Surgical Site Infection

Introduction

Ignaz Semmelweis and Joseph Lister became the pioneers of infection control by introducing antiseptic surgery in middle of 19th century.

Since then a number of significant developments, particularly in the field of microbiology, have made surgery safer

In 1992, the US Centers for Disease Control (CDC) revised its definition of 'wound infection', creating the definition 'surgical site infection' (SSI) to prevent confusion between the infection of a surgical incision and the infection of a traumatic wound

Classification

Incisional organ, or other organs and spaces manipulated

during an operation

Incisional infections are further classified into-

superficial (skin and subcutaneous tissue) and

deep (deep soft tissue-muscle and fascia)

Microbiology of Surgical Site Infections In clean surgical procedures, in which the

gastrointestinal, gynecologic, and respiratory tracts have not been entered, Staphylococcus aureus from the exogenous environment or the patient’s skin flora is the usual cause of infection

Factors influencing SSIs (Lancet2000) Surgical considerations Skin preparation Site, duration and complexity of the surgery. Presence of suture or foreign body Suturing quality. Pre-existing local or systemic infection Prophylactic atibiotic Haematoma Mechanical stress on wound

Anesthetic considerations

Tissue perfusion Normovolaemia or hypovolaemia Concentration of the inspired oxygen Perioperative body temperature Pain Blood transfusion

Patient related factors Diabetes Alcoholism Smoking Poor nutrition Jaundice Obesity Advanced age Poor physical condition

Surgical Factors- Decreased collagen synthesis

Anesthetic factors- Vasoconstriction

Patient factors -Immunosuppression

Decreased tissue perfusion

Decreased PtO2

Decreased collagen Decreased neutrophil Deposition Bactericidal activity Decreased wound Increased wound tensile strength Infection

Wound break down

Classification for operative wounds

Clean- Elective, not emergency, non-traumatic, primarily closed; no acute inflammation; no break in technique; respiratory, gastrointestinal, biliary and genitourinary tracts not entered. 

Clean contaminated- Urgent or emergency case that is otherwise clean; elective opening of respiratory, gastrointestinal, biliary or genitourinary tract with minimal spillage (e.g. appendectomy) 

Contaminated- Non-purulent inflammation; gross spillage from gastrointestinal tract; entry into biliary or genitourinary tract in the presence of infected bile or urine; major break in technique; penetrating trauma <4 hours old; chronic open wounds to be grafted or covered. 

Dirty- Purulent inflammation (e.g. abscess); preoperative perforation of respiratory, gastrointestinal, biliary or genitourinary tract; penetrating trauma >4 hours old. (Ann Surgery 1964)

Rates of Infection

clean 2.1%, clean-contaminated 3.3%, contaminated 6.4% and dirty 7.1%

US National Nosocomial Infection Surveillance (NNIS) system

Prevention of SSI

Appropriate use of antibiotics; Appropriate hair removal; Maintenance of postoperative glucose

control Maintenance of postoperative

normothermia

Antibiotics

One dose of antibiotic to be given preoperatively

It is generally recommended in elective clean surgical procedures and clean contaminated procedures that a single dose of cephalosporin to be administered intravenously

Involve pharmacy, infection control, and infectious disease staff to ensure appropriate timing, selection, and duration of antibiotic

Hair removal

Hairs to be removed in OT just before surgery.

Use of clippers than razors reduces the chances of infection

Glucose control

Implement a glucose control protocol. Develop one protocol to be used for all

surgical patients. Regularly check preoperative blood glucose

levels on all patients to identify hyperglycemia;

Assign responsibility and accountability for blood glucose monitoring and control.

CDC surgical site infections prevention guidelines, 1999 Category 1A- Strongly recommended for

implementation and supported by well-designed experimental, clinical, or epidemiologic studies

Treat remote infection before elective operation;

Postpone surgery until treated;

Do not remove hair from operative site unless necessary to facilitate surgery; If hair is removed, do immediately before surgery, preferably with electric clippers

Select an antimicrobial agent with efficacy against expected pathogen;

Intravenous route used to ascertain adequate serum levels during operation and for at most a few hours after incision closed

Category 1B- Strongly recommended for implementation and supported by some experimental, clinical, or epidemiologic studies and strong theoretical rationale

Control serum blood glucose perioperatively; Cessation of tobacco use 30 days before

surgery; Do not withhold necessary blood products to

prevent SSIs

Shower or bath on night before operative procedure;

Wash incision site before performing antiseptic skin preparation with approved agent

Do not routinely use vancomycin for antimicrobial prophylaxis

Category II- Suggested for implementation and supported by suggestive clinical or epidemiologic studies or theoretical rationale

Prepare skin in concentric circles from incision site;

Keep preoperative stay in hospital as short as possible

Superficial incisional surgical site infections

occur within 30 days of procedure involve only the skin or subcutaneous tissue

around the incision.

purulent drainage from the incision organisms isolated from an aseptically

obtained culture of fluid or tissue from the incision

at least one of the following signs or symptoms of infection - pain or tenderness, localised swelling, redness or heat - and the incision is deliberately opened by a surgeon, unless the culture is negative

Don’t considered superficial SSIs stitch abscesses infection of an episiotomy or neonatal

circumcision site infected burn wounds incisional SSIs that extend into the fascial

and muscle layers

Deep incisional surgical site infections occur within 30 days of procedure (or one

year in the case of implants) are related to the procedure involve deep soft tissues, such as the

fascia and muscles.

purulent drainage from the incision but not from the organ/space of the surgical site

a deep incision spontaneously dehisces or is deliberately opened by a surgeon when the patient has at least one of the following signs or symptoms - fever (>38°C), localised pain or tenderness - unless the culture is negative

an abscess or other evidence of infection involving the incision is found on direct examination or by histopathologic or radiological examination

(CDC definitions of surgical wound infections )

Wound assessment

ASEPSIS –to assess wounds resulting from cardiothoracic surgery

Southampton Wound Assessment Scale –

categorized according to any complications and their extent

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 Grade Appearance

0 Normal

I Normal healing with mild bruises and erythema

A Some bruising B considerable brusing C Mild erythema

Grade Appearance II Erythema plus other signs

of infection A At one point B Around sutures C Along wound D Around wound

Grade Appearance III Clean or haemoserous

discharge A At one point only B Along wound C Large volume D Prolonged

Grade Appearance IV Major wound

complication like pus A At one point only B Along wound

V Deep or severe

infection with or without

breakdown

Treatment

Surgical debridement of wound and antibiotics according to sensitivity

Thank you