What do systematic reviews say?

Gram‐negative and anaerobic coverage vs gram‐positive, gram‐negative, and anaerobic coverage

It is very uncertain whether gram‐negative and anaerobic coverage changes abdominal surgical site infection compared with gram‐positive, gram‐negative, and anaerobic coverage (very low certainty).

• Prophylactic antibiotics for penetrating abdominal trauma: duration of use and antibiotic choice 2019 · Cochrane Headline outcomes only
  RR 1.4 [0.55, 3.56]
  6 studies · 516 participants
  Very low

Gram‐negative and anaerobic coverage vs gram‐positive, gram‐negative, and anaerobic coverage

• Prophylactic antibiotics for penetrating abdominal trauma: duration of use and antibiotic choice 2019 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 177 participants
  Very low

Gram‐negative and anaerobic coverage vs gram‐positive, gram‐negative, and anaerobic coverage

It is very uncertain whether gram‐negative and anaerobic coverage changes intra‐abdominal infection compared with gram‐positive, gram‐negative, and anaerobic coverage (very low certainty).

• Prophylactic antibiotics for penetrating abdominal trauma: duration of use and antibiotic choice 2019 · Cochrane Headline outcomes only
  RR 1.19 [0.43, 3.28]
  5 studies · 430 participants
  Very low