Antibiotic Recommendations After Laceration Repair
For obstetrical anal sphincter injuries (OASIS), a second- or third-generation cephalosporin should be administered, with consideration of adding metronidazole and gentamicin (or clindamycin in penicillin-allergic patients) to provide adequate coverage for both vaginal and bowel flora. 1
Antibiotic Selection Based on Laceration Type
Obstetrical Perineal Lacerations
- For third and fourth-degree lacerations (OASIS), preoperative antibiotics should be administered before repair 1
- A second or third-generation cephalosporin is the primary agent of choice 1
- Metronidazole should be added for anaerobic coverage 1
- Consider adding gentamicin for enhanced gram-negative coverage 1
- For penicillin-allergic patients, clindamycin is recommended as an alternative 1
Simple Hand Lacerations
- Routine antibiotic prophylaxis is not consistently recommended for simple hand lacerations 2
- Only 27% of simple hand lacerations nationally receive prophylactic antibiotics 3
- The most commonly prescribed antibiotic when used is cephalexin 3
- The degree of contamination is the most important factor (91%) in physicians' decision to prescribe antibiotics 3
Contaminated Wounds (Class III)
- For contaminated wounds such as those with visible dirt or foreign material, a first-generation cephalosporin (e.g., cefazolin) is recommended 4
- For more severe injuries or visible contamination, an aminoglycoside should be added for gram-negative coverage 4
- Penicillin should be added for anaerobic coverage, particularly against Clostridium species that may be present in soil 4
Evidence Supporting Antibiotic Use
- A randomized, placebo-controlled study showed that antibiotic administration at the time of primary OASIS repair was associated with lower rates of postpartum wound complications (8.2% vs 24.1%, P=0.037) 5
- Another study found that antibiotic administration was associated with decreased risk of wound infection (adjusted odds ratio, 0.50; 95% CI, 0.27-0.94; P=0.03) 1
- A quality improvement initiative aimed at administering antibiotics at the time of OASIS repair resulted in a 55% decrease in wound infection or dehiscence 1
Timing of Administration
- Antibiotics should be started as soon as possible after injury 4
- For contaminated wounds, delay beyond 3 hours significantly increases infection risk 4
- For OASIS, antibiotics should be administered before repair begins 1
Duration of Therapy
- For most laceration repairs, a single preoperative dose may be sufficient 6
- For contaminated wounds, antibiotics should be continued for 3-5 days depending on wound severity 4
- Prolonged use of prophylactic antibiotics may increase the incidence of antibiotic-resistant infections 6
Common Pitfalls to Avoid
- Delaying antibiotic administration beyond 3 hours post-injury significantly increases infection risk 4
- Using only prophylactic dosing rather than therapeutic dosing for contaminated wounds 4
- Failure to cover anaerobes in wounds with soil contamination 4
- Extending antibiotic therapy unnecessarily beyond 5 days, which may increase risk of antibiotic resistance 4
- Neglecting to consider local factors such as degree of contamination when deciding on antibiotic prophylaxis 3