557 - Lumbar Punctures in Febrile Infants: A Longitudinal View of Procedural Success in a Changing Clinical Landscape

Publication Number: 2542.557

Rafaela Todd, Children's Hospital of Philadelphia, Atlanta, GA, United States; Jessica Kelly, Children's Hospital of Philadelphia, Philadelphia, PA, United States; Chris Penney, Children's Hospital of Philadelphia, Bala Cynwyd, PA, United States; Aaron Chen, Childrens Hospital of Philadelphia, Bala Cynwyd, PA, United States; Laura Sartori, Childrens Hospital of Philadelphia, Philadelphia, PA, United States

Background: Febrile infants are at risk for bacterial meningitis, investigated through the performance of a lumbar puncture (LP): a procedure at the core of pediatric training. In 2021, the American Academy of Pediatrics recommended inflammatory markers to guide risk stratification, potentially reducing LP rates. The impact of changing guidelines on procedural success is unknown.

Objective: To evaluate trends in 1) frequency of LP performance and 2) procedural success rates in infants < 56 days presenting to the Emergency Department (ED) with fever.

Design/Methods: Retrospective cohort study of febrile infants 0-56 days presenting to one of two children's EDs: a tertiary teaching ED (Main) and a standalone non-teaching ED (KOP) from January 2019 to December 2024. Infants were included if they had a measured temperature of ≥38° Celsius before arrival or during the ED visit and had blood, urine, or cerebrospinal fluid (CSF) cultures obtained. LP success was defined as either "Any Success," CSF fluid sent for culture from the ED, regardless of cell counts; or "Optimal Success," CSF obtained on first attempt with RBC < 1,000/mm³. Three time periods were evaluated: 1) pre-COVID 2) COVID 3) post-COVID. Chi-squared was used to compare groups and logistic regression to evaluate longitudinal trends.

Results: Among 2,572 eligible febrile infants, 1,020 (40%) underwent LP: 858 (84%) Any Success, 133 (13%) Optimal Success, and 162 (16%) failed. Demographics were similar across groups (Table 1). Proportion of infants undergoing LPs decreased (OR 0.96, 95% CI 0.95-0.97, p< 0.001), with steep decline in the post-COVID period (OR 0.56, 95% CI 0.45-0.70, p< 0.001) (Figure 1). Rates of Any Success did not differ between sites (p=0.36), but rates of Optimal Success were higher at the non-teaching site (12.5% vs 17.9%, p=0.044) (Table 2). Number of attempts was lower in successful LPs (1.77 ± 0.89) than failed LPs (3.09 ± 0.83) (p < 0.001).

Conclusion(s): The proportion of LPs performed among eligible infants decreased, with steepest decline correlated with updated AAP Guidelines. Decreasing frequency of LP performance did not result in decreased ability to obtain CSF for culture at either site, but Optimal Success rates were higher at the non-teaching site. These results suggest decreased first-time success in febrile infants evaluated at teaching hospitals. With trainee LP opportunities declining, LP success rates warrant close monitoring, with focus on medical education interventions to augment procedural skills.

Table 1: Cohort characteristics stratified by successful performance of LP


Table 2: LP Success Rates by Site


Figure 1: Trends in Eligible Febrile Infants and Lumbar Punctures quarterly, stratified by ED site, from 2019 to 2024
Figure 1A: Number of Eligible Infants and Number of Lumbar Punctures Performed. Black bars represent eligible infants presenting the Main ED, while gray bars represent eligible infants presenting to the KOP ED, which opened in 2022. Stacked black and gray bars represent total number of eligible infants. Dark blue bars represent LPs performed in eligible infants at the Main ED, while light blue bars represent LPs performed in eligible infants at the KOP ED. Stacked blue bars represent total LPs performed in eligible infants. Three periods were evaluated 1) pre-COVID: 2019 2) COVID: 2020-2021 3) post-COVD: 2022-2024. Proportion of febrile infants undergoing LP decreased overall (OR 0.96, 95% CI 0.95-0.97, p<0.001), with steep decline in the post-COVID period (OR 0.56, 95% CI 0.45-0.70, p<0.001).
Figure 1B: Optimal and Any Success Lumbar Puncture Rates. Solid lines represent Any Success in LP performance, defined as CSF fluid sent for culture from the ED, regardless of cell counts. Dashed lines represent Optimal Success in LP performance, defined as CSF obtained on the first attempt with RBC <1,000/mm³). Dark blue lines represent LPs performed at the Main ED, while light blue lines reflect LPs performed at the KOP ED. Any Success rates ranged from 61-100%, with similar rates between sites. Optimal Success rates ranged from 0 to 31%, with higher rates at non-teaching KOP ED (p=0.044).