When a child comes to the office with abdominal pain, the two things you don’t ever want to miss as a doctor are an ectopic pregnancy (a pregnancy in the fallopian tubes) that could rupture and potentially cause fatal bleeding, or an appendicitis that could rupture and cause a fatal infection.
Ectopic pregnancies can only occur in sexually active girls and women thus in that category you get a pregnancy test and if positive you refer directly to the surgeon.
For the rest of the children (or adults for that mater) with severe abdominal pain that might be appendicitis, we need ways to avoid operating on those who don’t have appendicitis and ways to quickly identify those that have it so they can get to surgery before the appendix ruptures (usually it ruptures in 24-36 hours after the onset of symptoms, though this can vary a lot).
The study, ‘Use of White Blood Cell Count and Polymorphonuclear Leukocyte Differential to Improve the Predictive Value of Ultrasound for Suspected Appendicitis in Children,.” confirms what we already knew about the importance of a CBC (complete blood count) in determining if the infection is bacterial or not. Appendicitis is basically always associated with a bacterial infection and a high white blood cell count (WBC) with a left shift meaning more neutrophils and immature neutrophils compared to other cell types, like lymphocytes for example. You can read the study here…
What this study does so well is gives us data on exactly how accurate you can get by combining the use of the WBC with ultrasound. When the exam was suspicious for appendicitis, the labs were indicative of bacterial disease AND the ultrasound showed signs of appendicitis the risk of appendicitis reached 96.8%. This is enough accuracy to prevent the need for CT scans and allow hospitals to identify those at greatest risk and needing surgery without waiting for a CT scan which may or may not be available and, in many cases, seems would not be necessary.
Use of the CT scan is still the gold standard in my opinion, but I remember the days when kids went to surgery just based on the surgeon’s exam and in the hands of an experienced pediatric surgeon a thorough history and exam were about all you really needed.