From the Guidelines
Abdominal guarding and rigidity are primarily caused by peritonitis, which can result from conditions like appendicitis, perforated ulcer, or intra-abdominal infection, as indicated by the 2017 WSES guidelines for management of intra-abdominal infections 1.
Causes of Abdominal Guarding and Rigidity
The causes of abdominal guarding and rigidity can be attributed to various factors, including:
- Perforation of the gastrointestinal tract, such as a perforated duodenal ulcer
- Direct invasion from infected intra-abdominal viscera, such as gangrenous appendicitis
- Anastomotic dehiscences, which are common causes of secondary peritonitis in the postoperative period
- Intra-abdominal infections, which can be primary, secondary, or tertiary peritonitis
Diagnosis and Assessment
To properly assess for abdominal guarding and rigidity, the patient should lie supine with knees slightly flexed to relax the abdominal muscles. Gentle, steady pressure with a flat hand, starting away from the area of pain, can help identify these signs. Involuntary guarding and rigidity are more clinically significant than voluntary guarding, which patients may exhibit due to anxiety or anticipation of pain.
Physiological Basis
The physiological basis for these signs is that inflammation of the peritoneum triggers reflex contraction of the overlying muscles to protect the inflamed area. When these signs are present, especially if accompanied by other peritoneal signs like rebound tenderness, prompt surgical consultation is typically warranted as they often indicate a surgical emergency requiring immediate intervention, as suggested by the 2017 WSES guidelines 1.
Key Considerations
It is essential to note that the etiological factors of peritonitis show a wide geographical variation and different spectrum in various regions of the world, as summarized in the recent international WISS Study 1. Therefore, a thorough understanding of the underlying causes and appropriate management strategies is crucial for optimal patient outcomes.
From the Research
Causes of Abdominal Guarding and Rigidity
The causes of abdominal guarding and rigidity can be attributed to various conditions, including:
- Acute appendicitis, which is the most common abdominal surgical emergency in the world, with an annual incidence of 96.5 to 100 cases per 100 000 adults 2
- Perforation, which can lead to sepsis and occurs in 17% to 32% of patients with acute appendicitis 3
- Inflammation, which can cause abdominal rigidity and guarding, as seen in patients with acute appendicitis 3, 4
Diagnostic Factors
Diagnostic factors that contribute to abdominal guarding and rigidity include:
- Right lower quadrant pain, abdominal rigidity, and periumbilical pain radiating to the right lower quadrant, which are the best signs for ruling in acute appendicitis in adults 3
- Absent or decreased bowel sounds, a positive psoas sign, a positive obturator sign, and a positive Rovsing sign, which are most reliable for ruling in acute appendicitis in children 3
- Imaging findings, such as appendiceal dilatation, appendicoliths, and mass effect, which can identify patients at higher risk of treatment failure 2, 5, 6
Imaging Modalities
Imaging modalities, such as CT scans, ultrasound, and MRI, can help diagnose acute appendicitis and contribute to abdominal guarding and rigidity, with: