From the Guidelines
The most effective test for diagnosing appendicitis is a CT scan with contrast, as recommended by the 2024 clinical practice guideline update by the Infectious Diseases Society of America 1. When diagnosing appendicitis, a combination of physical examination, laboratory tests, and imaging studies is used. Physical examination findings include right lower quadrant pain, rebound tenderness, and guarding. Laboratory tests typically include a complete blood count to check for elevated white blood cell count and C-reactive protein.
Key Considerations
- The 2024 guideline update suggests using CT as the initial imaging modality to diagnose acute appendicitis, with a conditional recommendation and very low certainty of evidence 1.
- Intravenous (IV) contrast is usually appropriate whenever a CT is obtained in adults with suspected acute appendicitis, but CT without IV contrast also has high diagnostic accuracy in detecting acute appendicitis and may be appropriate 1.
- Ultrasound (US) and MRI are also reasonably accurate and may precede CT, depending on the patient and clinical circumstances, as noted in the 2020 update of the WSES Jerusalem guidelines 1.
Diagnostic Approach
- The Alvarado score, which combines symptoms, signs, and laboratory findings, can help assess the likelihood of appendicitis, with scores of 7 or higher suggesting a high probability.
- Early diagnosis is crucial as delayed treatment can lead to perforation, abscess formation, peritonitis, and increased morbidity and mortality.
- The role of diagnostic imaging, such as ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI), is another major consideration in the diagnosis of appendicitis 1.
From the Research
Diagnosis of Appendicitis
The diagnosis of appendicitis is based on a combination of clinical evaluation, laboratory tests, and imaging studies. The clinical diagnosis of acute appendicitis is made in approximately 90% of patients presenting with classic symptoms, which include:
- Vague periumbilical pain
- Anorexia/nausea/intermittent vomiting
- Migration of pain to the right lower quadrant
- Low-grade fever 2
Imaging Studies
Imaging studies, such as computed tomography (CT) and ultrasonography, are useful in confirming the diagnosis of appendicitis. CT scans have a high sensitivity and specificity for diagnosing appendicitis, with summary sensitivity and specificity of 0.95 and 0.94, respectively 3. Ultrasonography is also a useful imaging modality, particularly in patients with atypical presentation or findings 4, 5.
Diagnostic Criteria
The Alvarado score, Pediatric Appendicitis Score, and Appendicitis Inflammatory Response score are clinical scoring systems that can help stratify patients as low, moderate, or high risk for appendicitis 4. These scores incorporate common clinical and laboratory findings, such as right lower quadrant pain, abdominal rigidity, and periumbilical pain radiating to the right lower quadrant.
Treatment
The treatment of appendicitis typically involves surgical removal of the appendix, either through open laparotomy or laparoscopy. However, in selected patients, intravenous antibiotics may be considered as first-line therapy 2, 4. Pain control with opioids, nonsteroidal anti-inflammatory drugs, and acetaminophen is also an important aspect of treatment.
Complications
Perforation is a potential complication of appendicitis, occurring in 17% to 32% of patients, and can lead to sepsis 4. Prolonged duration of symptoms before surgical intervention raises the risk of perforation. Therefore, timely surgical consultation and intervention are crucial in reducing morbidity and mortality resulting from perforation.