Surgical Site Infection & Wound Dehiscence .pdf

An approach to deal with problems arising from surgical wounds.

1. Surgical Site Infection (SSI)
& Wound Dehiscence
21 September 2021

2. Objectives
•De!ine the Surgical Site Infection (SSI)
•Epidemiology of SSI
•Common micro organisms causing SSI
•Classi!ication of SSI
•Signs & Symptoms, risk factors of SSI
•Management and prevention of SSI
•De!ine wound dehiscence
•Epidemiology of wound dehiscence
•Causes of wound dehiscence
•Management and prevention of wound dehiscence

3. Invasion of organisms into tissues following a breakdown of
local and systemic host defences, leading to either cellulitis,
lymphangitis, abscess formation or bacteraemia.
An SSI typically occurs within 30 days after surgery.
Surgical Site Infection

4. Common??
Surgical site infection (SSI) is the most common health care
associated infection following surgery and is associated with
signi!icant morbidity and mortality, transfer to an intensive care
unit setting, prolonged hospitalizations, and hospital readmission.
Among those who undergo surgical procedures annually in the
United States, 2-4% will develop an SSI, representing a signi!icant
burden on the health care system as a whole.
The !igures are even higher following major gastrointestinal
surgery, a"ecting between 25% and 40% of patients.

5. Classi!ication
SSI is classi!ied according to:
SeverityTimingSource of infectionDepth of infection

6. Depth of infection
The CDC describes 3 types of surgical site infections according to
depth of infection:
•Super!icial incisional SSI: This infection occurs just in the area
of the skin where the incision was made.
•Deep incisional SSI: This infection occurs beneath the incision
area in muscle and the tissues surrounding the muscles.
•Organ or space SSI: This type of infection can be in any area of
the body other than skin, muscle, and surrounding tissue that
was involved in the surgery. This includes a body organ or a
space between organs.

8. Sources of infection
● Endogenous: present in or on the host e.g. SSSI following
contamination of the wound from a perforated appendix
● Exogenous: acquired from a source outside the body such as
the operating theatre (inadequate air !iltration, poor antisepsis)
or the ward (e.g. poor hand-washing compliance). The cause
of hospital acquired infection (HAI)
**In modern hospital practice, endogenous organisms colonising
the patient are by far the most common source of infection.

9. Timing
Early
Infection within 30 days of procedure
Intermediate
Occurs between 1 and 3 months of procedure
Late
Presents after 3 months of procedure

10. Severity
Minor: Wound infections may discharge pus or infected serous
!luid but should not be associated with excessive discomfort,
systemic signs or delay in return home.

Major: A major SSI is de!ined as a wound that either discharges
signi!icant quantities of pus spontaneously or needs a secondary
procedure to drain it.

11. •Major wound infection with
super!icial skin dehiscence.
•Minor wound infection that settled
spontaneously without antibiotics.

12. •Major wound infection and delayed healing presenting as a faecal
!istula in a patient with Crohn’s disease on steroid treatment

13. Common Microorganisms
•Staphylococcus Aureus
•Staphylococcus Epidermidis
•Enterococci
•E-coli
•Pseudomonas
•Klebsiella spp.
•Streptococci
•Clostridia
•Bacteroides

14. The decisive period
There is up to a 4-hour interval before bacterial growth becomes
established enough to cause an infection after a breach in the
tissues, whether caused by trauma or surgery. This interval is called
the ‘decisive period’ and strategies aimed at preventing infection
from taking a hold become ine"ective after this time period. It is
therefore logical that prophylactic antibiotics should be given to
cover this period and that they could be decisive in preventing an
infection from developing, before bacterial growth takes a hold. The
tissue levels of antibiotics during the period when bacterial
contamination is likely to occur should be above the minimum
inhibitory concentration (MIC) for the expected pathogens.

15. Factors that determine whether a wound will become
infected:
● Host response
● Virulence factors and inoculum size of pathogen
● Vascularity and health of tissue being invaded (including local
ischaemia as well as systemic shock)
● Presence of dead or foreign tissue
● Presence of antibiotics during the ‘decisive period’

16. Risk Factors
● Malnutrition (obesity, weight loss)
● Metabolic disease (diabetes, uraemia, jaundice)
● Immunosuppression (cancer, AIDS, steroids, chemotherapy
and radiotherapy)
● Colonisation and translocation in the gastrointestinal tract
● Poor perfusion (systemic shock or local ischaemia)
● Foreign body material
● Poor surgical technique (dead space, haematoma)

17. Clinical Features
Features depend on the depth of the infection and thus
we have 3 categories:
•Super!icial Incisional SSI
•Deep Incisional SSI
•Organ/Space SSI

18. Super!icial incisional SSI is characterized by the following:
•Occurs within 30 days after the operation.
•Involves only the skin or subcutaneous tissue.
•Includes at least one of the following: (a) purulent drainage is
present (culture documentation not required); (b) organisms are
isolated from !luid/tissue of the super!icial incision; (c) at least
one sign of in!lammation (eg, pain or tenderness, induration,
erythema, local warmth of the wound) is present; (d) the wound
is deliberately opened by the surgeon; (e) the surgeon or
clinician declares the wound infected.

