A 17 year old female presents to the emergency department with one day of intermittent RLQ abdominal pain. Patient has associated nausea, vomiting, and diarrhea. She has no other medical problems and has not had abdominal surgeries in the past.
Vitals are stable and she is afebrile. On physical exam, she has RLQ tenderness and Rovsing sign.
What bedside study could help diagnose the patient’s abdominal pain?
Ultrasound of the appendix. If inconclusive, and clinical suspicion is high, one may consider ordering a CT Abdomen/Pelvis.
What patient characteristics influence your probe of choice?
The curvilinear probe can help identify the appendix in individuals with greater body fat, as it provides increased depth when imaging. The linear probe can be used in patients with less body fat and pediatric patients when increased depth is not needed, as it provides higher resolution of one’s image.
What techniques can be used in identifying this organ?
- Crossing legs: Ask the patient to cross their right leg over their left leg to theoretically bring the appendix closer to the anterior abdominal wall and thereby facilitating visualization
- Identify the site of pain: one can place the probe at the site of the patient’s pain
- Lawnmower technique: start in the RLQ and scan the patient’s abdomen in a vertical and systematic fashion to find the appendix
- Remember your landmarks: The appendix is bordered by the iliac crest laterally, the iliac vessels medially, and the psoas muscle posteriorly
- Following the bowel: Follow the small intestine to the ileum and find the cecum of the large intestine. The appendix will be coming off of the ileocecal junction. The small intestine is a smooth structure, while the large intestine is bumpy with haustra.
Images from the patient’s RLQ abdominal US are shown below, what are some key findings that are important for making this diagnosis?
Blind ending tubular structure > 6mm in diameter
Noncompressible
Ring of fire: peripheral wall hyperemia
Fecalith
What might you see in the setting of a ruptured appendix?
Significant surrounding edema with possible blind ending tubular structure (appendix)
Is US more specific or sensitive in diagnosing appendicitis?
US is more specific, meaning that if you come across the findings discussed, you can be relative confident that the patient has appendicitis. However, if you do not see the findings discussed, you probably won’t be able to rule out appendicitis.
Specificity 97.9% > Sensitive 42.8%
Case Conclusion
The patient was diagnosed with acute appendicitis and taken to the operating room by general surgery for appendectomy.