Antibiotic Prophylaxis Before Surgery

Primary Recommendation

Cefazolin 2g IV administered 30-60 minutes before surgical incision is the first-line antibiotic for surgical prophylaxis across most procedures, with a single preoperative dose sufficient for the majority of surgeries. 1, 2

Antibiotic Selection by Surgery Type

Standard First-Line: Cefazolin

Cefazolin is recommended by WHO, Australian Therapeutic Guidelines, and French Society of Anesthesia as first-line prophylaxis for:

Orthopedic surgery (joint prosthesis, spine with implants, fractures with osteosynthesis): 2g IV slow 3, 1
Cardiac surgery (CABG, valve replacement): 2g IV slow 3, 1
Vascular surgery (aorta, lower limb arteries, carotid with patch): 2g IV slow 3
Neurosurgery (craniotomy, CSF shunt): 2g IV slow 3, 1
Colorectal surgery: 2g IV slow 1, 4
Gynecological surgery (hysterectomy): 2g IV slow 1

Beta-Lactam Allergy Alternatives

For documented beta-lactam allergy, use vancomycin or clindamycin as alternatives: 5

Vancomycin 30 mg/kg IV infused over 120 minutes (must complete before incision, optimally 30 minutes prior) 3, 5
Clindamycin 900 mg IV slow infusion within 60 minutes before incision 3, 5

For contaminated wounds or limb amputation in allergic patients:

Clindamycin 900 mg IV + gentamicin 5 mg/kg/day 3, 5

Special Indications for Vancomycin (Even Without Allergy)

Vancomycin should replace cefazolin in these specific circumstances: 3

Suspected or proven MRSA colonization 3
Reoperation in patient hospitalized in unit with MRSA ecology 3
Recent antibiotic therapy 3

Critical Timing Principles

Preoperative Administration

Administer cefazolin within 30-60 minutes before surgical incision to ensure adequate tissue concentrations. 1, 6, 2

If incision is delayed >1 hour after initial cefazolin dose, redose with full 2g before incision 6
Administering antibiotics >60 minutes before incision reduces efficacy 1

Vancomycin requires 120-minute infusion and must complete before incision, optimally 30 minutes prior. 3, 5

Intraoperative Redosing

Redose cefazolin 1g if surgical duration exceeds 4 hours to maintain adequate tissue levels. 3, 1, 6, 2

For cefamandole or cefuroxime (1.5g initial): redose 0.75g if duration >2 hours 3
Vancomycin: redose 5 mg/kg at hour 24 if procedure extends 3

Dosing Adjustments

Obesity

For patients weighing ≥120 kg or BMI >35 kg/m², consider cefazolin 3g for adequate dosing. 1

Renal Impairment

Adjust cefazolin dosing based on creatinine clearance: 2

CrCl 35-54 mL/min: Full dose every 8 hours minimum 2
CrCl 11-34 mL/min: Half usual dose every 12 hours 2
CrCl <10 mL/min: Half usual dose every 18-24 hours 2

Duration of Prophylaxis

Discontinue prophylactic antibiotics within 24 hours after surgery for all procedures. 1, 5, 4

Single preoperative dose is sufficient for most procedures 1
Maximum duration is 24 hours postoperatively, exceptionally 48 hours for specific high-risk cases 3, 1
Prolonging prophylaxis beyond 24 hours increases antibiotic resistance without reducing infection rates 1, 4

Exception for devastating infection risk (open-heart surgery, prosthetic arthroplasty): May continue 3-5 days postoperatively 2

Procedures NOT Requiring Prophylaxis

No antibiotic prophylaxis is indicated for: 3

Arthroscopy without implant (with or without meniscectomy) 3
Extra-articular soft tissue surgery without implant 3
Carotid surgery without patch 3
Vein surgery 3
Closed fracture requiring isolated extrafocal osteosynthesis 3

Procedure-Specific Recommendations

Cataract Surgery

Intracameral injection of 1 mg cefuroxime after surgery is standard. 3

Risk of endophthalmitis without prophylaxis: 2-3/1000 3

Contaminated/Traumatic Wounds

For open fractures stage I or contaminated wounds: 3

Cefazolin 2g IV slow, limited to operative period (24 hours max) 3
If beta-lactam allergy: clindamycin 900 mg + gentamicin 5 mg/kg/day 3, 5

Common Pitfalls to Avoid

Critical Errors in Practice

Ceftriaxone is NOT first-line despite common use - WHO specifically did not prioritize it 1
Administering antibiotics too early (>60 minutes before incision) reduces efficacy 1, 6
Continuing antibiotics postoperatively as routine practice increases resistance without benefit 1, 4
Failing to redose when incision is delayed >1 hour after initial dose 6
Using aminoglycosides (gentamicin, amikacin) as monotherapy - these are second-choice only or combination agents 1

Vancomycin-Specific Pitfalls

Vancomycin infusion must be completed before incision - starting it too late leaves inadequate tissue levels 3, 5
Infusion duration is 120 minutes, requiring earlier start than cefazolin 3, 5

Target Pathogens by Surgical Site

Orthopedic/Prosthetic surgery: S. aureus, S. epidermidis, Propionibacterium, Streptococcus spp, E. coli, K. pneumoniae 5

Neurosurgery: Enterobacteriaceae (especially craniotomies), staphylococci (S. aureus, S. epidermidis), anaerobic bacteria (cranio-cerebral wounds) 3

Cardiac surgery: S. aureus, S. epidermidis, some Gram-negative bacteria 5

Contaminated wounds: S. aureus, Streptococcus, Gram-negative bacteria, anaerobes 5

What are the guidelines for antibiotic prophylaxis before surgery, considering the type of surgery, patient's allergies, and potential pathogens?

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