What are the guidelines for managing a patient with acute appendicitis?

Management of Acute Appendicitis

Laparoscopic appendectomy performed within 24 hours of diagnosis is the gold standard treatment for acute appendicitis, offering superior outcomes including less pain, fewer infections, shorter hospital stays, and faster recovery compared to open surgery. 1, 2, 3

Diagnosis

Clinical Presentation

• Look for characteristic abdominal pain starting periumbilically then migrating to the right lower quadrant, accompanied by anorexia, nausea, intermittent vomiting, and low-grade fever—this constellation identifies approximately 90% of appendicitis cases 4, 5
• Localized right lower quadrant tenderness with laboratory evidence of acute inflammation (elevated WBC) strongly suggests appendicitis 4

Imaging

• Helical CT of abdomen and pelvis with intravenous contrast (without oral or rectal contrast) is the recommended imaging modality 4
• All female patients of childbearing potential must undergo diagnostic imaging to avoid missing alternative diagnoses 4
• CT findings that predict treatment failure with antibiotics alone include: appendiceal diameter ≥13 mm, presence of appendicolith, or mass effect—these patients require surgery 2, 5

Surgical Management

Timing of Surgery

• For uncomplicated appendicitis: perform appendectomy within 24 hours of admission 1, 2, 3
• For complicated appendicitis (perforation, abscess, peritonitis): perform urgent appendectomy within 8 hours 1, 2, 3
• Delaying beyond 24 hours increases complication risk 1

Surgical Approach

• Laparoscopic appendectomy is strongly preferred over open surgery due to significantly less postoperative pain, lower surgical site infection rates (especially important in complicated cases), decreased hospital stay, and earlier return to work 1, 2, 3
• The only disadvantage is slightly higher intra-abdominal abscess rates, but overall complication rates still favor laparoscopy 3

Intraoperative Technique

• Use monopolar or bipolar electrocautery for mesoappendix dissection (most cost-effective) 1
• Use endoloops, suture ligation, or polymeric clips for stump closure 1
• Simple ligation is strongly preferred over stump inversion—inversion increases operative time and postoperative ileus without benefit 1
• Perform suction alone without peritoneal irrigation for complicated appendicitis with collections 1
• Do not place abdominal drains after appendectomy, even in complicated cases 1
• Use wound ring protectors in complicated appendicitis to decrease surgical site infection risk 1
• Perform primary skin closure with single absorbable intradermal suture 1
• If appendix appears normal but no other pathology found, still remove the appendix 1
• Send all specimens for histopathology to identify unexpected findings 1

Antibiotic Management

Preoperative Antibiotics

• Administer single dose of broad-spectrum antibiotics 0-60 minutes before surgical incision covering aerobic/facultative and obligate anaerobes 4, 1, 2, 3
• Appropriate regimens include: piperacillin-tazobactam, ceftriaxone plus metronidazole, or amoxicillin-clavulanate 2
• Avoid ampicillin-sulbactam (E. coli resistance >20%), cefotetan, or clindamycin (increasing Bacteroides fragilis resistance) 2

Postoperative Antibiotics

• For uncomplicated appendicitis: discontinue antibiotics within 24 hours postoperatively—do not continue beyond prophylaxis 4, 2, 3
• For complicated appendicitis: continue broad-spectrum antibiotics for 3-5 days maximum with adequate source control 4, 1, 2, 3
• Base discontinuation on clinical and laboratory criteria (resolution of fever and leukocytosis) rather than fixed duration 4
• Total antibiotic duration should not exceed 7 days postoperatively 3

Non-Operative Management (Antibiotics Alone)

Patient Selection Criteria

Non-operative management may be considered ONLY for carefully selected patients meeting ALL criteria:

• Uncomplicated appendicitis confirmed on imaging 2, 5
• Appendiceal diameter <13 mm on CT 2, 5
• No appendicolith present (appendicoliths predict 40% failure rate) 2, 5
• No mass effect 2, 5
• Patient fit for urgent surgery if treatment fails 5

Antibiotic Protocol

• Initial IV therapy: amoxicillin-clavulanate 1.2-2.2g every 6 hours OR ceftriaxone 2g daily plus metronidazole 500mg every 6 hours 2
• Transition to oral antibiotics after 48-72 hours 2
• Total duration 7-10 days 2
• Success rate: 70-88.5% initially, but only 63-73% remain surgery-free at one year 2, 5

