antibiotic prophylaxis

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Antibiotic Prophylaxis In OBSTETRICAL AND
GYNECOLOGICAL SURGERY
BY Dr. JEHAD YOUSEF FICS, FRCOG. ALHAYAT
HOSPITAL, AMMAN - JORDAN
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CLINICAL USE OF ANTIBIOTICS

• Prophylactic therapy Given to patients before
  contamination or infection has occurred
• Anticipatory therapy Includes situations where
  contamination has already occurred and therapy is
  aimed at minimizing post-op infection
• Empiric therapy Non-directed therapy in absence
  of pathogen identification
• Directed therapy Pathogen identified

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Surgery associated infection

• Approximately 60 of patients admitted to the
  hospital are "surgericed" at some point during
  their stay in hospital
• Incidence
• Depends upon type of surgery, patient risk
  factors hospital antimicrobial practices
• Estimated to account for up to 70 of nosocomial
  infections

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Factors Associated with Increased Risk of
Surgical Infection

• Host Factors
• Older age
• Obesity
• Malnutrition
• Diabetes mellitus
• Immunocompromising diseases or therapies
• Presence of other infections
• Skin diseases

• Surgical Factors
• Inadequate skin antisepsis
• Emergency procedure
• Prosthetic implants
• Prolonged procedure
• Use of drains
• Poor technique
• Unexpected contamination

Environmental Factors Staph. or Strep.
carrier Excessive activity in OR Contaminated
antiseptics Inadequate ventilation
Inadequately sterilized equipment

• Preoperative Factors
• Prolonged pre-op stay
• Shaving the skin
• Inadequate antibiotic prophylaxis

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Pathogenesis of Surgical Site Infection
Simply stated, infections of surgical wounds
occurs whenever the microbial inoculum in the
wound is sufficient to overcome the local host
defense mechanisms and establish progressive
growth
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Classification of Operations(National Research
Council (NRC) American college of surgeons)

• Clean--nontraumatic, uninfected wound
  respiratory, gastrointestinal, genitourinary
  tract or oropharyngeal cavity not entered
  elective, primarily closed, undrained wound
• Clean-contaminated--respiratory,
  gastrointestinal, genitourinary tract or
  oropharyngeal cavity entered without unusual
  contamination and under controlled conditions
  mechanically drained wound
• Contaminated--open, fresh traumatic wounds gross
  spillage from gastrointestinal tract major break
  in sterile technique acute, nonpurulent
  inflammation
• Dirty/Infected--old traumatic wounds clinical
  infection perforated viscera

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Surgical Site Infection RatesWHO Prevalence
Survey
Conducted in 47 hospitals in 14 countries during
1983-85
Mayon-White et al. An international survey of the
prevalence of hospital-acquired infection. J Hosp
Infect 1988
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Annual Surgical Site Infection Rate by Wound
Class in a Large U.S. Hospital
Olson Lee. Continuous, 10-year wound infection
surveillance. Arch Surg 1990125794.
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ANTIBIOTIC PROPHYLAXIS

• Antibiotic prophylaxis is the peri-operative
  and/or intra-operative administration of
  antibiotics to patients to reduce the risk of
  postoperative infection

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Antibiotic Prophylaxis Goals

• The aim of prophylaxis is to augment host defense
  mechanisms at the time of bacterial invasion,
  thereby decreasing the size of the inoculum
• Use antibiotics in a manner that is supported by
  evidence of effectiveness
• The use of prophylactic antibiotics is an adjunct
  to and not a substitute for good surgical
  technique.

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Antibiotic Prophylaxis

• Benefits
• Decreased incidence of infection (wound/distal)
• Reduce overall costs - Prolonged stay

• Risks
• Toxic reactions
• Allergic reactions
• Emergence of resistant bacteria
• Drug interactions
• Super infection

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The 6 laws of prophylactic antibiotic
administrationIn prevention of surgical
infection
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Law 1
Use antibiotic when the risk of infection is high
or sequalae is significant
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Law 2

• Don't start too early, don't start too late
• Tissue levels should peak when the knife goes in

Administration must occur 30 - 45 minutes prior
to incision or with the induction of anesthesia
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Effect of timing of Prophylactic Antibioticon
the infection rate
Classen DC, et alN Engl J Med 1992

• 2847 patients undergoing elective clean or
  clean-contaminated surgical procedures.
• Patients divided into 4 categories based upon
  timing of administration of antibiotic
• Early 2-24 hours before surgery
• Pre-operatively 0-2 hours before surgery
• Perioperative 0-3 hours after surgery
• Post-operative 3-24 hours after surgery

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Law 3 Give the right antibiotic

• An appropriate prophylactic antibiotic should
• (1) Be effective against microorganisms
  anticipated to cause infection.
• (2) Need not eradicate every potential pathogen.
• (3) Achieve adequate local tissue levels.
• (4) Cause minimal side effects.
• (5) Be relatively inexpensive.
• (6) Have no adverse effect on the microbial flora
  of the patient or hospital.

