Surgical Prophylaxis

What is prophylaxis?

Prevention of disease

What are the 3 types of prophylaxis?

Primary: prevention of an initial infection

Secondary: prevention of recurrence or reactivation of a preexisting infection

Eradication: prevention of an infection by eliminating a colonized organism

What are 5 goals of surgical prophylaxis?

1. Prevent surgical-site infection (SSI)

2. Prevent SSI-related morbidity and mortality

3. Reduce duration of hospital stay and healthcare associated costs

4. Produce no adverse effects

5. Produce no adverse consequences for patient's microbial flora

What are some patient related risk factors for SSI?

1. Comorbidities

2. Advanced age

3. Staphylococcus aureas nasal colonization

4. Immunosuppression

5. Nutritional status

6. Smoking

7. Alcohol use

8. Coexisting infections at distal body sites

9. Length of preoperative stay

What are some operation-related risk factors for SSI?

- Preoperative shaving

- Preoperative skin prep

- Duration of surgical scrub

- Duration of operation

- Antimicrobial prophylaxis

- Operative room ventilation

- Implantation of prosthetic materials

- Surgical drains

- Surgical technique

- Sterilization of instruments

What are the 3 classifications of SSIs?

1. Superficial incisional - skin or subQ tissue

2. Deep incisional - fascial and muscle layer involvement

3. Organ/space - any part of body, excluding skin incision, fascia, or muscle layers, that is manipulated during the procedure

Surgical-site infections occur within...

30 days of surgey or within 1 year for prosthetics (stent)

What are the major gram (-) pathogens in SSIs?

1. Enterobacter spp.

2. Proteus mirabilis

3. Klebsiella pneumoniae

4. Escherichia coli

5. Pseudomonas aeruginosa

6. Bacteroides fragilis

What are the major gram (+) pathogens in SSIs?

1. Staph aureus

2. CONS

3. Enterococci

What is a major fungus that causes SSIs?

Candida albicans

Indication influences _________ and __________ of antimicrobial therapy

choice and duration

How are antibiotics for surgical prophylaxis usually given?

Within a couple hours of the surgery and stopped 24 hours post-procedure. Shorter than a full treatment

What are the 4 surgical operation classifications?

1. Clean

2. Clean-contaminated

3. Contaminated

4. Dirty

Describe a "clean" surgical operation, the SSI risk, and if antibiotic prophylaxis is indicated

- No inflammation, transection, or technique break

- Low SSI risk

- Prophylaxis not indicated

Describe a "clean-contaminated" surgical operation, the SSI risk, and if antibiotic prophylaxis is indicated

- Controlled opening with minimal spillage or minor break

- Medium SSI risk

- Prophylaxis indicated

Describe a "contaminated" surgical operation, the SSI risk, and if antibiotic prophylaxis is indicated

- Inflammation, major spillage or break

- High SSI risk

- Prophylaxis indicated

Describe a "dirty" surgical operation, the SSI risk, and if antibiotic prophylaxis is indicated

- Pre-existing infection

- Prophylaxis not indicated, used for treatment instead

Describe the appropriate timing of antibiotics for prophylaxis

- Should be started within 60 minutes before surgical incision

- Exception = 120 minutes for vancomycin or fluoroquinolones

When might redosing of surgical prophylaxis antibiotics be needed?

If the procedure exceeds 2 half-lives of the drug (called a redosing interval)

Describe the appropriate duration of antibiotics for prophylaxis

Should be less than 24 hours for most procedures

DO NOT prescribe antibiotics to be given...

"on call to the OR"

What are the 4 types of hypersensitivity?

Type 1 = anaphylaxis

Type 2 = cytotoxic

Type 3 = immune complex formation

Type 4 = cell-mediated hypersensitivity

Does antimicrobial prophylaxis need to be modified for renal dysfunction?

Not often, it's only given as a single preoperative dose. However, redosing may not be warranted in patients in whom the half-life is prolonged. For patients at high risk of Candida infection, fluconazole adjustment for renal function may be considered.

________ has been linked to an increased risk for SSIs. What adjustment must be made for surgical prophylaxis?

Obesity (BMI > 30). Increasing the dose is recommended. Can double with cephalosporins

____ is the preferred route of antibiotic administration for surgical prophylaxis

IV, PO has not been studied as much

When are oral antibiotics used for surgical prophylaxis?

In colorectal procedures (erythromycin base, metronidazole, neomycin)

Is vancomycin as surgical prophylaxis recommeneded?

NOT for any procedure due to: limited evidence of efficacy, concerns of glycopeptide resistance, less effective than cefazolin for preventing SSIs caused by MSSA

When is vancomycin considered for surgical prophylaxis?

- Risk for MRSA is high (MRSA colonization)

- Patients with beta-lactam allergies

Extra-abdominal sites of surgery require what coverage?

