What's the Pediatric Appendicitis Score (PAS) and is it actually helpful?

So who hasn't received the call for a kiddo with 'classic' appendicitis only to see the kid and send him home because he's constipated.

What if there was a consistent and reliable way of communicating the "classic'ness" of someone's abdominal pain between healthcare workers; NP from an outside hospital calling for a transfer or ED physician calling for a surgical consult.

Enter PAS.

The PAS was introduced by Maden Samuel in 2002 as a way to stratify children's risk of having appendicitis when they present with abdominal pain. The scoring system consists of 8 findings (6 worth 1 point, and 2 worth 2 points for a total score of 10 points). Since Samuel's inception, several studies have addressed the sensitivity and specificity of this scoring system and attempted to develop strategies for it's use, mostly in deciding whom to take to the OR without imaging, whom to image, and whom to send home.

Goldman et al from Sick Kids in Toronto prospectively tested the PAS on unselected children with abdominal pain. Based on the scoring system, they noted that if they had sent kids with a score less than or equal to 2 home, there would have been a 2.5% missed appendicitis rate. on the other hand, if they took anyone with a score greater or equal to 7 to the OR, the rate of negative appendectomies would have been 4%.

Another study by Bhatt et al looked at the use of PAS on children suspected of having appendicitis and noted that sending home children with a PAS of 4 or less would have resulted in a missed appendicitis rate of 2.4%, while operating on those with a PAS greater or equal to 8 would have resulted in a negative appendectomy rate of 8.8%.

Reading through the papers, it is clear that the PAS is not perfect. What about the female who is mid cycle and has severe, sudden onset abdominal pain, nausea, and right lower quadrant tenderness. I wouldn't take her to the OR without imaging even if her score was 10/10. Clearly there's an important role of the "intangible ingredient" in patient evaluation, and no scoring system could take the place of a thorough history, exam, and experience. What the PAS does do is help standardize the way we communicate the level of suspicion for appendicitis, and may have a role in developing pathways to help physicians decide on whom to image, and whom not to, before a surgical consult is called.

So instead of 'classic' appendicitis (which clearly means different things to different people), a phone call about a patient with PAS of 8 would probably be much more meaningful to all parties involved.

References:

Maden S. Pediatric appendicitis score. Journal of Pediatric Surgery 2002;37:877

Goldman et al. Prospective validation of the pediatric appendicitis score. Journal of Pediatrics 2008;153:278

Bhatt et al. Prospective validation of the pediatric appendicitis score in a Canadian pediatric emergency department. Academic Emergency Medicine 2009;16:591