Critical Caveat

Do not attempt non-operative management in immunocompromised, transplanted, or pregnant patients—these populations require urgent surgery 1, 2, 6

Management of Complicated Appendicitis with Abscess/Phlegmon

Treatment Algorithm Based on Available Expertise

If advanced laparoscopic expertise available:

• Proceed directly with laparoscopic appendectomy as first-line treatment 1, 2
• This approach achieves 90% uneventful recovery versus 50% with conservative management 1
• Results in fewer readmissions and fewer additional interventions 1
• Lower incidence of bowel resection compared to initial non-operative management that subsequently fails 1

If advanced laparoscopic expertise NOT available:

• Initial non-operative management with IV broad-spectrum antibiotics 4, 1, 2
• Add percutaneous image-guided drainage for well-circumscribed periappendiceal abscess 4, 1
• Appendectomy is generally deferred in such patients 4
• Selected patients with phlegmon or small abscess not amenable to drainage may delay or avoid source control procedure 4

Interval Appendectomy

• Not routinely recommended after successful non-operative management in young adults (<40 years) and children 1
• Perform interval appendectomy only for patients with recurrent symptoms 1

Special Populations

Immunocompromised and Transplanted Patients

• Perform appendectomy as soon as possible, typically within 24 hours of diagnosis 1, 2, 3
• These patients have higher rates of complicated appendicitis (perforation rate 8.2%) 2
• Perforation rate increases dramatically if surgery delayed beyond 24 hours 2
• Laparoscopic approach preferred when feasible 1, 2
• Do not attempt conservative management—operative management is strongly preferred 1, 2

Elderly Patients

• Perform appendectomy as soon as possible once operation indicated—this population has higher mortality and morbidity with delayed surgery 4
• Preoperative broad-spectrum antibiotics strongly recommended 4
• For uncomplicated appendicitis: do not administer postoperative antibiotics 4
• For complicated appendicitis: administer postoperative broad-spectrum antibiotics for 3-5 days 4
• Consider higher probability of multidrug-resistant pathogens in antibiotic selection 4

Pregnant Patients

• Laparoscopic appendectomy is recommended over open appendectomy when surgery indicated 1
• Short in-hospital delay with observation and repeated transabdominal ultrasound acceptable for equivocal cases 1
• Timely surgical intervention strongly recommended to decrease complication risk 6

Obese and High-Risk Patients

• Laparoscopic appendectomy suggested for obese patients, older patients, and those with high perioperative risk factors 1

Clinical Pathways

Standardization

• Establish local clinical pathways involving surgeons, infectious disease specialists, emergency medicine physicians, radiologists, nursing, and pharmacists 4
• Pathways should standardize diagnosis, in-hospital management, discharge, and outpatient management 4

Outpatient Management

• Outpatient laparoscopic appendectomy may be considered for uncomplicated appendicitis in selected patients 1
• Requires well-defined ERAS (Enhanced Recovery After Surgery) protocols and appropriate patient information/consent 1

Common Pitfalls to Avoid

• Do not delay surgery beyond 24 hours for uncomplicated appendicitis 1, 2, 3
• Do not delay surgery beyond 8 hours for complicated appendicitis 1, 2, 3
• Do not continue postoperative antibiotics beyond 24 hours for uncomplicated appendicitis 4, 2, 3
• Do not continue postoperative antibiotics beyond 3-5 days for complicated appendicitis with adequate source control 4, 1, 2, 3
• Do not place abdominal drains routinely after appendectomy 1
• Do not perform stump inversion 1
• Do not attempt non-operative management in immunocompromised, transplanted, or pregnant patients 1, 2, 6
• Do not attempt antibiotics-first approach if CT shows appendicolith, mass effect, or appendiceal diameter ≥13 mm 2, 5
• Do not use ampicillin-sulbactam, cefotetan, or clindamycin due to resistance patterns 2
• Do not perform routine interval appendectomy after successful non-operative management unless recurrent symptoms develop 1
• Recognize that surgeon's macroscopic judgment of early appendicitis is inaccurate and highly variable 1