What is the initial antibiotic strategy for a surgical abdomen with suspected intra-abdominal infection?

• A. Narrow-spectrum penicillin only
• B. No antibiotics until source control
• C. Antivirals
• D. Broad-spectrum coverage including anaerobes (e.g., piperacillin-tazobactam) with timely source control and de-escalation to targeted therapy

Answer: (D)

Intra-abdominal infections from a surgical abdomen are usually polymicrobial, involving both aerobic and anaerobic bacteria. This makes broad initial antibiotic coverage essential to reliably cover the likely pathogens, rather than a narrow antibiotic that may miss key bugs such as anaerobes and enteric Gram-negatives. Coupled with this, timely source control—removing the source of infection through drainage or surgical debridement—is critical to stopping ongoing contamination and improving outcomes.

After starting broad empiric therapy, de-escalation to a targeted antibiotic should occur once culture results and clinical status are available, reducing exposure to broad-spectrum agents, toxicity, and resistance. Antivirals aren’t indicated for bacterial intra-abdominal infection. Therefore, the preferred approach is broad-spectrum coverage including anaerobes (for example, piperacillin-tazobactam) with timely source control and de-escalation to a targeted therapy as data emerge.