A 19-year-old male with no PMH presented to the ED with complaints of abdominal pain. He reported that the pain started 1 day prior to presentation and was initially generalized. He had one episode of non-bloody diarrhea at onset, and then the pain had somewhat improved. On the day of presentation, the patient reported that the pain was now worsening and located in the right lower quadrant. He reported a subjective fever. He denied vomiting, dysuria, frequency, hematuria, and any further episodes of diarrhea.
Initial VS: BP 116/75, HR 102, T 36.6 °C (97.9 °F), RR 18, SpO2 100%
On physical exam, he had TTP in the RLQ with rebound present, but no guarding.
Labs were ordered, and an ED bedside ultrasound to look for appendicitis was performed. See the images that were obtained below:
A tubular blind-ended structure was seen in the RLQ. It measured 10 mm, which meets the criteria for appendicitis (abnormal being >6 mm). It was noted to be non-compressible. You can also see there is some anechoic fluid surrounding the tip of the structure. The experienced sonographer, however, was not convinced. At times it was hard to reproduce these images, and the structure could not be traced to the cecum.
WBC returned at 6.4.
A CT scan of the abdomen was obtained because of the uncertainty of the ultrasound.
Radiology read the scan as having marked inflammation involving long segment of the distal ileum extending into the terminal ileum. There was associated mesenteric inflammation with interloop fluid and possible entero-enteric fistulae. These findings were concerning for inflammatory bowel disease such as Crohn’s disease. There was no evidence of appendicitis.
He was started on ciprofloxacin and metronidazole and admitted to the hospital. GI and surgery consulted while he was in the hospital, however, he improved clinically with the antibiotics and no other intervention was needed.
At follow-up after hospital discharge, he was doing well. He underwent MR enterography, which showed decreased inflammatory changes compared to his initial CT.
Bottom Line: Ultrasound is good, but not perfect for ruling in appendicitis. The specificity has been reported to be 93-94%. You can see that the images in this case met all three diagnostic criteria for appendicitis: blind-ended tubular structure, non-compressible, and measuring more than 6 mm in diameter; yet, this case turned out to not be appendicitis.