SURGICAL SITE INFECTION

INTERN Dr. AMIT POUDEL

WHAT IS SURGICAL SITE INFECTION?

• A surgical site infection is an infection that occurs in the wound created by an invasive surgical procedure.

• It leads toincreased morbidityincreased mortalityIncreased duration of hospital stay (7 days on an average)increased cost

Types of SSI• Superficial incisional SSI

• Deep incisional SSI

• Organ / space SSI

Superficial incisional SSI• Infection occurs within 30 days after surgical procedure

AND • Involves only skin and subcutaneous tissue of the incision

AND • Patient has at least 1 of the following:

• a. Purulent drainage from the superficial incision • b. Organism isolated from an aseptically-obtained culture of fluid or tissue • c. Superficial incision that is deliberately opened by a surgeon and is culture

positive or not cultured and patient has at least one of the following signs or symptoms: pain or tenderness, localized swelling, redness, heat

• d. Diagnosis of superficial SSI by surgeon or attending physician

Do not report the following condition as SSI• Stitch abscess (minimal inflammation and discharge confined to the

points of suture penetration)• Infection of an episiotomy or newborn circumcision site• Infected burn wound• Incisional SSI that extends into the fascial and muscle layers.

Deep Incisional SSI • Infection occurs within 30 days after the operation if no implant is left in place or within 1

yr. if implant is in place and the infection appears to be related to the operation. AND

• Involves deep soft tissues of the incision, e.g., fascial & muscle layers AND • Patient has at least 1 of the following:

a. Purulent drainage from deep incision b. Deep incision spontaneously dehisces or opened by surgeon and is culture

positive or not cultured and fever >38 C, localized pain or tenderness (Note: a culture negative finding does not meet this criterion)

c. Abscess or other evidence of infection found on direct exam, during invasive procedure, by histopathologic exam or imaging test

d. Diagnosis of deep SSI by surgeon or attending physician

Organ Space SSI • Infection occurs within 30 days after the operation if no implant is left in place or within

1 yr. if implant is in place and the infection appears to be related to the operation. AND

• Infection involves any part of the body, excluding the skin incision, fascia, or muscle layers that is opened or manipulated during the operative procedure

AND • Patient has at least 1 of the following:

a. Purulent drainage from drain placed into the organ/space b. Organism isolated from an aseptically-obtained culture of fluid or tissue in the

organ/space c. Abscess or other evidence of infection found on direct exam, during invasive

procedure, or by histopathologic or exam or imaging test d. Diagnosis of an organ/space infection by a surgeon or attending physician

Further classification• Severity a) Minor discharge without cellulitis or deep tissue destruction b) Major

Pus discharge with tissue breakdown ,Partial or total dehiscence of the deep fascial layers of wound Systemic illness is present.

a) Early Infection presents within 30 days of procedure b) Intermediate Occurs between one and three months c) Late Presents more than three months after surgery

Pathophysiology• Micro-organisms are normally prevented from causing infection in tissues

by• mechanical: intact epithelium• chemical: low gastric pH;• humoral: antibodies, complement and opsonins;• cellular: phagocytic cells, macrophages, polymorphonuclear

cells and killer lymphocytes.

……….may be compromised by any comorbid condition of the patient, surgical intervention and treatment leading to SSI.

Risk factors for developing SSI• Patient factor

• Local factor

• Microbial factor

Patient factor• Older age • Immunosuppression • Obesity • Diabetes mellitus • Chronic inflammatory process • Malnutrition • Peripheral vascular disease • Smoking• Anaemia • Radiation • Steroid use

Local factor• Poor skin preparation • Contamination of instruments • Inadequate antibiotic prophylaxis • Prolonged procedure• Site and complexity of procedure• Local tissue necrosis • Hypoxia • Hypothermia

Microbial factor• Wound Class

• Prolonged hospitalization (leading to nosocomial organisms)

• Resistance

Wound Class

Common pathogen in surgical patients

Wound assessment

• ASEPSIS

• SOUTHAMPTON

• enable surgical wound healing to be graded according to specific criteria, usually giving a numerical value, thus providing more objective assessment of wound

ASEPSIS wound scoring system

• Score 0-10-satisfactory healing• 11-20-disturbance of healing• 20-30-minor wound infection• 31-40-moderate wound infection• >41-severe wound infection

Southampton scoring system

SENIC Risk Index (the study of the effect of nosocomial infection control)

• Abdominal operation• Operation greater than

2 hours• Class III or IV surgical

wounds• Three or more

diagnosis at time of discharge

Risk of Infection0 1%1

3.6%2 9%3

17%4

27%

Management of surgical site infection • Most SSIs respond to the removal of sutures with drainage of pus if present

and, occasionally, there is a need for debridement and open wound care.

