Surgical site infection pdf - D. Muhanned

What is surgical site infection

? Discuss the methods to reduce surgical site

infection.

Enumerate the factors responsible for surgical site infection.

Nosocomial Infection

An infection acquired in hospital by a patient who was admitted for a reason other

than that infection.

Infections occurring for more than 48 hours after admission are usually considered

nosocomial

Amongst surgical patients, SSI are the most common nosocomial infections

Classes of SS

Superficial incisional SSI

: Infection occurs within 30 days after the operation

and infection involves only skin of subcutaneous tissue of the incision and at least

one of the following:

–

Purulent drainage with or without laboratory confirmation from the superficial

incision

–

Organisms isolated from an aseptically obtained culture of fluid or tissue from

the superficial incision

–

At least one of the following signs or symptoms of infection: --Pain or

tenderness

Localised swelling

Redness

Heat

And superficial incision deliberately opened by a surgeon, unless incision is culture

negative

Deep incisional SSI

: Infection occurs within 30 days after the operation if no

implant is left in place or within one year if implant is in place and the infection
appears to be related to the operation and infection involves deep soft tissues (e.g.

fascial and muscle layers) of the incision and at least one of the following

–

Purulent drainage from the deep incision but not from the organ/space

component 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)

Localized pain

Tenderness unless site is culture-negative

–

An abscess or other evidence of infection involving the deep incision is found on

direct examination, during re-operation or by histopathological or radiological

examination

Organ/space SSI

: Infection occurs within 30 days after the operation if no

implant is left in place or within one year if implant is in place and the infection

appears to be related to the operation and infection involves any part of the

anatomy (e.g. organs or spaces), other than the incision, which was opened or

manipulated during an operation and at least one of the following:

–

Purulent discharge from a drain that is placed through a stab wound into the

organ/ space

–

Organisms isolated from an aseptically obtained culture of fluid or tissue in the

organ/space

–

An abscess or other evidence of infection involving the organ/space that is found

on direct examination, during re-operation, or by histopathologic or radiological

examination

trategies to prevent SSI

Objectives

Reduce the inoculum of bacteria at the surgical site 2-Surgical site preparation

Antibiotic prophylaxis strategies

Optimize the microenvironment of the surgical site 5-Enhance the physiology of

the host (host defenses)

isk factors of SSI classified

as:

Patient-related (intrinsic)

Preoperative

Operative

atient-related factors

-Diabetes—recommendation Preoperative Control serum blood glucose—reduce

HbA1C levels to <7% before surgery if possible Maintain the postoperative blood

glucose level at less than 200 mg/dL

-Smoking, anemia, malnutrition

Hypoalbuminemia, jaundice

Obesity,

hyperlipidemia

-Ascites, PVD

-Immunosupression.

Procedure-related risk factors

Hair removal technique (clipping> on table shaving > previous night shaving)

-Preoperative infections control and bath

Surgical scrub

-Skin preparation

Antimicrobial prophylaxis

Surgeon skill/technique/instruments

-Asepsis

Operative time (should be within 1.5 times the normal) j-Operating room

characteristics/OT sterility.

Surgeon skill and technique

Excellent surgical technique reduces the risk of SSI

Includes

Gentle traction and handling of tissues

-Effective hemostasis

-Removal of devitalized tissues

-Obliteration of dead spaces

-Irrigation of tissues with saline during long procedures f-Use of fine, nonabsorbed

monofilament suture material h-Wound closure without tension.

Cellulitis

Cellulitis is a common infection of skin and subcutaneous tissues, most frequently

caused by Streptococcus

pyogenes and occasionally Staphylococcus species. Infection occurs after the skin is

breached (e.g. insect bite, scratching, skin rash, minor trauma).

Cellulitis may

seem to occur spontaneously, although careful inspection reveals a break in the skin

After subcutaneous inoculation, streptococci release toxins which permit rapid

spread

of organisms. The acute inflammatory response results

in the clinical features of warmth, pain and tenderness, erythema, and oedema.

Severe cellulitis may progress
to suppuration and skin necrosis.

Differential diagnosis includes other causes of limb swelling, deep venous

thrombosis, rupture of a Baker’s cyst, calf haematoma and erythematous skin

conditions.

excretion of penicillin. Erythromycin or a third generation cephalosporin is used

in patients with penicillin

allergy. Any predisposing cause (e.g. tinea pedis) is treated vigorously. If cellulitis

does not resolve rapidly, the antibiotic is increased or changed.