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Agents not recommendedFor prophylaxis

• Third-generation cephalosporins (Cefotaxime,
  Ceftriaxone, Cefoperazone, Ceftazidime or
  Ceftizoxime)
•  Fourth-generation cephalosporins e.g. cefepime
• Why
• Expense
• Some are less active than 1ST generation against
  staphylococci
•  Non-optimal spectrum of action (activity against
  organisms not commonly encountered in elective
  surgery)
•  Widespread use for prophylaxis encourages
  emergence of resistance

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Law 4

• give the drug intravenously as oral absorption
  may be unreliable
• The effective dose should be governed by the
  patient's weight.
• e.g Cephalosporin (Cefazolin)
• lt 70 kg 1 g
• gt70 kg 2 g

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Law 5

• Use additional intra-operative dose only when
  necessary
• long procedures (gt 2-3 hours)
• high blood loss (cardiac, liver procedures)

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Law 6

• Keep post-operative doses to a minimum
• 0 doses adequate for most procedures
• Further doses Up to 48 hours for selected
  procedures

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ANTIBIOTIC PROPHYLAXISIN OBSTETRICAL AND
GYNECOLOGICAL SURGERY
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Endogenous Pathogens Commonly Isolated from
Postoperative Pelvic Infections

• Aerobic gram-positive cocci
• - Viridans and nongroup A, B, and D streptococci
• - Group B streptococci
• - Enterococcus
• strept faecalis,  Staphylococcus aureus
• - Staphylococcus epidermidis
• Aerobic gram-negative bacilli
• - Escherichia coli
• - Klebsiella species
• - Proteus mirabilis
• - Gardnerella vaginalis

• Anaerobic organisms
• -  Peptostreptococcus species
• -  Bacteroides fragilis group
• -  Prevotella bivia
• -  Prevotella disiens
• - Fusobacterium species
• Mycoplasmas
• - Mycoplasma hominis
• - Ureaplasma urealyticum

Clinical infection in Obst.gyn. Maclean A,
1995.
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Observations in Obgyn surgical infections

• Febrile morbidity is more common after abdominal
  than after vaginal hysterectomy
• Age has inconsistently been shown to be a risk
  factor after hysterectomy, with premenopausal
  women shown to be at increased risk in some
  studies, especially after vaginal hysterectomy

Clinical infection in Obst.gyn. Maclean A,
1995.
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Observations in Obgyn surgical infections

• Bacterial vaginosis has been associated with an
  increased risk of infection after abdominal
  hysterectomy
• Patients scheduled for elective hysterectomy
  should be screened for bacterial vaginosis one
  month before the planned procedure. Those found
  to have bacterial vaginosis should be treated and
  allowed several weeks to reestablish a normal
  lactobacillus-dominant flora before surgery

Clinical infection in Obst.gyn. Maclean A,
1995.
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Observations in postC.S infection
Duration of rupture membrane post C.S infection
Pelle et al. Wound infection after cesarean
section. Infect Control 19867456.
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ANTIBIOTIC PROPHYLAXIS Cesarean section

• There are sufficient data to recommend routine
  antibiotic prophylaxis in CS.
• 1st and 2nd generation cephalosporinsand and
  Augmentin have similar efficacy in reducing
  postoperative infection endometritis.
• Despite the theoretic need to cover gram-negative
  and anaerobic organisms, studies have not
  demonstrated a superior result with
  broad-spectrum antibiotics compared with 1st and
  2nd generation cephalosporins.

The Cochrane Library, 1, 2004
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ANTIBIOTIC PROPHYLAXIS IN GYNAECOLOGICALSURGERY

• Clean Procedures Antibiotic prophylaxis is
  considered optional for most clean procedures,
  although it may be indicated for certain patients
  that fulfill specific risk criteria
• Rationale Likely infecting organism are
  gram-positive cocci (S. aureus or S. epidermidis)
  and aerobic coliforms (E. coli).
• Agents Cefazolin, cefuroxime, augmentin or
  metronidazole.