19. Deep incisional SSI is characterized by the following:
•Occurs within 30 days of the operation or within 1 year if an implant is
present.
•Involves deep soft tissues (eg, fascia and/or muscle) of the incision.
•Includes at least one of the following: (a) purulent drainage is present
from the deep incision but without organ/space involvement; (b)
fascial dehiscence or fascia is deliberately separated by the surgeon
because of signs of in!lammation; (c) a deep abscess is identi!ied by
direct examination or during reoperation, by histopathology, or by
radiologic examination; (d) the surgeon or clinician declares that a
deep incisional infection is present.

20. Organ/Space SSI is characterized by the following:
•Occurs within 30 days of the operation or within 1 year if an implant is
present.
•Involves anatomic structures not opened or manipulated during the
operation.
•Includes at least one of the following: (a) purulent drainage is present
from a drain placed by a stab wound into the organ/space; (b) organisms
are isolated from the organ/space by aseptic culturing technique; (c) an
abscess in the organ/space is identi!ied by direct examination, during
reoperation, or by histopathologic or radiologic examination; (d) a
diagnosis of organ/space SSI is made by the surgeon or clinician.

21. Assessment
For surgical wound assessment, several scoring systems are
employed, the two most important are:
•ASEPSIS wound score
•Southampton wound grading system
These enable surgical wound healing to be graded according to
speci!ic criteria, usually giving a numerical value, thus providing
more objective assessment of wound.

24. Prevention
There are measures to follow in order to prevent SSI, these
include the following:
•Pre-Operative factors
•Operative characteristics
•Post-Operative Issues

25. Pre-Operative factors
•Preoperative antiseptic showering
•Preoperative hair removal (best to be just at the time of surgery)
•Patient skin preparation in the operating room
•Preoperative hand/forearm antisepsis
•Antimicrobial prophylaxis

26. Operative characteristics
•Operating room environment
•Surgical attire and drapes
•Asepsis and surgical technique

27. Post-Operative Issues (Incision Care)
The type of postoperative incision care:
•Closed primarily: the incision is usually covered with a sterile
dressing for 24 to 48 hours.
• Left open to be closed later: the incision is packed with a sterile
dressing.
•Left open to heal by second intention: packed with sterile moist
gauze and covered with a sterile dressing.

28. Treatment
Management depend on type of SSI
Surgical Debridement of wound
Suture? >>> remove sutures, free drainage
Fluid? >>> Culture/Sensitivity and give suitable antibiotics
Signs of healing? >>> Secondary suturing

29. Treatment
E#lux of purulent material and pus
If fascia is intact:
•Debridement
•Irrigated with normal saline,
•Packed to its base with saline moistened guaze
If fascia is separated: >> drainage or reoperation
**Most SSIs healing is by secondary intention

30. Discharge Planning
The intent of discharge planning is to:
•Maintain integrity of the healing incision.
•Educate the patient about the signs and symptoms of infection.
•Advise the patient about whom to contact to report any
problems.

31. Wound dehiscence is disruption of any or all of the layers in a
wound. Dehiscence may occur in up to 3% of abdominal wounds
and is very distressing to the patient.
Wound dehiscence most commonly occurs from the 5th to 8th
postoperative day when the strength of the wound is at its
weakest.
The patient may have felt a popping sensation during straining or
coughing. Most patients will need to return to the operating
theatre for resuturing. In some patients it may be appropriate to
leave the wound open and treat with dressings or vacuum-assisted
closure (VAC) pumps.
Wound Dehiscence

33. Risk Factors
General
● Malnourishment
● Diabetes
● Obesity
● Renal failure
● Jaundice
● Sepsis
● Cancer
● Treatment with steroids
Local
● Inadequate or poor closure of wound
● Poor local wound healing, e.g.
because of infection, haematoma or
seroma
● Increased intra-abdominal pressure,
e.g. in postoperative patients su"ering
from chronic obstructive airway
disease, during excessive coughing

34. Incidence
•1-3% of all andominal operations
•Develops 7-10 days post-op(but may occur anytime from day 1 to
day 20)
•Martality rate is ~16%
•Male:female ratio is 2:1
•Age: <45 years is 1.3%
>45 years is 5.4%

35. Clinical Features
Symptoms
Patient may present with one
or more of the following:
•Bleeding
•Swelling
•Redness
•Pain
•Fever
•Unexpained tachcardia
•Broken sutures
•Pus &/or frothy discharge
Signs:
•serosanguinous(pink) or blood-
stained discharge
•bowel or omentum protruding
through the wound spontaneously
after removal of sutures
•edema/swelling

36. Diagnosis
Lab tests
•Wound and tissue cultures to determine if there’s an infection
•Blood tests to determine if there’s an infection
Imagining studies
•X-ray
•US
•CT

37. Treatment
Drug therapy:
•Antibiotics.
Medical treatment:
•When appropriate, frequent changes in wound dressing to prevent infection.
•When appropriate, wound exposure to air to accelerate healing and prevent
infection, and allow growth of new tissue from below.
Surgical intervention:
•Surgical removal of contaminated, dead tissue.
•Resuturing.
•Placement of a temporary or permanent piece of mesh to bridge the gap
below the wound.

38. Prevention
•Antibiotic prophylaxis before and after surgery.
•When using wound dressing, maintain light pressure on wound.
•Keep wound area clean.
•Correct the precipitating factors before surgery.

39. Summary
•SSI is a major problem in surgical patients.
•Signi!icant morbidity/mortality and expense.
•Prophylactic antibiotics, ASA grade and timely surgery
important risk factors.
•WHO Safety checklist proven all over the world – highly
recommended.
•Importance of SSI surveillance in hospitals.
•Safe surgery saves lives!

40. ?