Use of Procalcitonin in a Febrile Infant Clinical Pathway and Impact on Infants Aged 29 to 60 Days

Objectives: Recent evidence suggests that measuring the procalcitonin level may improve identification of low-risk febrile infants who may not need intervention. We describe outcomes after the implementation of a febrile infant clinical pathway recommending measurement of the procalcitonin level for risk stratification.

Methods: In this single-center retrospective pre-post intervention study of febrile infants aged 29 to 60 days, we used interrupted time series analyses to evaluate outcomes of lumbar puncture (LP), antibiotic administration, hospital admission, and emergency department (ED) length of stay (LOS). A multivariable logistic regression was used to evaluate the odds of LP.

Results: Data were analyzed between January 2017 and December 2019 and included 740 participants. Procalcitonin use increased post-pathway implementation (PI). The proportion of low-risk infants receiving an LP decreased significantly post-PI ( = .001). In the adjusted interrupted time series analysis, there was no immediate level change (shift) post-PI for LP (0.98 [95% confidence interval (CI): 0.49-1.97]), antibiotics (1.17 [95% CI: 0.56-2.43]), admission (1.07 [95% CI: 0.59-1.96]), or ED LOS (1.08 [95% CI: 0.92-1.28]), and there was no slope change post-PI versus pre-PI for any measure (LP: 1.01 [95% CI: 0.94-1.08]; antibiotics: 1.00 [95% CI: 0.93-1.08]; admission: 1.03 [95% CI: 0.97-1.09]; ED LOS: 1.01 [95% CI: 0.99-1.02]). More patients were considered high risk, and fewer had incomplete laboratory test results post-PI ( < .001). There were no missed serious bacterial infections. A normal procalcitonin level significantly decreased the odds of LP ( < .001).

Conclusions: Clinicians quickly adopted procalcitonin testing. Resource use for low-risk infants decreased; however, there was no change to resource use for the overall population because more infants underwent laboratory evaluation and were classified as high risk post-PI.