From the Guidelines
Broad-spectrum antibiotics are recommended for acute appendicitis.
Antibiotic Regimens
- A single dose of broad-spectrum antibiotics given preoperatively (from 0 to 60 min before the surgical skin incision) is effective in decreasing wound infection and postoperative intra-abdominal abscess, with no apparent difference in the nature of the removed appendix 1.
- For patients with uncomplicated appendicitis, no postoperative antibiotics are recommended 1, 2.
- For patients with complicated acute appendicitis, postoperative broad-spectrum antibiotics are suggested, especially if complete source control has not been achieved, and discontinuation of antibiotics after 24 h seems safe and is associated with shorter length of hospital stay and lower costs 3.
- The optimal course of antibiotics remains to be identified, but current evidence suggests that longer postoperative courses do not prevent surgical site infections (SSI) compared with 2-3 days of antibiotics 3.
Key Considerations
- The timing of pre-operative antibiotics does not affect the frequency of SSI after appendectomy for acute appendicitis 1.
- In patients with intra-abdominal infections who had undergone an adequate source control, the outcomes after fixed-duration antibiotic therapy (approximately 3–5 days) are similar to those after a longer course of antibiotics 3, 4.
- Postoperative antibiotics can be administered orally if the patient is otherwise well enough to be discharged 4.
From the Research
Antibiotics Used for Acute Appendicitis
- The use of antibiotics alone in the treatment of uncomplicated acute appendicitis has been controversial, with some studies suggesting possible benefits with reduced complications, length of hospital stay, and the number of days off work 5, 6.
- Broad-spectrum antibiotics, such as piperacillin-tazobactam monotherapy or combination therapy with either cephalosporins or fluroquinolones with metronidazole, have been shown to successfully treat uncomplicated acute appendicitis in approximately 70% of patients 7.
- Antibiotic regimens used in studies include amoxicillin + clavulanic acid, cefotaxime, or a fluoroquinolone, often with metronidazole or tinidazole added 8.
- A population-based study found that 77% of patients on primary antibiotics recovered, while 23% had subsequent appendectomy due to failed initial treatment on antibiotics 9.
Specific Antibiotic Regimens
- Piperacillin-tazobactam monotherapy has been used as an effective treatment for uncomplicated acute appendicitis 7, 9.
- Combination therapy with cephalosporins or fluroquinolones with metronidazole has also been shown to be effective 7.
- Amoxicillin + clavulanic acid, cefotaxime, or a fluoroquinolone, often with metronidazole or tinidazole added, have been used in various studies 8.
Efficacy and Complications
- Antibiotic therapy has been shown to have fewer immediate complications than surgery, but more subsequent failures 6, 8.
- The overall incidence of complications of appendicitis was 25% in the immediate appendectomy group versus 18% in the antibiotic group 8.
- Primary antibiotic treatment had fewer complications compared to primary surgery, but the risk of long-term relapse must be weighed against the unpredicted but well-known risk for serious major complications following surgical intervention 9.