What is the standard workup and management for suspected appendicitis?

Standard Workup and Management for Suspected Appendicitis

For adults with suspected appendicitis, obtain helical CT of the abdomen and pelvis with IV contrast as the primary diagnostic imaging modality, initiate broad-spectrum antibiotics covering gram-negative and anaerobic organisms immediately upon diagnosis, and proceed with appendectomy as soon as reasonably feasible. 1

Initial Clinical Assessment

Key Clinical Findings to Evaluate

• Right lower quadrant pain with periumbilical pain migration is highly suggestive of acute appendicitis and should trigger immediate workup 1, 2
• Assess for abdominal rigidity and localized tenderness, which are among the most reliable physical examination findings in adults 3
• Check for peritoneal signs including positive psoas sign, obturator sign, and Rovsing sign, particularly valuable in children 3
• Bradycardia in the presence of fever and abdominal pain is a critical warning sign indicating possible severe peritoneal irritation and requires urgent evaluation 2

Risk Stratification Tools

• Apply validated scoring systems such as the Alvarado score (adults) or Pediatric Appendicitis Score to stratify patients as low, moderate, or high risk 3
• These scoring systems should serve as documentary aids but should not replace clinical judgment 4
• Use clinical findings to guide decisions about immediate surgery, diagnostic imaging, or observation 1

Diagnostic Imaging Protocol

Adults

• Helical CT of abdomen and pelvis with IV contrast is the recommended imaging study for adults with suspected appendicitis 1
• CT demonstrates 100% specificity and 97% sensitivity in atypical presentations, superior to ultrasound 5
• Imaging is recommended for all patients except males under 40 years with classical presentation 4

Women of Childbearing Age

• All female patients must undergo diagnostic imaging regardless of presentation 1
• Obtain pregnancy testing prior to imaging in all women of childbearing potential 1
• For pregnant patients in the first trimester, use ultrasound or MRI instead of CT to avoid ionizing radiation 1

Pediatric Patients

• Perform imaging when diagnosis is uncertain 1
• Ultrasound is a reasonable alternative to CT in children to minimize radiation exposure 1
• Be aware that children under 5 years may have atypical presentations leading to delayed diagnosis and higher perforation rates 1

Antimicrobial Therapy

Immediate Antibiotic Administration

• Administer antimicrobial therapy to all patients diagnosed with appendicitis without delay 4, 1
• Antibiotics should be given immediately once diagnosis is established or strongly suspected 1
• Delaying antibiotics increases complication risk including perforation and sepsis 1

Antibiotic Selection

• Use agents effective against facultative/aerobic gram-negative organisms AND anaerobic organisms 4, 1
• Acceptable regimens include combinations such as cefotaxime with metronidazole, fluoroquinolone with metronidazole, or amoxicillin-clavulanate 6
• Coverage must be broad-spectrum to address the polymicrobial nature of appendiceal infections 2

Surgical Management

Timing and Approach

• Operative intervention should be performed as soon as reasonably feasible for acute non-perforated appendicitis 1
• Both laparoscopic and open appendectomy are acceptable, with approach determined by surgeon expertise 1
• For uncomplicated appendicitis, surgery should occur within 24 hours of admission 1
• For complicated appendicitis, early appendectomy within 8 hours is recommended 1

Perforated Appendicitis

• Patients with perforated appendicitis require urgent intervention for adequate source control 1
• Large appendiceal abscess or phlegmon may be managed with percutaneous drainage and antibiotics, with interval appendectomy considered based on age and recurrence 7

Special Population Considerations

High-Risk Patients Requiring Surgery

• Pregnant patients should undergo timely surgical intervention to decrease complication risk 7
• Immunosuppressed patients require prompt appendectomy rather than conservative management 7

Patients Over 40 Years

• Those with complicated appendicitis treated non-operatively should undergo colonoscopy and interval contrast-enhanced CT due to 3-17% incidence of appendicular neoplasms 8

Management of Negative or Equivocal Imaging

Follow-Up Protocol

• If appendicitis is excluded by imaging but no alternative diagnosis confirmed, base management on clinical and social factors 4
• When clinical suspicion persists, hospitalize for observation to evaluate symptom evolution 4
• Mandatory 24-hour follow-up (even by telephone) for discharged patients due to measurable false-negative imaging rates 4, 8
• Consider re-examination, re-imaging, or diagnostic laparoscopy if symptoms fail to improve 4

Critical Pitfalls to Avoid

• Never administer analgesics like metamizol before completing diagnostic evaluation, as this masks critical clinical findings 2
• Do not rely solely on clinical findings without appropriate imaging in atypical presentations, as this leads to missed diagnoses or unnecessary surgeries 1
• Avoid assuming absence of peritoneal signs excludes appendicitis, especially in atypical presentations 2
• Do not delay antibiotics while awaiting imaging in high-suspicion cases 1
• Pain control with opioids, NSAIDs, and acetaminophen should be prioritized and does not result in delayed or unnecessary intervention 3

Alternative Management Consideration

• For highly selected patients with uncomplicated appendicitis without fecalith, antibiotic therapy alone may be considered as an alternative to immediate surgery 7
• However, appendectomy remains the standard of care with superior one-year outcomes (97% vs 73% optimal outcome) 6
• Recurrence rates after non-operative management range from 12-24% 8