[size=20px]A 10 year-old girl presents with a 1 day history of emesis, diarrhea, and abdominal pain. She has had 5 episodes of nonbilious, nonbloody emesis and 3 loose bowel movements. Her pain is diffuse and intermittent in nature and relieved following a bout of emesis or diarrhea. On exam, she is thin and has mild bilateral lower quadrant tenderness without guarding. WBC count is 11K/uL and UA is negative. Ultrasound is unable to visualize the appendix and shows no free fluid or inflamed bowel. Following administration of IV fluids, she feels better. What is the most appropriate next step in management?

 

A Discharge if tolerates PO trial

 

B Treat with antibiotics alone

 

C Treat with antibiotics and laparoscopic appendectomy

 

D Obtain abdominal/pelvic CT scan

 

E Obtain abdominal/pelvic MRI​[/size]

C

C

correct answer

A Discharge if tolerates PO trial

 

Diagnosing appendicitis remains challenging as only about 50% of patients will present with the classic findings on history and physical examination. Laboratory data is a useful adjunct to help make the diagnosis, but lab values alone are not specific or sensitive. Due to the relatively poor predictive value of clinical and laboratory data, imaging tests are often employed to aid in the diagnosis of appendicitis in children. In some scenarios, US is often obtained in children presenting with abdominal pain prior to examining the child and/or obtaining laboratory results. Ultrasound (US) is an inexpensive test and requires no sedation, contrast agents, or radiation exposure. Accuracy of US has significantly improved and a meta-analysis (7448 patients) reported a pooled sensitivity of 88% and specificity of 94%. However, these results may not reflect the local experience and findings in community practices.

 

When the appendix is visualized, the results are nearly as accurate as CT scans. Unfortunately, the appendix is not always visualized on US making the study inconclusive. Nonvisualization of the appendix has been correlated with operator experience and patient factors (obesity). When the appendix is not seen on US, there are many possible next steps in management depending on the clinical course of the patient. In this scenario, there is low suspicion of appendicitis based on the patient’s clinical presentation and laboratory data. Although the US did not visualize the appendix, there were no secondary signs of appendicitis seen making the risk of appendicitis roughly 2%. If she tolerates clear liquids and has a reliable family, she may be safely discharged from the ER with return precautions.

 

When there is a higher suspicion for appendicitis, then additional imaging studies are helpful. If available, MRI would be the preferred imaging study as this study avoids radiation exposure and is highly accurate (sensitivity = 96% and specificity = 96%). However, MRI is not always available and younger children will often require sedation to obtain this study. CT scans are fast and accurate, but expose children to ionizing radiation, which increases the risk of future hematologic malignancies. Treatment of appendicitis with antibiotics alone or antibiotics and laparoscopic appendectomy should only be implemented after the diagnosis of appendicitis is made.​