Diagnosing acute pancreatitis in children: what is the diagnostic yield and concordance for serum pancreatic enzymes and imaging within 96 h of presentation?

BACKGROUND/OBJECTIVES: There are limitations and challenges with the diagnosis of acute pancreatitis (AP) in children. We evaluated the diagnostic yield and concordance for serum pancreatic enzymes and imaging in children with AP.

METHODS

A retrospective review of laboratory and radiographic results within 96 h of AP presentation (January 2000-July 2011) was performed at two paediatric hospitals. Observed agreement and kappa statistics (κ) were determined between outcomes of bloods (lipase and/or amylase) and imaging (ultrasound (US) and/or computed tomography (CT)).

RESULTS

A total of 103/131 (79%) AP cases had both bloods and imaging performed (within 96 h). Overall, lipase, amylase, US and CT were consistent with an AP diagnosis in 93% (93/100), 54% (43/80), 27% (21/77) and 67% (28/42) of cases respectively. The diagnostic yield for combinations of blood(s) and imaging(s) tests was higher than any single test and blood tests alone. The observed agreement between bloods 'lipase or amylase' and imaging 'US or CT,' was 40%. The κ was -0.083 suggesting no agreement. In 55% of cases, enzymes were positive whilst imaging was negative and the converse was evident in 5% of cases. There was no agreement between the various diagnostic tests, except between amylase and US, which had fair agreement.

CONCLUSION

Elevations in serum lipase contributed to the diagnosis more often than other tests. Combinations of blood(s) and imaging(s) tests have an increased diagnostic yield. Serum enzyme elevation and imaging changes poorly correlated. At least 5% of cases of AP may be missed if imaging is not performed.