Guidelines for using antimicrobial prophylaxis in surgery. This lecture was prepared primarily from Pharmacotherapy: Principle and Practice, the 5th edition.

1. Antimicrobial Prophylaxis
in Surgery
Abdulsalam Halboup
M. Pharm (Clinical)

2. Type of surgery
Colorectal Surgery
Gynecologic and Obstetric
Orthopedic Surgery
Cardiothoracic surgery
Vascular Surgery
Appendectomy

3. 0
0

4. INTRODUCTION
• Surgical site infections (SSIs) are a significant cause of
morbidity and mortality.
• Approximately 2% to 5% of patients undergoing clean
extra-abdominal operations and 20% undergoing intra-
abdominal operations will develop an SSI.
• SSIs have become the second most common cause of
nosocomial infection.
• Patients who develop SSIs are five times more likely to be
readmitted to the hospital and have twice the mortality of
patients who do not develop an SSI.

5. Surgical site infections (SSIs)
according to CDC
SSIs
incisional
superficial
incisional SSI
deep
incisional SSI
organ/space
SSI : is the infection that
occurs within 30 days of the
operation (either incisional
or organ/space).
 If a prosthesis is
implanted during the
operation, the
timeline extends out
to 1 year.

6. Risk factors for
SSIs
Patient factors (age,
comorbid disease states,
mal.,imm, colonization
operative characteristics
(Shaving, sterilization of equi,
staff, appropriate use of ABx
Risk factors for SSIs

7. PATHOPHYSIOLOGY
Prophylaxis Versus Treatment:
• Antimicrobial prophylaxis begins with the idea that no infection
exists but that during the operation there can be a low-level
inoculum of bacteria introduced into the body. However, if sufficient
antimicrobial concentrations are present, bacteria can be controlled
without infection developing.
– no major breaks in sterile technique or spillage of GI contents. Example:
hysterectomy done with optimal surgical technique.
• If an infection is already present, or presumed to be present, then
antimicrobial use is for treatment, not prophylaxis, and the goal is to
resolve the infection.

8. • The distinction between prophylaxis and treatment influences the
choice of antimicrobial and duration of therapy.
– A regimen for antimicrobial prophylaxis ideally involves one
agent and lasts less than 24 hours.
– Treatment regimens can involve multiple antimicrobials with
durations lasting weeks to months depending on desired
antimicrobial coverage and the surgical site.

9. Types of Surgical Operations
Surgical operations are classified at the time of
operation?!!
antifungal prophylaxis for surgery is not currently

10. Types of Surgical Operations

12. Choosing an Antibiotic
• Ideal criteria for an antimicrobial in surgical prophylaxis
include the following:
– 􀁴 Spectrum that covers expected pathogens
– 􀁴 Inexpensive
– 􀁴 Parenteral
– 􀁴 Easy to use
– 􀁴 Minimal adverse-event potential
– 􀁴 Longer half-life to minimize need for redosing during
procedure

13. Choosing an
Antibiotic Prophylaxis
Operations
extra-abdominal
gram-positive
Intra-abdominal
anaerobes gram-negative

14. Choosing an Antibiotic prophylaxis
Operations can be separated into two basic categories:
 Extra-abdominal : gram-positive aerobes.
– Cefazolin provides a benign adverse-event profile, simple dosing,
and low cost, making cefazolin the mainstay for surgical
prophylaxis of extra-abdominal procedures.
– For patients with a β-lactam allergy, clindamycin or vancomycin
can be used as an alternative.
 Intra-abdominal: gram-negative organisms and anaerobes.
• Anti-anaerobic cephalosporins, cefoxitin and cefotetan, are widely
used.