ACOG Practice Bulletin. Antibiotic prophylaxis
for gynecologic procedures. Obstet Gynecol
2001232.
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ANTIBIOTIC PROPHYLAXIS IN GYNAECOLOGICALSURGERY

• Vaginal/abdominal hysterectomy
• . Augmentin 1.2 g single dose
• . Cefazolin 1 - 2 g single dose
  Metronidazole 500 mg IV single dose
• . Cefuroxime 1.5 g IV single dose
  Metronidazole 500 mg IV single dose
• Laparotomy In high risk patients
• Laparoscopy None
• Hysteroscopy None

ACOG Practice Bulletin. Antibiotic prophylaxis
for gynecologic procedures. Obstet Gynecol
2001232.
29
ANTIBIOTIC PROPHYLAXIS IN GYNAECOLOGICALSURGERY

• Infertility promoting surgery
• . Augmentin 1.2 g single dose
• . Cefazolin 1 - 2 g or Cefuroxime 1.5 g IV single
  dose Metronidazole 500 mg IV single dose
• . In salpingostomy for hydrosalpinx extend
  prophylaxis up to one week (doxycycline
  metronidazole OR Augmentin)

ACOG Practice Bulletin. Antibiotic prophylaxis
for gynecologic procedures. Obstet Gynecol
2001232.
30
ANTIBIOTIC PROPHYLAXIS IN GYNAECOLOGICALSURGERY

• DC missed abortion or induced abortion with
  risk factors, (e.g. history of previous PID,
  multiple partners, young, known gonococcal or
  chlamydia infections)
• 200 mg Doxycycline one hour before, followed
  by 100 mg x 2 daily x 4 days
• IUCD insertion and HSG with risk factors
• Prohylaxis is probably indicated -
  Doxycycline as above

ACOG Practice Bulletin. Antibiotic prophylaxis
for gynecologic procedures. Obstet Gynecol
2001232.
31
ANTIBIOTIC PROPHYLAXIS IN OBSTETRIC AND
GYNAECOLOGICALSURGERY

• Penicillin/Cephalosporin
• allergy
• Clindamycin, IV, 150 mg 6 hourly for
• 23 doses may be used for such patients

ACOG Practice Bulletin. Antibiotic prophylaxis
for gynecologic procedures. Obstet Gynecol
2001232.
32
Endocarditis prophylaxis

• High-risk patients
• Ampicillin, 2 g IM or IV, plus gentamicin,
  1.5 mg/ kg (not to exceed 120 mg) within 30
  minutes of starting the procedure six hours
  later, ampicillin, 1 g IM/IV, or amoxicillin, 1 g
  orally
• Patients allergic to ampicllin / amoxicillin
• Vancomycin, 1 g IV over 1-2 hours, plus
  gentamicin, 1.5 mg/ kg IV/IM (not to exceed 120
  mg) injection/infusion within 30 minutes of
  starting the procedure

ACOG Practice Bulletin. Antibiotic prophylaxis
for gynecologic procedures. Obstet Gynecol
2001232.
33
Other Important Factors in Preventing Surgical
Infection

• Remove hair by clipping, not shaving, immediately
  before operation
• Vigilance for breaks in aseptic technique by
  operating room team
• Limit sutures and ligatures
• Use monofilament sutures
• Employ closed suction rather than open drainage
  use no drainage if possible

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Other Important Factors in Preventing Surgical
Infection

• Exercise meticulous skin closure
• Administer high intraoperative and postoperative
  inspired oxygen
• Maintain normothermia during operation
• Use surveillance of wound infection with review
  of preventive measures

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SUMMARY

• - It is generally agreed that antibiotic
  prophylaxis is warranted in all procedures in the
  category of clean-contaminated surgery.
• - Antibiotic prophylaxis is considered optional
  for most clean procedures, although it may be
  indicated for certain patients that fulfill
  specific risk criteria.
• - Single preoprative dose is adequate in the
  majority of cases except in prolonged
  procedures and when there is excessive blood
  loss.

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SUMMARY cont.

• - Antibiotic selection is influenced by the
  organism most commonly causing infection in the
  specific procedure and by the relative costs of
  available agents.
• - First or second generation cephalosporines
  provides adequate coverage for most clean and
  clean-contaminated procedures in Obgyn
  surgery.

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FINALLY

• Surgical technique remains the paramount factor
  in preventing infection, but antibiotic
  prophylaxis assists the patients host response
  when some bacterial contamination is inevitable.

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Dr. JEHAD YOUSEF FRCOG, FICS. ALHAYAT HOSPITAL
AMMAN - JORDAN
Thank you for your Attention
E-mail ramoamman_at_yahoo.co.uk