Gram (+) aerobes (cefazolin, clindamycin, anaerobes)

Intra-abdominal sites of surgery require what coverage?

Gram (-), anaerobes (cephalosporins, beta-lactam allergy)

What is considered when selecting a prophylactic antibiotic?

1. Antibiotic spectrum should cover expected pathogens

2. COST

3. IV formulation

4. Adverse-event potential minimal

What are 4 goals of antimicrobial coverage for prophylaxis?

1. Coverage against most common pathogens at the surgical site

2. Appropriate dosing and start times

3. Safety

4. Administered for the shortest effective period (minimize AE, cost, resistance)

Which 3 major cardiac procedures require surgical prophylaxis?

1. Coronary artery bypass

2. Cardiac device insertion (pacemaker)

3. Ventricular assist devices

What is the recommended drug for cardiac procedures? Give dose and redosing interval

- Cefazolin 2 g (3 g if ≥120 kg)

- Redosing interval = 4 hours

What are 2 alternative drugs for cardiac proedures? Give dose and redosing interval

- Clindamycin 900 mg, redosing interval = 6 hours

- Vancomycin 15 mg/kg, no redosing interval

What are some common thoracic procedures that often require prophylaxis?

Lobectomy, pneumonectomy, lung resection, thoracotomy, video-assisted thoracoscopic surgury

What are the 2 recommended drugs for thoracic procedures?

1. Cefazolin 2-3 g, redosing interval = 4 hours

2. Ampicillin-sulbactam 3 g, dosing interval = 2 hours

What are the 2 alternative drugs for thoracic procedures?

- Clindamycin 900 mg, redosing interval = 6 hours

- Vancomycin 15 mg/kg, no redosing interval

What are some common gastroduodenal procedures needing prophylaxis?

- Procedures involving entry into the lumen of the GI tract (bariatric)

- Procedures without entry into GI tract for high-risk patients

What drug is recommended for gastroduodenal procedures?

Cefazolin 2-3 g, dosing interval = 4 hours

What are 3 alternative drug therapies for gastroduodenal prophylaxis?

1. Clindamycin or vancomycin PLUS aminoglycoside (gentamicin)

2. Aztreonam

3. Fluoroquinolone (cipro, levo, moxi)

What is the prophylactic dose and redosing interval for gentamicin?

- 5 mg/kg

- No redosing interval

What is the prophylactic dose and redosing interval for aztreonam?

- 2 g

- redosing interval = 4 hours

What is the prophylactic dose and redosing interval for ciprofloxacin?

- 400 mg

- No redosing interval

What is the prophylactic dose and redosing interval for levofloxacin?

- 500 mg

- No redosing interval

What is the prophylactic dose and redosing interval for moxifloxacin?

- 400 mg

- No redosing interval

What are the 5 recommended antibiotics for biliary tract procedures (laparoscopic, open, high risk)?

- Cefazolin

- Cefoxitin

- Cefotetan

- Ceftriaxone

- Ampicillin-sulbactam

What are the 2 alternative drug therapies for biliary tract procedures?

1. Clindamycin or vancomycin PLUS aminoglycoside or aztreonam or fluoroquinolone

2. Metronidazole PLUS aminoglycoside or fluoroquinolone

What is the prophylactic dose and redosing interval for cefoxitin?

- 2 g

- redosing interval = 2 hours

What is the prophylactic dose and redosing interval for cefotetan?

- 2 g

- redosing interval = 6 hours

What is the prophylactic dose and redosing interval for ceftriaxone?

- 2 g

- No redosing interval

What is the prophylactic dose and redosing interval for metronidazole?

- 500 mg

- No redosing interval

What are some small intestine procedures that need prophylaxis?

Incision or resection of the small intestine. Includes enterectomy, intestinal bypass, and strictureoplasty

What is the recommended drug for non-obstructed small intestine procedures?

Recommended: Cefazolin

Alternative: Clindamycin PLUS aminoglycoside or aztreonam or fluoroquinolone

What is the recommended drug for obstructed small intestine procedures?

Recommended: Cefazolin PLUS metronidazole, cefoxitin, or cefotetan

Alternative: Metronidazole PLUS aminoglycoside or fluoroquinolone

What are 5 recommended drugs for colorectal procedures?

1. Cefazolin + metronidazole

2. Cefoxitin

3. Cefotetan

4. Ampicillin-sulbactam

5. Ceftriaxone + metronidazole

6. Ertapenem

What is the dose and redosing interval for ertapenem?

- 1 g

- No redosing interval

What are 2 alternative drug therapies for colorectal procedures?

1. Clindamycin or vancomycin PLUS aminoglycoside, aztreonam, or fluoroquinolone

2. Metronidazole + aminoglycoside or fluoroquinolone