Lymphangitis

Lymphangitis is associated with bacterial infections of extremities where the

inflamed lymphatic vessels appear

as several thin, red, tender lines on the slightly

oedematous skin progressing towards the regional

lymph nodes which are enlarged and tender (lymphadenitis).

Cellulitis of an extremity is treated by elevation and immobilisation with a splint or

plaster ‘back slab’, and antibiotics. Penicillin (2 million units every 6 hours)

or flucloxacillin (1–2 g every 6 hours) is given intravenously for 3–5 days and then

continued orally

for a further 10 days. Blood levels of penicillin may be increased by oral probenecid,
which reduces renal

Lymphangitis usually is caused by streptococci

and staphylococci. Chemical lymphangitis may
result from irritative compounds used for lymphangiography.

Treatment is the same as for cellulitis, consisting

of rest and elevation of the extremity and antibiotics. Rarely, suppurative regional

lymph nodes require surgical drainage.

Folliculitis, furuncles and carbuncles

‘

Folliculitis’ refers to infection with pus formation within a hair follicle and is limited

to the dermis. It may be extensive if many follicles are infected over a wide area,

such as the face.

A ‘furuncle’ is infection of a small number of hair

follicles within a small confined area. A ‘carbuncle’ is

an abscess involving a number of adjacent hair follicles where the infection has

penetrated through the dermis

and formed a multiloculated subcutaneous abscess between the fibrous septa which
anchor the skin to the

deep fascia

Furuncles and carbuncles occur most frequently

on the back of the neck, lower scalp, and the torso. Abscesses on the upper part of

the body are usually

caused by staphylococci, while infections below

the umbilicus are due largely to aerobic and anaerobic

coliform organisms.

Local hygiene is usually sufficient to treat folliculitis, although antibiotics are

required for extensive infections. Furuncles and carbuncles require incision and

drainage. Fibrous tissue septa must be broken down

so that all pockets of pus can be drained completely. Antibiotics are indicated for

severe and spreading infections, and in immunocompromised patients.

Hidradenitis suppurativa

Hidradenitis suppurativa refers to infection of apocrine sweat glands, and occurs in

the axillae, around the external genitalia, and the inguinal and perianal regions

Apocrine sweat glands have tortuous

secretory ducts within the skin and produce thick secretions, and infection occurs

when ducts become blocked, most commonly during excessive glandular activity at

adolescence.Staphylococci or Gramnegative bacilli and anaerobes are causative
organisms.

Patients present with multiple small but painful abscesses and sinuses, often

bilaterally. Repeated or long-standing infection results in considerable scarring,

Antibiotic therapy alone is

often inadequate, although long-term antibiotic therapy may be useful in
suppressing acute infections. Abscesses require incision and drainage. Excision of the

affected hair-bearing area and the subcutaneous fat usually is required, and results

in good symptomatic relief.

Synergistic gangrene

‘

Synergistic gangrene’ refers to a group of soft tissue

infections characterised by tissue necrosis and caused by several species of

microorganisms acting synergistically. Previous nomenclature (necrotising fasciitis,

necrotising

erysipelas, Meleney’s gangrene, Fournier’s gangrene, non-clostridial gangrenous

cellulitis(

Clinical features

Synergistic gangrene is caused by micro-aerophilic streptococci acting synergistically

with aerobic staphylococci, with or without Gram-negative bacilli. It usually

occurs in debilitated patients with other disorders
)

e.g. diabetes, malnutrition, alcoholism, liver disease,

renal failure, malignant disease, immune compromise (

Synergistic gangrene presents initially as cellulitis

with severe pain which is out of keeping with the minor
local clinical signs but consistent with the seriousness

of the condition. Infection spreads rapidly along fascial and subcutaneous planes

without a severe inflammatory reaction.

Bacterial toxins cause tissue and skin

necrosis. Crepitus occurs when gas-forming organisms

are present. Signs of systemic sepsis and toxaemia occur quickly.
‘

Fournier’s gangrene’ is the name given to synergistic gangrene involving the

perineum and scrotum. It

may be extensive and involve the abdominal wall and buttocks, and is a rare

complication of anorectal and

perineal surgery, trauma or minor infection.

Select the single correct answer to each question.

1:Cellulitis

a-is occasionally caused by Gram-negative coliforms b-often
occurs spontaneously without any apparent cause or organism

c- is treated with rest, immobilisation and high-dose penicillin
d-frequently requires surgical drainage
e-is often complicated by suppuration and skin necrosis

2:Fournier’s gangrene

a-is a form of pyomyositis
b-occurs mainly in debilitated patients and can be life-
threatening

c -is usually due to stapylococcal infection
d-can be treated by hyperbaric oxygen alone
e-is seldom managed surgically