentation include loss of function of a
joint, abscess in an organ, localised peritonitis/
collection and ultrasound/ CT scan confirm
infection within 30 days and 1 year if implant is
used

16. Complications
 Sepsis
 Shock
 Death

17. Diagnosis
 Based on clinical presentation
 Culture test
 Complete blood count
 Erythrocyte sedimentation rate
 C reactive protein
 Procalcitonin
 Neutrophil CD64

18. Non Pharmacological Treatment
 Recommended steps to patients and care takers
during different phases of surgery:
Pre operative phase
 Patient preparation- Pre operative washing, hair
removal, nasal MRSA decontamination, antimicrobial
prophylaxis guidance, staff preparation and theatre
movement
Intra operative phase
 Operating team preparation, patient skin preparation,
maintaining patient homeostasis and wound
dressings
Post operative phase
 Dressing and cleaning the wound, antimicrobial
treatment for SSI, debridement of SSI

19. Treatment Algorithm
1. Gastrointestinal surgery
a. Upper GIT
↓
Bowel flora/ Staphylococcus aureus/ Gram
negative bacilli
↓
Co amoxiclav/ Cefuroxime/ Gentamycin

20. Treatment Algorithm
1. Gastrointestinal surgery
b. Biliary surgery
↓
Staphylococcus aureus/ Gram negative bacilli
↓
 Co amoxiclav/ Cefuroxime+ Metronidazole
 Gentamycin+ Metronidazole

21. Treatment Algorithm
1. Gastrointestinal surgery
c. Colorectal surgery / Appendicectomy
↓
Staphylococcus aureus/ Gram negative
bacilli/ Anaerobes
↓
 Co amoxiclav/ Cefuroxime+ Metronidazole
 Gentamycin+ Metronidazole

22. Treatment Algorithm
2. Urogenital
a. Transrectal biopsy
↓
Staphylococcus aureus/ Gram negative bacilli/
Anaerobes
↓
 Co amoxiclav/ Cefuroxime+ Metronidazole
 Gentamycin+ Metronidazole

23. Treatment Algorithm
2. Urogenital
b. Transurethral resection of prostrate
↓
Staphylococcus aureus/ Gram negative bacilli
↓
Co amoxiclav/ Cefuroxime/ Gentamycin

24. Treatment Algorithm
3. Obstetric/ Gynaecological
a. Caesarean section
↓
Staphylococcus aureus/ Gram negative bacilli/ Anaerobes
↓
Co amoxiclav/ Cefuroxime + Metronidazole
b. Hysterectomy
↓
Staphylococcus aureus/ Gram negative bacilli/ Anaerobes
↓
Co amoxiclav/ Cefuroxime + Metronidazole

25. Treatment Algorithm
4. Vascular
a. Reconstructive arterial surgery
↓
Skin flora-Staphylococci
↓
Co amoxiclav/ Cefuroxime
b. Amputation
↓
Staphylococcus aureus/ Anaerobes
↓
 Co amoxiclav/ Cefuroxime + Metronidazole
 Vancomycin +Metronidazole

26. Treatment Algorithm
5. Orthopedic
Joint replacement surgery
↓
Skin flora-Staphylococci
↓
Co amoxiclav/ Cefuroxime / Flucloxacillin+
Gentamycin

27. Drug Category Mode of action Dose Adverse effects
Cefuroxime Cephalosporin Inhibit cell wall
synthesis
1.5g-IV  Diarrhea
 Anemia
 Eosinophilia
 Vaginitis
 Tranaminitis
Ciprofloxacin Fluroquinolone Inhibit DNA Gyrase 400mg-IV  Abdominal pain
 Diarrhea
 Transaminitis
 Increased serum creatinine
 Rashes
Co amoxiclav Pencillin+
Beta lactamase
inhibitor
Inhibit cell wall
synthesis+ Reduce
resistance power of
microbes
1.2g-IV  Diarrhea
 Mycosis
 Candidiasis
 Vaginitis
 Hypersensitivity reactions- if
patient is allergic
Cotrimazole Sulfonamide Inhibit folic acid
synthesis
960mg-IV  Anorexia
 Vertigo
 Peripheral neuritis
 Hyperkelemia
 Rashes
Flucloxacillin Pencillin Inhibit cell wall
synthesis
1g-IV  Rashes
 Arthralgia
 Neutropenia
 Pseudomembranous colitis
 Transaminitis

28. Gentamycin Aminoglycoside Inhibit protein
synthesis
5mg/kg-IV
1 hour prior
to surgery
 Neurotoxicity
 Gait instability
 Ototoxicity
 Nephrotoxicity
 Edema
Metronidazole Miscellaneous Inhibit nucleic acid
synthesis
500mg-IV  Anorexia
 Candidiasis
 Diarrhea
 Dark urine
 Furry tongue
Vancomycin Glycopeptide Inhibit cell wall
synthesis
1g-IV  Redman syndrome
 Steven Johnsan’s
Syndrome
 Acute kidney injury
 Tinnitus
 Hearing loss
 Muscle pain
Teicoplainin Glycopeptide Inhibit cell wall
synthesis
200mg-IV  Redman syndrome
 Steven Johnsan’s
Syndrome
 Acute kidney injury
 Tinnitus
 Hearing loss

29. Choice of antimicrobial agent
should consider following
 Likely infecting organism
 Local susceptibility of potential pathogens to
antimicrobials
 Pharmacokinetics
 Patient’s allergy status to antibiotics
 Administration time
 Drug cost
 Carriage of resistant organisms
 Prevalence of Clostridium defficile infection in
hospital

30. Resources
 https://www.sciencedirect.com/science/article/pii/
S1479666X1830074X
 https://www.sciencedirect.com/science/article/pii/
S000296101830672X
 https://www.sciencedirect.com/science/article/pii/
S1201971219300049
 https://www.sciencedirect.com/science/article/pii/
S000293781930432
 https://www.sciencedirect.com/science/article/pii/
S0195670119301124