Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:
-- The first section of this topic is shown below --
- Most common abdominal emergency
- Acute obstruction of appendiceal lumen results in distension followed by organ ischemia, bacterial overgrowth, and eventual perforation of the viscus
- Pain migration:
- Periumbilical pain: Appendiceal distension stimulates stretch receptors, which relay pain via visceral afferent pain fibers to 10th thoracic ganglion.
- RLQ pain: As inflammation extends to surrounding tissues, pain occurs owing to stimulation of parietal nerve fibers and localizes to position of appendix.
- 28–57% misdiagnosis in patients <12 yr (nearly 100% in patients <2 yr)
- 70–90% perforation rate in children <4 yr
- Perforation correlates strongly with delayed diagnosis.
- Decreased inflammatory response
- 3 times more likely to have perforation owing to anatomic changes
- Diagnosis often delayed owing to atypical presentations
- Slightly higher rate in 2nd trimester compared to 1st/3rd/postpartum periods
- Increased perforation rate (25–40%), highest in 3rd trimester
- RLQ pain remains the most common symptom
- 7–10% fetal loss, up to 24% in perforated appendicitis
- Luminal obstruction of appendix
- Appendiceal lumen becomes distended, inhibiting lymphatic and venous drainage.
- Bacterial invasion of wall, with edema and blockage of arterial blood flow
- Perforation and spillage of contents into peritoneal cavity, causing peritonitis (usually 24–36 hr from onset)
- May wall off and form abscess
- Gram-negative rods and anaerobic organisms predominate