Transcript In The Name of Allah Guidelines For Surgical Chemoprophylaxis By

In The Name of Allah
Guidelines For Surgical
Chemoprophylaxis
By:
Dr. M. Minaiyan
Dept. of Pharmacology, IUMS
Surgical Site Infection
(SSI)
Definition
 SSI is an infection related to the operation
procedure that occur within 30 days of
procedure or 1 year if an implant is left in place.
 SSIs account for about 38% of nosocomial
infections and an average total cost increament
of $3380 per patient and 1.5 $ billions annually
in USA.
FACTS
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One out of every 24 patients who have inpatient
surgery in the United States has a postoperative
SSI
The cost of SSIs are substantial: an increased
total cost of more than 300%
SSIs increase the post operative length of
hospital stay by 7-14 days
Definitions of SSI
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Superficial incisional SSI: Infection involves only
skin and subcutaneous tissue of incision.
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Deep incisional SSI: Infection involves deep
tissues, such as fascial and muscle layers. This
also includes infection involving both superficial
and deep incision sites and organ/space SSI
draining through incision.
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Organ/space SSI: Infection involves any part of
the anatomy in organs and spaces other than the
incision, which was opened or manipulated during
operation.
Risk factors
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Decreased host resistance can be due to:
1- Systemic factors affecting the patient's healing
response
2- Local wound characteristics
3- Operative characteristics.
Systemic factors include age, malnutrition,
hypovolemia, poor tissue perfusion, obesity,
diabetes,steroids, and other immunosuppressants.
Risk factors
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Wound characteristics include nonviable tissue in
wound; hematoma; foreign material, including
drains and sutures; dead space; poor skin
preparation, including shaving; and preexistent
sepsis (local or distant).
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Operative characteristics include poor surgical
technique; lengthy operation (>2 h);
intraoperative contamination, including infected
theater staff and instruments and inadequate
theater ventilation; prolonged preoperative stay in
the hospital; and hypothermia
The type of procedure is a risk factor too
Risk Factors Which Justify Surgical
Antimicrobial Prophylaxis
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1. Operation in the abdomen
2. Operations lasting more than 2 hrs
3. Contaminated or dirty wounds (expected
infection rate >20%)
4. Presence of at least three medical diagnosis
5. Immuno -compromised host
6. Placement of prosthetic material
Prophylactic Antibiotics
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General agreement exists that prophylactic antibiotics
are indicated for clean-contaminated and
contaminated wounds
Antibiotics for dirty wounds are part of the treatment
because infection is established already.
Clean procedures might be an issue of debate. No
doubt exists regarding the use of prophylactic
antibiotics in clean procedures in which prosthetic
devices are inserted because infection in these cases
would be disastrous for the patient.
General Principles of Surgical
Prophylaxis
1. The antibiotic should have proved efficacy
in clinical trials
 2. The antibiotic should be active against
common surgical pathogens; unnecessary
broad coverage should be avoided
 3. The antibiotic must achieve concentrations
greater than the MIC of suspected pathogen at
the time of incision
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General Principles of Surgical
Prophylaxis
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4. The shortest possible course; ideally a single
dose of the most effective and least toxic agent
should be used(Postoperative administration of preventive systemic
antibiotics beyond 24 hours has not been demonstrated to reduce the risk of
SSIs )
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5. The newer broad spectrum antibiotics should
be reserved for resistant infections
6. If all other factors are equal, the least
expensive drug should be used
Prevention of SSI
Main Factors
1. The general health of the patient
 2. Meticulous operative techniques
 3. Timely administration of effective
preoperative antibiotics
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Useful common Practices
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1. Preoperative showering with antimicrobial
soaps
2. Application of antiseptics to the skin of
patients
3. Washing and gloving of the surgeons' hands
4. Use of sterile drapers
5. Use of gowns and masks by operative room
personnel
Causes
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Table 1. Pathogens
Commonly Associated
with Wound Infections
and Frequency of
Occurrence*
Pathogen Frequency
(%) *NNIS System (CDC,
1996)
Staphylococcu 20
s aureus
Coagulasenegative
staphylococci
enterococci
14
Escherichia coli
Pseudomonas
enterobacter
Proteus
Mirabilis
Klebsiella pn.
Bact. fragilis
8
8
7
3
12
3
2
Antibiotic Selection
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Cefazolin (1-2g IV) has been effective for most
clean procedures because of its activity against
many Staphylococci and Streptococci species
Cefuroxime (1.5g IV) can be given instead of
cefazolin in thoracic and orthopedic procedures
Antibiotic Selection
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For procedures that might involve exposure to
bowel anaerobes (B. fragilis) choices are:
Cefazolin + Metronidazole (0.5g IV) or
monotherapy with Ampicillin+ Sulbactam (3g
IV)
Two above mentioned therapies are preferred to
2nd generation cephalosporins like: Cefoxitin or
Cefotetan
Antibiotic Selection
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Vancomycin (10-15mg/kg ~1g, IV) or
Clindamycin (600-900mg, IV) are useful drugs
for patients are highly allergic to pencillins and
cephalosporins
In colorectal procedures, hysterectomy and
vascular surgery a drug which add a gramΘ
coverage e.g. Gentamicin, Ciprofloxacin and
Aztreonam is needed.
Antibiotic Selection
Vancomycin is the drug of choice for following
conditions:
1- Local resistance pattern (MRSA)
2- Patients with a long preoperative hospitalization
3- Patients have recently taken broad spectrum
antibiotics
4- Patients with prosthetic graft implantation
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