Post-Appendectomy Antibiotics: Annals of Surgery | October 2026

What Did the Study Find?

This study evaluated 1,539 patients undergoing appendectomy for acute appendicitis, excluding patients with abscess or peritonitis, to determine whether postoperative antibiotics reduce infectious complications.

• 57.2% had intra-abdominal fluid at surgery: 474 serosanguinous and 406 purulent.
• Postoperative antibiotics were prescribed in 18.1% of patients.
• Postoperative antibiotics did not significantly reduce infectious complications, including among patients with intra-abdominal fluid.
• Importantly, the presence of fluid—including its serosanguinous or purulent character—did not by itself identify patients who benefited from postoperative antibiotics.
• Three independent predictors of postoperative infection emerged:
• Higher ASA score (HR 5.13)
• Symptoms lasting >2 days (HR 2.29)
• Presence of an appendicolith (HR 2.20)
• When antibiotics were indicated, inadequate antimicrobial therapy was associated with more infectious complications and readmissions.

Why Does It Matter?

Surgeons frequently continue antibiotics when fluid—particularly purulent fluid—is encountered during appendectomy. These findings challenge the assumption that intraoperative fluid alone represents sufficient justification for postoperative antibiotics after adequate source control.

GastroAGI Takeaway

“There is fluid” should not automatically mean “continue antibiotics.”

After appendectomy for acute appendicitis without abscess or peritonitis, routine postoperative antibiotics showed no demonstrable benefit even when intra-abdominal fluid was present. Clinical risk appears to depend more on patient status, duration of symptoms and appendicolith than on fluid alone.