Surgical site infections &

AMP

Dr. Anil Ganju

Surgical Site Infections (SSI)

Def: Infections that occur in the wound created by an invasive surgical procedure .

Most important causes of HCAIs. (14-16% )

Most common surgical patient nosocomial infection (38%)

Over 1/3rd of postoperative deaths are related to SSI.

Deaths in patients with nosocomial infections—77% related to infection.

2/3 involved surgical incision, 1/3 deep structures accessed by incision

SSIs, Soft tissue/wound infections

Range from a relatively trivial wound discharge with no other complications to a life-threatening condition.

Considerable morbidity

poor scars that are cosmetically unacceptable, hypertrophic or keloid, persistent pain and itching, restriction of movement, impact on emotional wellbeing

SSI can double the length of time a patient stays in hospital and thereby increase the costs.

SSI – Surgery Classification

1. Clean Surgeries

2. Clean contaminated

3. Contaminated

4. Dirty infected

SSI – Wound Classification

Class 1 = Clean

Class 2 = Clean contaminated

Class 3 = Contaminated

Class 4 = Dirty infected

Class I (clean)

Atraumatic wound w/o inflammation. No respiratory, GU,GI,or biliary tract entered

e.g-Hernia repair

1.5% infection rate

Class II(clean/contaminated)

entrance into respiratory, GU,GI,or biliary tracts

e.g.-

Cholecytectomy,

elective bowel resection

? infection rate

Class II(clean/contaminated)

Controlled entrance into respiratory, GU,GI,or biliary tracts

Cholecytectomy, elective bowel resection

7.5% infection rate

Class III(contaminated)

Traumatic wounds, major breaks in sterile techniques, gross spillage of GI contents, Acute non-purulent inflammation

e.g.-

Appendectomy

? infection rate

Class III(contaminated)

Traumatic wounds, major breaks in sterile techniques, gross spillage of GI contents, Acute non-purulent inflammation

Appendectomy

15% infection rate

Class IV (dirty)

Old trauma wounds; devitalized tissue; existing clinical infection, perforated viscera. e.g.-

Hartmann’s for diverticular perforation

? Infection rate

Class IV (dirty)

Old trauma wounds; devitalized tissue; existing clinical infection, perforated viscera.

Hartmann’s for diverticular perforation

40% infection

Extend of Incisional SSI

Superficial Surgical Site Infection

Deep Surgical Site Infection

Organ/Space Surgical Site Infection

Risk of Infection(Pathogenesis)

Bacterial dose Virulence

Impairedhost resistance

Transmission Cycle in OT

Infectious agentsbacteria,virus,etc.

Susceptible Hosts(clients, service providers,

commu. members, Ancillary staffs)

Reservoirspeople,water,air,

Instruments

Places of exitResp.,GU,GI

Modes of transmissionContact, droplet, airborne,

vehicle

Place of entrybroken skin, surgical site,

mucous membrane

SSI – Risk Factors Operation Factors

Duration of surgical scrub

Maintain body temp.

Skin antisepsis

Pre-operative shaving

Duration of operation

Antimicrobial prophylaxis

Operating room ventilation

Inadequate sterilization of instruments

Foreign material at surgical site

Surgical drains

Surgical technique

Poor hemostasisFailure to obliterate dead

space Tissue trauma

Opportunity to Prevent SSI

An estimated 40%–60% of SSIs are preventable.

Overuse, underuse, improper timing, and misuse of antibiotics occurs in 25%–50% of operations.

Four main strategies:

Prevent infection, diagnose and treat infection use antimicrobials wisely, and prevent transmission.

Antimicrobial prophylaxis

Def.: Surgical antimicrobial prophylaxis (AMP) refers to a brief course of an antimicrobial agent just before an operation begins.

AMP is not an attempt to sterilize tissues, but a critically timed use to reduce the microbial burden of intraoperative contamination to a level that cannot overwhelm host defenses.

AMP does not pertain to prevention of SSI caused by postoperative contamination.

Intravenous infusion is the mode of AMP delivery in modern surgical practice.

Essentially all confirmed AMP indications pertain to elective operations in which skin incisions are closed in the operating room.

Antimicrobial prophylaxisFour principles to maximize the benefits of AMP:

Use an AMP agent for all operations or classes of operations in which its use has been shown to reduce SSI rates or for those operations after which incisional or organ/space SSI would represent a catastrophe.

Use an AMP agent that is safe, inexpensive, and bactericidal that covers the most probable intraoperative contaminants for the operation.

Time the infusion of the initial dose of antimicrobial agent so that a bactericidal concentration is established in serum and tissues by the time of skin incised.

Maintain therapeutic levels of the antimicrobial agent in both serum and tissues throughout the operation and until, at most, a few hours after the incision is closed in the operating room.

SSI – Wound/Surgery Classification

• Class 1 = Clean• Class 2 = Clean contaminated• Class 3 = Contaminated• Class 4 = Dirty infected

.

Prophylactic antibiotics indicated

Therapeutic antibiotics

AMP indications for clean operations

Two well-recognized indications for such clean operations are:

(1) when any intravascular prosthetic material or a prosthetic joint will be inserted, and

(2) for any operation in which an incisional or organ/space SSI would pose catastrophic risk. Examples are all cardiac operations, including cardiac pacemaker placement, vascular operations involving prosthetic arterial graft placement at any site or the revascularization of the lower extremity, and most neurosurgical operations

Some have advocated use of AMP during all operations on the Breast.