Preoperative Preparation of Appendicitis

When the decision is made to perform an appendectomy for acute appendicitis, the patient should proceed to the operating room with little delay to minimize the chance of progression to perforation. Such occurrences are rare, however, as most cases of appendiceal perforation occur prior to surgical evaluation. Patients with appendicitis may be dehydrated from fever and poor oral intake, so intravenous fluids should be begun, and pulse, blood pressure, and urine output should be closely monitored. Markedly dehydrated patients may require a Foley catheter to ensure adequate urine output. Severe electrolyte abnormalities are uncommon with nonperforated appendicitis, as vomiting and fever have typically been present for 24 hours or less, but may be significant in cases of perforation. Any electrolyte deficiencies should be corrected prior to the induction of general anesthesia.

Intravenous antibiotics have been shown to reduce significantly the incidence of postoperative wound infection and intra-abdominal abscess. Antibiotics should be administered 30 minutes prior to incision to achieve adequate tissue levels. The typical flora of the appendix resembles that of the colon and includes gram-negative aerobes (primarily Escherichia coli) and anaerobes (Bacteroides spp.). No standardized antibiotic regimen exists. Acceptable options include a second-generation cephalosporin or a combination of antibiotics directed at gram-negatives and anaerobes. In nonperforated appendicitis, a single preoperative dose of cefoxitin suffices. In cases of perforation, an extended course of at least 5 days of antibiotics is advocated.