15. • Vancomycin should be considered when a cluster of methicillin-
resistant S. aureus (MRSA) or coagulase negative staphylococci
have been identified.
• vancomycin use in institutions where MRSA rates are “high”.
• Ertapenem was superior to standard cefotetan in the
prevention of SSIs after elective colorectal surgery.
– Clostridium difficile

16. Principles of Antimicrobial Prophylaxis
 Route of Administration
• IV antimicrobial administration is the most common delivery
• method for surgical prophylaxis.
 Timing of First Dose:
• The National Surgical Infection Prevention Project recommends
infusing antimicrobials for surgical prophylaxis within 60
minutes of the first incision.
• Exceptions to this rule are fluoroquinolones and vancomycin,
which can be infused 120 minutes prior to avoid infusion-related
reactions.
Principle of anti. Proph.
1. Route
2. Timing
3. Redosing
4. Duration

17.  Dosing and Redosing:
• The newest guidelines recommended higher doses of cefazolin based on
pharmacokinetic/pharmacodynamics data:
– 2 g for all patients less than 120 kg;
– 3g for patients more than or equal to 120 kg
– Clindamycin should be given as a 900-mg preoperative intravenous
dose (β-lactam allergy).
• If an operation exceeds two half-lives of the selected antimicrobial, then
another dose should be administered.
– For example, cefazolin has a half life of about 2 hours, thus another
dose should be given if the operation exceeds 4 hours.
 Duration:
• The duration of antimicrobial prophylaxis should not exceed 24 hours (48

19. PROPHYLAXIS REGIMENS
Antimicrobial Prophylaxis in Specific Surgical Procedures:
 Gynecologic and Obstetric: Possible pathogens: enteric gram-
negative bacilli, anaerobes, group B streptococci(GBS),
enterococci.
• Prophylaxis for Cesarean section: cefazolin
– Alternatives for β-lactam allergy: clindamycin and aminoglycoside
• Prophylaxis for hysterectomy: cefazolin, cefotetan, cefoxitin,
ampicillin-sulbactam
– Alternatives for β-lactam allergy: clindamycin or vancomycin
combined with aminoglycoside, aztreonam, or fluoroquinolone;
– metronidazole combined with fluoroquinolone or aminoglycoside.
Antimicrobials should not be administered until after the first incision and
the umbilical cord has been clamped. ???

20.  Orthopedic Surgery: Possible pathogens: gram-positive cocci,
mostly staphylococci.
• Prophylaxis for total joint arthroplasty (hip or knee): cefazolin
– 􀁴 Alternatives for β-lactam allergy: clindamycin, or vancomycin
 Cardiothoracic and Vascular Surgery: Possible pathogens: gram-
positive cocci, mostly staphylococci
– Prophylaxis for cardiac surgeries: cefazolin, cefuroxime
– Prophylaxis for noncardiac thoracic surgeries: cefazolin,
ampicillin-sulbactam
– Prophylaxis for vascular surgeries: cefazolin
• 􀁴 For all cardiothoracic and vascular surgeries

21.  Colorectal Surgery: Possible pathogens: gram-positive, gram-
negative, and anaerobic organisms.
• Parenteral prophylaxis: cefazolin and metronidazole; cefoxitin;
cefotetan; ampicillin-sulbactam; ceftriaxone and metronidazole
; ertapenem.
– Alternatives for β-lactam allergy: clindamycin combined
with aminoglycoside, aztreonam, or fluoroquinolone;
– metronidazole combined with aminoglycoside or
fluoroquinolone.
 Appendectomy is one of the most common intra-abdominal
operations. Antimicrobial prophylaxis used for appendectomy
is similar to that used for colorectal regimens.

22. Alternative Methods to Decrease SSI
• Intensive glucose control (maintaining blood glucose to 80–110
mg/dL versus conventional control (blood glucose < 220 mg/dL
reduced operative site infections and improve outcomes .
• O2
• Irrigation with detergent solutions, rather than antimicrobials,
appears to provide the same results but with less wound-healing
problems encountered with antimicrobial irrigation.
• decolonization : Guidelines endorse the use of
mupirocin(Bactroban ) for S. aureus decolonization, especially in
cardiac and orthopedic surgery 5 days prior to surgery.
– Additionally, skin decolonization with 4% chlorhexidine for 5 days
prior to surgery has also been recommended.

23. OUTCOME EVALUATION
• According to CDC criteria, SSIs may appear up to 30 days
after an operation and up to 1 year if a prosthesis is implanted.
• Distal infections, such as pneumonia, are not considered SSIs
even if these infections occur in the 30-day period.
• Check the appearance of the surgical site regularly and
document any changes (eg, erythema, warmth, swelling, or
pus).
• The presence of pus or other signs suggestive of SSI must be
treated accordingly.