Written by Joshua Belfer
Spoon Feed
The PECARN rule is highly sensitive for identifying kids needing acute intervention after blunt abdominal trauma—but it misses some clinically important injuries that still warrant admission or monitoring.
By the way, Dr. Belfer has started a new, dedicated PEM blog called HipPEMcrates.com! Check it out! ~Clay Smith
It’s low risk, not no risk
The PECARN intra-abdominal trauma (IAI) rule is a widely used tool to guide CT use after pediatric blunt abdominal trauma. While prior studies have validated the rule’s performance for injuries needing acute intervention, this is the first to evaluate its accuracy using a broader definition of intra-abdominal injury, including those not requiring immediate procedures but still warranting hospitalization or follow-up care. This multicenter, prospective external validation study applied the PECARN rule to 2,188 children under 16 years old across 14 trauma centers. It found that the rule identified 60 of 62 IAIs needing intervention (sensitivity 96.8%, NPV 99.8%) – strong results consistent with the original study.
However, for any IAI (including non-surgical injuries), sensitivity dropped to 86.6%, and 13.4% of injuries were missed – mostly solid organ injuries, especially liver lacerations. Notably, 34 of the 35 missed injuries had abnormal trauma labs or imaging (i.e. AST >200, abnormal CXR), suggesting that adjunctive testing can catch what PECARN misses. One key limitation is that the study was conducted exclusively at level 1 pediatric trauma centers and excluded patients presenting more than 6 hours post-injury, which may limit its generalizability to other settings and delayed presentations.
How does this change my practice?
I’ve always found the PECARN rule helpful for cutting down on unnecessary CTs in kids with blunt abdominal trauma – especially after a recent prospective validation showed near-perfect performance for identifying injuries needing intervention. But this reminds me “very low risk” doesn’t mean “no risk.” If the story or the labs (like an elevated AST or lipase) raise my concern, I won’t be quick to send them home – even if PECARN is negative. It’s still a great tool, but like all rules, it works best alongside good clinical judgment.
Source
Multicenter external validation of the Pediatric Emergency Care Applied Research Network rule to identify children at very low risk for intra-abdominal injury requiring acute intervention. J Trauma Acute Care Surg. 2025 Jun 1;98(6):966-972. doi: 10.1097/TA.0000000000004597. Epub 2025 Apr 2. PMID: 40170217