• Incomplete sealing of the wound edges can often be managed by using a delayed primary or secondary suture or closure with adhesive tape, but in larger open wounds the granulation tissue must be healthy with a low bio-burden of colonizing or contaminating organisms if healing is to occur.

Prevention of SSI• Pre-op factors

• Intra-op factors

• Post-op factors

Pre-op factors

• Preoperative antiseptic showering

• Preoperative hair removal

• Patient skin preparation in the operating room

• Preoperative hand/forearm antisepsis( Alcohol solution, Chlorhexidine gluconate, Iodophors)

• Antimicrobial prophylaxis

Antibiotic prophylaxis

• Give antibiotic prophylaxis to patients before: • clean surgery involving the placement of a prosthesis or implant • clean-contaminated surgery • contaminated surgery.

Do not use antibiotic prophylaxis routinely for clean non-prosthetic uncomplicated surgery. •Consider giving a single dose of antibiotic prophylaxis intravenously on starting anaesthesia.

WoundClassification

Antibiotic Penicillin Allergy

I1st generation Cephalosporin

Vancomycin Clindamycin

II-Biliary,GU, Upper Digestive

1st generation Cephalosporin

Vancomycin Clindamycin

II-Distal Digestive2nd generation Cephalosporin

Aztreonam and Clindamycin/metronidazole

III/IV Generally Therapeutic

Point to rememberOnce the incision is

made, antibiotic

delivery to the wound is impaired.

Hence must given before

incision!

Intra operative factors• Operating room environment

Temperature: 68o-73oF, depending on normal ambient temp Relative humidity: 30%-60% Air movement: from “clean to less clean” areas

• Surgical attire and drapes• Asepsis and surgical technique

Post operative factors• 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.

• Changing dressings Use an aseptic non-touch technique for changing or removing surgical

wound dressings. • Postoperative cleansing

•Use sterile saline for wound cleansing up to 48 hours after surgery. •Advise patients that they may shower safely 48 hours after surgery. •Use tap water for wound cleansing after 48 hours if the surgical

wound has separated or has been surgically opened to drain pus. •Topical antimicrobial agents for wound healing by primary intention

Severe inflammatory response syndrome and sepsisSIRSTwo of:

hyperthermia (> 38°C) or hypothermia (< 36°C)tachycardia (> 90 /min, no β-blockers) or tachypnea (> 20 /min)white cell count > 12 × 109 / l or < 4 × 109 l

• Sepsis is SIRS with a documented infection• Severe sepsis or sepsis syndrome or MODS is sepsis with evidence of one or more

organ failures [respiratory (acute respiratory distress syndrome), cardiovascular (septic shock follows compromise of cardiac function and fall in peripheral vascular resistance), renal (usually acute tubular necrosis), hepatic, blood coagulation systems or central nervous system]

Surviving sepsis• Initial evaluation and infection issues

• Initial resuscitation ( cvp :8-12 mm hg, MAP>65 mm hg and urine output>0.5 ml/kg/hr)• Diagnosis ( via appropriate cultures)• Antibiotic therapy ( BSAb at the beginning then organism specific)• Source control

• Hemodynamic support and adjunctive therapy • Fluid therapy• Vasopressor/inotropic therapy ( MAP> 65) (nor epi and dopamine)• Steroids• Recombinant human activated protein c (in adults with sepsis induced organ

dysfunction)

• Other supportive therapy• Blood product administration (if hb < 7 gm%)• Mechanical ventilation(TV- 6 ml/kg, PEEP-to avoid collapse and pleateu

pressure < 30 mm hg)• Glucose control• Prophyllaxis ( stress ulcers and dvt)

To sum it up• SSI is an infected 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• MSOF ultimately leads to death.

Thank you.