BACKGROUND AND PURPOSE:

• First-line antibiotic to prevent surgical site infection following cesarean section is a first-generation cephalosporin like cefazolin
• Alternative for penicillin allergy is clindamycin and aminoglycoside
  • This regimen has not been well studied
• Kawakita et al. (Obstetrics & Gynecology, 2018) sought to determine surgical site infection in women undergoing cesarean section who received a non-cephalosporin antibiotic regimen

METHODS:

• Retrospective cohort study
• Participants
  • Women undergoing cesarean delivery (2012-2017)
  • ≥23 weeks
  • Labored, unlabored, and scheduled sections were all included
  • Women with chorioamnionitis were excluded
• Patients were treated with either
  • Cefazolin IV (2 g or 3 g if BMI ≥40)
  • A standard alternative
    • Clindamycin IV (900 mg) and gentamicin (5 mg/kg)
    • Azithromycin (500 mg)
  • Inappropriate alternatives (such as clindamycin only)
• Primary outcome: Composite of surgical site infections within 6 weeks after section including
  • Cellulitis | Endometritis | Deep wound infection | Abdominopelvic abscess | Sepsis
• Secondary outcomes included
  • Hematoma and seroma | Wound dehiscence (greater than 1 cm) | Any main emergency department (ED) visit postpartum period | Main ED visit as a result of wound complication (infection, hematoma and seroma, or dehiscence) | Any hospital readmission occurring up to 6 weeks after surgery
• Statistical analysis
  • Confounding was addressed using propensity score-adjusted logistic regression models

RESULTS:

• 6,584 cases identified
  • Cefazolin: 6,163 (93.6%)
  • Standard alternative: 274 (4.2%)
  • Inappropriate alternatives: 147 (2.2%)
• Use of standard alternative antibiotics compared with cefazolin was not associated with increased odds of the primary outcome
  • Crude odds ratio (OR) 1.50; 95% CI, 0.92–2.46
  • Adjusted OR 1.63; 95% CI, 0.97–2.60
• Standard alternatives were associated with increased odds of cellulitis compared to cefazolin
  • Crude OR 2.07; 95% CI, 1.16–3.70
  • Adjusted OR 1.93; 95% CI, 1.03–3.31
  • Excluding women (1) who delivered after azithromycin was made available (2) with HIV or (3) who used illicit drugs resulted in similar findings
• Use of inappropriate alternative antibiotics compared with cefazolin was associated with increased odds of
  • The primary outcome
    • Crude OR 4.37; 95% CI, 2.80–6.83
    • Adjusted OR 4.13; 95% CI, 2.59–6.36
  • Endometritis before discharge
    • Crude OR 6.85; 95% CI, 3.94–11.90
    • Adjusted OR 6.68; 95% CI, 3.69–11.44
  • Cellulitis
    • Crude OR 3.36; 95% CI, 1.78–6.34
    • Adjusted OR 3.23; 95% CI, 1.63–5.81

CONCLUSION:

• Cefazolin was associated with a reduced risk of surgical site infections, compared to both standard and inappropriate alternatives
• Inappropriate alternatives were especially problematic and associated with higher odds of wound complications
• The authors note that only 10 to 20% of women who self-report β-lactam allergy truly have an allergy and they further state that

A thorough evaluation of patient-reported β-lactam allergy and adherence to ACOG-recommended antibiotic regimen may lower the rates of postcesarean surgical site infections. Further studies that examine alternatives to ACOG-recommended alternative antibiotics would be useful.

Learn More – Primary Sources:

Choice of Prophylactic Antibiotics and Surgical Site Infections After Cesarean Delivery

Related ObG Topics:

ACOG Guidance: Antibiotic Prophylaxis during Labor and Delivery

ACOG Guidance on Use of Sulfonamides and Nitrofurantoin for UTIs in the First Trimester

CDC GBS Algorithms for Screening and Intrapartum Antibiotic Prophylaxis